The effect of salinity on some endocommensalic ciliates from shipworms

The ciliates, Nucleocorbula adherens, Boveria teredinidi, Trichodina balakrishnia, Thingmozoon fencheli and Nyctothereus marina, live inside the mantle cavity of the shipworms in the estuaries and backwaters of the south-west coast of India. Seasonal incidence and relative abundance of these ciliates showed that they were more abundant during the low saline than the high saline periods. Even though these ciliates can endure higher salinities through gradual acclimatization of their habitat it was found that they prefer low salinity for active growth and healthy existence.

Biodeterioration of cellulose materials in Karingote, Nileswaram, Kavvayi and Ramapuram Backwater systems of Kerala

The hydrographic conditions prevailing in an estuarine system along the southwest coast of India are described. The nature of destruction of timber in these backwaters has been examined in detail which revealed the existence of 8 species of shipworms, 2 species each of pholads and isopods. The shipworms are represented by Dicyathifer manni, Lyrodus pedicellatus, Teredo furcifera, T. clappi, Nausitora dunlopei, Bankia carinata, B. campanellata; the pholads by Martesia striata and M. (Purticoma) nairi; and the isopods by Sphaeroma terebrans and S. annandalei. The incidence and relative abundance of these pests are discussed in relation to the salinity profile of the estuary.

Some observations on the problem of marine timber destroying organisms of Indian coasts

In India the chief marine timber boring organisms are 2 species of Martesia, 28 species of shipworms, 4 species and a variety of Sphaeroma and 9 species of Limnoria besides bacteria and fungi. The occurrence, abundance and activity of the various species of borers show remarkable variations and fluctuations in the different harbours of India, each harbour or area having its own dominant set of species and an assemblage of less important forms. These species have their own characteristic preferences, life history and seasons of attachment and a scheme evolved for one locality may prove ineffective for another. Through a delicate and complex ecological adjustment the borers occurring in a locality have reached an interrelationship reducing interspecific and intraspecific competition. The seasons of settlement of the dominant borers in the different harbours of India are indicated. The need for a detailed biological enquiry is stressed.