Teredo navalis
(naval shipworm)

Pictures

Identity

Preferred Scientific Name

• Teredo navalis Linnaeus, 1758

Preferred Common Name

• naval shipworm

Other Scientific Names

• Teredo novangliae Bartsch, 1922

International Common Names

• English: great shipworm
• French: taret commun
• German: Bohrmuschel; Bohrwurm; Holzbohrmuschel; Pfahlwurm; Schiffsbohrwurm

Local Common Names

• Czech Republic: sášeň lodni
• Denmark: pæleorm
• Estonia: harilik laevaoherd
• Finland: laivamato
• Lithuania: laivagraužis
• Norway: pelemark
• Poland: świdrak okrętowiec
• Sweden: skeppsmask

Summary of Invasiveness

The bivalve mollusc Teredo navalis has a brownish elongate worm-like body, with the anterior part covered by a small calcareous tube shell acting as a wood-boring instrument. T. navalis has been found worldwide and is accepted as a well-established species in the European, North American and Northwestern Pacific coastal areas. However, its origin is still to be defined and its status is currently accepted as cryptogenic in many areas. The main vectors of species spread are shipping and larval dispersal with currents. The species is both eurythermic and euryhaline, withstanding a wide range of temperatures and salinities. Its life-history strategy of being larviparous (with long larval life) is considered the most effective to survive in patchy ephemeral habitats, such as wood. Due to its boring activity, the species quickly destroys wooden structures submerged in water at depths of 0 to 20 m, posing a great hazard to wooden maritime structures in coastal areas and incurring millions of dollars of damage per year. The recent range expansion of T. navalis into the Baltic Sea suggests species adaptation to lower salinity conditions.

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Metazoa
•         Phylum: Mollusca
•             Class: Bivalvia
•                 Subclass: Heterodonta
•                     Order: Myoida
•                         Family: Teredinidae
•                             Genus: Teredo
•                                 Species: Teredo navalis

Notes on Taxonomy and Nomenclature

The subfamily Teredininae includes the wood borer mollusc species known as common shipworm or naval shipworm (Culha, 2010). The subfamily comprises about 80 species divided into five genera, including Teredo. The Teredo genus includes about 30 species inhabiting wooden material such as logs, pilings, ships and nearly any other submerged wooden constructions from temperate to tropical zones of the world’s oceans. The most comprehensive taxonomical revision of teredinids, including species descriptions and a review of geographical distributions, can be found in Turner (1966).

The scientific name Teredo navalis comes from teredo, which refers to the wood-gnawing worm (terebro = drill) and navalis, which refers to ships in the sea. According to WoRMS (2014), the species name has 15 synonyms, but there are likely to be more.

Description

The first description of T. navalis was provided by Linnaeus in 1758 and based on material collected by Sellius in the Netherlands. All aspects of its morphology have now been well described by several authors, on which the description below is based (Grave, 1928; Turner, 1966; Nair and Saraswathy, 1971; Rowley, 2005; Culha, 2010; Didžiulis, 2011; EOL, 2014).

T. navalis is a highly specialized bivalve mollusc that drills into wood. Accordingly, the typical mollusc appearance is lost, and the species has a rather worm-like body. The anterior part of the adult is covered by a small (up to 2 cm long) helmet-like shell consisting of two valves. The protective role of the shell has been lost, because the animal spends all its life surrounded by wood, but it acts instead as a wood-boring instrument. Having small teeth on the valves, the shell is used as a rasp. Up to 2300 rasps are performed per hour, with the rotation of 360° every 20-40 rasps (Mann and Gallagher, 1985). In T. navalis adults, the shell consists of two parts, with anterior and posterior lobes that are similar in size. Each shell is triangular in shape and white, with a light brown outermost layer. The valves of the shell are divided into regions with differing sculptures and breaks situated near the anterior end (Fuller et al., 1989). A pair of retractable siphons and the two species-specific pallets are found at the posterior end. The tube-like siphons are used for plankton filtration and for obtaining oxygen. This is the only part of the animal that may be visible outside the wood. T. navalis can rapidly withdraw the siphons and seal their burrow with the pallets, a calcareous pair of white paddle shaped plates about 0.5 cm long, thus avoiding adverse conditions and surviving for at least 3 weeks upon stored glycogen (Lane, 1959). This also makes T. navalis practically undetectable from outside of wood, with the mollusc often only being detected when the damage is extensive and the wooden construction breaks.

In the Baltic Sea, T. navalis usually grows as large as 20 to 25 cm, sometimes reaching more than 35 cm in length (Sordyl et al., 1998; Paalvast and van der Velde, 2011a). In tropical waters, individuals may be as long as 60 cm (Kristensen, 1979). According to Wreck Protect (2011), depending on age, population density, wood type and environment, adult size of T. navalis ranges from a few millimetres to one metre.

Distribution

The species is known from all oceans except the Antarctic, but many of those records need verification. The Encyclopaedia of Life (EOL, 2014) indicates the species to be present from -37.6°S to 58.39°N, but teredinids have very patchy distributions depending on the presence of suitable substrata.

In the Northeast Atlantic, the species is found in the Norwegian, North and Baltic Seas and in the coastal Atlantic waters of the UK and France. It is also found in the Mediterranean, Black and Azov Seas. Detailed distribution information is provided by Borges et al. (2014). T. navalis has questionably invaded America from Europe, where it is considered cryptogenic (Carlton, 1992). The species is now found in all coastal waters of North America (Grave, 1928). On the Atlantic coast, it is distributed from Newfoundland southward to Texas and, on the Pacific coast, it is spread from British Columbia (Pendrell Sound) to Southern California (San Francisco Bay) (Carlton, 1992). In the Western Pacific, most records are from the northern area. T. navalis is found along the entire Japanese coast and it has been recorded from the South and East China Seas, Xisha Island, Beibu Gulf, Hainan, Taiwan, Yellow and Bohai Seas. The species is also common in Russian Far East waters (Tsunoda, 1979; Bernard et al., 1993). There are few verified records from the Indian Ocean and South Pacific, but the probability of finding the species there is high. Nair and Saraswathy (1971) indicated the species to be present in the Eastern Indian Ocean and the South Pacific (Indonesia, Burma, New Zealand and Australia), although Sliwa et al. (2009) referred to the Australian distribution of this species as only “recorded through literature surveys”.

Distribution Table

The distribution in this summary table is based on all the information available. When several references are cited, they may give conflicting information on the status. Further details may be available for individual references in the Distribution Table Details section which can be selected by going to Generate Report.

History of Introduction and Spread

The invasion history of T. navalis may be characterized as sequences of activity outbreaks lasting 2-3 years, followed by subsidence periods. Some authors suggest that the species was introduced to Northern European waters from the Indo-Pacific (Gollasch and Nehring, 2006), the West Pacific (Hopkins, 2001), the East Indies (authors cited in Gollasch et al., 2009), the Mediterranean (Elam, 2009) or that it originated in the North Sea area (Van Benthem Jutting, 1943; Schütz, 1961; Didžiulis, 2011). However, the species actual origin remains uncertain and its status is mainly considered cryptogenic (Carlton, 1992; Främmande arter, 2006; Gollasch, 2006; Borges et al., 2014).

Accounts of the damage caused by shipworms in Europe can be traced back to the writings of Greek (e.g. Theophrastus, 371-328 BC) and Latin (e.g. Ovid, 43 BC to 17 AD) authors (Steinmayer and Turfa, 1996; Borges et al., 2014). Paleontological material and historical records (Van Benthem Jutting, 1943) indicate that T. navalis may have inhabited European waters much earlier than the time of the first confirmed records at the beginning of the eighteenth century (Gollasch et al., 2009), when the species was, for the first time, identified as a mollusc. At that time (1730), catastrophic damage to wooden structures occurred in the Netherlands (Kramp, 1945), which encouraged the Dutch zoologist Gotfren Sellius to study shipworms (Sellius, 1733; Jeffreys, 1865; Lambert, 1971). Invasions of T. navalis into the coastal area of the Netherlands (North Sea) were recorded later again in 1770, 1827 and 1858-1859, probably due to dramatic increases in salinity caused by droughts (Tarasov, 1943; Hubschman, 1979; Iljin, 2010). Thus, in the eighteenth and nineteenth centuries, it was claimed that the activity of the shipworm had destroyed 50 km of the West Frisian dike system and seriously weakened another 20 km, as well as having caused several catastrophic floods in the Netherlands.

In the nineteenth century, the species was observed on the southwest coast of Sweden, in the Skagerrak and Kattegat regions (Främmande arter, 2006).

There is evidence of the species having occurred around Warnemünde on the Baltic coast of Germany as early as 1875. During the 1930s and 1950s, several periodical mass occurrences that lasted a few years, were observed in the Baltic Sea near Germany, Denmark and southernmost Sweden (Didžiulis, 2011). The outbreaks were probably triggered when minor populations of the species were exposed to a combination of favourable environmental factors. Since 1993, an outbreak of shipworms has been observed along the shores of Mecklenburg-Western Pomerania (Bönsch and Gosselck, 1994; Gercken et al., 1994-1996; Sordyl et al., 1998), Bremerhaven (Tuente et al., 2002) and in Dutch waters (Wolf, 2005). It is thought that distribution of the species in the Baltic Sea is constrained by low salinity (Hoppe, 2002; Iljin, 2010), with the eastern border of distribution near Ruegen Island, Germany (Sordyl et al., 1998; Didžiulis, 2011). Accordingly, there is a history of frequent invasions of the species into Danish straits. However, on the southern and western coasts, T. navalis is often recorded in floating wood and storm cast materials (Roch, 1940; Tarasov, 1943; Bönsch and Gosselck, 1994; Sordyl et al., 1998). Recent research has shown that T. navalis range expansion into the eastern Baltic may happen at salinities as low as 7 ppt (Borges et al., 2014). This might indicate that the species is adapting to the lower salinity conditions of the region, while having little competition from other woodborers (Norman, 1977a) and only few known predators (Nair and Saraswathy, 1971) in this part of the Baltic.

The shipworm was probably carried from the Mediterranean into the Black Sea by ancient ships in 750-500 BC (Gomoiu and Skolka, 1996). A low degree of Teredo infestation existed in the nineteenth century, when wooden structures in the Black Sea ports remained functional (Ryabchikov, 1957; Iljin, 1992), whereas in the middle of the twentieth century several outbreaks of Teredo were described, with wooden structures in several Black Sea ports (Odessa, Sevastopol, Yalta) being destroyed (Iljin, 1992). In 1951-1952, there was an outbreak of T. navalis in the coastal area of Odessa, probably because the average monthly water salinity became higher, at around 15-16‰.

T. navalis was not found in the Azov Sea until the 1950s, when it was recorded in surveys in 1954 and 1958-1964 (Ryabchikov et al., 1961; Iljin, 1992; 2010). This can perhaps be explained by changes in salinity: the Azov Sea average annual salinity until mid-twentieth century was 10-11 ppt (Voronkov and Svitashev, 1941) but, from the 1950s, excessive extractions of freshwater from rivers in the Azov basin lead to the salinization of the sea. Thus, in 1952, the Azov Sea average salinity was 12.3 ppt and, in later decades, it usually reached 13 ppt, sometimes even higher than 15-17‰ (Zaklinskii and Limonov, 2005; Iljin, 1992; 2010). A large increase in the number of wooden constructions in the Azov Sea and the presence of the species in the adjacent Black Sea contributed to the quick and wide distribution of T. navalis in the area.

The Russian waters of the Sea of Japan are permanently inhabited by T. navalis and it is believed that, in these waters, the distribution and development of the species is determined by water temperature (Iljin, 1992; 2010). For example, due to low water temperature, the species is not permanently found 40 miles northeast of Cape Povorotny, Sea of Japan, while invasions have been repeatedly recorded to the south of the area.

In Atlantic waters of North America, if introduced, the shipworm may have arrived centuries ago, with the earliest European vessels (Turner, 1966; Carlton, 1979; 1992). The species was first reported in Massachusetts Bay infesting foreign wooden vessels in 1839, and established populations were recorded in New York in 1843 (Russell, 1839; De Kay, 1843). In Chesapeake Bay, it was recorded as early as 1878, from where it spread southwards to North Carolina, Florida, Texas, the Bahamas and Puerto Rico in the 1950s. By the end of the twentieth century, it became abundant north of Massachusetts Bay, in Nova Scotia, Canada. The donor region for the Pacific coast of North America was the Northeast Atlantic (Carlton, 1979). The species was probably transported there prior to the 1870s, when oyster industries started to develop and were mainly ship-mediated. Causing a great deal of damage to coastal structures, around 1913 T. navalis appeared in San Francisco Bay, where there had previously been no records of its presence (Calma, 1926; Hill and Kofoid, 1927). In 1957, the species was first recorded as established in Willapa Bay, Washington, and in Coos Bay, Oregon, in 1988 and 2000. For all events, the primary pathway may have been shipping hull fouling (Elder, 2009). Its arrival to the Pacific at the beginning of the twentieth century caused major damage, because T. navalis tolerates lower levels of salinity than Pacific native shipworms from the genus Bankia. Many wooden constructions in estuaries and brackish waters built at the time took into consideration the known salinity tolerance of this native shipworm (Cohen, 2004), thus becoming susceptible to damage by the new invader.

Risk of Introduction

A high risk of introduction of T. navalis may arise in areas where suitable hydrological conditions and substrata already exist, or might arise, as a result of climate change. Paalvast and van der Velde (2011b) suggested that global warming may cause dry and warmer summers in Northern Europe, decreasing river discharges, leading to increased salinity upstream in the summer and autumn. This may cause upstream expansion of T. navalis, not only in northwest European estuaries, but in southern Europe as well.

Many authors consider T. navalis a potential invader of the Eastern parts of the Baltic Sea (Iljin, 2010; Borges et al., 2014). According to ecological data modelling (Wreck Protect, 2011), the maximum possible spread of the species until 2020 is along the Swedish coast up to the north to Kalmar strait, and along the German and Polish coasts eastwards up to the Gulf of Gdansk, Poland. Estuaries of large European rivers that flow into the Baltic are under serious threat, because of the low indigenous species richness and intensive international shipping traffic in those waters (Nehring, 2006).

Other European areas at risk of further invasion are the Mediterranean and Black Seas. For example, Iljin (2010) suggests that, after the construction of the Volga-Don shipping canal, the probability of appearance of T. navalis in the Caspian Sea, where some areas are especially favourable to this species (Kudinova-Pasternak, 1957), has increased.

Habitat

T. navalis inhabits both fixed and floating timber. Any type of untreated wood may be attacked, although hard types, such as oak, can be less affected than, for example, fir wood (Paalvast and van der Velde, 2011a). Tree barks are more resistant, providing longer protection from T. navalis to wooden constructions (Tarasov, 1943).

T. navalis can be found at depths up to 30 m, but is mostly found from the surface to a depth of about 5 m (Tarasov, 1943; Turner, 1966; EOL, 2014). According to Iljin (1992), in Japan, the Azov and Black Seas, T. navalis most often occurs near the bottom, where salinity is higher than at the surface. In the southern part of the Black Sea, the species is found at a depth of 0.5-5 m, on old tree roots and wood pieces on stony-sandy bottoms (Culha, 2010).

Tsunoda (1979) noted that heavier borer infestations are generally found on horizontal surfaces, rather than on vertical ones. Of horizontal surfaces, the upper areas were liable to be attacked more severely than the lower ones.

Habitat List

Biology and Ecology

Genetics

Distel et al. (2011) found that the bivalve subfamilies Teredininae and Bankiinae of the family Teredinidae are non-monophyletic and that the main traits used for their taxonomic diagnosis may be phylogenetically misleading.

Reproductive Biology

Reproductive strategy is very important under patchy, ephemeral habitats, such as wood immersed in water. Multiple species and genera of shipworms, competing under similar conditions, exhibit differing peak recruitment seasons and reproductive modes, with free-spawning, short-term brooding and long-term brooding occurring (MacIntosh et al., 2012). Reproductive mode is a key contributor to recruitment success, with habitat constraints favouring a 'middle of the road' strategy of short duration larval brooding, most effectively balancing fecundity, larval retention and dispersion ability. The reproductive pattern of T. navalis demonstrates a highly effective mode of this strategy (Borges et al., 2014).

T. navalis is sex separate, but adult gender cannot be distinguished externally. Young animals are potentially hermaphroditic and pass through alternating sexual phases during their development (Coe, 1941; Grave, 1942; Nair and Saraswathy, 1971). At temperatures of 20°C, T. navalis becomes sexually mature at 3 weeks old (Culliney, 1975). However, in Japan, the youngest T. navalis found spawning was 6 weeks old and 38 mm in length (Tsunoda, 1979). After fertilization, larvae develop in a brood pouch for 2 weeks before they disperse. As many as 1 to 5 million larvae can brood in the gills of an individual shipworm (Grave, 1928) and several generations can be produced per year. T. navalis produces a planktotrophic larva at an advanced veliger stage, which feeds on plankton during the free-swimming phase (Lebour, 1946). Closer to settlement, the larva forms a shell, which is first single, but soon becomes bivalved (Costello and Henley, 1971). After about 20 days and at a size of approximately 0.25 mm, animals are mature enough to settle on wood. If no suitable substrate is available, they can survive for an additional 2 weeks, allowing larvae to colonize new areas (Scheltema, 1971; Nair and Saraswathy, 1971). After successful settlement, larvae undergo metamorphosis, changing from a juvenile to an adult that will never leave the piece of wood.

Physiology and Phenology

In Pacific waters (Japan), shipworms usually breed for 7 months from June through December, with local settlements in January and February (Tsunoda, 1979). Settlement peak varies with localities and depends on fluctuations of water temperature throughout the year, the amount of wood available for the borers and activity of fouling communities. Overall, in Japan, settlement has been observed all year round (excluding spring months), in water temperatures between 9 and 30°C and salinity between 25.7 and 37 ppt. In Russian waters (Ussuriysky Bay), T. navalis pelagic larvae have been found from June to September in the inner part of the bay, and in August-September in the open part of the bay, where their frequency of occurrence was nearly two times higher than in the inner part (Kulikova et al., 2013). In European waters, in Rotterdam, Netherlands, T. navalis spawns from August until the end of November, with mass infestations taking place from September (Paalvast and van der Velde, 2011a). In Atlantic American waters, the breeding season of T. navalis lasts from May to October, starting at water temperatures of 11-12°C, and spawning occurs several times during the year (Grave, 1928).

Longevity

Life duration of T. navalis ranges from one to three years (Sordyl et al., 1998).

Population Size and Density

Population size and density of T. navalis vary considerably depending on habitat and season. In the Azov Sea, the number of borings per dm² of a saw cut of piles sometimes reached over 100 (Iljin, 2010). In the Japan Sea, near Vladivostok, the number of borings per dm² was initially about 15, while after three years at 2 m depth, it reached 278 per dm² (Iljin, 1992). Near the Swedish coast, the number of borings was 91 per dm² at 0-1 m depth and only 8 per dm² at 1-10 m depth (Norman, 1976). This difference can be explained by the fact that surface waters warm faster than deeper ones. In Northern Germany, the maximum number of borings found was over 10,000 per m² in fir floating fenders, 4600 per m² in oak piles and 200 per m² in fir pier posts (Tuente et al., 2002).

Nutrition

T. navalis has the ability to consume wood as food (xylotrophy) (e.g. Gallager et al., 1981; Distel et al., 2011) and can survive on a wooden diet only (Hoppe, 2002). Symbiotic cellulolytic nitrogen-fixing bacteria (Teredinibacter turnerae) are harboured within specialized epithelial cells (bacteriocytes) located within the gills of T. navalis (Popham and Dikson, 1973; Distel et al., 1991). The unique bacteria produce cellulolytic enzymes that degrade wood to sugar molecules, on which T. navalis feeds, thus eating its way into wood (Distel et al., 2002).

The ability to feed on wood may have arisen just once in Bivalvia, in a single wood-feeding lineage that subsequently diversified into distinct shallow (where T. navalis belongs) and deep water branches, both of which have been broadly successful in colonizing the world’s oceans (Distel et al., 2011).

Wood consumption, however, may not be the main food source for T. navalis, as recent research has argued. Paalvast and van der Velde (2013), who used a stable isotope approach, found that filter feeding on seston may constitute the main nutrition means for the species. The filtration, supporting food, but also an oxygen supply, occurs with the help of the tube-like siphons. By filter feeding, the woodborers receive mainly nutritional lipids and proteins (Mann and Gallager, 1985). However, they can survive and reproduce without plankton feeding for at least two years, because the cellulolytic nitrogen-fixing symbionts also provide an internal source of dissolved nitrogen, incorporating it into essential aminoacids and thus supplementing the host’s protein-deficient diet (Waterbury et al., 1983; Ahuja et al., 2004).

A detailed account of the functional anatomy of the feeding organs and digestion of the species is given by Morton (1970).

Associations

T. navalis colonies are frequently associated with other wood-boring and fouling organisms. For example, wood degradation seems to be slower when Teredo is associated with Limnoria (wood-boring isopods). The settlement of Teredo larvae is inhibited by the “spongy” surface of Limnoria-infested wood (Kofoid and Miller, 1927). Heavy marine fouling also restricts teredinids activity and slows down wood degradation (Weiss, 1948; Nair and Saraswathy, 1971).

An important association with the endosymbiont bacteria Teredinibacter turnerae, located within the gills of T. navalis, allows wood to be degraded into sugar molecules, on which the species feeds (Distel et al., 2002).

Environmental Requirements

Although preferring rather brackish habitats, T. navalis is both eurythermic and euryhaline (Roch, 1932; Nehring, 2006). T. navalis can survive temperatures from 1 to 30°C and salinity from about 7 to nearly 40 ppt (10-35 ppt being optimal), thus outcompeting all European teredinids (Borges et al., 2014). However, the upper and lower limits of the suggested salinity range may significantly affect T. navalis life cycle, thus restricting its distribution.

In laboratory experiments, adult T. navalis survive at salinities as low as 2 ppt for 24 days, although their activity decreases abruptly below 9 ppt (Blum, 1922). Kudinova-Pasternak (1958) found that adult T. navalis can survive inside wood in freshwater for 3 weeks. If water temperature was close to the animal’s lower or upper range limit, the mollusc died on the 8th or 3rd day, respectively. An increase in water flow also reduced the survival period of T. navalis to 12-14 days. In a population in Sweden, Spicer and Strömberg (2003) described that T. navalis withdraw their siphons and seal their burrows at salinities from 4 to 8 ppt. At salinities less than 4 ppt, burrows can remain closed for at least 6 days, at 22°C, with siphons re-emerging within minutes of a return to 4 ppt. This may be explained by metabolic responses to low salinity: the oxygen uptake of excised gill tissue decreased with decreasing salinity. For larvae, lethal salinity in Bremerhaven harbours, northern Germany, was 5 ppt (Tuente et al., 2002).

The lower limit of water temperature that T. navalis adults can withstand varies considerably according to different publications (Roch, 1940; Tarasov, 1943; Ryabchikov and Nikolaeva, 1963; Ryabchikov et al., 1963; Kudinova-Pasternak, 1971). For T. navalis larvae, temperatures lower than 10°С and higher than 30°C are lethal. The lowest water temperature that allows larvae settling is 15-17°C (Iljin, 2010). Boring activity of the mollusc decreases at 10°C and stops at 5°C (Norman, 1977a, b).

Т. navalis can survive more than 25-27 days inside wood that is not immersed in water, depending on air temperature and humidity conditions (Lane, 1959; Iljin, 1992).

Ice cover can create favourable thermal conditions for the woodborer, because it prevents bottom water layers from fast cooling, leading to the formation of temperature and salinity conditions more suitable for these animals. This is believed to be the cause of high abundance of borer molluscs, and T. navalis in particular, in areas with complete ice cover, and their absence or low abundance in areas without such cover (Ryabchikov, 1957).

Latitude/Altitude Ranges

Water Tolerances

Natural enemies

Notes on Natural Enemies

Many protozoa (Nair and Saraswathy, 1971), fungi (Kohlmeyer, 1969) and Haplosporidiidae (McGovern and Burreson, 1989; 1990; Hillman et al., 1990) have been associated with teredinids, although their parasitic role remains under studied. The parasitic Atlantic Ciliophora Boveria teredinidi has been recorded from the gills (ctenidia) of T. navalis in San Francisco Bay (Pickard, 1927). Polychaetes are also often found in association with Teredo (Hoagland and Turner, 1980), with some species predating on teredinids (Roch, 1940; Tarasov, 1943).

Means of Movement and Dispersal

Natural Dispersal

Very often teredinid invasions occur as a result of combined dispersal modes. Although plankton larvae are the only mobile stage of the woodborer life cycle, adults may also be dispersed in floating wood. Thus, water currents play a significant role in the spread of this species. The distance that larvae can be transported depends on the length of pelagic larval development and on current velocity (Scheltema, 1971). This may constitute many hundreds of kilometres in a few weeks, along the coasts of continents and across ocean basins. This must be an important factor contributing to geographical distribution of adult forms and the maintenance of genetic continuity between populations otherwise isolated from one another. Water currents may have been involved in the invasion of T. navalis from the Black to the Azov Sea (Iljin, 2010) and, in the Baltic Sea, free drifting pieces of wood carved by shipworms can be found floating hundreds of kilometres away from the original wooden constructions (Didžiulis, 2011).

Tidal currents may also contribute to T. navalis dispersal. Paalvast and van der Velde (2011a) observed the shipworm in fir panels 20 km upstream of polyhaline harbours in the Port of Rotterdam, Netherlands. This demonstrates that T. navalis has the ability to travel with tidal currents over considerable distances and to settle once abiotic conditions become favourable.

Accidental Introduction

Shipping is another important vector of T. navalis dispersal. The species larvae can be released from sea-water tanks of ships in ports and docks, or adults can travel in wooden hulls and release larvae in new areas (Nair and Saraswathy, 1971).

Pathway Vectors

Economic Impact

T. navalis is very destructive to any unprotected and untreated wooden constructions submersed in marine water, such as wooden ships, harbour buildings and constructions, piles and piers. The species also destroys archaeologically valuable ancient wooden shipwrecks (Jöns, 2003; Gregory, 2004; Wreck Protect, 2011). Because of the many burrows bored into wood by T. navalis, its structure becomes degraded and wood becomes fragile and damaged beyond repair. The destruction may occur very quickly: pine tree poles can be destroyed within 16 weeks, oak timber within 32 weeks (Didžiulis, 2011), fir piles around 15 cm in diameter in six weeks (Snow, 1917) and oak pilings measuring 10 m long and 25 cm thick in 7 months (Cobb, 2002).

The impact of the species has been documented from numerous sites worldwide and from the coasts of both the North and Baltic Seas since the eighteenth century (and perhaps even earlier). In San Francisco Bay, Pacific Ocean, from 1919 to 1921, the borer activity resulted in more than US$ 900 million damage to wooden piers and wharfs (Thompson et al., 2005). Currently, damage in this area is estimated to be approximately US$ 200 million per year (Cohen and Carlton, 1995). In the Baltic area, since 1993, the damage has reached €50 million (Hoppe, 2002). According to German authorities, only along the coast of Mecklenburg-West Pomerania, almost €10 million of damage was done to wooden structures over a 5-year period in the 1990s (Främmande arter, 2006). Worldwide, the damage caused by woodborers is estimated to be more than US$ 1 billion dollars annually (Distel et al., 2011).

Environmental Impact

Shipworms play an important ecological role, as they break down cellulosic plant materials, thus modifying shallow marine and brackish environments (Gollasch and Nehring, 2006). By processing wood debris, the borer also releases energy stored in submerged wood and driftwood.

Impact: Biodiversity

The tunnelling activity of T. navalis creates niches for other small organisms. For example, some other species of crustaceans (such as Idotea and Limnoria) are known to reuse caves carved in the wood by Teredo (Iljin, 1992).

Social Impact

Teredinid damage may cause unexpected failures of wooden constructions, followed by risks to human health and safety. Damage or destruction of constructions with historical or heritage value is also a major negative social impact.

Risk and Impact Factors

• Proved invasive outside its native range
• Highly adaptable to different environments
• Highly mobile locally
• Benefits from human association (i.e. it is a human commensal)
• Fast growing
• Has high reproductive potential
• Gregarious

• Damaged ecosystem services
• Ecosystem change/ habitat alteration
• Increases vulnerability to invasions
• Infrastructure damage
• Modification of natural benthic communities
• Modification of nutrient regime
• Negatively impacts cultural/traditional practices
• Negatively impacts livelihoods
• Negatively impacts aquaculture/fisheries
• Negatively impacts tourism
• Reduced amenity values
• Transportation disruption

• Fouling
• Interaction with other invasive species
• Rapid growth

• Highly likely to be transported internationally accidentally
• Difficult to identify/detect as a commodity contaminant
• Difficult to identify/detect in the field
• Difficult/costly to control

Uses

Economic Value

The shipworm was the inspiration for the first shield tunnel constructed under the Thames River in the nineteenth century (Wood, 1995). Simultaneous burrowing of a tunnel, while lining the tunnel, during the digging process was devised by Sir M. I. Brunel and still remains a common method for tunnel construction today.

Social Benefit

Shipworms are a culinary delicacy in the Philippines (Elam, 2009).

Detection and Inspection

The detection of new invasive teredinid species in coastal waters is of particular importance. However, they are hard to detect both in the early and late colonization phases, because living inside wood makes them inconspicuous to most types of surveys.

Shipworms enter the wood as larvae, producing minute holes in the wood surface (about 1 mm), hardly visible to the naked eye (Hoppe, 2002). Once inside the wood, the complex tunnels they excavate are not visible from the exterior, meaning the organisms can go undetected until the wood is heavily infected (Turner, 1966).

Tunnels inside the wood are up to 1 cm in diameter and can be found just below the surface of the infected wood. These tunnels are numerous and give the wood a characteristic lace-like appearance and a sponge-like structure. Inspection of tunnelled wood and of animals under the microscope allows infestations of teredinids to be detected and the species to be identified. Identification guides, such as those by Turner (1966; 1971), can be very useful.

The mollusc can be found with the aid of divers, who look for siphons protruding from wooden structures (Nair and Saraswathy, 1971). Stethoscopes and microphones can also be used to detect the rasping sound (boring activity) of the teredinids.

Several methods have been suggested to estimate the degree of species infestation: to saw the infected wood every 1 m and count the number and diameter of holes (Iljin, 1992); to count the number of surface entrance holes (Dons, 1940); to estimate weight loss of the infected wood (Iljin, 1992); to measure wood resistance (Bozich, 1939); and others. More recently, Sivrikaya et al. (2012) found that using a non-destructive measurement of dynamic modulus of elasticity (MOE) is very effective for evaluation of the degree of wooden material deterioration. The MOE showed a very good correlation with the deterioration determined by visual assessment both in untreated and treated wood. Dynamic MOE allows rapid on-site evaluation of infestation, rather than requiring measurements in a laboratory and without causing damage to the structures being evaluated.

It is important to distinguish boring activities of teredinids from those of some crustaceans, such as species from the genus Limnoria (Isopoda). Limnorid tunnels are smaller, usually interconnecting, and have a series of pinhole-sized punctures along their length (CABI, 2018).

Similarities to Other Species/Conditions

The Teredo genus includes about 30 species that live in very particular conditions, i.e. inside wooden material, such as logs, pilings and ships. Because of this, the woodborers form a particular morphotype that is very similar in different species, making teredinids a difficult group to identify from morphological features. Identification is based almost entirely on the morphology of the pallets, shell details and siphons morphology. All species of the genus retain the young to veliger stage and have largely calcareous pallets, variable in shape, but with the blade always in one piece, usually with a small cup that may be divided medially (Turner, 1966). Turner (1966) provides identification keys to teredinids, where different species are illustrated. Rowley (2005) suggests to use the following characteristics for identification of T. navalis in the field: small white shell; light brown soft body tissues; reduced trilobed shell up to 2 cm in length; tube up to 60 cm long and 0.8 cm in diameter; anterior and posterior lobes of the shells similar in size; shells triangular in shape.

A combined use of morphology, DNA barcoding and nuclear locus sequences has been shown to be useful in investigating the taxonomy and systematics of Teredinidae (Borges et al., 2012).

Prevention and Control

Prevention

Historically, no completely effective prevention methods against T. navalis have been identified. In ancient times, the hulls of wooden ships used to be protected from woodborers with copper sheathing and, before that, with tar. In the Netherlands, after a large dike collapse in 1731 due to woodborers activity, the only solution was a major change in the dike construction, which was rebuilt from imported stone (Hubschman, 1979). Despite obvious progress in the study of T. navalis, no effective protection measures have so far been developed.

Chemical defence has been widely used. Historically, creosote (composed mainly of phenol derivatives) is a popular chemical means of defence against T. navalis. Poles impregnated with creosote can resist 10 years in the Caribbean Sea, up to 20 years near California, up to 15-30 years near San Francisco, and even up to 50 years in other USA waters (Iljin, 1992). In the Black Sea, near Novorossiysk, treated poles remained intact for 13 years (Ryabchikov, 1957).

Chemical impregnation with copper chemicals, such as chrome copper arsenate (CCA) or borax (CKB) may also temporarily prevent wood from deterioration. Wood treated with copper compounds can be defended from teredinids for 15 or even up to 40 years. Hormonal treatment can affect some stages of the bivalve’s life cycle, such as settlement, metamorphosis and shell formation, preventing normal development and, therefore, heavy infestation (Turner, 1976).

Humar and Lesar (2013) investigated performance of copper-ethanolamine-treated wood exposed to sea water at the Port of Koper, Slovenia. The authors found that, while untreated wood was completely degraded after 10 months of exposure, chemical impregnation prolonged the service life of wood. Even using the lowest concentration of preservative solution (0.31%), wood samples were only slightly decayed, whereas wood impregnated with higher copper concentrations (> 0.31%) showed almost no defects after exposure to marine borers.

In the Black Sea, untreated wooden samples, particularly of Scots pine, were severely attacked by T. navalis, while samples of oak and chestnut treated by copper-chromium-arsenic (CCA) were moderately attacked and treated samples of Scots pine sapwood and heartwood were sound (Sivrikaya et al., 2012).

Alongside chemicals, some simple non-chemical defence methods may be surprisingly effective. For example, freshwater treatment, by keeping wooden ships in freshwater rivers, estuaries or lagoons for several months; airing for a month, or keeping the ship in quarantine; utilization or elimination of sunken wood in ports; functional construction engineering; using temperatures that are lethal to woodborers; use of naturally resilient types of wood, such as barked wood. Tsunoda (1979) considered landing of wooden material as one of the most reliable ways to protect logs against shipworm attack. Covering in a thin layer of metal is also a widely used protective method. More recent research has involved the use of a fiberglass and polymer composite shield to protect wooden piers and marine structures (Elam, 2009).

Valuable shipwrecks can be protected by being wrapped in different types of textiles, thus providing a physical barrier to prevent access by the organisms, without totally preventing water movement. This method has proven to be cheap, easily applied and to have a low environmental impact. Eriksen et al. (2014) examined the ability of two plastic materials (geotextile fabric and a plastic membrane) to stop both initial attack by T. navalis and their effects on archaeological wood. Blocks of pinewood were submerged in the southern part of the Kattegat, Denmark. After settling and attack by T. navalis had been confirmed, the blocks were removed and wrapped in either a geotextile fabric (polypropylene and polyethylene) or in a proprietary plastic membrane (polyethylene). After one week, oxygen levels around the test blocks wrapped in plastic membrane had dropped drastically and led to the death of all shipworms. Although no new shipworms attacked the wood wrapped in geotextile fabric, it did not prevent the passage of oxygenated seawater, as living individuals were found in the test blocks after 46 weeks of wrapping and submersion.

The only efficient way to prevent economical losses caused by Teredo is to build coastal protection and submerged constructions using non-wood materials, such as stone, concrete or plastic.

Control

Physical/Mechanical Control

Using electricity has been suggested for elimination of woodborers (Iljin, 1992). Norman and Henningsson (1975) described positive results of using explosives in elimination of wood-boring organisms: non-treated poles were destroyed in 3 years, while poles in the area where explosives were used remained intact for 5 years.

References

Abbott, R. T., 1974. American Seashells: The Marine Mollusca of the Atlantic and Pacific Coasts of North America, (Edn 2) . New York, USA: Van Nostrand Reinhold Company.663 pp.

Ahuja SK, Ferreira GM, Moreira AR, 2004. Production of an endoglucanase by the shipworm bacterium, Teredinobacter turnirae. Journal of Industrial Microbiology & Biotechnology, 31(1), 41-47.

Ardovini R, Cossignani T, 2004. Ancona, Italy: L'Informatore Piceno.319 pp.

Backeljau T, 1986. Brussels, Belgium: Koninklijk Belgisch Instituut voor Natuurwetenschappen.106 pp.

Bernard FR, Cai YY, Morton B, 1993. Hong Kong, China: Hong Kong University Press.146 pp.

Blum HF, 1922. On the effect of low salinity on Teredo navalis. University of California Publications in Zoology, 22(4), 349-368.

Borges LMS, Merckelbach LM, Sampaio I, Cragg SM, 2014. Diversity, environmental requirements, and biogeography of bivalve wood-borers (Teredinidae) in European coastal waters. Frontiers in Zoology, 11, 13.

Borges, L. M. S., Sivrikaya, H., Roux, A. le, Shipway, J. R., Cragg, S. M., Costa, F. O., 2012. Investigating the taxonomy and systematics of marine wood borers (Bivalvia: Teredinidae) combining evidence from morphology, DNA barcodes and nuclear locus sequences. Invertebrate Systematics, 26(5/6), 572-582. http://www.publish.csiro.au/nid/120.htm doi: 10.1071/IS12028

Bozich PK, 1939. ?oscow, Russia: Vodnij Transport.128 pp.

Bönsch R, Gosselck F, 1994. English title not available. (Untersuchungen zum Befall der Buhnen durch Teredo navalis Linnaeus 1758 (Molusca: Bivalvia) an der Ostseeküste Mecklenburg-Vorpommerns). Gutachten im Auftrag des Staatlichen Amtes Rostock, 1-16.

CABI, 2018. Limnoria lignorum [original text by Ekaterina Shalaeva]. In: Invasive Species Compendium, Wallingford, UK: CAB International.www.cabi.org/isc

Calma WT, 1926. The shipworm. Nature, 2953, 795-797.

Camp DK, Lyons WG, Perkins TH, 1998. Checklists of selected shallow-water marine invertebrates of Florida. FMRI Technical Report TR-3. Florida, USA: Florida Department of Environmental Protection.238 pp. http://aquaticcommons.org/124/1/TR3A.pdf

Carlton, J. T., 1979. History, Biogeography, and Ecology of the Introduced Marine and Estuarine Invertebrates of the Pacific Coast of North America. Davis, CA, USA: University of California. 449-453.

Carlton, J. T., 1992. Introduced marine and estuarine mollusks of North America: an end-of-the-20th-century perspective. Journal of Shellfish Research, 11, 489-505.

Çinar, M. E., Bilecenoglu, M., Öztürk, B., Katagan, T., Yoke?, M. B., Aysel, V., Dagli, E., Açik, S., Özcan, T., Erdogan, H., 2011. An updated review of alien species on the coasts of Turkey. Mediterranean Marine Science, 12(2), 257-315. http://www.medit-mar-sc.net/files/201112/13-135337466_MMS_v12n2_CINAR.pdf

Clapp, W. F., Kenk, R., 1963. Marine borers. An annotated bibliography, Washington, D.C, USA: Office of Naval Research, Dept. of Navy.1136 pp.

Cobb K, 2002. Return of a castaway: the gripping story of a boring clam. Science News, 162, 72-74.

Coe WR, 1941. Sexual phases in wood-boring mollusks. Biological Bulletin, 81, 168-176.

Cohen AN, 1997. The exotic species threat to California's coastal resources. [Proceedings of the California and World Ocean '97 Conference], San Diego, USA: ASCE Publications. 1-6.

Cohen AN, 2004. Invasions in the sea. Park Science, 22(2), 37-41.

Cohen, A., Carlton, J. T., 1995. Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and delta. U. S. Fish and Wildlife Service, Washington DC and the National Sea Grant College Program, Connecticut Sea Grant. In: Nonindigenous aquatic species in a United States estuary: a case study of the biological invasions of the San Francisco Bay and delta. U. S. Fish and Wildlife Service, Washington DC and the National Sea Grant College Pro , USA: NOAA.1-251.

Costello DP, Henley C, 1971. Woods Hole, Massachusetts, USA: Marine Biological Laboratory.247 pp.

Culha, M., 2010. The presence of Teredo navalis Linnaeus, 1758 (Mollusca, Bivalvia, Teredinidae) in the southern Black Sea, Turkey. Journal of Animal and Veterinary Advances, 9(10), 1515-1518. http://docsdrive.com/pdfs/medwelljournals/javaa/2010/1515-1518.pdf

Culliney, J. L., 1975. Comparative larval development of the shipworms Bankia gouldi and Teredo navalis. Marine Biology, 29, 245-251. doi: 10.1007/BF00391850

de Bruyne RH, 1991. Utrecht, Netherlands: Jeugdbondsuitgeverij Stichting Uitgeverij KNNV.165 pp.

De Kay JE, 1843. Albany, USA: Carroll & Cook.271 pp.

Didžiulis V, 2011. NOBANIS – Invasive Alien Species Fact Sheet – Teredo navalis. In: Online Database of the European Network on Invasive Alien Species, www. nobanis.org

Distel DL, Amim M, Burgoyne A, Linton E, Mamangkey G, Morrill W, Nove J, Wood N, Yang J, 2011. Molecular phylogeny of Pholadoidea Lamarck, 1809 supports a single origin for xylotrophy (wood feeding) and xylotrophic bacterial endosymbiosis in Bivalvia. Molecular Phylogenetics and Evolution, 61, 245–254.

Distel, D. L., Beaudoin, D. J., Morrill, W., 2002. Coexistence of multiple proteobacterial endosymbionts in the gills of the wood-boring bivalve Lyrodus pedicellatus (Bivalvia: Teredinidae). Applied and Environmental Microbiology, 68(12), 6292-6299. doi: 10.1128/AEM.68.12.6292-6299.2002

Distel, D. L., DeLong, E. F., Waterbury, J. B., 1991. Phylogenetic characterization and in situ localization of the bacterial symbiont of shipworms (Teredinidae: Bivalvia) by using 16S rRNA sequence analysis and oligodeoxynucleotide probe hybridization. Applied and Environmental Microbiology, 57(8), 2376-2382.

Dons C, 1940. English title not available. (Marine boreorganismer. II. Vekst og voksemate hos Teredo megotara). Kongelige Norske Videnskabers Selskabs Forhandlinger, 12(39), 141-144.

Edmondson CH, 1962. Teredinidae, ocean travelers. Occasional Papers of the Bernice Pauahi Bishop Museum of Polynesian Ethnology and Natural History, 23(3), 1-59.

Elam ML, 2009. Pacific Northwest aquatic invasive species profile: great naval shipworm Teredo navalis. Fish, 423, 1-9. http://depts.washington.edu/oldenlab/wordpress/wp-content/uploads/2013/03/Teredo-navalis_Elam.pdf

Elder N, 2009. Teredo navalis. In: Nonindigenous Aquatic Species Database, Gainesville, USA: US Geological Survey.http://nas.er.usgs.gov/

EOL, 2014. Encyclopaedia of Life. https://www.eol.org/

Eriksen, A. M., Gregory, D. J., Botfeldt, K., 2014. The survival of Teredo navalis L. in timber wrapped in TERRAM4000 and a plastic membrane. International Biodeterioration & Biodegradation, 86(Part B), 96-101. http://www.sciencedirect.com/science/article/pii/S0964830513002461 doi: 10.1016/j.ibiod.2013.06.021

Främmande arter, 2006. Alien species in Swedish seas. (Främmande arter i svenska hav). http://www.frammandearter.se/index.html

Fuller SC, Hu YP, Lutz RA, Castagna M, 1989. Shell and pallet morphology in early developmental stages of Teredo navalis Linnaeus (Bivalvia, Teredinidae). Nautilus, 103(1), 24-35.

Gallager, S. M., Turner, R. D., Berg, C. J., Jr., 1981. Physiological aspects of wood consumption, growth, and reproduction in the shipworm Lyrodus pedicellatus Quatrefages (Bivalvia: Teredinidae). Journal of Experimental Marine Biology and Ecology, 52(1), 63-77. doi: 10.1016/0022-0981(81)90171-4

Gercken J, Gosselck M, Kreuzberg M, Sordyl H, 1994-1996. English title not available. (Untersuchungen zum Befall der Buhnen durch Teredo navalis Linnaeus 1758 (Molusca: Bivalvia) an der Ostseeküste Mecklenburg-Vorpommerns). In: Gutachten im Auftrag des Staatlichen Amtes für Umwelt und Natur Rostock

Gollasch, S., 2006. Overview on introduced aquatic species in European navigational and adjacent waters. Helgoland Marine Research, 60(2), 84-89. http://www.springerlink.com/(vbc5i445bmwdkp45y4ynpj45)/app/home/contribution.asp?referrer=parent&backto=issue,3,13;journal,2,169;linkingpublicationresults,1:103796,1 doi: 10.1007/s10152-006-0022-y

Gollasch, S., Haydar, D., Minchin, D., Wolff, W. J., Reise, K., 2009. Introduced Aquatic Species of the North Sea Coasts and Adjacent Brackish Waters. In: Biological Invasions in Marine Ecosystems. Ecological Studies, 204 [ed. by Rilov, G., Crooks, J. A.]. Berlin Heidelberg, Germany: Springer-Verlag. 507-528.

Gollasch, S., Nehring, S., 2006. National checklist for aquatic alien species in Germany. Aquatic Invasions, 1(4), 245-269. http://www.aquaticinvasions.ru/2006/AI_2006_1_4_Gollasch_Nehring.pdf doi: 10.3391/ai.2006.1.4.8

Gomoiu MT, Skolka M, 1996. English title not available. (Changements recents dans la biodiversite de la mer Noire dus aux immigrants). Geo-Eco-Marina, Romanian Centre of Marine Geology and Geoecology, 1, 34-48.

Grave BH, 1928. Natural history of shipworm, Teredo navalis, at Woods Hole, Massachusetts. Biological Bulletin, 55, 260-282.

Grave BH, 1942. The sexual cycle of the shipworm, Teredo navalis. The Biological Bulletin, 82, 438-445.

Gregory T, 2004. Degradation of wooden shipwrecks: threats. Monitoring, safeguarding and visualizing North-European shipwreck sites: common European cultural heritage - challenges for cultural resource management. In: A shipwreck research project funded by the European Union Culture 2000 Programme. MOSS Newsletter , 2. http://moss.nba.fi/download/moss_newsletter7.pdf

Hall, G. S., Saunders, R. G., 1967. Incidence of marine borers around Britain's coasts. In: Research Report. Timber Development Association , B/RR/6. 17 pp.

Hayward, P. J., Ryland, J. S., 1990. The marine fauna of the British Isles and north-west Europe. Vols. 1 & 2, Oxford, UK: Clarendon Press.996 pp.

Hill CL, Kofoid CA, 1927. Marine borers and their relation to marine constructions on the Pacific coast. In: Final report of the San Francisco Bay Marine Piling Committee . San Francisco, USA: The Committee.357 pp.

Hillman, R. E., Ford, S. E., Haskin, H. H., 1990. Minchinia teredinis n. sp. (Balanosporida, Haplosporidiidae), a parasite of teredinid shipworms. Journal of Protozoology, 37(5), 364-368.

Hoagland, K. E., Turner, R. D., 1980. Range extensions of teredinids (shipworms) and polychaetes in the vicinity of a temperate zone nuclear generating station. Marine Biology, 58(1), 55-64.

Hopkins, C. C. E., 2001. Actual and potential effects of introduced marine organisms in Norwegian waters, including Svalbard. Research report 2001-1. In: Actual and potential effects of introduced marine organisms in Norwegian waters, including Svalbard. Research report 2001-1 . Trondheim, Norway: Directorate for Nature Management.

Hoppe KN, 2002. Teredo navalis - the cryptogenic shipworm. In: Invasive aquatic species in Europe. Distribution, impacts and management, [ed. by Leppakoski S, Gollasch S, Olenin S]. Dordrecht, Netherlands: Kluwer Academic Publishers. 116-120.

Hubschman JH, 1979. The lowly invertebrates: an historical perspective. The Ohio Journal of Science, 79(6), 243.

Humar, M., Lesar, B., 2013. Performance of native and copper-ethanolamine-treated wood exposed to seawater at Port of Koper, Slovenia. Drvna Industrija, 64(4), 273-279. http://hrcak.srce.hr/index.php?show=clanak&id_clanak_jezik=166353 doi: 10.5552/drind.2013.1251

Iljin IN, 1992. Marine woodboring organisms in the USSR and their eradication. In: Biofouling and biodamage. Ecological problems, [ed. by Iljin IN]. Moscow, Russia: Nauka. 21-56.

Iljin, I. N., 2010. Known and possible invasions of marine mollusks of the families Teredinidae and Pholadidae (Bivalvia) in the waters of Russia and adjacent countries. Russian Journal of Biological Invasions, 1(2), 74-80. http://www.maik.ru/abstract/bioinv/10/bioinv0074_abstract.pdf doi: 10.1134/S2075111710020049

Jeffreys JG, 1865. 3. London, UK: John Van Voorst.393 pp.

Jones, E. B. G., Kuhne, H., Trussell, P. C., Turner, R. D., 1972. Results of an international cooperative research programme on the biodeterioration of timber submerged in the sea. Material und Organismen, 7(2), 93-118.

Jöns H, 2003. The late medieval shipwreck-sites of the southwestern Baltic. Monitoring, safeguarding and visualizing North-European shipwreck sites: common European cultural heritage - challenges for cultural resource management. In: A shipwreck research project funded by the European Union Culture 2000 Programme. MOSS Newsletter , 2. http://moss.nba.fi/download/moss_newsletter3.pdf

Kofoid, C. A., Miller, R. C., 1927. Marine borers and their relation to marine construction on the Pacific Coast. In: Final Report of the San Francisco Bay marine piling committee [ed. by Hill, C. L., Kofoid, C. A.]. San Francisco, USA: The Committee.188-343.

Kohlmeyer J, 1969. The role of marine fungi in the penetration of calcareous substances. American Zoologist, 9(3), 741-746.

Kramp PL, 1937. Polypdyr. II. Gopler. Danmarks Fauna, 43, 1-223.

Kramp PL, 1945. English title not available. (Pæleorm og pælekrebs). Natur og Museum, 1944-45, 22-55.

Kristensen ES, 1979. Observations on growth and life cycle of the shipworm Teredo navalis L. (Bivalvia, Mollusca) in Isefjord, Denmark. Ophelia, 18(2), 235-242.

KRISTENSEN, E., 1969. Attacks by Teredo navalis L. in inner Danish waters in relation to environmental factors. Videnskabelige Meddelelser fra Dansk Naturhistorisk Forening i Kjobenhavn, 132, 199-210 pp.

Kudinova-Pasternak RK, 1957. On the penetration possibility of Teredo navalis into the Caspian Sea. Zoologicheskii Zhurnal, 36, 847-851.

Kudinova-Pasternak RK, 1958. Survival rate of the marine borer Teredo navalis L. in fresh water and in the air. Nauchnye Dokladi Vysshei Shkoly Biologicheskoi Nauki, 2, 10-13.

Kudinova-Pasternak RK, 1971. Moscow, Russia: Moscow University Press.174-228.

Kulikova VA, Kolotukhina NK, Omelyanenko VA, 2013. Pelagic larvae of the Bivalves of Ussuriysky Bay, Sea of Japan. Russian Journal of Marine Biology, 39(6), 440-446.

Lambert AM, 1971. London and New York, UK and USA: Seminar Press.412 pp.

Lane CE, 1959. Some aspects of the general biology of Teredo. In: Marine boring and fouling organisms, [ed. by Ray DL]. Seattle, USA: University of Washington Press. 137-144.

Lebour MV, 1946. The species of Teredo from Plymouth waters. Journal of the Marine Biological Association of the United Kingdom, 26, 381-389.

MacIntosh H, de Nys R, Whalan S, 2012. Shipworms as a model for competition and coexistence in specialized habitats. Marine Ecology Progress Series, 461, 95-105.

Mann R, Gallager SM, 1985. Growth, morphometry and biochemical composition of the wood boring molluscs Teredo navalis L., Bankia gouldi (Bartsch), and Nototeredo knoxi (Bartsch) (Bivalvia: Teredinidae). Journal of Experimental Marine Biology and Ecology, 85, 229-251.

McGovern, E. R., Burreson, E. M., 1989. Immunoassay comparison of haplosporidan spores from Teredo navalis and Haplosporidium nelsoni spores from Crassostrea virginica. Journal of Protozoology, 36(3), 289-292.

McGovern, E. R., Burreson, E. M., 1990. Ultrastructure of Minchinia sp. spores from shipworms (Teredo spp.) in the western North Atlantic, with a discussion of taxonomy of the Haplosporidiidae. Journal of Protozoology, 37(3), 212-218.

Miloslavich P, Díaz JM, Klein E, Alvarado JJ, Díaz C, Gobin J, Escobar-Briones E, Cruz-Motta JJ, et al., 2010. Marine biodiversity in the Caribbean: regional estimates and distribution patterns. PLoS ONE, 5(8), e11916.

Moll, F., 1940. The behaviour of unprotected timber towards Pholas. (Das Verhalten ungeschutzter Holzer gegen die Bohrmuschel). Kolonialforstliche Mitteilungen, 3, 288-302.

Morton BS, 1970. The functional anatomy of the organs of feeding and digestion of Teredo navalis Linnaeus and Lyrodus pedicellatus (Quatrefages). Proceedings of the Malacological Society of London, 39, 151-167.

Müller, Y., 2004. Faune et flore du littoral du Nord, du Pas-de-Calais et de la Belgique: inventaire, France: Commission Régionale de Biologie Région Nord Pas-de-Calais.1-307.

Möbius K, 1873. English title not available. (Die faunistischen Untersuchungen. A. Die wirbellosen Thiere der Ostsee. Untersuchungen uber die Deutschen). Meere Kiel Jahresbericht, 1, 97-144.

Nair NB, 1962. Ecology of marine fouling and wood-boring organisms of western Norway. Sarsia, 8, 1-88.

Nair NB, Saraswathy M, 1971. The biology of wood boring teredinid molluscs. Advances in Marine Biology, 9, 355-509.

Nehring, S., 2006. Four arguments why so many alien species settle into estuaries, with special reference to the German river Elbe. Helgoland Marine Research, 60(2), 127-134. http://www.springerlink.com/(vbc5i445bmwdkp45y4ynpj45)/app/home/contribution.asp?referrer=parent&backto=issue,9,13;journal,2,169;linkingpublicationresults,1:103796,1 doi: 10.1007/s10152-006-0031-x

Norman E, 1977a. The geographical distribution and the growth of the wood-boring molluscs Teredo navalis L., Psiloteredo megotara (Hanley) and Xylophaga dorsalis (Turton) on the Swedish west coast. Ophelia, 16, 233-250.

Norman E, 1977b. The time of settlement on the Swedish west coast of the woodboring Molluscs Teredo navalis, Psiloteredo megotara and Xylophaga dorsalis. Material und Organismen, 3, 531-542.

Norman, E., 1976. The vertical distribution of the wood-boring molluscs Teredo navalis L., Psiloteredo megotara H. and Xylophaga dorsalis T. on the Swedish west coast. Material und Organismen, 11(4), 303-316.

Norman, E., Henningsson, B., 1975. Description of a trial with wood preservatives against marine wood boring organisms. In: Meddelande, Svenska Traskyddsinstitutet , (No. 118) . 15 pp.

Paalvast P, van der Velde G, 2013. What is the main food source of the shipworm (Teredo navalis)? A stable isotope approach. Journal of Sea Research, 80, 58-60.

Paalvast, P., van der Velde G, 2011. Distribution, settlement, and growth of first-year individuals of the shipworm Teredo navalis L. (Bivalvia: Teredinidae) in the Port of Rotterdam area, the Netherlands. International Biodeterioration & Biodegradation, 65(3), 379-388. https://www.sciencedirect.com/science/article/pii/S0964830511000035 doi: 10.1016/j.ibiod.2010.11.016

Paalvast, P., van der Velde G, 2011. New threats of an old enemy: the distribution of the shipworm Teredo navalis L. (Bivalvia: Teredinidae) related to climate change in the Port of Rotterdam area, the Netherlands. Marine Pollution Bulletin, 62(8), 1822-1829. http://www.sciencedirect.com/science/article/pii/S0025326X11002736 doi: 10.1016/j.marpolbul.2011.05.009

Pickard EA, 1927. The neuromotor apparatus of Boveria teredinidi Nelson, a ciliate from the gills of Teredo navalis. University of California Publications in Zoology, 29, 405-428.

Popham JD, Dikson MR, 1973. Bacterial associations in the teredo Bankia australis (Lamellibranchia: Molusca). Marine Biology, 19(14), 338-340.

Roch F, 1932. English title not available. (Einige Beobachtungen zur Ökologie und Physiologie von Teredo navalis L). Arkiv för Zoologi, 24(5), 1-17.

Roch F, 1940. English title not available. (Die Terediniden des Mittelmeeres). Thalassia, 14(3), 1-147.

Rowley SJ, 2005. Teredo navalis Great shipworm. In: Marine Life Information Network: Biology and Sensitivity Key Information Reviews [ed. by Tyler-Walters H, Hiscock K]. Plymouth, UK: Marine Biological Association of the United Kingdom.http://www.marlin.ac.uk/speciesinformation.php?speciesID=4447

Russell JL, 1839. Familiar notice of some of the shells found in the limits of the Essex County, Massachusetts, with reference to descriptions and figures. Essex County Natural History Society (Salem, Massachusetts), 1, 47-76.

Ryabchikov PI, 1957. Moscow, Russia: Academy of Sciences of the USSR.230 pp.

Ryabchikov PI, Nikolaeva GG, 1963. The settling of the shipworm larvae and water temperature in the Gelendzhiksk Bay of the Black Sea. Trudy Instituta Okeanologii Akademii Nauk SSSR, 70, 179-185.

Ryabchikov PI, Soldatova IN, Esakova SE, Petukhova TA, 1963. The start of the colonization of the Sea of Azov by some species of shipworms of the Family Teredinadae. Trudy Instituta Okeanologii Akademii Nauk SSSR, 70, 157-178.

Santhakumaran LN, Sneli JA, 1984. Studies on the marine fouling and wood-boring organisms of the Trondheimsfjord (Western Norway). Gunneria, 47, 7-30.

Scheltema RS, 1971. Dispersal of phytoplanktotrophic shipworm larvae (Bivalvia: Teredinidae) over long distances by ocean currents. Marine Biology, 11(1), 5-11.

Schütz L, 1961. Distribution and dispersal of the borer Teredo navalis L. and its entering of the Kiel Canal near Kiel. Kieler Meeresforschung, 17, 228-236.

Sellius G, 1733. Trajecti ad Rhenum, 353 pp.

Sen, S., SIvrIkaya, H., YalcIn, M., BakIr, A. K., Ozturk, B., 2010. Fouling and boring organisms that deteriorate various European and tropical woods at Turkish seas. African Journal of Biotechnology, 9(17), 2566-2573. http://www.academicjournals.org/AJB/PDF/pdf2010/26Apr/Sen%20et%20al.pdf

Sivrikaya H, HafIzoglu, H., Cragg, S. M., CarrIllo, A., MIlItz, H., MaI, C., Borges, L. M. S., 2012. Evaluation of wooden materials deteriorated by marine-wood boring organisms in the Black Sea. Maderas: Ciencia y Technologia, 14(1), 79-90. http://www.scielo.cl/scielo.php?script=sci_serial&pid=0718-221X&lng=en&nrm=iso

Sliwa C, Migus S, McEnnulty F, Hayes KR, 2009. Marine bioinvasions in Australia. In: Biological invasions in marine ecosystems: ecological, management, and geographic perspectives, 204, [ed. by Rilov G, Crooks J]. Germany: Springer. 425-437.

Snow CH, 1917. New York, USA: cGraw-Hill Book Company.496 pp.

Sordyl H, Bönsch R, Gercken J, Gosselck F, Kreuzberg M, Schulze H, 1998. English title not available. (Vorbreitung und Reproduction des Schiffsbohrwums Teredo navalis L. an der Küste Mecklenburg-Vorpommerns). Deutsche Gewässerkundliche Mitteilungen, 42(4)

Spicer, J. I., Strömberg, J. O., 2003. Metabolic responses to low salinity of the shipworm Teredo navalis (L.). Sarsia, 88(4), 302-305. http://www.ingenta.com/isis/searching/ExpandTOC/ingenta;jsessionid=2g484psr4p6g2.circus?issue=pubinfobike://tandf/ssar/2003/00000088/00000004&index=6 doi: 10.1080/00364820310002263

Steinmayer AG Jr, Turfa JM, 1996. Effects of shipworm on the performance of ancient Mediterranean warships. The International Journal of Nautical Archaeology, 25(2), 104-121.

Streftaris, N., Zenetos, A., Papathanassiou, E., 2005. Globalisation in marine ecosystems: the story of non-indigenous marine species across European seas. Oceanography and Marine Biology: An Annual Review, 43, 419-453.

Tarasov NI, 1943. Moscow, Russia: Voenmorizdat.191 pp.

Thompson J, Parchaso F, Alpine A, Cloern F, Cole B, Mace O, Edmunds J, Baylosis J, Luoma S, Nichols F, 2005. The history and effects of exotic species in San Francisco Bay. In: San Francisco Bay Project : Water Resources Division, US Geological Survey.http://sfbay.wr.usgs.gov/benthic_eco/exotic_species/exoticsp.pdf

Tsunoda, K., 1979. Ecological studies of shipworm attack on wood in the sea water log storage site [Teredinidae in Japan]. Wood Research, Kyoto University, (No. 65), 11-53.

Tuente U, Piepenburg D, Spindler M, 2002. Occurrence and settlement of the common shipworm Teredo navalis (Bivalvia: Teredinidae) in Bremerhaven harbours, northern Germany. Helgoland Marine Research, 56(2), 87-94.

Turgeon DD, Lyons WG, Mikkelsen P, Rosenberg G, Moretzsohn F, 2009. Bivalvia (Mollusca) of the Gulf of Mexico. In: Gulf of Mexico origin, waters, and biota: Volume 1, Biodiversity, [ed. by Felder DL, Camp DK]. Texas, USA: Texas A&M University Press. 711-744.

Turner RD, 1971. Methods of identification of marine borers and fungi. In: Marine borers, fungi and fouling organisms of wood, [ed. by Jones SK, Eltringham GEB]. Paris, France: Organisation for Economic Co-operation and Development. 18-63.

Turner RD, 1976. Some factors involved in the settlement and metamorphosis of marine bivalve larvae. [Proceedings of the 3rd International Biodegradation Symposium. Kingston, Rhode Island, USA. 17-23 August 1975], [ed. by Sharpley JM, Kaplan AM]. London, UK: Applied Science Publishers. 409-416.

Turner, R. D., 1966. A survey and illustrated catalogue of the Teredinidae (Mollusca: Bivalvia), Cambridge, Mass, USA: Museum of Comparative Zoology, Harvard University.265 pp.

Van Benthem Jutting T, 1943. Mollusca. C. Lammellibranchia. Fauna van Nederland, 12, 1-477.

Vanderperren JP, 1989. The Natural History archive 1988. (Het Natuurhistorisch archief 1988). De Strandvlo, 9(4), 89-90.

Voronkov PP, Svitashev AI, 1941. Experimental estimation of the possible salinity of the Sea of Azov resulting from the planned change of its regime. Trydi NIU GMS SSSR, 5(2)

Waterbury JB, Calloway CB, Turner RD, 1983. A cellulolytic nitrogen-fixing bacterium cultured from the gland of deshayes in shipworms (Bivalvia: Teredinidae). Science, 221(4618), 1401-1403.

Weiss, C. M., 1948. An observation on the inhibition of marine wood destroyers by heavy fouling accumulation. Ecology, 29(1), 120. doi: 10.2307/1930351

Wolff, W. J., 2005. Non-indigenous marine and estuarine species in The Netherlands. Zoologische Mededelingen, 79(1), 1-116.

Wood A, 1995. The Thames Tunnel 1825-43. Where shield tunnelling began. Proceedings of the Institution of Civil Engineers-Civil Engineering, 108(2), 88-89.

WoRMS, 2014. World Register of Marine Species. http://www.marinespecies.org/

Wreck Protect, 2011. Wreck Protect Project. National Museum of Denmark.http://wreckprotect.org/

Zaklinskii GV, Limonov AF, 2005. Sea of Azov. In: [Great Russian Encyclopedia] Bolshaya Rossiyskaya Entsiklopediya, 1. Moscow, Russia: Big Russian Encyclopedia. 297 pp.

Zettler ML, Regine Bönsch R, Gosselck F, 2000. English title not available. (Verbreitung des Makrozoobenthos in der Mecklenburger Bucht (südliche Ostsee) - rezent und im historischem Vergleich). Meereswissenschaftliche Berichte, 42, 1-144.

Principal Source

Draft datasheet under review

Contributors

02/06/14 Original text by:

Ekaterina Shalaeva, Consultant, London, UK

Distribution Maps