Penaeid broodstock development and management

In the context of the global interest in the aquaculture of penaeid prawns, production of large quantities of quality prawn seed in hatcheries has become imperative. For efficient planning of hatchery operations, ripe spawners of the desired species should be readily available at the proper time

Methods of culturing zooplankton

Successful hatchery production of the fry of fish and crustaceans for aquaculture purposes depends, among other things, on the availability of zooplanktonic organisms of appropriate size for feeding the larvae. Freshly hatched Artemia nauplii have been the popular larval feed used by scientists and aquaculturists for a long time. But the high cost of Artemia cysts has lead the' aquaculturists to search for other suitable zooplankters which could be easily cultured on a large scale

Spawning biology of prawns in relation to conservation of prawn resources

The stagnation in prawn catch from the sea in recent years has raised anxious enquiries about the possibility of depletion of prawn stocks, and the remedial measures, if any, needed to increase marine prawn production. The frequent capture of large quantities of mature prawns with ripe ovaries by the trawlers has been alleged to be one of the possible causes of depletion of the prawn resources. The data collected by the CMFRI over the years were examined to throw light on the spawning habits of prawns and their management Implications

Prawn Fisheries of Maharashtra Coast and Problems of Prawn Culture in the State

Maharashtra is the leading prawn producing state in India, accounting for 75 % of the uon-penaeid and 34.3% of the penaeid prawn landings in the country. The marine prawns catch in the state during the five years 1982-'86 were studied here. It is immediately apparent that the prawn fishery of Maharashtra is multispecies with different species fluctuating widely in abundance from year to year. However, there has been a general increase in prawn catch during the past five years. The prawn fishery along the Maharashtra coast appears to be in fairly good shape

Artificial insemination of Penaeus monodon

Viable nauplii of the tiger prawn Penaeus monodon have been produced by artificial insemination. A technique of implanting electroejaculated spennatophores from the males into the thelycum of newly moulted, eyeablated females is described. The implanted spennatophores are retained by the female till the next moult. Three females were artificially inseminated 10 times and every time they matured and spawned. One of the spawnings yielded healthy normal larvae which were reared to postlarval stage in the laboratory

Induced breeding of the Indian white prawn Penaeus Indicus

A steady supply of spawners is an essential requirement for effective planning of the operations in a penaeid prawn hatchery. The difficulty in obtaining the fully ripe spawners of the desired species from the sea as and when required, and the high cost of fishing and transporting them, are some of the main constraints in the development of hatcheries for large scale culture operations. To overcome this difficulty research is being undertaken in many countries to induce maturation of penaeid prawns under controlled conditions and to domesticate them. One of the techniques employed for the purpose is the ablation of the eye stalk in which the organs that secrete and store the gonad inhibiting hormones are situated. This note reports the successful application of the method for inducing maturation in the Indian white prawn Penaeus Indicus for the first time

On a new species of Penaeus (Crustacea, Decapoda: Penaeidae) from North Borneo.

A new species of penaeid prawn, Penaeus silasi from North Borneo is described in detail and compared with the closely related species such as P. indicus, P. merguiensis and P. penicillatus. The new- species is characterized by the following features: The 3rd maxilliped of the adult male has a dactylus as long as or slightly shorter tha n the propodus which has only a rudimentary tuft of hair instead of a long tuft of bristles as in P. indicus ; the anterior plate of the thelycum is triangular and relatively prominent

On the distinction between Penaeus indicus H. Milne Edwards and Penaeus merguiensis De Man (Crustacea : Penaeidae) with special reference to juveniles

Clear-cut differences between the juveniles of Penaeus indicus and Penaeus merguiensis are pointed out in this paper. On the basis of the colour pattern of the antennal flagella, antennular flagella and the pleopods, and the disposition of the rostral teeth it is now possible to identify the juveniles of P. indicus and P. merglliensis with certainty

Present status of marine prawn hatchery technology in India

One of the reasons for the rather slow growth of the prawn culture industry in India is the non-availablity of the seed of desirable species of prawns at the proper time in adequate quantities to stock the grow-out ponds

Hydrostatic pressure effect on Tc of new BiS2 based Bi4O4S3 and NdO0.5F0.5BiS2 layered superconductors

We investigate the external hydrostatic pressure effect on the superconducting transition temperature (Tc) of new layered superconductors Bi4O4S3 and NdO0.5F0.5BiS2. Though the Tc is found to have moderate decrease from 4.8 K to 4.3 K (dTconset/dP = -0.28 K/GPa) for Bi4O4S3 superconductor, the same increases from 4.6 K to 5 K (dTconset/dP = 0.44 K/GPa) upto 1.31 GPa followed by a sudden decrease from 5 K to 4.7 K upto 1.75 GPa for NdO0.5F0.5BiS2 superconductor. The variation of Tc in these systems may be correlated to increase or decrease of the charge carriers in the density of states under externally applied pressure.Comment: 3 pages text +Fig