Lutjanus kasmira
(blueline snapper)

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).

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.

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).

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 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.

General

• Sport (hunting, shooting, fishing, racing)

Human food and beverage

• Meat/fat/offal/blood/bone (whole, cut, fresh, frozen, canned, cured, processed or smoked)

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).

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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.

20/12/07 Original text by:

Brett Schumacher, Hawaii Cooperative Fishery, Research Unit Dept. of Zoology, University of Hawaii at Manoa, 2538 McCarthy Mall, Edmondson 152, Honolulu,, HI 96822, USA