Picture book on Marine Gastropods

Gastropods includes snails, slugs and their relatives is a hyper diverse with respect to number of species, structure and habitat and many other attributes. Gastropods are characterised by having single shell and an operculum. Widely ranging in size, the shell has been modified enormously in many groups. A total of 80,000 to 100,000 mollusc species are known world over. About 3271 species of molluscs are found in India, of which 1900 marine species of gastropods are known to date. These resources are exploited by either mechanised trawlers, bottom set gillnets or by diving. Very few species forms a regular fishery and most of them are obtained in smaller magnitude making them unnoticed. While these resources are smaller in magnitude compared to other fisheries, they play an important role as raw materials for the multi-million dollar ‘SHELLCRAFT INDUSTRIES’ world over. In India, the resource is harvested in almost all the landing centres of both the coasts. In southeast coast of India, where the most part of landings of marine gastropods are occurring is considered a hub of shellcraft industry. A total of more than 250 species has been recorded and representing forty odd families in gastropods. The Federation of Sea Shell Handicrafts Merchants Association (FOSSHMA), estimates around 90 active seashell handicrafts traders in India, comprising of 20 very active, 30 minimal functioning and 40 dormant units. The major destinations of export is found to be the United States of America, Australia, Europe, Japan, Philippines, Vietnam, Africa, Malaysia, Belgium, Croatia, England, Haiti Island, Sri Lanka,France, Netherlands, Germany, South Africa etc. The major species exported are Conus sp, Umbonium sp, Chicoreus ramosus, Lambis lambis, Babylonia spirata, B. zeylanica, Telescopium sp, Terebralia sp, Tonna spp and Cerithium sp. Around 20-25 species are imported by shellcraft industries and the major species imported are Busycon sp, Haliotis sp, Cypraea tigris, Mitrella sp. The major importing countries includes USA, Mexico, New Zealand, South Africa, Australia, Philippines, Spain and other African countries. This picture book contains 165 photographs of seashells used in the Indian seashell industries clustered under the common name of the respective species along with vernacular (Tamil) names

Ornamental gastropod shell trade in India : A macroeconomic assessment

The capture fisheries results in landing of sizeable amount of by-catch which includes molluscs, crustaceans (certain varieties of crabs, and Squilla spp.), finfishes (non-edible varieties), sea snakes and echinoderms

Cephalopod fishery off Thoothukudi coast, Tamil Nadu

In Thoothukudi district of Tamil Nadu, cephalopod resources are principally exploited by single day trawlers followed by hook and line. During 2012-18, nearly 54% of cephalopods landed were caught by mechanised trawl net; 32% by outboard crafts operating hook and line, 8% by gill net and rest by other gears. From 2012-18, the cephalopod landing showed a fluctuating trend and major cephalopod species landed by trawl net were Sepia pharaonis, S. prabahari, Sepioteuthis lessoniana, Uroteuthis (P) singhalensis and U. (P) duvaucelii. In hook and line, S. pharaonis was the dominant species followed by S. lessoniana and Octopus cyanea

Screening of Banana Hybrids for Resistance to Pratylenchus coffeae

The reaction of twenty-four new synthetic banana hybrids to Pratylenchus coffeae was studied under artificially inoculated pot conditions. Two banana hybrids, H-04-05 and H-04-06 were found to be resistant and ten hybrids, H-04-01, H-04-03, H-04-04, H-04-07, H-04-09, H-04-11, H-04-16, H-04-19, H-04-21 and H-04-24 were found to be tolerant to the lesion nematode, Pratylenchus coffeae and the remaining were rated as susceptible

Hatchery production of juveniles of pharaoh cuttlefish, Sepia pharaonis (Ehrenberg,1831) from stranded eggs and sea ranching along the Thoothukudi coast

Accidentally entangled and stranded egg masses of Sepia pharaonis in fishing gears were collected from various landing centres of Thoothukudi district. The stranded egg masses were incubated, hatched and larval rearing was carried out at the Molluscan Fish Hatchery of Tuticorin Research Centre of CMFRI. The average hatching rate of S. pharaonis was 95 % for the eggs collected from the fishing nets. The size of day 1 paralarvae of S. pharaonis was 5.46±0.06 mm and reached the average size of 40.10±1.15 mm length and 9.6±0.20 g weight on day 60 with the average survival rate of 70 %. Maximum weight gain (%) was noticed between 20 – 40 days. The paralarvae of S. pharaonis fed with suitable live feeds until 50 days, after which fed with dead fish and shrimp. The juveniles were transformed as broodstock with an average length of 137.4±8.08 mm and weight of 229.7±21.54 g on 180th day of culture. In the hatchery, the first captive spawning was witnessed on 167th day and the eggs laid by the females ranged from 46 – 118. However, the captive bred egg masses failed to hatch out. Therefore, the hatchery technology needs to be perfected through the development of nutritionally improved broodstock diet to ensure better hatching. During the years 2016 – 2018, altogether 8400 numbers of hatchery reared 60 days old juveniles of S. pharaonis were ranched into the fishing grounds off Tuticorin coast. The biological significance of sea ranching activities to replenish the natural stocks requires further research and evaluation

Hatchery production of juveniles of pharaoh cuttlefish, Sepia pharaonis (Ehrenberg, 1831) from stranded eggs and sea ranching along the Thoothukudi coast

Accidentally entangled and stranded egg masses of Sepia pharaonis in fishing gears were collected from various landing centres of Thoothukudi district. The stranded egg masses were incubated, hatched and larval rearing was carried out at the Molluscan Fish Hatchery of Tuticorin Research Centre of CMFRI. The average hatching rate of S. pharaonis was 95 % for the eggs collected from the fishing nets. The size of day 1 paralarvae of S. pharaonis was 5.46±0.06 mm and reached the average size of 40.10±1.15 mm length and 9.6±0.20 g weight on day 60 with the average survival rate of 70 %. Maximum weight gain (%) was noticed between 20 – 40 days. The paralarvae of S. pharaonis fed with suitable live feeds until 50 days, after which fed with dead fish and shrimp. The juveniles were transformed as broodstock with an average length of 137.4±8.08 mm and weight of 229.7±21.54 g on 180th day of culture. In the hatchery, the first captive spawning was witnessed on 167th day and the eggs laid by the females ranged from 46 – 118. However, the captive bred egg masses failed to hatch out. Therefore, the hatchery technology needs to be perfected through the development of nutritionally improved broodstock diet to ensure better hatching. During the years 2016 – 2018, altogether 8400 numbers of hatchery reared 60 days old juveniles of S. pharaonis were ranched into the fishing grounds off Tuticorin coast. The biological significance of sea ranching activities to replenish the natural stocks requires further research and evaluation

Minimum Legal Size proposed for commercially exploited marine finfish and shellfish resources of Tamil Nadu

Marine fisheries in Tamil Nadu have undergone tremendous change in terms of fishing pattern, fishing method, extension of fishing grounds, composition of fish catch and consequent increase in the total fish catch in recent years. The recent demand from industries involved in fish meal and fish oil encourages targeted fishing for by-catch resulting in heavy landing of low value by-catch in certain places along Tamil Nadu coast. These by-catch are often dominated by juveniles of many commercially important marine finfishes and shell fishes. So it warrants some caution and intervention. One of the methods to discourage the indiscriminate exploitation of juveniles is to impose a Minimum Legal Size (MLS) which is the size at which a particular species can be legally retained if caught. The advantage of a MLS is that it aids in the control of two major problems in the fisheries management, growth overfishing and recruitment overfishing either by increasing the minimum size of harvest or by increasing or maintaining the size of the spawning stock. The most common method of increasing the reproductive output through the use of size limits is to set the minimum size at which the females become sexually mature. As the individuals of a species do not attain sexual maturity at the same size, it can be a size at which higher proportions are mature