Relevance of the study of marine fish eggs and larvae in India

India is a tropical, peninsular country, situated between about Lat. 3° and 38® N and between about Long' 68' and 80'' E. There is an extensive coastline of more than 6,500 Km, dotted with many estuaries, creeks, backwaters bays, lagoons, etc. frequented by quite a few species of fishes. According to Talwar and Kacker (1984)^ there are about 1,400 marine and estuarine fish species in India, Of these/ about 100 species belong to the group of sharks, rays and skates (Esasmobranchii), which are mostly viviparous, giving birth to their young ones and hence do not pose any problems with regard to their identity in their young stages

On the identification of the early developmental stages of clupeiform fishes from Indian waters

Among about 65 species of clupeiform fishes present in the seas around India, most are distributed along both the east and west coasts and have similar spawning seasons and spawning grounds. The most difficult problem experienced with regard to the identification of their early developmental stages is the overlapping sets of diagnostic features among many species within the same genus as well as among species belonging to two or more genera. From studies carried out recently, the present paper sites a few instances wherein certain subtle characters have been used for distinguishing the early developmental stages of a few allied species

Present status of work on marine fish eggs and larvae in India and outlook for the future

In India, interest on a study of marine fish eggs and larvae is found to have begun only in the first decade of the present century, when Bhattacharya (1916) has identified the larvae of a few estuarine fishes. Although there has, been a steady increase-in the output of research thereafter, most of the publications till the end of the thirties are on estuarine species only

An introduction to demersal finfish resources

An estimated 250 species of demersals form regular fisheries of van.\ing magnitude in Indian coastal bottom, with greater diversity in the east coast compared to the west coast and occupy all types of habitats. They are exploited by a variety of traditional and mechanised craft and gear. Their production has reached 7 lakh tonnes in 1994, comprising of sciaenids (24 %), pink perch (12%), silverbellies (9%), elasmobranchs (9%), large perches (8%), flatfishes (7%), catfishes and powfrets (6% each), and lizard Jishes (5%). The paper overviews the demersal fisheries research in India since the inception ofCMFRI

On judicious exploitation of marine fishery resources

The principal aim in marine fisheries Tesearch is to find ways and means of obtaining 'maximum sustained yield' from year to year and to practise conservation procedures for realizing such an end. By 'maximum sustained yield' is meant the maximum quantity of fish th at can be harvested by man in a given year, without adversely affecting the regenerating or repleni shing potentialities of the stock with reference to future fisheries

Terminology of the early developmental stages of marine fishes

A perusal of literature shows that over the years various authors have used different terminologies for the various early developmental .stages or, phases of marine fishes

A review of marine finfish culture experiments in India

Although India is blessed with many cultivable marine fin flshes, their seeds and unpolluted coastal water bodies, commercial culture of this resource has remained in a primitive condition all along. The traditional methods practiced in West Bengal, Kerala, Goa, etc. fall short of the advanced technology developed in countries such as Indonesia, Philippines and Taiwan. Certain experiments undertaken have revealed that by resorting to systematic and scientific steps of pond preparation, water management and selective stocking, the growth and production of most of the species could be enhanced considerably. However, certain drawbacks observed in most of the experiments are: lack of published data on the cost of cultivation, lack of technologies to grow ideal food for species such as milk fish and to construct and maintain grow-out structures in relation to the environmental and soil conditions, lack of adequate water supply to culture facilities and lack of seeds. The paper examines these aspects and presents suggestions for a more effective approach to solve the problems as well as to ensure commercial culture of marine fin fishes as a successful proposition

Development of eggs and larvae of marine fishes

For an individual fish, the beginning of development is fertilisation of the egg by spermpatozoa. Most marine teleosts have pelagic eggs which drift with the plankton in a ll water layer between the surface and the bottom However, fishes like the British herring and Blennier and Gobier have demersal eggs, which attach to substrata like stones, shells and weeds. Usually, pelagic eggs are transparent and spherical, with the exception of the eggs of certain engraulids t o l e v h o r u s which are oblong. When the embryo is fully developed, ' &t hatches out as larva and undergoes further development, Fertilisation end Embryonic developmen

Guidelines for the identification of marine fish eggs

Occurrence of early developmental stages in the plankton and of spawners, spent, mature and/or recovering stages in fish catches can be used to identify the former as belonging to the latter only in a circumstantial manner, Delsman (1922-1938) has made use of such a method for assigning the early developmental stages; but, in addition to this he has also assigned cogent reasons of taxonomic nature in arriving/at his conclusion. -Thus, this circums tantial evidence of coincident occurrence of the eggs in the plankton and the spawning adults in the fishery can be only of limited value

Notes on postlarval stages of the wWhite sardine, Kowala coval (Cuvier)

Kowala coval popularly called the ' white sardine', is one of the pelagic shoaling clupeids occurring in the seas around India. It appears frequently in the catches of the indigenous crafts and mechanised vessels operating in the coastal waters. Also, it contributes a fishery of some magnitude along certain areas. (Chidambaram and Venkataraman, 1946 ; Mookerjee and Bhattacharya, 1950 ; Nair, 1952), particularly in the southwest region. Delsman (1926 b ; 1933) collected the plahktonic eggs of this species from the Java Sea and gave descriptions of a few early larval stages. Subsequently Devanesan and John (1941), Nair (1952) and Bapat (1955) have dealt with certain aspects of its biology including maturity, spawning season, eggs, early larvae etc