• Login
    View Item 
    •   DSpace Home
    • Institute's contributions
    • Scholarly literature
    • View Item
    •   DSpace Home
    • Institute's contributions
    • Scholarly literature
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    The biology of Nausitora hedleyi (Schepman) in the Cochin backwaters

    Thumbnail
    View/Open
    Recent_Res_Estuar_Biol_1975_137.pdf (488.8Kb)
    Date
    1973
    Author
    Nair, N.B.
    Saraswathy, M.
    Metadata
    Show full item record
    Abstract
    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
    URI
    http://drs.nio.org/drs/handle/2264/5794
    Collections
    • Scholarly literature [9141]

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV
     

     

    Browse

    All of DSpaceCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    LoginRegister

    DSpace software copyright © 2002-2016  DuraSpace
    Contact Us | Send Feedback
    Theme by 
    Atmire NV