The biology of Nausitora hedleyi (Schepman) in the Cochin backwaters
DRS at CSIR-National Institute of Oceanography
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Title |
The biology of Nausitora hedleyi (Schepman) in the Cochin backwaters
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Creator |
Nair, N.B.
Saraswathy, M. |
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Contributor |
Natarajan, R.
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Subject |
Invertebrate Biology
Estuarine Organisms Invertebrate Zoology Reproductive Cycle Biochemical Composition Nausitora Hedleyi ISW, India, Kerala, Cochin Backwaters |
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Description |
The tropical estuarine shipworm Nausitora hedleyi is a highly destructive species in the Cochin backwaters, Kerala, India. In this area this species occurs throughout the year, during the course of which the salinity of the medium may fluctuate between 33.63 ppt and 0.65 ppt. The reactions and nature of activity of N. hedleyi in different salinities are described, the lethal salinity determined and the effects of gradual acclimatisation ascertained. The most suitable salinity range for the early development has also been determined for the species. The sequence of sexual phase in N. hedleyi has been elucidated, the reproductive cycle is described based on a study of the gonad index, and the nature of settlement has been studied using test panels. The results of the above mentioned tests indicate that the breeding of N. hedleyi is strictly seasonal in the estuarine conditions prevailing in the Cochin backwaters being restricted to the period of medium salinities. Growth rates of N. hedleyi were followed based on a scrutiny of the burrow length, increase in weight of the body, increase in length of the pallet and increase in the size of the shell. The effect of over crowding on growth rates is explained. A brief account is also presented on the fluctuations of the various biochemical constituents of the body of the shipworm in relation to the breeding cycles. The effects of hydrographical conditions on the activities of this species are discussed
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Date |
2007-03-29T09:56:40Z
2017-09-29T13:47:17Z 2007-03-29T09:56:40Z 2017-09-29T13:47:17Z 1973 |
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Type |
Book Chapter
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Identifier |
Recent researches in estuarine biology. Delhi:Hindustan Pub. Co; 1973; 137-145
http://drs.nio.org/drs/handle/2264/5794 |
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Language |
en
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Relation |
Symposium on Estuarine Biology, Porto Novo, India; 20-24 Jan 1972
NON-SCI |
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Publisher |
Delhi: Hindustan Pub. Co
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