115 research outputs found
Utilization of saline mud flats for fish culture-An experiment in marine fish farming
The scope for economically feasible fish farms in brackish water areas in
India has long been realised and practically demonstrated by the numerous
fish and prawn farms adjoining the backwaters of Cochin along the west
coast. Apart from these even some of the other low-lying saline coastal mud
flats of the south-east coast of the Indian Peninsula, which periodically get
flooded with sea water but usually with a relatively low biological productivity
owing to certain inherent ecological drawbacks, also show potentialities
for development. Attempts at fish culture in similar marine environments
have not been many in this country except for the earlier enterprises
by the Madras Fisheries Department as reviewed by Chacko and Mahadevan
(1956). A project was recently undertaken at the Central Marine Fisheries
Research Station in order to determine to what extent these apparently low
productive areas can be brought under more effective utilization for fish
culture purposes and the preliminary results are given in this account
Some observations on the reproduction of the milkfish Chanos chanos (Forskal)
Several aspects of reproduction of the milkfish are still baffling and the progressive
reproductive phases of the gonads and the spawning cycle in the fish
are not properly understood. The validity of a statement by Chaudhuri
(1916) that the ripe roe of Chanos is dried, smoked and sold by fishermen
around the Chilka Lake which conveys an impression of common occurrence
of the breeders was inquired into and it is understood thai the fish are now rare
in these places
Pituitary of Chanos chanos (Forskal)
It is well established by previous workers that the glandular component of the pituitary in teleosts is derived from the ectoderm of the buccal cavity. Haller, Matthews, and Kerr have obsorved that the first appearance of the pituitary in all teleosts is as a solid ectodermal inpushing of the buccal epithelium, without any cellular differentiation, which extends below the brain and bocomes stalked
Salt Water Fish Culture in India
Despite a tradition that dates back to the very ancient times, salt water fish culture
as a profitable industry is only a recent development in India, largely prompted by the urgent
need to increase our much-needed protein food. But within the past half a century even
after the realisation of our potential, it must be said at the outset that we have not made
adequate progress in harnessing our resources, especially when compared to the great strides
this industry has taken in the east-Asian countries or along the Adriatic coast of the Mediterranean
region. Generally speaking, fresh water fish culture has shown much greater
promise and improvement and this practice is fast developing in our country, perhaps on
account of easier management and quicker results that are obtained. The following discussion,
however, will be confined to some of the special aspects involved in fish farming in
environments that are more akin to marine conditions, and the scope for improvement in the
existing methods of salt water fish culture
Anatomy of Armandia leptocirris Grube (Polychaeta)
The genus Armandia is one of the three genera of subfamily Polyophthalminae
belonging to the Family Opheliidae (Hempelmann, 1927)
and includes four known species A . polyophthalma, A. cirrosa, A. lanceolata
and A. leptocirris. Of these the last two species occur in restricted
localities in the Indo-Pacific region and have been collected from the
Indian Ocean in the Persian Gulf, Gulf of Mannar, around the Andaman
Islands and the Mergui Archipelago (Fauvel, 1932
New hope for salt water fish culture
With the recent success in induced
fish-breeding techniques
a major impediment in fresh water
fish culture has been removed and
henceforth we may expect greater
progress in inland fish culture. However,
our low-lying, coastal, saline
areas remain neglected except for
brief spells of fishing activity
Utilization of saline lagoons for fish farming
While exploring the possibilities of increasing our food resources, the question of proper utilization of coastal mud-flats and lagoons has special significance. On account of their highly saline nature, agriculture of any kind is impossible in these areas and as such extensive
coastal regions remain barren
Pelagic swarming of Polyophthalmus (Family Opheliidae-(Polychaeta)
The Opheliid is identified as a-juvenile Polyophthalmus pictus
(Djuardin) and a slightly contracted specimen is shown in the figure.
When freshly caught these worms swim about vigorously with a
wriggling or more often a darting movement characteristic of many
of the adult Opheliid
Oxygen consumption and viability of Chanos chanos (Forskal) in relation to size
The importance of the size factor in metabolic studies on fish has been emphasised by Rubner (1924) who found that the oxygen consumption in the pike and in the tench was correlated exponentially with the body weight of the fish. More recently, Busnel, Drilhon and Raffy (1946) have investigated the oxygen consumption of the fry and alevins of the rainbow trout in waters of varying salinity; their results indicate that the salinity of the external
medium is a second decisive factor influencing respiration
Review of work programmes carried out in India on the biology of the milkfish Chanos chanos
This account is a brief review of the investigation carried out in India on the various aspects of the biology of the milkfish. It covers the records of observations on the distribution of Chanos fry in the coastal areas, food and feeding of the fish, its growth, maturity, fecundity and spawning, and also certain experimental results on the physiological adaptation of the fish together with the histological structures of its kidney, pituitary and thyroid. While emphasising the paucity of data on the adult milkfish in the wild, the priority areas where information is lacking especially on the spawning ground, reliable identifying characters of the egg as well as on the possible existence of different racial stocks have been discussed
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