Artificial spawning by stripping in Dussumieria acuta, a marine pelagic fish and studies on its early development

Artificial spawning was successfully conducted in Dussumieria acuta Valenciennes (Family: Dussumieriidae), a marine pelagic fish, by stripping the fully ripe female and male. The experiment was conducted on board a privately owned shrimp trawler operated in the Palk Bay, by participating in one of its night fishing trips, on 2nd March, 1973. The stripped eggs and milt were mixed in filtered sea water. Majority of the eggs were fertilized. Detailed microscopic studies were conducted the next day in the laboratory. The first larva hatched out 24 hours after fertilization. The larvae could be reared only upto 48 hours after hatching. The developmental stages of the embryo and the larva are described and discussed. It is suggested that the technique of artificial spawning by stripping and early ranching of the embryos into the sea, if arried out by the fishermen in a variety of commercially important species which it is possible on board the fishing vessels on a large scale, can increse the natural production

Carangid resources of India

A review of the research work carried out so far on various aspects of the carangid resources has been made in this paper based mainly on the published contributions of Central Marine Fisheries research Institute. The fluctuations in the fishery since 1950 and its present status, in the light of the improved tackling devices and changed fishing patterns, have been analysed. A drastic increase in the landings was noticed since 1985 which was mainly due to the mechanization of the country crafts, the use of purse seine and ringseine, intensification of trawling and the introduction of multiday fishing. The studies on the food and feeding habits have revealed that almost all species of carangids are pelagic carnivores, feeding mainly on a variety of smaller crustaceans and fishes. The stock assessment studies conducted on certain commercially important species have shown that most of them are either optimally or under-exploited and hence there is scope for increasing the production without adverse effect on the sustainability of the stocks

विषिंजम की करंजिड मात्स्यिकी

कृपया पूरा लेखा पढ

टिकाऊ चिंगट उत्पादन के लिए नदीमुख और तटीय आवास तंत्रों के परिरक्षण की परम आवश्यकता

कृपया पूरा लेखा पढ

Construction of Control Charts Based On Six Sigma Initiatives for the Number of Defects and Average Number of Defects per Unit

A control chart is a statistical device used for the study and control of a repetitive process. In 1931, Shewart suggested control charts based on 3 sigma limits. Today manufacturing companies around the world apply Six Sigma initiatives, with a result offewer product defects. Companies practicing Six Sigma initiatives are expected to produce 3.4 or less number of defects per million opportunities, a concept suggested by Motorola in 1980. If companies practicing Six Sigma initiatives use control limits suggested by Shewhart, then no points will fall outside the control limits due to the improvement in the quality of the process. ASix Sigma based control chart is constructed for the number of defects and average number of defects per unit. Tables are providedto aid engineers in decision making

കക്കവര്‍ഗ്ഗ ജീവികളുടെ ഉല്പാദനരംഗത്ത് വനിതകള്‍ക്ക് തൊഴിലവസരങ്ങള്‍

Training Material for Post Harvest handling of Shrimp and Clam Products കക്കവര്‍ഗ്ഗ ജീവികളുടെ ഉല്പാദനരംഗത്ത് വനിതകള്‍ക്ക് തൊഴിലവസരങ്ങള്

The resources of the Indian mackerel - characteristics, exploitation and future prospects

The Indian mackerel contributed to an annual average (1993-'99) catch of 2.17 lakh tonnes (t). The west coast landed about 80% of its total catch and remaining by the east coast. The resource is rich in upwelling areas of the west coast with a catch contribution of 38.68% from Kerala followed by Kamataka and Maharashtra. The fishery is characterized by annual fluctuations in the catch ranging from 0.14 lakh t in 1968 to 2.9 lakh t in 1989. The annual fluctuations do not show any pattern; whereas the decade! trends show a cyclic pattern of ups and downs. The fluctuations are more pronounced along the upwelling areas of the west coast. In 1990s, there was a quantum leap in the annual catch chiefly due to the introduction of large seine nets and motorization of country crafts. The increase was maximum in Kerala, moderate in Maharashtra and poor in Kamataka. Along the east coast also fishery showed considerable improvement. Of late, the role of trawl net in the mackerel fishery is gaining importance. The surface fishery using large seines along the upwelling areas seems to depend very much on the intensity and duration of upwelling which is perhaps causing the fluctuations in catch rather than the variations in the abundance of the resource. The behaviour of the fish to ascend with upwelling and spreading to deeper waters with sitiking of thermocline seem to control exploitation and protect the resilience of the stocks. Perhaps the richness of the resource is much stronger than hitherto believed. With proper management the production can reach further heights