Peroderma tasselum sp. Nov. (Lernaeoceriformes; Copepoda) parasitic on the fish Stolephorus commersonii Lacepede

The female of a copepod parasite, Peroderma tasselum sp. nov. parasitic on the fish Stolephorus commersonil is described from Tuticorin, southeast coast of India. The species can be distinguished from the only other known species of the genus, P. cylindricum, by the characteristic shape of the trunk

Study on the stomach contents of pearl oyster Pinctada fucata (Gould) with reference to the inclusion of bivalve eggs and larvae

The pearl oyster which is a filter-feeder as any other bivalve mollusc, has been considered to feed On phytoplankton including detritus. A detailed study made on the feeding of pearl oyster Pinctada fucata collected from the pearl culture farm as well as natural beds showed the presence of bivalve eggs and larvae along with copepods and crustacean larvae, spicules of sponges, etc. Several samples of oysters collected at different periods of 1977 and 1978 gave the same results indicating that this is a regular feature

Pearl culture

Pearl culture gives the highest gross income for unit area among aquaculture systems. The techniques developed by CMFRI to suit Indian condition have attracted the entrepreneurs to enter into the venture of pearl culture. The rate of return works out to more than 50%. The recent line of research on the onshore pearl oyster farming and pearl culture, can easily revolutionize the concept and this can be profitably taken up in the east and west coasts of India where prawn farming was successfully conducted. In this paper the cost of seed production and economics of pearl production is dealt with The possibilities of taking up production of seed of desired qualities through selective breeding, manipulation of conditions in the onshore tanks culture are counted as priorities. Black pearl production and farming and pearl culture in the natural beds are the other priorities

Biotechnical aspects in marine pearl production

India is one in the countries in the World having pearl oyster resource. The oysters are available in the Gulf of Mannar (southeast coast) in large number and ill the Gulf of Kutch northwest coast in lesser numbers. From time immemorial the oysters from thes regions were fished for natural pearls. The famed "Oriental pearls" of the ancient times were the pearls produced from here and the Middle-East Asia

Growth and biometric relationship of pearl oyster Pinctada fucata (Gould)

The Indian pearl oyster, Pinctadafucata (Gould) produced in the hatchery and grown at the protected farm at Tuticorin Harbour, attains a dorsoventral length of 47.0, 64.0 and 75.0 mm at the end of 12th, 24tb and 36th months and the corresponding averages in weight are 8.3, 31.6 and 45.4 g. The estimated von Bertalanffy growth parameters are £- oc a: 79.31 ram, K = 0.0757 per month and t^ = 0.44 months. Relationships between total weight, shell weight, flesh weight and dry weight of flesh and length with depth were found by least square techniques

Biology of pearl oyster Pinctada fucata (Gould)

Comprehensive account on the biology of the Indian pearl oyster, Pinctada fucata (Gould) has been wanting. Age and growth of pearl oysters of the Gulf of Mannar was studied by Herdman (1903), Hornell (1922), Devanesen and Chidambaram (1956), Chacko (1970) and Chellam (1978). The age and growth of th6 pearl oysters of the Gulf of Kutch was studied by Gokhale et al. (1954), Narayanan and Michael (1968) and Pandya (1975). Chellam (MS) has traced the growth of the pearl oyster from the settlement of the spat in the hatchery, whose day of spawning is known, to the age of three years, reared in the farm at Tuticorin Harbour

Reproductive bionomics of the wedge clam Mesodesma glabratum (Lamarck) along the south-east coast of India

The intertidal zone, being a precarious marine habitat, is characterised by heavy wave action, and the po~.ible erosion and accretion caused by climatic changes of land and sea. Therefore, the organisms living therein, have contrieved special adaptive features. The intertidal zone of the sandy beach can be classified into three zones. They are: (a) the supralittoral fringe <otherwise known as eulittoral fringe), <b) midlittoral zone <eulittoral zone) and (c) infralittoral fringe <sublittoral fringe) (Pichon, 1967). The organisms living in the supralittoral fringe are subjected to prolonged aerial expowure, and therefore specialised to survive, feed and reproduce under aerial conditions. The organi§ms that inhabit the midlittoral zone are e xperiencing about 50% of aquat ic and aerial conditions, whereas those inhabiting the infralittoral fringe ar@ truely aquatic, but well adapted to resi.t short period~ of exposure to aerial conditions. The organisms of the supralittoral fringe are e xpofied to aquatic conditions only for a brief p.riod during the spring tide. Con vergely, the organisms of th. infralittoral fringe are e xposed to aerial conditions only for a short duration of few hours in each fortnight (Newell, 1979)

Marine pearl production

Pearls are harvested manually. Oysters are opened and pearls are squeezed out. In case 9,500 reuse, the pearls are removed carefully by opening the pearl- sac through the gonad without damaging it. The harvested pearls are washed in distilled water polished in refined salt and again washed in distilled wate

Growth of pearl oyster Pinctada fucata in the Pearl culture farm at Veppalodai

Growth of pearl oyster, Pinctada fucata, under conditions of raft culture at Vcppalodai, Gulf of Mannar, has been studied during the period March 1973- September 1974, with reference to growth of the dorsoventral dimension, hinge line, thickness and weight. The first two dimensions showed positive growth up to a certain period and was followed by growth recession. Thickness increased uniformly throughout the period of study in the younger size groups (30-45 mm) but it showed a stagnation in the older size groups (45-60 mm) during certain times of the year. Weight of oysters increased steadily but showed retardation, except in younger groups (30-40 mm), in a few months. The progress of growth was better in younger size groups than in the older groups. The growth of pearl oysters in the shallow area is considered moderate. Growth was relatively faster during September- January than in other months as observed from the formation of growth processes and growth increments. It has been inferred that the intensity of fouling and boring organisms, b-jsides other factors, might influence the growth of pearl oysters

A report on window pane oyster fishery in Tuticorin bay

The window pane oyster (Placenta placenta) are fished regularly for pearls and shells from Kakinada Bay of Andhra Pradesh and Okhamandal Coast of Gulf of Kutch