L. kasmira is a small snapper (Lutjanidae) with a maximum size of 40 cm (Torres, 1991). It is a brightly colored fish with four horizontal blue stripes on a yellow body. L. kasmira has a broad native geographic range, and is found in near-shore marine waters and coral reef habitats from eastern Africa through Polynesia. It is found outside its native range only in the Hawaiian archipelago, where it was deliberately introduced in the mid-twentieth century as part of an attempt to enhance local fisheries. Like many invasive species, L. kasmira quickly became naturalized to its new environment. It became established and began to reproduce successfully within a few years of being introduced. Once this species became naturalized, it advanced rapidly through the Hawaiian archipelago, with populations spreading from island to island at an average rate of 60 km per year (see History of Introduction/Spread).
Rather than enhancing local fisheries, there is a common public perception that L. kasmira has caused declines through competition with, or predation on, native species. However, scientific studies to date have not been able to detect or quantify impacts attributable to L. kasmira. It should be noted that certain aspects of the ecology of this species have not been thoroughly researched, and future studies may yet elucidate mechanisms through which L. kasmira adversely affects native species or habitats (see Gaps in Knowledge/Research Needs). L. kasmira is not listed as a regulated pest or on alert lists.
Taxonomy and scientific nomenclature of Lutjanus kasmira have been well established for some time. Forsskål (1775) originally named this fish Sciaena kasmira, but later re-classified it as L. kasmira. Contemporary literature should refer to this species as L.kasmira.
There are a multitude of common names in a variety of languages for L. kasmira, owing to the many nations, islands, and associated dialects encompassed by its native range. In Hawaii, where it was introduced, it is called by its Tahitian name, ta`ape. Several species of snapper have similar coloration to L. kasmira (see Similarities to Other Species/Conditions), and share descriptive English names such as bluestripe snapper or blueline snapper. To avoid confusion that might arise from these common names, L. kasmira will used throughout this datasheet.
L. kasmira is a bright yellow snapper with four horizontal blue stripes on each side. The yellow colour grades to white in the lower third of the body. All the fins are yellow, which distinguishes it from other similar species (see Similarities to Other Species/Conditions). L. kasmira generally grows to about 35 cm total length, though specimens up to 40 cm have been reported (Torres, 1991). The body is moderately compressed laterally, with a length equal to 2.4-2.8 times the height (Allen, 1985). A detailed diagnostic description of L. kasmira, including information on meristic characters and keys to snapper species, can be found in Allen (1985).
Eggs of L. kasmira are planktonic, and measure 0.78-0.85 mm in diameter (Suzuki and Hioki, 1979). Larvae hatch with a large yolk sac and are approximately 2 mm in length. Initially they are elongate, colourless, and bear no discernable resemblance to the adult form. However, larval fish grow rapidly as they absorb their yolk sacs, and eventually develop protective spines and an appearance that is more recognizable as a snapper. A detailed description and drawings of larval stages can be found in Suzuki and Hioki (1979) and Allen (1985).
Although many reef fish, notably parrotfish (Scaridae) and wrass (Labridae), have one colour pattern as juveniles, another during their “initial” adult phase as females, and then acquire yet another colour pattern when they change to their “terminal” male phase. However, male and female snappers look the same, and maintain the same sex and colour pattern throughout their life. Juveniles have the same colour pattern as the adults, and look like smaller, though more slender, versions of the larger fish.
L. kasmira has a wide geographic range, spanning over half the circumference of the globe from eastern Africa through Polynesia (Allen, 1985; Anderson, 1986). It is, however, restricted to tropical or subtropical marine environments. It is found in only one location outside of its native range, having been introduced to the Hawaiian archipelago, in the central Pacific Ocean.
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.
Details of the introduction of L. kasmira are reported in Schumacher and Parrish (2005). L. kasmira were deliberately released at three locations around the island of Oahu. The initial release site was off Barber’s Point, which is the point at the west end of Oahu’s south shore. The second site was in Maunalua Bay, which is a broad, open bay toward the east end of the south shore. This bay is approximately 40 km east of Barber’s Point. The third release point was near Coconut Island (Moku`o Loe). Coconut Island is a small islet located on a patch reef in Kane`ohe Bay, which is a large bay (13 by 4 km) on Oahu’s northeast-facing coast. Coconut Island is nearly 80 km from Maunalua Bay by sea.
Groups of L. kasmira were released on four occasions over a six-year period. Several (likely less than 12) individuals were released at Barber’s Point in December of 1955; 1400 individuals were released at Coconut Island on 23 June 1958; another 1035 individuals were released the following day in the same location; and 728 individuals were released in Maunalua Bay in December of 1961. The fish released in 1955 and 1958 were collected in the Marquesas, while the fish released in 1961 were collected at Mo`orea in the Society Islands.
Details of the spread of L. kasmira are adapted from Sladek-Nowlis and Friedlander (2004) and Conklin (2002). The first record of a fish captured away from an introduction site was on 12 July 1958, when two fish were captured in a trap 25 km northwest of the Barber’s Point introduction site. Whether these fish represent dispersal by released fish or colonization of a new area by recruits is not known. Continuous, shallow-water reef environments are available between the sites, so direct dispersal is a possibility.
The first record of an individual captured at an island other than Oahu was off the island of Hawaii. A fish was caught in 1960 at a location north of Hilo. This location is 350 km from the nearest introduction site in Maunalua Bay, Oahu. Between Oahu and Hawaii are the islands of Molokai, Lanai, and Maui; but the channels between these islands are up to thousands of meters deep and 50 km across. These channels are also swept by strong currents, and they present a formidable barrier to direct dispersal for a small, demersal (bottom-associated) fish. It is therefore likely that the fish captured near Hilo represents the first evidence of larval dispersal and recruitment, and hence, naturalization by L. kasmira.
The first recorded capture of L. kasmira northwest of Oahu was in 1969 off the island of Ni`ihau. After this report, fish were caught or sighted at successively more remote locations: L. kasmira were recorded at French Frigate Shoals in the northwestern Hawaiian Islands in 1977, at Laysan Island in 1979, and near the far, northwestern end of the archipelago at Midway Island in 1992 (Randall et al., 1993). Sampling for L. kasmira was not systematic throughout the archipelago, and this is particularly true in the remote northwestern Hawaiian Islands. As such, it is probable that L. kasmira arrived at these locations before they were recorded. However, if it is assumed that the fish arrived at Midway Island just prior to being recorded, they had dispersed 2200 km in (at most) 37 years. Therefore their average minimum dispersal rate was approximately 60 km per year.
Risk of introduction to new locations is probably low to moderate. The introduction to Hawaii occurred as a result of a deliberate effort to establish a new population of L. kasmira, and such a venture is not likely to be repeated given contemporary views on species introductions. L. kasmira is restricted to tropical or subtropical habitats, and is already found throughout these habitats in the Indian and western and central Pacific Oceans. As such, potential introduction sites would be limited to the tropical eastern Pacific or Atlantic Oceans. L. kasmira is also found in the Red Sea, and could potentially enter the Mediterranean through the Suez Canal, as other species have done (Golani, 1994).
Other potential avenues of dispersal for marine organisms are through ballast water in ships, or through the live fish or marine ornamental trades. Though many marine fishes (including L. kasmira)have pelagic eggs that could be taken up by a ship as it draws water for ballast, introductions of fish through ballast water are uncommon. One reason for this is that L. kasmira is not known to spawn in harbors where ships take in ballast water. Rangarajan (1971) suggests that L. kasmira move to offshore locations to spawn. It is therefore unlikely that a sufficient number of eggswould be taken up in ballast water in order to allow enough to survive transport to establish a new population.
L. kasmira would be most likely to be introduced to a new location through the marine ornamental fish trade. Lionfish (Scorpaenidae) have become established in the western Atlantic through the release of aquarium fish, and it is possible that this could occur with L. kasmira as well. Other snappers, including the closely-related L. viridis (see description in Similarities to Other Species/Conditions), are marketed for saltwater aquaria by online distributors. A search of these distributors (December 2007) did not find any selling L. kasmira, though it has been sold as a marine ornamental in the past (Jonklaas, 1975). If L. kasmira were released in the tropical eastern Pacific, its presence could go undetected for some time due to its similarity to the L. viridis native to the area.
L. kasmira is a species most closely identified with shallow-water reef habitats. It is common on coral reefs and artificial structures in shallow bays (see also discussion in Environmental Requirements) and nearshore reef habitats throughout its range. It generally schools over hard-bottom areas during the day (Friedlander et al., 2002; Schumacher and Parrish, 2005), and is likely familiar to many divers who have spent time in the water in the Indo-Pacific. In addition to the well-known shallow water schools, the fish is also found in deeper waters, at least in a handful of locations. Allen (1985) reports that L. kasmira has been reported to depths of 180 m in the Marquesas and 265 m in the Red Sea. A study of the habitat use of L. kasmira in Hawaii (Parrish et al., 2000) reported that the fish were found as deep as 150 m. It is possible that L. kasmira occurs in similar depths in other locations, but has not yet been reported. The majority of scientific investigations and recreational diving occur shallower than 60 m, and most deep water investigations involve submersibles or remote operated vehicles. These investigations generally focus on deeper habitats or more valuable species than L. kasmira. As such, habitats in middle depths are relatively unstudied. The increasing use of closed-circuit SCUBA (a.k.a. rebreathers) will undoubtedly increase our understanding of the depth range of these and other species across their geographic range.
L. kasmira has a diploid number of chromosomes of 48 (Choudhury et al., 1979; Klinkhardt et al., 1995). Recent molecular study has tested the long-standing taxonomic arrangement of lutjanid snappers. The work is detailed in Miller and Cribb (2007), and also reports mitochondrial nucleotide sequences. This research confirms the existing classification of snappers, and found that across Lutjanus species, colouration and morphological patterns (e.g. spot versus no spot) are closely mirrored by genetic similarities. Studies of the genetics of L. kasmira populations in Hawaii are ongoing, but indicate that descendants of fish introduced from both the Marquesas and from Mo`orea are present in the current population (Gaither et al., 2006).
Reproductive Biology
Snappers such as L. kasmira have separate sexes, and individual fish remain the same sex throughout their life. Snappers are broadcast spawners, meaning that they spawn in the water column rather than deposit their eggs on the bottom (Allen, 1985). These eggs are buoyant and disperse in ocean currents while they develop. This reproductive strategy facilitates the rapid dispersal of young, and likely is a factor that contributes to the broad native range of L. kasmira and its rapid spread through the Hawaiian archipelago.
The planktonic larval phase is difficult to study in the wild, but Suzuki and Hioki (1979) were able to observe spawning and larval development of L. kasmira in aquaria. In this study, L. kasmira spawned in groups after sunset during August, when water temperatures were between 22.5 and 25.2ºC. The spawning season was reported to be longer in areas closer to the equator (Allen, 1985). In the study in Japan, larvae hatched 17 to 27 hours after fertilization. L. kasmira larvae hatch with a large yolk sac that provides nutrition for the first three to four days. At this point, when they are 3-4 mm in length, the fish must begin to feed in order to survive. They eventually settle in reef habitats after four to nine weeks.
L. kasmira start to become sexually mature at slightly more than half their maximum length. Rangarajan (1971) reported that a small percentage (1.5%) of individuals between 16-17 cm were sexually mature. The percentage of mature individuals increased with size until greater than 50% were mature between 20 and 21 cm, and 100% of fish larger than 22 cm were mature. L. kasmira reach this size at about 2 years of age (Morales-Nin and Ralston, 1990). Myers (1999) reported similar maturation sizes in South Africa.
Rangarajan (1971) found that fecundity (measured as the number of eggs in a fish at one time) can differ by at least an order of magnitude in L. kasmira. There were as few as 42,100 eggs found in some individuals, and as many as 332,620 in others. It should be noted that the largest female examined in this study was 23 cm, which is considerably less than the maximum size of this species. The maximum fecundity for females in large size categories would likely be considerably greater. Fecundity was found to be highly correlated with fish weight (r=0.83), and is described by the formula:
Log y = 1.5983+1.7065 log x,
where y is the number of eggs and x is the weight of the fish in grams.
Rangarajan (1971) did not believe that L. kasmira spawned more than once per year, though the reasoning behind this assumption was dubious. Suzuki and Hioki (1979) observed the same individuals spawning multiple times over an 18-day period during their study. Given that many populations of L. kasmira often have a protracted spawning period (Allen, 1985), it is likely that individual fish spawn multiple times per year.
Physiology and Phenology
It appears likely that L. kasmira is able to adapt to a wide variety of environments, given its broad geographic distribution. It is however, limited to tropical and subtropical marine environments. Water temperatures, suitable habitat and available prey in Hawaii are similar to those found in equatorial and subtropical oceans throughout the world, and L. kasmira was likely absent prior to its introduction simply because it had not been able to disperse there naturally. In contrast to the niche expansion commonly exhibited by some alien species, L. kasmira does not occupy different habitats in Hawaii than it does in its native range.
Nutrition
Several studies have described the diet of L. kasmira in its native range. Some of these were studies that focused on L. kasmira or a small number of species, such as Rangarajan (1972) in the Andaman Sea or Mizenko (1984) in Samoa. Other reports come from studies in which L. kasmira is one of several species whose diet is described. These studies, including Kulbicki et al. (2005) in New Caledonia and Sano et al. (1984) in Okinawa, draw upon smaller sample sizes but still provide useful information about the diet of L. kasmira. The diet is also described generally in Bagnis et al. (1972) and Allen (1985).
L. kasmira is a generalist carnivore, feeding on a wide variety of prey. The majority of this prey is benthic (found on or in the bottom), but some planktonic prey is also consumed. Principal prey items are stomatopods (mantis shrimp), decapod shrimp, cephalopods (octopus and squid), gastropods (snails), crabs and small fish. Some algae is also found in the gut of L. kasmira, though this may be taken incidentally while the fish are feeding on benthic prey.
In addition to these studies of the diet of L. kasmira in its native range, there are several studies that report aspects of the diet of this fish in Hawaii, including four studies in shallow water < 50 m) (Hobson, 1974; Oda and Parrish, 1982; DeFelice and Parrish, 2003; Parrish and Schumacher, 2005), and one study in deep water (> 50 m) (Parrish et al., 2000). The diet of L. kasmira in Hawaii does not appear to differ notably from the diet reported in its native range. Although there is a persistent public perception in Hawaii that L. kasmira prey upon commercially valuable fish and invertebrate species, this belief is not supported by scientific studies.
Associations
The “mimic goatfish,” Mulloidichthys mimicus is believed to be a mimic of L. kasmira (Randall and Guézé, 1980) and/or other similar species. This goatfish has similar coloration to L. kasmira, and forms mixed schools with the snapper, presumably to gain protection from predators (Randall and Guézé 1980). Snappers have numerous stiff fin spines to discourage predation, but goatfish are considerably less well protected. This mimicry could therefore benefit the goatfish by discouraging predators that cannot readily distinguish between the species. The mimic would also gain additional protection in these mixed-species schools because of the “safety in numbers” advantage associated with being part of a larger group. Randall and Guézé (1980) also note that M. vanicolensis is occasionally found with a blue stripe in some parts of its range where L. kasmira is native, and sometimes schools with L. kasmira. Whether these blue-striped M. vanicolensis are the result of hybridization with M. mimicus has not been determined genetically.
L. kasmira and M. vanicolensis also form mixed-species schools in Hawaii, though the blue-striped colour morph of M. vanicolensis is not found there. Schumacher and Parrish (2005) determined that in mixed schools in Hawaii, M. vanicolensis generally comprise the part of the school highest in the water column which is the part of the school that is most exposed to predators. However, this position did not appear to be their preferred position, because they would descend closer to the substrate if the L. kasmira moved off, or if the snappers were not present. Reports of mixed species schools in areas to which L. kasmira is native did not report the relative position of the fish in the schools, so it is not currently known if this phenomenon is unique to Hawaii.
Recently, M. mimicus has been reported from the island of Kauai in Hawaii. It is unlikely that this species would have gone undetected for several decades if it had been incidentally brought in with L. kasmira, given that the snapper has been collected in large numbers for scientific studies and as a low-value market species. It appears then, that this appearance may be the result of a natural dispersal from its native range.
The previously reported range of M. mimicus extended to the Line Islands (Lieske and Myers, 1994). Though these islands are several hundred km south of the Hawaiian archipelago, they could be linked to it by Johnston Atoll. Johnston Atoll lies between the island groups, and modeling studies have found a potential transport corridor between this atoll and the area near Kauai (Kobayashi, 2006). If M. mimicus does persist in Hawaii, it will be interesting to see if it affects current behavioral dynamics between L. kasmira and M. vanicolensis.
Environmental Requirements
Froese and Pauly (2007) report that L. kasmira is found in marine waters between 20 and 28ºC, and Suzuki and Hioki (1979) reported that they spawned when water temperatures were between 22.5 and 25.2ºC. However, these temperatures were not experimentally manipulated, so they cannot be interpreted as minima and maxima. Focused empirical study would be required to determine reproductive and general temperature ranges.
Little empirical study has been done to determine environmental requirements of Lutjanus kasmira such as salinity, dissolved oxygen, or other physical or chemical characteristics. Studies of the physiological tolerances of L. kasmira would serve to clarify these matters, and could provide insight into types of habitats that would be likely to be resistant or susceptible to invasion by this species.
L. kasmira is a relatively small snapper species and is potentially subject to predation by a variety of larger, piscivorous predators such as jacks and sharks. However, L. kasmira, like other snappers, has numerous spines in its fins that serve to make it less palatable than other reef species such as goatfish (Mullidae), wrass (Labridae) or parrotfish (Scaridae). Predators that prey preferentially on L. kasmira have not been reported, and it is likely that any biocontrol effort based on predation would be unsuccessful. This is evidenced by the rapid expansion of L. kasmira throughout the northwestern Hawaiian Islands. These remote islands and atolls are generally uninhabited and have very little fishing pressure. Thus they have robust populations of apex predators, including jacks (Carangidae) and sharks (Friedlander and DeMartini, 2002). In spite of the presence of healthy populations of these predators, predation pressure was unable to prevent the expansion of the range of L. kasmira.
L. kasmira is commonly infected with a number of parasites (Font and Rigby, 2000; Work et al., 2005; Aeby and Work, 2007). However, these parasites have been similarly unable to prevent the spread of L. kasmira, and are known to infect native fish as well. As such they do not appear to provide an effective means of biocontrol.
Following its introduction to the island of Oahu in Hawaii, L. kasmira became naturalized and spread throughout the archipelago at an average rate of 60 km per year. Most, if not all, of this dispersal was accomplished through larval dispersal. L. kasmira, like many marine species, produces buoyant eggs that are dispersed from adult habitat by ocean currents. These eggs hatch into transparent larvae that continue to drift on ocean currents for several weeks. The pelagic life history stage provides an effective means of dispersing long distances across open ocean waters and colonizing new habitats, or re-colonizing former habitats following local extinctions. For more details, see History of Introduction/Spread.
Accidental Introduction
No accidental introductions of L. kasmira have been reported to date.
Intentional Introduction
L. kasmira was introduced to Hawaii to provide an additional fishery resource. Approximately 3,200 individuals were released to the nearshore marine environment of the island of Oahu between 1955 and 1961. This species is now found throughout the Hawaiian archipelago, but is not a preferred target species in local fisheries.
Studies thus far do not indicate that L. kasmira has had a measurable biological impact on populations of native resource species. L. kasmira does attack baited fishhooks readily and could the decrease efficiency of commercial fishing operations intending to target more valuable species (Parrish et al., 2000). To date, however, the value of any economic hardship arising from this phenomenon has not been calculated.
Although L. kasmira is a relatively low-value species, it is sold in small fish markets in Hawaii. These sales should result in a modest economic benefit for part-time and artisanal fishermen, as well as to the fish markets. Commercial fishers in the state of Hawaii reported landing approximately 18,000 kg of L. kasmira in 2005, the last year for which data are available (Division of Aquatic Resources, 2006). L. kasmira sells for approximately $4 US per kg. However, sale of tropical reef fish is often limited to local markets because of concerns about ciguatera poisoning.
Ciguatera poisoning is caused by a family of toxins produced by tropical marine dinoflagellates. The toxins pass up the food chain to a variety of reef fish, including L. kasmira (Hokama et al., 1987). This toxin is not denatured by cooking, and can cause moderate to severe illness in people who consume contaminated fish. Locally, this risk is currently perceived to be low for L. kasmira and does not appear to influence sales, but such concerns may prevent development of a larger export market.
Submarine tours and a number of recreational SCUBA companies visit artificial reef sites off the south shore of Oahu, where schools of L. kasmira are often the most conspicuous fish. Such activities are not built around any one species per se, but schools of these brightly colored snappers undoubtedly provide some visual appeal that enhances the overall experience for clients. In that respect, L. kasmira likely has a positive effect on these economic ventures.
In addition to these multi-species fish viewing activities, there are also charter-fishing boats that offer “fun fishing” trips for a variety of species. These trips are marketed as a family-friendly alternative to more expensive offshore fishing trips for marlin, mahi-mahi (dorado, dolphin-fish) or other pelagic fishes. As with fish-viewing activities, the value of such trips cannot be ascribed to one species in particular, though L. kasmira is one of the more commonly-caught species. According to advertisements the cost of a fishing trip ranges from US $70-$130 per person.
L. kasmira has not had an apparent impact on habitats in Hawaii.
Impact on Biodiversity
Ecological studies to date have focused largely on competitive or predatory interactions between Lutjanus kasmira and commercially important fishery species. These studies have not detected a level of interaction likely to affect these species, and it remains a possibility that L. kasmira may have occupied a vacant ecological niche. However, if this species is indeed feeding differently than native species, it could cause changes in relative abundances of prey species such as small fish, crabs and shrimps. Preferred prey populations could decrease relative to less preferred prey, which would undoubtedly affect local biodiversity. To date, studies of the potential impact of this species on prey communities (e.g. small crabs, shrimp, or other crustaceans) have not been done.
Studies of pathogens in L. kasmira indicate that this fish can host a variety of parasites, and that these parasites also infect native goatfish (Font and Rigby, 2000; Work et al., 2004). It has been suggested that a parasitic nematode may have been introduced with L. kasmira (Font and Rigby, 2000; Aeby and Work, 2007), though this suggestion has not been confirmed. Future investigations should place a high priority on determining if these or other parasites were introduced with L. kasmira, and what effect these pathogens have on populations of native reef fish.
The introduction of L. kasmira has had a largely negative impact from a socio-cultural standpoint. Although scientific research has not found evidence of impacts to other native fishery species, the public perception that L. kasmira has caused major declines in a variety of more desirable species remains. Efforts to initiate new fisheries management strategies are often met with the argument that L. kasmira is the problem, not fishing pressure. Because the territorial government released this fish in Hawaii, the issue is a frequent source of contention at public meetings. Such discussions often impede dialogue on other salient issues.
As discussed in the Impacts section, a limited amount of businesseshave tourist activities that incorporate L. kasmira into wildlife viewing and fishing opportunities. L. kasmira does not comprise the entire focus of these activities, however. This fish is also sold as a food item in fish markets, and consumed by recreational and subsistence fishers.
Commercial fishers in Hawaii are required to report catch of all species, so annual catches of L. kasmira are monitored. It is also listed as a “Bottomfish Management Unit Species” under the federal Fishery Management Plan for Bottomfish in Hawaii (Western Pacific Regional Fishery Management Council, 1986). As such, fishers who fish in federal waters in the northwestern Hawaiian Islands also report catch of L. kasmira. Apart from these reporting requirements, L. kasmira is not actively managed in Hawaii, and harvest of this species is unrestricted. No minimum size restrictions, closed seasons, or catch limits are in place, nor are any planned. L. kasmira is a commercially important food fish in parts of its native range (Tomascik et al., 1997), and it remains a possibility that a viable local market could be developed, or it could be exported from Hawaii, possibly to areas where it is native and local supply cannot meet demand.
There are several fish species with which L. kasmira might be confused in the field. Most, not surprisingly, are closely related Lutjanid snappers (Lutjanus bengalensis, Lutjanus coeruleolineatus, Lutjanus notatus, Lutjanus quinquelineatus and Lutjanus viridis). The other species that could be confused with L. kasmira is a goatfish (Mullidae), Mulloidichthys mimicus. All these species share the bright yellow colouration and blue stripes of L. kasmira. However, they differ somewhat from the specifics of the colour pattern of L. kasmira, which is yellow on about the upper two-thirds of its body, while the ventral area is white. L. kasmira also has yellow fins and four blue stripes on each side.
L. bengalensis is quite similar in appearance to L. kasmira, with four blue stripes. However, the yellow colouration on L. bengalensis only extends about halfway down its body. Also, only the dorsal and anal fins are yellow; the paired fins (pelvic and pectoral) are white. These two species overlap in a substantial portion of their native ranges. Both are found from East Africa to Indonesia and Papua New Guinea (Allen, 1985; Kailola, 1987). However, only L. kasmira is also native to the Pacific Ocean as far as east as French Polynesia, and has been introduced to Hawaii (Allen, 1985).
L. coeruleolineatus (also sometimes called blueline snapper) has two characters to distinguish it from L. kasmira. Instead of four blue lines on each side, it has seven or eight. It also has a dark spot on the upper, rear portion of its body just below the anterior-most soft rays of its dorsal fin. This species is found primarily in the northwestern Indian Ocean near the Arabian Peninsula (Allen, 1985).
L. notatus has six blue stripes, and also may have a dark spot on the upper rear portion of its body. This fish is found in the western Indian Ocean, in the seas around eastern Africa and Madagascar and nearby islands (Allen, 1985; Anderson, 1986).
L. quinquelineatusis similar in size, shape, and general colouration to L. kasmira, but has a dark spot like L. coeruleolineatus and L. notatus. As its name indicates, L. quinquelineatus also has five stripes on each side of its body, compared to the four onL. kasmira. This species has a native range similar to L. kasmira, and is found from the Western Indian Ocean to Polynesia, and north to Micronesia and southern Japan (Allen, 1985).
L. viridis has very similar coloration to L. kasmira, and lacks the dark spot that distinguishes some of the other similar species. The only readily apparent distinguishing character is that this species has five blue stripes. The present ranges of L. kasmira and L. viridis do not overlap, as the range L. viridis is restricted to the tropical Eastern Pacific (Allen, 1985; Bearez, 1996).
Mulloidichthys mimicus, as its name implies, is a mimic of L. kasmira and/or other similar snapper species. M. mimicus is bright yellow and has four blue stripes. However, its body is more fusiform (torpedo-shaped) than the lutjanids. M. mimicus also has two dorsal fins that are widely separated, and a forked tail. Snappers such as L. kasmira have a single, long dorsal fin and an emarginate or slightly forked tail. It should be noted that L. kasmira often lay the anterior portion of their dorsal fins flat against their backs, and M. mimicus often lay their anterior dorsal fins flat against their backs. When the fins are held in this position, it may not be immediately obvious if there is one fin or two. Goatfish such as M. mimicus also have two barbels on their chins. These barbels are chemosensory organs used to find prey. When they are extended, these barbels would clearly distinguish M. mimicus from L. kasmira. However, similar to the anterior dorsal fin, M. mimicus generally hold the barbels against their chins when they are not feeding. The range of this species extends from the western Indian Ocean to the Line Islands in Polynesia (Lieske and Myers, 1994). A specimen was also recently collected from Kauai in Hawaii.
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
Given that the L. kasmira is already found throughout its potential habitat in the Indo-Pacific region, introduction opportunities are most likely limited to the tropical eastern Pacific and Atlantic Oceans. Likely avenues of introduction of L. kasmira might include (1) management action, (2) live fish trade, or (3) ornamental fish trade. Because this species is only found outside its native range as a result of deliberate human activity, management action is the most likely mode of successful introduction to new habitats. However, it seems unlikely that such a venture would be attempted considering contemporary views regarding species introductions. Also, one of the reasons for introducing this snapper to Hawaii was that native snappers were not found there. This is not the case in the eastern Pacific or Atlantic Oceans.
The live fish trade is generally confined to Asia, where L. kasmira is already present, so it would not likely be introduced to new areas this way. L. kasmira is not currently distributed in the ornamental fish trade, though the similar and closely related L. viridis is. Restricting the importation of such fish to areas with suitable natural habitat (e.g. Florida) would help prevent aquarium releases from establishing populations in these areas.
Control
No attempts were made to eradicate or control populations of L. kasmira in Hawaii because of the intentional nature of its introduction. To the contrary, fishing for the snappers was initially discouraged so that it could become established. By the time opposition to the introduction began, the fish was well-established, had a broad geographic range, and eradication would not have been feasible. Given the limited scientific support for detrimental effects from this introduction, eradication or control efforts would be an unwise use of resources at this time. The best means of controlling populations of L. kasmira, to mitigate any as yet undiscovered detrimental effect, would be through utilization of the species. This species can be targeted by fishers, and concentrated fishing activity would likely be able to reduce populations of this species as it has countless other species worldwide. A viable commercial market would have to be developed to provide an incentive to exploit this fish.
As with many tropical reef fish, additional work should be done on the growth, reproductive capacity, and larval dynamics of L. kasmira. Without a thorough understanding of the life history characteristics of this species, it is not possible to understand its spread through the Hawaiian archipelago, or predict its spread should it be introduced elsewhere. Along with studies of life history characteristics, studies of physiological tolerances of this species could help identify habitats that are vulnerable to invasion by L. kasmira. For example, identifying areas where water temperatures are suitable for survival and reproduction of L. kasmira would help to predict where it could become established. Such analyses should be interpreted in the context of how oceanic water temperatures are predicted to change in response to global warming, since areas that are not now suitable habitat for L. kasmira might become suitable in coming years.
Also, with respect to impacts on the nearshore ecosystem in Hawaii, several questions should be addressed. As Work et al. (2004) note, additional research will be needed to clarify the origin of pathogens found in L. kasmira and native reef fishes, and to determine the effect of these pathogens on their hosts. With respect to feeding and competition studies, work has been completed or is ongoing that will clarify the relationship of L. kasmira to deepwater snappers and to some shallow-water reef fish. However, studies have not specifically looked at the potential for competitive interactions between L. kasmira and fish that live at intermediate depths. In particular, juvenile deepwater snappers (e.g. Pristipomoides filamentosus, - crimson jobfish or opakapaka) live at these depths for a time before moving to deeper water, and could experience a competition bottleneck during this part of their life cycle.
There are also a limited number of predatory interactions that would be most effectively studied using molecular techniques. For example, one of the more recent complaints concerning L. kasmira in Hawaii is that these fish are eating baby octopus. Such predation might be an economic or social concern if it were focused on young individuals of one of the two species harvested for food. One of these species in particular, Octopus cyanea (Octopodidae), is the principal recreational/subsistence animal harvested from the ocean in some areas (Everson and Friedlander, 2004). Although dietary analysis confirms that L. kasmira do occasionally eat octopods, it remains unclear whether L. kasmira are consuming early life stages of commercially important species, or adults of species that never grow very large. Species-level identification of this prey has been problematic in part due to the difficulty associated with identifying soft-bodied prey such as octopus, which lose many identifying characters due to digestion. This problem is further exacerbated in Hawaii because several of the 15 species of octopus reported locally have not been described scientifically (Eldridge and DeFelice, 2000). Use of genetic markers or other molecular techniques could resolve this issue even in the absence of complete scientific description of some species.
Brett Schumacher, Hawaii Cooperative Fishery, Research Unit Dept. of Zoology, University of Hawaii at Manoa, 2538 McCarthy Mall, Edmondson 152, Honolulu,, HI 96822, USA
