80 research outputs found
A note on host specificity of the isopod parasite, Nerocila sp.
Host specificity is very strongly expressed in a great number of fish parasites, especially in the majority of ectoparasites like isopods. While engaged in the
length frequency studies of the Indian Herring, Ilisha filigera (Val.) landed by bull trawlers of the New India Fisheries Company Limited at Sassoon Docks, the
isopod parasite, Nerocila sp. was seen very commonly in Ilisha indica during the months of December and February. Though this has been already observed by Chidambaran| and Devidas Menon (1945) in Calicut, the case of host specificity among the species of the same genus has not been pointed out so far
The ribbonfish resources
Che ribbonfishes are an important group of food fishes in
India and their annual average production during 1971-*82 was
estimated at 55,300 tonnes which formed 4.3% of the total marine
fish landings and occupied 7th position. The studies indicate that
various species of ribbonfishes constitute substantial fishery in the
States of Andhra Pradesh, Tamil Nadu, Kerala and Maharashtra
showing considerable variations in the species composition,
season^ abundance and production trends
Determination of the relative fishing powers (power factors) of the vessels of the Government of India deep sea fishing station, based at Bombay.
The Government of India Deep Sea Fishing Station at Bombay and the
Offshore Fishing Stations at Veraval, Mangalore, Cochin, Visakhapatnam and
Tuticorin have been employing in the exploratory fishing operations different
types of power vessels which vary greatly in their gross tonnage, net tonnage,
brake horse power, length of body, draught etc. even though most of them
use more or less the same or similar types of otter trawls. It is well known
that, suitably geared a larger boat would generally bring about a greater fishing
mortality than a smaller one in a unit amount of time when fishing in the same
ground. The capacity of a vessel to catch more or to catch less as compared
with another vessel is independent of the density of the population and is
related in some way to the makeup of the vessel itself. In computing catch
statistics of different vessels, 'standardisation of fishing time according to their
fishing powers' (Beverton and Holt 1957, P. 172) being essential, the present
work has been attempted based on available data from the exploratory fishing
operations of the vessels viz-, 'Jheenga', 'Bumili' and 'Meera' from Bombay
Large scale movements of Caranx sexfasciatus Quoy & Gaimard into the inshore areas of Madras
During the routine observations on the fishery along the Madras coast the authors visited the Mullikuppam landing centre in Madras City and observed the shore seine
catches landed on 12th December, 1968. In Madras shore seines are operated within a distance of 1 km. from the shore at a depth of 4 to 8 metres during the anchovy fishery season, extending from November to May, While the catches in most of the nets on that day were anchovies, a huge quantity of Caranx sexfasciatus was observed in a haul which consisted of 925 fish weighing a total of nearly 3 tons. Enquiries with an elderly fisherman on the spot revealed that although the fish occur in large quantities in shore seine during this season in certain years no such huge catches were witnessed anytime in the past
Relative abundance of trawl fishes in the Bombay-Saurashtra waters
With the help of skilled Japanese technicians very intensive commercial fishing by
two pairs of bull trawlers, ' Arnalla'тАФ' Paj' and ' Satpati'тАФ' Pilotan ' (each of 29
meters length, 250 BHP and about 91 gross tonnage) of the New India Fisheries
Company, Bombay, was carried out from April 1956 to October 1963 in Bombay-
Saurashtra waters, landing a total catch of 26,304 metric tons offish sold at a whole
sale price of about Rs. 1.6 crores (Anon, 1965). The annual effort varied from
2,850.97 hours to 5,453.27 hours and the catch rates from 601.60 to 899.70 kg. per
hour of trawling for a pair of vessels. Fishing by these vessels was preceded by
exploratory buU-trawling by the Government of India cutters, M. T. Ashok and
M. T. Pratap of the Deep Sea Fishing Station, Bombay during 1953-'55. These
cutters, prior to 1953 using otter trawl had annual catch rates varying from 94.4 to
195.4 lbs. per hour of fishing, but during 1953-'55 when they had taken to the
Japanese method of paired trawling (bull-trawling) the average catch per vessel had
gone upto 1,562.4 lbs. per hour of trawling (Jayaraman et al., 1959). The present
report shows that the best of trawling grounds in Bombay-Saurashtra waters are in
Kutch region, the fishery potential of which was hitherto unexplored
Sea turtle research and conservation
Five species of sea turtles are known from the Indian Seas and all are today protected and are placed in
Schedule I of the Indian Wildlife (Protection) Act, 1972. The Convention of International Trade in
Endangered Species of Wild Fauna and Flora (CITES) which prohibits trade in turtle products places these
species in Appendix I of the Convention.
AUfive species have very wide distribution and there has been a traditional subsistence fishery for the green
turtle Chelonia mydas along the Tuticorin Coast which has now been phased out. A new event in the recent
past was the explosive development of an outlet for the olive ridley in the Calcutta-Howrah markets chiefly
from the Orissa Coast, despite the Indian Wildlife (Protection) Act. This happens mainly during the mating
and mass nesting of this species along the Gahirmatha Coast of Orissa and the capture is mainly in the
gillnet fishing operations. This has been reported in detail in Marine Fisheries Information Service, Technical
and Extension Series, No. 50 of this Institute. Incidental catch of turtles in fishing operations has been a
matter of great concern and only an intensive extension programme can help to minimise the mortality from
this source
Coastal Aquaculture - Mussel farming; Progress and prospects
я╗┐During the seventies, the Central Marine Fisheri^ lleseardi Institute gave a lead in researches on
mariculture and has carved for itself a pioneering role in the R& D programmes of mariculture in the countiy
which has been well recognised. Impressed by the outstanding contributions made during the decade, the
infrastructure facilities built up and, above all, the scientific and techni<ial competence it has acquittdi jm
UNDP/ICAR Centre of Advanced Studies in Mariculture has been instituted at the Central Marine Fisheries
Research Institute since June 1979. The Centre aims at providing postgraduate education in the new
discipline of Mariculture and improvmg the quality of research through doct(┬╗ral and post-doctoral research
programmes in identified areas.
One of the priority areas of mariculture in India is mussel culture. Although considered a poor relation
of the oyster in Europe, mussel has one of the highest potentials in India for increaang production of protein-
rich sea food. Mussel gives the highest conversion of primary producera ^hytojrfankton) to human food and
culture production in column waters enhances the yield several fold. India has a traditional sustenance
fishery for the mmsels at a few centres but the scope for increasing natural production from the existing beds
is rather limited
Spawning periodicity of the ribbon fish, Trichiurus lepturus (F.), with a note on its rate of growth
The spawning periodicity of Trichiurus lepturus is briefly re-examined here in tlie
light of certain recent observations. It is seen that this species spawns more than once
in a year along the Madras coast and the two seasons are roughly around May-June and
later in November-December. This fact also leads to a revision in the interpretation
of the rate of growth of the fish. It is now estimated that the fish at the end of
one year attains an average of 300 mm in length and that those above about 900 mm
are just over four years
The present status of ribbonfish fishery in India
The ribbonfishes, of the family TrichiurkJae, an Important
group of food fishes in India, registered an average annual
catch of 53.475 tonnes during 1970-81. In this period, forming
4.25% of the total marine fish catch, thsy formed the 7th
exploited fish group in the order of predominance.
There are 8 known ribbonfish species in India (an identification
key to the species is given in the beginning of thearticle)
The information available on the various aspects of biology of
each of these species is summarised, which clearly indicates
that while our knowledge on the biology of Trichiurus lepturua,
Lepturecanthus savale, Eupleurogrammus nwticus and Eupleurogrammus
glossodon is considereble, we know little about
the other species.
Traditionally, the ribbonfishes are caught by boatseines,
shoreseines, bag nets and gill nets, operating from nonpowered
country crafts. But, during the last two decades, the small mechanized vessels (10-15 m long, with 15-100 hp engines)
that are operating otter trawls, too, are increasingly landing
ribbonfish. The fishery is confined to the depth-zone usually
shallower than 50 m. T. lepturus, the most widely distributed,
forms the mainstay of the ribbonfish fishery, contributing to
the bulk of the landings along almost all our coastline. Data
on spatial and seasonal variations in abundance, size and age
composition in the commercial catches and diurnal movements
and depthwise distributions of shoals of this species are
therefore reviewed.
Stock assessment studies show that, in the shelf region
from Ratnagiri on the west coast round to Gulf of Mannar on
the east, there had been an average standing stock of 67,200
tonnes of ribbonfish (mostly L Lepturus) in 1972-75, which is
about 4 times what was actually landed from the region during
the period.
It therefore follows that a doubling of the catch will not
adversely affect the stock in the region. Studies on the population
dynamics of T. lepturus from the Kakinada area during
1967-71 has shown that the fishing mortality and the exploitation
rates are low, at 0.3 and 0.17 respectively. The average
annual stock and average standing stock along the Andhra and
Tamil Nadu coasts are estimated at 85,000 and 48,000 tonnes,
respectively, for T. lepturus, against an estimated annual
average catch of 14,400 tonnes during 1967-71. It thus appears
that the stock of T. lepturus along the east coast also is likewise
underfishad,
The need for extension of fishing operations into the
Exclusive Economic Zone with larger vessels, equipped with
suitable gears like bottom and pelagic trawls, is emphasized-
Suggestions on future lines of research are given
Industrial fisheries off Madras coast based on exploratory surveys during 1973-1980
At the Madras Research Centre of CMFRI, there existed data for areas (Fig. 1) south of 15┬░40'N
Upto the latitude zone of I0┬░40'N off Velanganni in depths ranging from 10 to 130 m for a eight year period
From 1973 to 1980. The results of analysis of these data are presented here with a view to providing information on and extending our knowledge about the spatial and seasonal distribution of various indusirially important fisheries as also their resource potential along the north Tamil Nadu-South Andhra Coast
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