Crustacean biodiversity, conservation and management

The recent changes in fishing pattern involving destructive innovations of fishing gears, excessive fishing pressure on some of the traditional stocks and the multifarious activities of man causing damages to the natural habitat of crustaceans are potential threats to the biodiversity of this important grou

Candidate species and their special characteristics for aquaculture

Selection of suitable species is an important prerequisite for successful prawn culture. This becomes more 'essential when the prawn population of a given loca1i ty or region is multi-species in nature and the individual species possess different biological characteristic

Crab culture and crab fattening

Among the commercially important brachyuran crabs, the species of the genus Scylla, which are commonly known as mud crabs, green crabs or mangrove crabs, are widely used for aquaculture purpose in the Indo-West Pacific region. In countries like Thailand, Malaysia, Indonesia, Philippines, Singapore and Taiwan, mud crab farming is practised on commercial scale, mainly by the artisanal sector. The farming methods followed and production trends in these covmtries have been reviewed in detail at the Regional Seminar on 'mud crab culture and trade in the Bay of Bengal region' at Surat Thani, Thailand organised by the Bay of Bengal Programme (BOBP) in 1991 (Anon., 1992). The enthusiasm for mud crab farming is ever on the increase throughout the Indo-Pacific region

The prawn culture practices in salt-pan reservoirs at Manakkudy near Cape Comorin

The methods employed for culturing Penaeus indicus in the brackishwater reservoirs of the salt works adjoining Manakkudy Estuary near Cape Comorin are described together with notes on biology of the species. Observations were carried out in three reservoirs (3 hactares) from January 1973 to December 1973. Culturing is done in two seasons in a year, one from February to May and another from June to December

കങ്കിടി വര്‍ഗ വിഭവങ്ങള്‍ (Crustacean resources)

The crustacean resources which include prawns, lobsters and crabs form the major components of the marine products export industry in India. The crustacean resources form about 65% of the total marine products export from India for Rs. 3501 crore in the year 1995-96

Laboratory maturation and spawning of the penaeid prawn Metapenaeus dobsoni in brackishwater salinities

Experiments on maturation and spawning of the penaeid prawn M. dobsoni in different brnckishwater salinities ranging from 15 to 30 ppt were carried out in the laboratory. The results indicated that immature impregnated females collected from perennial brackishwater prawn culture fields readily matured in salinities above 26ppt. Prawns were m:lturation process had initiated, when furthermainm.ined in 20. 22 and 26ppt salinities indicating possibility of breeding this prawn in salinities as low as 22 ppt. Prawn maturation and spawning was observed to be size and salinity dependent. The details regarding initiation of maturation time taken to attain different maturity stages time of spawning and fecundity are also described

Size, count and meat recovery relationship in the penaeid prawn Metapenaeus dobsoni

Versova is a coastal fishing village within the city limits of Greater Bombay. Most of the inhabitants of the village derive their livelihood from fishing or related activities. 'It is also an important fish landing centre. The main varieties of the fishes landed at Versovaare Bombay Duck, Pomfret, RIbbon fish, Shrimp etc

On the scarlet shrimp Plesiopenaeus edwardsianus (Johnson) caught from the continental slope off Trivandrum, southwest coast of India - an indication of a potential deep-sea prawn resource

The Scarlet shrimp Plesiopenaeus edwardsianus (Johnson) is one of the larger species of the family Aristeidae known to be widely distributed in the continental slopes of the tropical and subtropical belt of the Atlantic and also reported from the Indo-West Pacific oceans. It contributes to commercial fisheries in some areas along the West African coast. The present communication deals with the occurrence of this species in Bobbin Trawl operations off Trivandnim at 876-976 m depth in the latter half of January, 1985. This is the first authentic report of the species from the Indian seas. While the catch in terms of quantity may not be significant, it is felt that it is indicative of the presence of a larger population, which might sustain a commercial fishery of this jumbo sized prawn. Taxonomy, distribution and available information on the existing commercial fisheries of the species are given

Marine Prawn Production in Low Energy Fishing sector of Indian Coast - present trend and future prospects

During the 1985-89 period, prawn lanclings in low energy fishing sector amounted to an annual average of 82800 tonnes. This forms over 4O%of the total prawn lancliI1gs in the country. Fixed bag nets, seine nets and bottom-set gill nets operated from mechanised as well as non-mechanised country crafts are the major gear employed in this sector contributing to about 77% ,17% and 4% of the lancliI1g respectively. Statewise % contribution by various gear are detailed while bag net catches are predominantly constituted by less valuable species of non-penaeid prawns, the catches of seine nets and gill nets comprise . mainly of penaeidprawns that fetch better economic returns to the fishermen. Gill net catches are the most profitable ones as they are predominantly supported by prawns of the Penaeus group which carry high unit value

Laboratory rearing and seed production of the mud crab Scylla oceanica (Dana)

The green mud crab Scylla oceanica (Dana) was successfully reared, from egg to crab instar under laboratory conditions. Maximum period of egg incubation was noted to be 13 days. The larvae were reared through five meal and one megalopa stage to crab instar. It took a minimum of 17 days to complete all the meal stages and a minimum of 6 days to moult from megalop to crab stage. Effect of individual food items such as Chlorella salina, Artemia, Brachionus, microencapsulated feed and egg custard as well as their three combinations viz., combination of frozen Artemia nauplii, Brachionus and microencapsulated feed (Treatment A) combination of frozen Artemia nauplii, Brachionus Chlorella (Treatment B) and combination of Artemia nauplii suspension, Brachionus with an antibacterial chemical prefuran (Treatment C) on the development and survival of the larvae was also studied