Caprella mutica

Pictures

Picture	Title	Caption	Copyright
Title Male and female Caption Caprella mutica; male (larger) and female (smaller). (Original image by T. Nickell.) Copyright Elizabeth J. Cook	Male and female	Caprella mutica; male (larger) and female (smaller). (Original image by T. Nickell.)	Elizabeth J. Cook
Title Dense aggregation Caption Experimental frame deployed west of Zeebrugge, Belgium in 2007 showing dense aggregations of Caprella mutica. Copyright Francis Kerckhof	Dense aggregation	Experimental frame deployed west of Zeebrugge, Belgium in 2007 showing dense aggregations of Caprella mutica.	Francis Kerckhof

Identity

Preferred Scientific Name

• Caprella mutica Schurin, 1935

International Common Names

• English: ghost shrimp; Japanese skeleton shrimp

Local Common Names

• Netherlands: macho spookkreeftje

Summary of Invasiveness

C. mutica was first described from sub-boreal areas of north-east Asia in 1935 (Schurin, 1935). The first reports of C. mutica outside its native habitat were from the Pacific and Atlantic coasts of North America in the 1970s (Carlton, 1979) and 1980s (Marelli, 1981; Cohen and Carlton, 1995) and it has since spread to both northern and southern hemispheres (Ashton et al., 2007a). C. mutica is one of the largest caprellid amphipods, mature males attain body lengths of up to 50 mm (Nishimura, 1995) and populations can attain densities > 300,000 individuals/m² (Ashton, 2006). C. mutica is an aggressive species, out-competing native caprellid amphipods for space, even at low densities (Shucksmith, 2008).C. mutica is frequently associated with man-made structures and is found in abundance on boat hulls, navigation/ offshore buoys, floating pontoons and aquaculture infrastructure. It is highly likely that its dispersal is associated with vessel movements whilst attached to hull fouling. Whilst the wider environmental implications of C. mutica have not yet been confirmed, it is likely that it has an important impact on benthic and plankton communities (Cook et al., 2007b). This species is currently not present on an alert list (e.g. IUCN, ISSG) or listed as a regulated pest etc.

Taxonomic Tree

• Domain: Eukaryota
•     Kingdom: Metazoa
•         Phylum: Arthropoda
•             Subphylum: Crustacea
•                 Class: Malacostraca
•                     Subclass: Eumalacostraca
•                         Order: Amphipoda
•                             Suborder: Caprellidea
•                                 Family: Caprellidae
•                                     Genus: Caprella
•                                         Species: Caprella mutica

Notes on Taxonomy and Nomenclature

The caprellid amphipod Caprella mutica was first described by Schurin (1935) in Peter the Great Bay, Vladivostok, Russia and was subsequently identified in the neighbouring Possjet Bay, Japan (Vassilenko, 1967) and Akkeshi Bay, Japan (Arimoto, 1976).

This species was initially described and recorded in European waters as Caprella macho by Platvoet et al. (1995), but was later confirmed to be C. mutica (Willis et al., 2004).

Description

C. mutica is one of the largest caprellid amphipods, mature males attain body lengths of up to 50 mm (Nishimura, 1995), whereas females are smaller and attain body lengths of up to 29 mm (Ashton, 2006). Juvenile, immature C. mutica typically range in body length from 0.81 to 7.95 mm (Ashton, 2006). Live specimens of C. mutica are pale brown to dark red in colour, and the brood pouch of the female is covered with dark red spots. The first two pereonites are elongated in the male and are densely covered with setae. The second pereonite is the longest of the seven pereonites. On the male, gnathopod 2 arises from the distal end of pereonite 2 and is also densely setose. There is no setation on the first and second pereonites in the females, which are greatly shortened compared with the male. Gnathopod two is located anteriorly on the second pereonite of the female. The third to seventh pereonites have dorsal and lateral spines and there are three spines around the base of each gill. The gills are located on pereonites 3 and 4. The antennule of the male is slightly greater than half the body length and has a flagellum of 22 (± 2 S.D.) articles. C. mutica can be definitively identified by the relative size of the three projections on the grasping margin of the propodus of gnathopod 2. In large males, the middle projection is the most prominent (Willis et al., 2004).

Distribution

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 first reports of C. mutica outside its native habitat were from the Pacific and Atlantic coasts of North America in the 1970s (Carlton, 1979) and 1980s (Marelli, 1981; Cohen and Carlton, 1995). It is unknown whether these records are the result of several independent cross-oceanic introductions with oyster spat (Carlton, 1979), or the result of local small-scale transport following the first introduction (Carlton, 1996). The next series of records are from Europe, with C. mutica first identified in 1994 in a harbour at Neeltje Jans in the Netherlands (M Faasse, National Museum of Natural History Naturalis, The Netherlands, personal communication, 2008). Direct sequencing of mitochondrial DNA indicates that C. mutica was introduced to Europe either directly from Asia or from the Atlantic coast of North America (Ashton, 2006). The exact mode of introduction is unknown, although it is highly likely that ballast water transport and/ or hull fouling could be involved rather than stock movements of cultured species (Cook et al., 2007b).

Introductions

Risk of Introduction

It is highly likely that C. mutica may be accidentally introduced to South America, southern Australia, and South Africa (Ashton et al., 2007a). All these regions are within the temperature boundaries for C. mutica and they are also key areas of shipping activity. South America and Australia are particularly well linked to south-east Asia as dispersal routes for introduced species (Carlton, 1987). Within Europe, this species is likely to continue to extend its current range, but is unlikely to survive in the central and eastern Baltic Sea due to low salinities (FIMR, 2006), and based on current knowledge it is not expected to become established in the Mediterranean Sea on account of the high summer seawater temperatures (Cook et al., 2006a). Long-range distribution will most probably depend on the movement of floating artificial structures, such as commercial and recreational vessels, whilst attachment to floating marine algae may account for more localised movements (Cook et al., 2007b). It is unlikely that C. mutica will be deliberately introduced to a region.

Habitat

In the native range, C. mutica is typically associated with either attached or drifting macroalgae, including Sargassum spp. or aquaculture structures, such as the ropes used for the culture of the macroalga Undaria spp. in Otsuchi Bay (Kawashima et al., 1999). In regions outside its native range, it has been found associated with areas of anthropogenic activity, such as harbours, marinas, navigation buoys, oil rigs and aquaculture sites (Willis et al., 2004; Ashton, 2006; Kerckhof et al., 2007).

Habitat List

Biology and Ecology

Direct sequencing of mitochondrial DNA (cytochrome c oxidase subunit I gene) has been used to investigate genetic variation between native and non-native populations of C. mutica. Three hundred individuals were PCR-amplified, which included 51 from the native area in Japan and 249 from non-native populations. Overall, base frequencies were biased towards A and T (A = 26%, T = 36%, C = 20%, G = 18%). All unique genetic sequences for C. mutica have been deposited with GenBank (accession numbers: DQ466220-466523). The genetic divergence between non-native populations of C. mutica in the northern hemisphere indicated significant differentiation between populations in different oceanic provinces and among populations in geographic regions. A total of seven haplotypes were found in the non-native populations, indicating considerably reduced genetic diversity relative to the native populations in Japan, where 31 unique haplotypes were observed. Collectively, the Atlantic populations were shown to have a comparatively high genetic diversity and most of the populations from this oceanic province share haplotypes. The unique haplotypes present on the Pacific coast of North America indicate strong genetic differentiation and no gene flow between the Atlantic and Pacific populations (Ashton, 2006).

Populations of C. mutica showed an increase in spring to a peak abundance in late summer (August – September), followed by a decline in population abundance during the winter in coastal waters on the west coast of Scotland. This cycle typically follows annual seawater temperatures for the region and is similar to that observed in the native habitat in the Sea of Japan (Fedotov, 1991). Juvenile C. mutica were present throughout the year on the west coast of Scotland in fish farm cages, which may indicate either continuous reproduction in this species or delayed growth of over-wintering juveniles. Females tend to dominate the population and this is most marked in autumn and winter (Ashton, 2006). Ovigerous females are found throughout the year and the number of eggs is positively related to the length of the female (Ashton, 2006). The greatest number of ovigerous females are found in the spring and summer months (April to October) (Ashton, 2006). The number of eggs per female is highly variable (min = 3, max = 363, average = 74, SD = 47.7) (Ashton, 2006). Females produce their first brood approximately 53 days post-hatching at an average body length of 8.5mm and at a seawater temperature of 13–14^oC (Cook et al., 2007b). Each female has an average of two sequential broods released at approximately 20 day intervals. The maximum number of recorded hatchlings produced by a single female at a seawater temperature of 13.0 ± 0.5°C is 82. Juveniles typically emerge from the brood pouch at a body length of approximately 1.3 mm (Cook et al., 2007b).

C. mutica is able to survive for up to 20 days without additional food under laboratory conditions (Cook et al., 2007b) andis tolerant of a broad range of temperature and salinity conditions, with 100% mortality at 30°C (48 h LT50, 28.3 ± 0.41°C), and salinities lower than 16‰ (48 h LC50, 18.7 ± 0.24‰) over a short (48 h) exposure period (Ashton et al., 2007b). Although lethargic at low temperatures (2°C), no mortality was observed, and the species is known to survive at temperatures as low as -1.8°C. The upper LC₅₀ was greater than the highest salinity tested (40‰), thus it is unlikely that salinity will limit the distribution of C. mutica in open coastal waters. However, the species will be excluded from brackish water environments such as the heads of sea lochs and estuaries. The physiological tolerances of C. mutica are beyond the physical conditions experienced in its native or introduced range and are thus unlikely to be the primary factors limiting its present distribution and future spread (Ashton et al., 2007a).

Nutrition

Caprellids are known to be opportunist feeders and to consume any readily available organic material (Keith, 1969). C. california and C. equilibria were found to consume organic detritus, diatoms, dinoflagellates and crustaceans, including other caprellids, amphipods, isopods, harpacticoid copepods and ostracods (Keith, 1969). In laboratory studies, C. mutica has been observed grazing upon the diatom Cylindrotheca fusiformis Reumann and Lewin and the macroalgae, Fucus vesiculosus L. They have also been observed actively filtering particles out of the water column using their second pair of setose antennae as filtering structures. Feeding trials with Artemia- nauplii revealed feeding rates of approximately 20 Artemia /hour for males and 13 Artemia /hour for females. Feeding rates remain constant over a period of 24 hours indicating continuous feeding throughout the day and night. Low temperatures led to a significant decline (about 60 and 50% for males and females, respectively) in feeding rates. When offered high food quantities, the average feeding rates were higher compared to when smaller quantities of food were offered (K Boos, Biologische Anstalt Helgoland, Alfred Wegener Institut for Polar- and Marine Research, Germany, personal communication, 2008).

C. mutica is typically found associated with attached macroalgae and drifting seaweeds in its native habitat, including Sargassum spp and on aquaculture structures, such as ropes for Undaria culture in Otsuchi Bay (Kawashima et al., 1999). In non-native habitats, this species typically clings to a wide range of artificial structures (aquaculture nets, ropes, pontoons, submerged lines and boat hulls) and on fouling organisms associated with these structures (including macroalgae - particularly red filamentous algae, such as Ceramium spp., hydroids, ascidians, mussels and barnacles) (Ashton, 2006; Cook et al., 2006a). In addition, studies have found that C. mutica, prefers to attach to filamentous (e.g. filamentous and branching macroalgae) and soft structures (e.g. solitary tunicates) compared with hard structures, such as bivalve shells (Shucksmith, 2008).

See Water Tolerances.

Water Tolerances

Natural enemies

Notes on Natural Enemies

Very little information is known about the natural enemies of C. mutica. A recent study, however, has found that the European shore crab Carcinus maenas will consume large quantities of C. mutica in laboratory experiments (Shucksmith, 2008).

Means of Movement and Dispersal

Natural dispersal for C. mutica is likely to be limited, as this species does not have a planktonic larval stage. Free-swimming (or natural dispersal) is, therefore, likely through short-distance swimming or current-driven dispersal following disturbance from the substrate (Ashton, 2006). Small numbers of caprellids have been identified in planktonic samples from marginal seas (Takeuchi and Sawamoto, 1998) and swimming has been observed for certain caprellid species (Caine, 1980). C. mutica has also been observed swimming short distances in the laboratory and field (E Cook, Scottish Association of Marine Science, UK, personal observation, 2008), however, the maximum distance of dispersal for this method is unknown.

C. mutica has been found on drifting seaweed in its native habitat (Sano et al., 2003) and on the west coast of Scotland (Ashton, 2006). It has been suggested that this mechanism is responsible for the long distance dispersal (> 1000 km) of several planktonic species (Jokiel, 1984; Helmuth et al., 1994). In a recent study on the west coast of Scotland, C. mutica was found on 27% of the drifting mats of macroalgae collected. The maximum number of individuals on one algal mat was 71, including ovigerous females and males (Ashton, 2006). It is most likely, however, that this mechanism for dispersal will be most frequent in the spring and summer months, when large quantities of algae are produced along the continental shelf (Thiel and Haye, 2006).

Accidental Introduction

Shipping has been identified as an important pathway for the transoceanic introduction of non-native species (Drake and Lodge, 2004). Many of the areas where C. mutica has been introduced are close to busy ports suggesting that ballast water transport and/ or hull fouling could be involved (Cook et al., 2007a). Living Caprella spp. have been found in ships’ ballast tanks (Carlton, 1985) and in sea-chests in a study in New Zealand (Coutts et al., 2003). Within its native environment, C. mutica may be found attached to the macroalgae Ulva spp. and the filamentous Cladophora spp. and these are regularly found attached to ships hulls (Mineur et al., 2007). It has also been seen associated with other algae at high densities on recreational boat hulls (Minchin and Holmes, 2006; G Ashton, Smithsonian Environmental Research Centre, USA and R Shucksmith, The Scottish Association for Marine Science, UK, personal communication, 2008) and in the Adriatic Sea the non-native Caprella scaura is thought to have been spread on the hulls of leisure craft (Sconfietti et al., 2005).

Stock movements of cultured species have also been identified as one means of globally spreading non-native species (Ruiz and Hewitt, 2002; Minchin, 2007). Introduction of C. mutica to the United States has been potentially linked to the importation of the Pacific Oyster, C. gigas for culture purposes (Carlton, 1987). In Europe, the Oosterschelde region in the Netherlands has received extensive shellfish imports and these movements may have been responsible for the introduction of C. mutica (Wolff, 2005). However, this region was regularly sampled between 1990 and 1995 and C. mutica was not found (M Faasse, National Museum of Natural History Naturalis, The Netherlands, personal communication, 2008). This suggests that the introduction to Europe of C. mutica is more likely to be via commercial shipping rather than stock movements of cultured species (Cook et al., 2007a).

There are no known reports of C. mutica being intentionally introduced to an area outside its native region.

Impact Summary

Economic Impact

There are no known economic impacts related to the presence of this species.

Environmental Impact

C. mutica is known to occur in marine protected areas in the UK (e.g. Firth of Lorne, west coast of Scotland), but the impact of this species on the habitats within these areas is unknown.

C. mutica is an aggressive species and it is highly likely, that this species will displace other native amphipod species and potentially compete with sessile suspension feeders for food.Experiments have shown that C. mutica and a common UK native species of caprellid, Caprella linearis share the same preference for fine filamentous branching structures and as a result, competition for space has been observed in both laboratory and in the field.C. mutica has been observed displacing native C. linearis at low structural diversity due to its aggressive behaviour. At higher structural diversity, however, increased availability of refuges provided shelter for the native caprellid and thus enabled the two species to co-occur. 

Further experiments, regarding density dependent interactions between C. mutica and the native caprellid C. linearis on the same substrate showed that only comparatively low numbers of the non-native C. mutica are needed to displace significantly higher proportions of the native species. However, displacement activity was restricted when population abundances of C. linearis declined to relatively low densities, suggesting that C. mutica may not entirely displace C. linearis and, therefore may allow coexistence in the field.

As C. mutica inhabits predominantly artificial structures in the field at present, the impact of this species on benthic biodiversity, native species and species of conservation remains low. Whereas, the impact on plankton biodiversity maybe significant considering their high feeding rates and population densities, particularly in the summer months (Ashton, 2006), however, the scale of this impact is unknown.

Social Impact

This is no known social impact related to the presence of this species.

Risk and Impact Factors

• Proved invasive outside its native range
• Has a broad native range
• Abundant in its native range
• Highly adaptable to different environments
• Pioneering in disturbed areas
• Tolerant of shade
• Capable of securing and ingesting a wide range of food
• Highly mobile locally
• Benefits from human association (i.e. it is a human commensal)
• Fast growing
• Has high reproductive potential
• Gregarious
• Has high genetic variability

• Conflict
• Modification of natural benthic communities
• Reduced native biodiversity
• Threat to/ loss of native species

• Competition - monopolizing resources
• Fouling
• Interaction with other invasive species
• Predation
• Rapid growth

• Highly likely to be transported internationally accidentally
• Difficult to identify/detect as a commodity contaminant

Uses

Economic Value

There is no known economic value for C. mutica.

Social Benefit

C. mutica provides no known social benefit.

Environmental Services

C. mutica provides no known environmental services.

Diagnosis

All unique genetic sequences for C. mutica have been deposited with GenBank (accession numbers: DQ466220-466523).

Detection and Inspection

The main difficulty in the detection of C. mutica has been with the identification of this species prior to 2002, as little taxonomic information was available outside its native region. This problem, however, should be rectified with the inclusion of a detailed identification notes on C. mutica in Willis et al. (2004) and the inclusion of this species in the new edition of Hayward and Ryland’s ‘Handbook of the Marine Fauna of North-West Europe’ later in 2007/08. 

Similarities to Other Species/Conditions

It is relatively easy to mistakenly identify C. mutica as the closely related Asian species Caprella acanthogaster. Detailed descriptions of the morphology of C. acanthogaster can be found in Arimoto (1976) and Guerra-Garcia and Takeuchi (2004).

Prevention and Control

Due to the variable regulations around (de)registration of pesticides, your national list of registered pesticides or relevant authority should be consulted to determine which products are legally allowed for use in your country when considering chemical control. Pesticides should always be used in a lawful manner, consistent with the product's label.

Prevention

Early warning systems

No known early warning system is in place specifically for C. mutica, but as this species becomes more widely known, it is likely that it will be identified more regularly in routine surveys.

Rapid response

No known rapid response system is available to manage C. mutica.

Public awareness

In the UK, public awareness has been largely funded by a charitable trust, the Esmée Fairbairn Foundation, with support from the UK government environment agencies which has enabled the establishment of a marine non-native species website including C. mutica, production of leaflets, posters, splash-proof ID guides and popular articles and public lectures throughout the UK. Public awareness of C.mutica in other invaded regions, however, is unknown.

Eradication

No known eradication attempts have been made for C. mutica.

No known containment/ zoning attempts have been made for C. mutica.

Control

No known control programmes have been undertaken for C. mutica.

Potential physical methods for the control of C. mutica may include:

Biological control

Potential use of benthic predators.

Chemical control

No known chemical control.

Monitoring and Surveillance

Monitoring for C. mutica is conducted on a regular basis in the UK, Belgium and the Netherlands. A monthly monitoring programme for C. mutica at a fish farm and marina in the Lynne of Lorne, west coast of Scotland has been conducted since 2004.

Mitigation

No mitigation measures have been developed for C. mutica.

Gaps in Knowledge/Research Needs

Limited factual information is available on the economic and environmental impacts and control methods for C. mutica and these areas would greatly benefit from future research.

References

Arimoto I, 1976. Taxonomic studies of caprellids (Crustacea, Amphipoda, Caprellidae) found in the Japanese adjacent waters. Special publications from the Seto Marine Biological Laboratory Series III. Osaka, Japan: Nippon Printing & Publishing Co. Ltd.

Ashton GV, 2006. University of Aberdeen PhD Thesis. Aberdeen, UK: University of Aberdeen.

Ashton GV; Willis K; Burrows M; Cook EJ, 2007. Environmental tolerance of Caprella mutica: implications for its distribution as a non-native species. Marine Environmental Research, 64:305-312.

Ashton GV; Willis KJ; Cook EJ, 2007. Global distribution of the Japanese skeleton shrimp, Caprella mutica (Crustacea, Amphipoda, Caprellidae) with a detailed account of the distribution in Scotland, UK. Hydrobiologia, 590:31-41.

Caine EA, 1980. Ecology of two littoral species of caprellid amphipods (Crustacea) from Washington, USA. Marine Biology, 56:327-335.

Carlton JT, 1979. University of California PhD Thesis. Davis, USA: University of California.

Carlton JT, 1985. Transoceanic and interoceanic dispersal of coastal marine organisms: the biology of ballast water. Oceanography and Marine Biology. Oceanography and Marine Biology. An Annual Review, 23:313-371.

Carlton JT, 1987. Patterns of transoceanic marine biological invasions in the Pacific ocean. Bulletin of Marine Science, 41:452-465.

Carlton JT, 1996. Pattern, process and prediction in marine invasion ecology. Biological Conservation, 78:97-106.

Cohen AN; Carlton JT, 1995. Nonindigenous aquatic species in a United States Estuary: A case study of the biological invasions of the San Francisco Bay and Delta. A Report for the United States Fish and Wildlife Service, Washington DC. http://www.anstaskforce.gov/sfinvade.htm

Cook EJ; Black KD; Sayer MDJ; Cromey CJ; Angel DL; Spanier E; Tsemel A; Katz T; Eden N; Karakassis I; Tsapakis M; Apostolaki ET; Malej A, 2006. The influence of caged mariculture on the early development of sublittoral fouling communities: a pan-European study. ICES Journal of Marine Science, 63(4):637-649. http://www.sciencedirect.com/science/journal/10543139

Cook EJ; Jahnke M; Kerckhof F; Minchin D; Faasse M; Boos K; Ashton G, 2007. European expansion of the introduced amphipod Caprella mutica Schurin 1935. Aquatic Invasions, 2(4):411-421. http://www.aquaticinvasions.ru/2007/AI_2007_2_4_Cook_etal.pdf

Cook EJ; Shucksmith R; Ashton GV, 2006. Proceedings of the 14th International Conference on Invasive Aquatic Species, Miami, Florida, 14-19 May 2006.

Cook EJ; Willis KJ; Lozano-Fernandez M, 2007. Survivorship, growth and reproduction of the non-native Caprella mutica Schurin, 1935 (Crustacea: Amphipoda). Hydrobiologia, 590:55-64. http://springerlink.metapress.com/content/1573-5117/

Coutts ADM; Moore KM; Hewitt CL, 2003. Ships' sea-chests: an overlooked transfer mechanism for non-indigenous marine species? Marine Pollution Bulletin, 46:1504-1515.

Drake JM; Lodge DM, 2004. Global hot spots of biological invasions: evaluating options for ballast-water management. Proceedings of the Royal Society of London. Series B, Biological Sciences, 271(1539):575-580. http://www.pubs.royalsoc.ac.uk/proc_bio_homepage.shtml

Fedotov PA, 1991. Population and production biology of amphipod Caprella mutica in Posyet Bay, Sea of Japan. Biologiya Morya, 4:53-60.

FIMR, 2006. FIMR monitoring of the Baltic Sea environment. In: Annual Report 2006. Finnish Institute for Marine Research Helsinki, Finland: Finnish Institute for Marine Research. http://www.fimr.fi/en/palvelut/bmp.html

Guerra-Garcia JM; Takeuchi I, 2004. The Caprellidea (Crustacea: Amphipoda) from Tasmania. Journal of Natural History, 38:967-1044.

Hayward PJ; Ryland JS, 1995. Handbook of the marine fauna of North-West Europe. UK: Oxford University Press.

Helmuth BS; Veit RR; Holberton R, 1994. Long-distance dispersal of a subantarctic brooding bivalve (Gaimardia trapesina) by kelp rafting. Marine Biology, 120:421-426.

Jokiel PL, 1984. Long distance dispersal of reef corals by rafting. Coral Reefs, 3:113-116.

Kawashima H; Takeuchi I; Ohnishi M, 1999. Fatty acid compositions in four of caprellid amphipod species (Crustacea) from Otsuchi and Mutsu bays in northern Japan. Journal of the Japanese Oil Chemists Society, 48:595-599.

Keith DE, 1969. Aspects of feeding in Caprella californica Stimpson and Caprella equilibra Say (Amphipoda). Crustaceana, 16:119-124.

Kerckhof F; Haelters J; Gollasch S, 2007. Alien species in the marine and brackish ecosystem: the situation in Belgian waters. Aquatic Invasions, 2(3):243-257. http://www.aquaticinvasions.ru/2007/AI_2007_2_3_Kerckhof_etal.pdf

Marelli DC, 1981. New records for Caprellidae in California, and notes on a morphological variant of Caprella verrucosa Boeck, 1871. Proceedings of the Biological Society of Washington, 94:654-662.

Minchin D, 2007. Aquaculture and transport in a changing environment: overlap and links in the spread of alien biota. Marine Pollution Bulletin, 55(7/9):302-313. http://www.sciencedirect.com/science/journal/0025326X

Minchin D; Holmes JMC, 2006. The first record of Caprella mutica Schurin 1935 (Crustacea: Amphipoda) from the east Coast of Ireland. Irish Naturalists' Journal, 28:321-323.

Mineur F; Belsher T; Johnson MP; Maggs CA; Verlaque M, 2007. Experimental assessment of oyster transfers as a vector for macroalgal introductions. Biological Conservation, 137:237-247.

Nishimura S, 1995. Guide to the Seashore Animals of Japan with Colour Pictures and Keys. Japan: Hoikusha.

Pederson J; Bullock R; Carlton J; Dijkstra J; Dobroski N; Dyrynda P; Fisher R; Harris L; Hobbs N; Lambert G; Lazo-Wasem E; Mathieson A; Miglietta M-P; Smith J; Smith JIII; Tyrell M, 2003. Marine Invaders in the Northeast: Rapid assessment survey of non-native and native marine species of floating dock communities. Report for the Massachusetts Institute of Technology Sea Grant Program.

Platvoet D; Bruyne RHde; Gmelig Meyling AW, 1995. Description of a new Caprella-species from the Netherlands: Caprella macho nov.spec. (Crustacea, Amphipoda, Caprellidae). Bulletin of the Zoological Museum,University of Amsterdam, 15:1-4.

Ruiz GM; Hewitt CL, 2002. Toward understanding patterns of coastal marine invasions: a prospectus. In: Invasive Aquatic Species of Europe. Distribution, Impacts and Management [ed. by Leppäkoski E, Gollasch S, Olenin S] Dordrecht, The Netherlands: Kluwer Academic Publishers.

Sano M; Omori M; Taniguchi K, 2003. Predator-prey systems of drifting seaweed communities off the Tohoku coast, northern Japan, as determined by feeding habit analysis of phytal animals. Fisheries Science, 69:260-268.

Schevchenko OG; Orlova TY; Maslennikov SI, 2004. Seasonal dynamics of the diatoms of the genus Chaetoceros Ehrenberg in Amursky Bay (Sea of Japan). Russian Journal of Marine Biology, 30:11-19.

Schurin A, 1935. [English title not supplied]. (Zur fauna der Caprelliden der bucht Peter der Grossen (Japanisches Meer)) Zoologischer Anzeiger, 122:198-203.

Sconfietti R; Mangili F; Savini D; Occhipinti-Ambrogi A, 2005. Diffusion of the alien species Caprella scaura Templeton, 1836 (Amphipoda: Caprellidae) in the Northern Adriatic Sea. Biologia Marina Mediterranea, 12:335-337.

Shucksmith R, 2008. Biological Invasions: The role of biodiversity in determining community susceptibility to invasion. Aberdeen, UK: University of Aberdeen.

Takeuchi I; Sawamoto S, 1998. Distribution of caprellid amphipods (Crustacea) in the western North Pacific based on the CSK International Zooplankton Collection. Plankton Biology and Ecology, 45:225-230.

Thiel M; Haye PA, 2006. The ecology of rafting in the marine environment. III. Biogeographical and evolutionary consequences. Oceanography and Marine Biology. Oceanography and Marine Biology. An Annual Review, 44:323-429.

Vassilenko SV, 1967. [English title not supplied]. (Issledovanija Fauny Morei (Explorations of the fauna of the seas of the USSR)) Biotzenozy Zalika Possjet Japanskovo Morja, 5:196-229.

Willis KJ; Cook EJ; Lozano-Fernandez M; Takeuchi I, 2004. First record of the alien caprellid amphipod, Caprella mutica, for the UK. Journal of the Marine Biological Association of the United Kingdom, 84:1027-1028.

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

Links to Websites

Organizations

UK: Scottish Association for Marine Science, Dunstaffnage Marine Laboratory, Oban, Argyll, PA37 1QA, Oban, Scotland, UK, http://www.sams.ac.uk/

Contributors

16/11/07 Original text by:

Elizabeth Cook, Scottish Association of Marine Science, Ecology Department, Dunstaffnage Marine Laboratory, Oban Argyll, Scotland, UK

Distribution Maps