Uganda Freshwater Fisheries Research Organization Annual Report 1977

Following the collapse of the East African Community on 30th June, 1977 Ugandan fisheries research employees who were stationed in Kenya and Tanzania were recalled by the Uganda Government. The return of these officers strengthened the staff position of the Department. Formally the Headquarters of the East African Freshwater Fisheries Research Organization (EAFFRO), the institution was re-named the Uganda Freshwater Fisheries Research Organization (UFFRO) and the Uganda Government took up the full responsibility for running and maintaining the Department. The Annual report presents activities and achievements during the reporting period 1977.

Study ectoparasite infestation of 10 common imported freshwater ornamental fish species

In the present study, ectoparasite infestation of common freshwater ornamental fish species imported into Iran including: Dwarf gourami (Colisa lalia), Angelfish (Pterophyllum scalare), Oscar (Astronatus ocellatus), Red eye Tetra ( Moenkhansia Sanctaefilomenae), Barb( Capoeta tetrazona), Arowana (Osteoglossum bicirrhosum), Goldfish(Carassius auratus), Red fin Shark (Lebeo elythrurus, Catfish (Hypostomus plecostomus) and Pangasius sutchi ( Pangasius hypophthalmus) from May until April was investigated.A total of 6 specimens sample of each fish species) randomly were obtained and taken alive to the lab. After observing gill and skin wet smear under the microscope , gill was dissected and examined carefully .Photo and films were taken from the isolated parasites and parasite identification was performed according to Yamaguti AP1), Bychowsky (■Y).From a total of examined fishes 1\ ► sample (YY.V.) were parasitized .Parasite groups that were observed consisting ciliated protozoan myxosporidian , monogenean Digenean metacercaria and crustacean .The only non-parasitized fish was Barb. Monogenea Trianchoratus sp. , Cleidodiscus sp. , Ancylodiscoides sp. , Thaparocleidus sp. , Centrocestus formosanus metacercaria and Myxobolus longisporus report for the first time in ornamental fish which imported from Southeast of Asia to Iran. According to the results, it seems that severe quarantine and sanitary rules are necessary.

East African Freshwater Fisheries Research Organization Annual Report 1974

The Annual report covers activities of the organization during the reporting period. It explains the scientific work carried out by the organization, the establishment of the Lake Victoria Fisheries Commission and the African Journal of Tropical Hydrobiology and Fisheries.

Freshwater medusae in Lake Kyoga

Freshwater medusae have been observed in Lake Kyoga by several members of the Fisheries Department on a few isolated occasions over the past two years. Sightings have been made at Lwampanga at the western end of the lake, at Bukungu near the inlet of the River Nile into Lake Kyoga, and at Lalle, on the eastern extremity of the main lake. Most sightings have been made near the margin of the lake under very calm conditions. At Lalle and Lwampanga large numbers of medusae have been seen swimming near the surface; on these occasions, the medusae were pulsating regularly and maintained a position within a few inches of the surface. Apart from noting that sightings have occurred under calm conditions near the lake margin, no other observations to indicate when medusae are likely to be seen have been made. Most of the medusae are of similar size, the largest being 12 mm in diameter.

East African Freshwater Fisheries Research Organization Annual Report 1973

The Annual report presents activities carried out by the Organization during the period 1973. It presents scientific work of the Organization which include: Tissue specificity of malate dehydrogenase in Astatoreochromis and two species of haplochromis, report on LaKe Babati Fishery, Observations on Engraulicypris orgenteus (PELLEGRIN) 1904 from Lake Victoria, Commercial trawl fishing on Lake Victoria: Fisheries development and conservation, Lunar periodicity and the breeding of Tilapia nilotica in the Northern part of Lake Victoria.

East African Freshwater Fisheries Research Organization Annual Report 1970

The Annual report presents activities carried out by the Organization during the reporting period 1970. It explains the scientific work carried out by the Organization which includes: bottom trawl survey, a limnological survey of Lake Victoria for the period January to December 1970, maturity, sex ration and fecundity of lung fish (protopterus aethiopicus Heckel) from Lake Victoria, On the fish species of Lake Baringo, identification of organisms in Lake Victoria responsible for ecosounder traces, further observations on the ecology of the Nile perch (Lates niloticus Linne) in Lake Victoria and Lake Kioga, fishery economics studies, The African journal of Tropical Hydrobiology and fisheries and observation on fish marketing experiments in Tanzania

The preservation of some East African freshwater fish

Quality changes during storage were investigated for several commercially important East African freshwater fish. Lates, Bagrus, Protopterus, Tilapia esculenta and T. nilotica were examined during storage in ice and at ambient temperature (250•C). After 24 hours at ambient temperature Lates and Bagrus were completely spoilt but Protopterus was still edible. In iced storage most fish were acceptable for at least 20 days. Organoleptic examination showed that T. nilotica was acceptable after 22 days storage in ice and that gutting was only marginally beneficial. Changes in physical appearance, which could form the basis of a fish inspection system, were recorded during storage. Possible chemical quality control indices were also investigated. It was found that total volatile bases and hypoxanthine are unlikely to be useful quality indices for the species studied with the possible exception of Lates. The bacterial counts of the flesh and skin of T. esculenta and T. niloticus were found to be low (a maximum of 10 organisms per sq cm of skin or per g of flesh) after 22 days storage in ice.

A review of the distribution of organic compounds in freshwater lakes and rivers

The paper reviews the distribution of organic compounds in freshwater lakes and rivers. The study of dissolved organic matter in natural lakes and rivers is of importance for a variety of reasons. The organic matter may serve in part or whole as an energy source for organisms living in the aquatic environment, or it may supply them with materials essential for their nutrition.

Preliminary observations on cage culture of Tilapia esculenta Graham and Tilapia xillii (Gervais) in Lake Victoria waters, at the Freshwater Fisheries Institute, Nyegezi, Tanzania

Cage culture of Tilapia is not suggested as a substitute for any known techniques in fish culture, but as one of the various techniques of obtaining more fish under controlled conditions. This fact has been very well accepted in various countries. Whererever facilities exist, this line of fish culture should be vigorously explored as a possible avenue in increasing fish production. High density stocking, management under controlled conditions, easy technique of fabricating the cage at relatively low cost, having no demand on land area, absence of prolific and effective breeding and easy availability of fish when a person needs it are a few of the attractions of the technique. The studies indicate that it is desirable to have different meshes for the cages, such as, small meshed cages for rearing fry to fingerlings stages, and larger meshed cages for rearing fingerlings to table sized fishes. II' the meshes are small, the resistance will be more and less water wilt pass through. While feeding with powdered food material, because of brisk activity of feeding fish, a part of the feed appeared wasted. This can be easily overcome if we would resort to feeding fish with cheap pelleted feeds which will no doubt reduce wastage. Precaution has to be taken against damage of the net and thereby loss of fish and against poaching by unauthorised persons. In the present attempt has been demonstrated the possibility of utilizing locally available species of Tilapia for cage culture and obtaining moderately satisfactory growth rates.

A key to the families and genera of freshwater fishes of Tanzania

The purpose of this key is to facilitate rapid and accurate identification, in the field, for fisheries workers. It is therefore based as much as possible on external characters only and an attempt has been made to keep it simple and straight forward. The only real difficulty arises in clearly demarcating the numerous cichlid genera of the great lakes, despite the fact that these have been treated in separate sections for each lake. Moreover, it hasn't been possible to revise the key to the lake Nyasa genera (taken from Jackson, 1961) to any significant extent, my experience with L. Nyasa fishes being limited; also, a few new genera have been or are still in the process of being published and I unfortunately haven't had access to these papers. A short bibliography is appended covering the major publications relevant to the systematics of Tanzania freshwater fishes and the sources from which these keys have been drawn up.