faculty of pure and applied sciences - The Department of Chemistry ...

O-11 RESEARCH INTO THE BIOLOGY OF JAMAICANFRESHWATER MACROINVERTEBRATES AND FISHES- DIRECTIONS AND AN OVERVIEWE. J. HyslopDepartment of Life Sciences, MonaDespite being well provided with river systems, Jamaica has seen little published work particularlyon the benthic macroinvertebrate fauna of these water bodies. In addition, development, in somecases at a rapid pace, throughout the country, in conjunction with inadequate environmental controlhas resulted in considerable input from anthropogenic processes to the country's river systems, theeffects of which, on the faunal communities, have been inadequately documented.The present paper sets out to demonstrate that a research programme to address, at least in part, theabove problems is being implemented and to discuss in brief the main directions being followed andoutline some of the preliminary findings. In addition the components of this research programme andtheir interrelationship are fully discussed.Taxonomic work is concerned with giving names to organisms and by extension to identifyingcommon associations or groupings, these include community composition and diversity. This in turncan be linked to information on the physico-chemical conditions under which the co munity isfound, including the presence of known or suspected pollutants. Rivers are longitudinal systems andit is necessary to establish whether changes in community composition and/or diversity are as aresult of altitudinal gradient (longitudinal zonation) or due to other factors. Some general publishedinformation on benthic macroinvertebrate distribution exists in relation to Jamaica (Boon, Jupp &Lee 1986). Recent detailed studies on the taxonomy of trichopterans (caddis flies) have resulted inthe description of seven new species and two sub-species for Jamaica (Botosaneanu & Hyslop, inpress 1 & 2 ) while work on freshwater Gastropoda indicates a predominance of two species of thefamily Thiaridae; Melanoides tuberculata and Thiara granifera, both of which are recentintroductions to the fauna, originally from Africa/Asia (Hyslop, unpublished data).The predominance of Thiaridae in most river systems has implications for the indigenous gastropodfauna and an analagous situation exists with regard to freshwater riverine fishes. Here again theJamaican freshwater ichthyofauna is dominated by an invading species or group of species, tilapia,belonging to the genus Oreochromis. The impact of Oreochromis on the indigenous fish fauna ispossibly minimal as the niche occupied by this species is unlikely to overlap significantly with themembers of the established ichthyofauna. One of the indigenous fish families found in Jamaicanfreshwaters is the Poeciliidae, the live-bearers or live-bearing toothcarps. Here again there isevidence of invaders in the form of species commonly imported as part of the aquarium trade. Theseinclude guppies, Poecilia reticula, and swordtails and platies genus Xiphiphorus. The indigenousPoeciliidae consists of a number (at least 4) species and some concern must be expressed as to thecompetitive effects of invading species of the same family.The potential for utilizing widespread benthic invertebrate species such as those belonging toThiaridae as biological monitors is being investigated and initial observations suggest the utility ofboth species in the monitoring of heavy metal pollution in Jamaican river systems. Similarlyinvestigations into the sub-lethal effects of exposure to the widely-used pesticide, endosulphan on thegrowth and fecundity of T. granifera and M. tuberculata are also being carried out.31