ANNEX 5
REVIEW OF FRESHWATER SPECIES WITH CULTURE POTENTIAL

Fish and shrimps with culture potential in fresh water in Jamaica are listed in Table 5.1. The native freshwater fish fauna of Jamaica is poor, and species being generally of a small size, they are not considered as valuable food fishes to be cultured. It is for these reasons that an exotic species - Tilapia mossambica - has been introduced at the end of the forties to start fish farming. Comments on the different proposed species follow.

1. LOCAL (INDIGENOUS) SPECIES

Agonostomus monticola: Mountain mullet occurs in mountain streams along the coast. The biology of A. monticola in captivity is not known. It is not presently cultured in Jamaica and is not known as a cultured species in other countries.

Anguilla rostrate (estuaries, mangrove swamps and rivers): Eels can be cultivated, but since they do not reproduce in captivity (ponds, etc.) fry has to be collected in the wild. Nothing is known about the abundance of the elvers and their availability (when, where?). Eels are not considered as a priority food fish for aquaculture.

Dormitator maculatus: God-a-me occurs in rivers and swamps (mainly in the Black River morass). The biology of this species in captivity is not known (feeding habits, reproduction, growth, etc.). D. maculatus is not cultured yet in other countries. It is a small species (maximum between 20 and 30 g) and is not considered of commercial value for Jamaican fish culture.

Gerres cinereus: Common name: Macaback. It occurs in rivers and swamps where it feeds mainly on detritus. It is not known as a species cultured elsewhere.

Joturus pichardi: Common name: striped mullet. No information is available concerning the biology of this species in captivity and it is not considered as a species to be cultured in Jamaica.

Limia caudofasciatus: Common name: Blue Poecilia and L. melanogaster, Poecilia, occur in rivers, lakes and swamps. They are very small aquarium fishes and of no importance as food fishes.

Lutjanus griseus: Common name: mangrove snapper. It is relatively common in mangrove swamps (Negril morass). It is a carnivorous species and presently not cultured in Jamaica. If large quantities of fry are available, experimental rearing of the mangrove snapper in floating cages could be tried.

Megalops atlantica: Common name: tarpon. Occurs in rivers, streams and swamps (Black River and Negril morasses). Has been reported as experimentally cultured in ponds in Jamaica as predator for Tilapia. The tarpon do not reproduce naturally in ponds, and fry has to be collected from the wild (rivers). Culture experiments are underway at Twickenham Park.

Mugil cephalus: Common name: striped mullet, and M. curema, white mullet. The mullets are relatively common in estuaries (brackishwater) and in rivers. They are captured in the Black River and Negril morasses where they feed on detritus, diatoms and filamentous algae. Mullets reproduce in sea water but have not so far been reported to reproduce naturally in captivity (ponds, etc.). Therefore, fry has to be collected in the wild. Mullets can be reared in brackishwater ponds or, when acclimatized, in fresh water (lakes, enclosures or ponds). Artificial reproduction (induced spawning) is being attempted in a few countries.

TABLE 5.1: Freshwater species with culture potential in Jamaica

2. EXOTIC FISH SPECIES

Tilapia mossambica was introduced into Jamaica in 1950 by the Fisheries Division, Ministry of Agriculture. This species was first introduced into St. Lucia from Malaya in 1950. In the same year about 400 of them were shipped by air from St. Lucia to Jamaica where they were stocked in ponds at the Twickenham Park fish farm. A breeding programme was started and the species was stocked in most major rivers and in ponds. The tilapia, locally known as African perch, soon became part of the local inland and brackishwater fisheries (ADCP, 1981).

Attempts were made to introduce monosex culture of T. mossambica. These were unsuccessful and by the mid-seventies there was virtually no controlled culture of tilapia in fish ponds.

By the end of the seventies, it had been generally accepted that T. nilotica was growing faster than T. mossambica, and T. nilotica has now replaced T. mossambica as the main species for pond fish farming in Jamiaca. This replacement was due mainly to consumer resistance because of its black colour (Cook and Moo Young, 1982).

T. nilotica was introduced at the Mitchell Town Farm in 1978 coming from the Auburn University, USA. It was managed similarly to T. mossambica (ADCP, 1981). T. nilotica fingerlings were first distributed to fish farmers in October 1979. Its greater acceptance by consumers is due to its silver-grey colour, a deeper body (more flesh) and a smaller head than T. mossambica. It also has a faster growth rate and reproduces at a later age. Intensive culture of T. mossambica has now ceased and they can be found in large quantities only in the wild (Cook and Moo Young, 1982).

Cyprinus carpio (mirror carp) has been introduced from Auburn, USA in 1980 and stocked at Twickenham Park. Artificial reproduction trials are underway and rearing is done on an experimental basis.

Ctenopharyngodon idella (grass carp) has also been introduced into Jamaica in 1980 from Auburn, USA. Fingerlings are being given since 1982 to some successful farmers for polyculture with T. nilotica.

Aristichthys nobilis (bighead carp), Hypophthalmichthys molitrix (silver carp) and hybrids of silver and bighead carp have been introduced in 1982 from Panama. They are stocked at Twickenham Park for experimental rearing and have not yet been distributed to fish farmers.

3. INDIGENOUS FRESHWATER SHRIMP

The indigenous shrimp occurring in fresh and brackish water in Jamaica belongs to the families Palaemonidae and Atyidae. The three main species are Macrobrachium acanthurus, M. carcinus and M. faustinum. Secondary species are Jonga serrei and xiphocaris elongata.

Macrobrachium acanthurus is found in fresh or brackish waters, usually on muddy bottoms, near the mouths of streams, normally being restricted to above sea level elevations of less than 45 m. Maximum total length: males 166 mm; females 110 mm. Maximum carapace length: males 36.5 mm and females 20.6 mm (Holthuis, 1980).

According to Holthuis (1980); aquaculture experiments with Macrobrachium acanthurus were undertaken only in the USA and Mexico.

M. carcinus occurs in streams from sea level up to elevations of about 600 m or more, living in pools or under large stones. Basically nocturnal species, living in fresh water, but part of the early development is passed in salt and brackish water, usually on sandy bottoms and stones.

According to Holthuis (1980), the great size of the adult M. carcinus makes the species attractive for aquaculture, and at several places in the USA, Mexico, Puerto Rico and Barbados experiments to this effect are under way. Maximum total length: males 233 mm; females 170 mm.

M. faustinum occurs in quiet pools and protected littoral areas of larger streams to elevations as high as 150 m, but is primarily an inhabitant of the lower reaches of streams. It shelters beneath stones, trunks of water-logged trees or larger pieces of debris. M. acanthurus and M. faustinum are the most widespread shrimp in Jamaica.

Work on larval culture of M. acanthurus was carried out in Jamaica by Choudhury (1970; 1971c). Larval development of M. carcinus was also studied by Choudhury (1971a; 1971b).

In 1982, IICA (Inter-American Institute for Co-operation on Agriculture), at the request of the Prime Minister, carried out a scientific and technical study of freshwater shrimp culture with a view to implementation of commercial aquaculture of the indigenous freshwater populations of Macrobrachium. The study proposes that scientific and technical trials be carried out to compare the several species under local conditions, in order to find out which one would be the most successful in terms of productivity at the commercial scale of aquaculture. A site was selected at the “Belle Air” estate along the Pear Tree Bottom River for the experimental freshwater shrimp farm and a project extending over a period of three years has been drawn up. The proposal includes special studies on the cannibalistic nature of the indigenous Macrobrachium species.

4. EXOTIC SHRIMPS

Macrobrachium rosenbergii was introduced into Jamaica in the early seventies. Commercial culture started, but the efforts were unsuccessful. In 1983, Jamaica Aqua-Farms Ltd. reopened the Macrobrachium rosenbergii hatchery at Ferris Cross near Savanna-la-Mar. Jamaica Aqua-Farms is now offering post larvae for sale.

Macrobrachium amazonicum: Fifty-one small specimens of this species were introduced in June 1981 from Panama and stocked in a half-acre pond at Twickenham Park. M. amazonicum is known to be a species having a complete life-cycle in fresh water. IFU intends to grow this fresh water shrimp as an experiment. M. amazonicum are stocked together with T. nilotica fingerlings. The pond had not been monitored regularly, but four months after the introduction (October 1981) reproduction of M. amazonicum was observed. The reproduction rate for this species is very high. It reproduces in the pond without any prompting. No special feed is given to the shrimp, but it probably eats some of what is not eaten by the fish in the pond.

During the study group's visit (26.1.83), a dozen shrimps were sampled using a small beach seine. Total length of most of the shrimp was between 3 and 4 cm, but the biggest specimens reached between 5 and 6 cm.

IFU intends in the near future to start experiments designed to reveal the natural reproduction rate in ponds, rate of growth and acceptance of artificial feeding. This species has been cultivated in Brazil on an experimental basis in laboratory facilities (Holthuis, 1980).