First record of the non-native three spot gourami , Trichogaster trichopterus ( Pallas 1770 ) ( Teleostei : Osphronemidae ) in Jamaica

Five specimens of the non-native three spot gourami (Osphronemidae: Trichogaster trichopterus) were collected from a small pond near the northern coast of Jamaica in June 2009. The collection represents the first documentation of this species in Jamaica. Origin of the introduction is not known. Herein, we discuss the occurrence of this species in Jamaica and possible threats posed to the island’s native fish fauna.


Introduction
The introduction and establishment of non-native fishes is a phenomenon occurring throughout the world causing major concerns for many freshwater ecosystems (Gozlan et al. 2010).Especially at risk may be areas with high endemism, where according to Ruesink (2005), the probability of establishment and impact appear to be greater.The Antillean islands of the Caribbean host a relatively unique freshwater fish fauna consisting of 71 species, many endemic to the islands (Burgess and Franz 1989).The Antillean island of Jamaica is quite depauperate in terms of its freshwater fish diversity, harboring only six native species, four of which are endemic to the island (Burgess and Franz 1989).Because the majority of the few native inland fishes present are endemic, the introduction and establishment of non-native fishes is of considerable concern.
Nine non-native fish species have previously been documented as being introduced or established in inland waters of Jamaica (Table 1).The presence of many of these species is the result of their use as food fishes in Jamaica over the past 60 years (Aiken et al. 2002;Watanabe et al. 2002).In contrast, there is less information available regarding the introduction history of the few non-native ornamental fishes present.The pathways of introduction for these species, including when and where, are not well estab-lished (Aiken et al. 2002), and their impacts, if any, have not been studied.In this paper we document the occurrence of a new ornamental non-native species, the Three Spot Gourami [Osphronemidae: Trichogaster trichopterus (Pallas 1770)], in an inland water body of Jamaica and discuss the possible implications of this introduction.

Methods
We sampled a small marsh pond adjacent to the Caribbean Sea near the North coast of Jamaica (18°30.113'N,77°42.585'W), on 26 June 2009.The specimens collected are permanently archived in the Southeastern Louisiana University Vertebrate Museum.The collection site was located in Trelawny Parish, 25 m North of Highway A-1, and approximately 5.7 km East of the town of Falmouth.Sampling was conducted using a 6-ft, ¼" (1.829 m, 0.6 cm) mesh cast net, and the sampling period was approximately one hour.The pond was shallow (<1 m) and extremely turbid.Salinity level was not measured, however we suspect the water to be brackish given the surrounding vegetation (mainly mangroves), the close proximity of the Caribbean Sea (10m), and the direct connection of the pond to the sea via a culvert (assumed to allow water through during high tide or wave surge events).

Results and discussion
Five adult Trichogaster trichopterus (SLU 6361; Figure 1A) were collected from the sample site (Figure 1B).No additional nearby sites could be sampled and we did not obtain this species at any other collection site on the island.Characters used for positive identification of specimens were based on information provided in Kottelat (1993).
All Jamaica specimens were characterized by the presence of a black blotch in the middle of the flank and another dark spot at the caudal base, traits that distinguish T. trichopterus from all other Trichogaster species.The five captured specimens consisted of two males (58-66 mm standard length [SL]) and three females (53-56mm SL).Other species collected with T. trichopterus included the native Poecilia caudofasciata (Regan 1913), and the non-native Oreochromis mossambicus (Peters 1852).
The presence of T. trichopterus in Jamaica is a potential threat to natives, partly due to its territorial nature as well as its known aggressiveness as an opportunistic carnivore (Webb et al. 2007).Moreover, it is known to be very tolerant of wide ranges of environmental conditions including, varying pH (6.0-8.8),temperature (21°-31°C), and dissolved oxygen levels (Priest 2002).Furthermore, the three spot gourami possesses a labyrinth apparatus, which allows it to breathe air in hypoxic conditions (Das 1928).It is known to tolerate brackish salinity levels, however the upper limit has not yet been determined (Webb et al. 2007).The salinity tolerance of this fish could be very problematic, creating a potential threat towards brackish native fishes, and furthermore allowing possible coastal dispersal.Native and some introduced populations are reported to reproduce year round (Hails and Abdullah 1982).
It is unclear if the T. trichopterus population in Jamaica is reproducing or is yet established.However, the presence of adult males and females in our sampled site suggests that a reproducing population may potentially be present in the region.Although the fishes of the inland waters of Jamaica do not appear to be routinely sampled or reported on, no prior records exist documenting the occurrence of T. trichopterus in Jamaica; therefore, at present we can only assume that its origin of introduction is, or is in close proximity to, our sampling site.The three spot gourami is a freshwater fish native to Southeast Asia; however, given past introductions its exact range is uncertain but possibly includes Thailand, Laos, Kampuchea, Vietnam, Malay Peninsula, Sumatra, Myanmar, Java, and Madura (Fuller et al. 1999).Its wide popularity as an ornamental fish has likely contributed to all or most introductions outside its native range.There is evidence that established populations exist in India (Daniels and Rajagopal 2004), Taiwan (Shen 1993), North Western Australia (Webb 2003), Philippines (Juliano et al. 1989), Papua New Guinea (Allen 1991), Southern Africa (FAO 1997), South America (Welcomme 1988) andDominican Republic (Lever 1996).The species has also been collected or reported from other regions, for example Florida (Fuller et al. 1999) and Canada (Crossman 1984), but without evidence of establishment.
Despite existence of multiple established populations across the world, the ecological  (1989); Lever (1996) impacts of this species have not been adequately explored.Past studies by Arthington et al. (1999), Bomford and Glover (2004) have emphasized the high invasiveness of T. trichopterus in Australia as compared to other nonindigenous fishes, however direct effects on native faunas are still in question.A study by Liao and Liu (1989) suggests that T. trichopterus may be a strong resource competitor, possibly causing declines in some Taiwanese native fishes.Humphrey (1995) reported that members of the genus Trichogaster carry a number of pathogenic diseases.This suggests introduction of T. trichopterus posses a possible threat as a vector of disease and parasites both to native fish faunas, as well as to fishes being raised in aquaculture conditions in the region.
Although its pathway of introduction is uncertain, the presence of T. trichopterus in Jamaica is likely the result of its importation as an ornamental fish.Over recent years there has been a push by the Jamaican government urging citizens to utilize ornamental fish rearing as a potential source of income (Jamaica Information Service 2006).Due to growing popularity of the ornamental fish trade in Jamaica, the documentation of T. trichopterus may just be the beginning of many concerns to come in Jamaica's aquatic ecosystems.A thorough survey of the distributional extent of this and other non-native fish species in Jamaica is warranted.To that extent, given the possibility of restriction to a single pond, or perhaps one or a few nearby locations, an attempt to immediately eradicate the population is in order.

Figure 1 .
Figure 1.(A) Photograph of a Trichogaster trichopterus specimen (SLU 6361) collected in Jamaica, June 2009 and (B) site in the foreground where specimens were collected (note its close proximity to the Caribbean Sea).Photographs by KRP.