Rare Chimaeroid and Elasmobranch fishes from the continental slope off the West Coast of India

During exploratory trawling from the upper continental slope in depths between 180 and 450 metres off the West Coast of India, specimens of the Chimreroid fish Neoharriotta pinnata (Schnackenbeck) and the rare elasmobranchs Echinorhinus b"UC11S (Bonnaterrc) and Atractophorus armatus Gilchrist have been obtained. All three are new distributional records for Indian Seas and they are described and illustrate

Frequent strandings of dolphins and whales along the gulf of Mannar coast

The present observations no specific reason could be attributed towards the frequent strandlngs of marine mammals in the Gulf of Meinnar region. It Is inferred that any one factor as given above or more would have contributed towards the strandlngs. As the Indian Ocean is declared as a sanctuary for whales,the frequent stranding of whales eind dolphins emphasise the need for Intensive study on conservation measures. The scientific Information on the extent of strandlngs of marine mammals all along the coast needs consolidation

Hypotheses on the mudbanks

The report gives a critical appraisal of the various hypotheses on the formation and the characteristic calmness of the mudbanks, in the light of the author's findings, with special reference to the Alleppey mudbank. A detailed account on various types of mudbanks along the southwest coast of India is also presented

Ecology of mudbanks - Hydrography

The variations in physical and chemical parameters of the Alleppey mudbank waters are discussed in this paper. The fluctuations in tem perature, salinity, oxygen and the comparatively high nutrient contents of the mudbank waters are highlighted

Diurnal variations in the distribution of zooplankton in relation to currents and other ecological parameters of the mud bank of Alleppey, Kerala

Diurnal variations in the distribution of zooplankton biomass of the mud bank at purakkad-Thottappally region south of Alleppey, Kerala h ave been investigated during May and August, 1975. Along with this, observations on currents, hydrography and phytoplankton productivity were also carried out and their effects upon the zooplankton of the mud bank region were studie

Ecology of mudbanks - The current system at Alleppey mudbank

The knowledge of the water currents in the locality being essential for understanding the causes of forma tion, maintenance, movement and dissipation of mudbanks, the current system over two tidal cycles, one in May, before the formation, and the other in August, toward the end of the mudbank period, in 1975, at Alleppey mudbank was studied. Marked difference in the direction and velocity of the current was noticed between the two occasions. In May the effect of the tides was not noticeable on the direction of the current, which was southerly, whereas in August, though the major current con tinued to be southerly, the speed was considerably reduced due to tidal influence. Introducing thereby a northerly component. Along with the current observations, the diurnal changes in the hydrologica! and biological aspects observed in the mudbank are reported

Source of mud at Alleppey mudbanks: Its distribution and physical and chemical characteristics

The chapter embodies the authors' findings, and the logical conclusions they drew from them, on the mud cones (or 'mud volcanoes') they found In the intertidal zone and on the beach of the Alleppey mudbank region in 1972. Their experiment with regard to these mud cones confirm beyond doubt the viscous nature of the mud that underlies at Allepey, and its being, for all probability, the source of Alleppey mudbank. Similar mud cones observed earlier by some workers are also discussed briefly

Mud of the mudbank: Its distribution and physical and chemical characteristics

Description of the texture, grain size, thickness and chemical properties, including mineralogical- studies, of the mud in the mudbanks is given. An echosurvey conducted in the mudbank revealed the pattern of distribution of mud and the extent of the area of the mudbank, which would provide answers to problems connected with the formation of the mudbank and the associated calmness

Ecology of mudbanks - Benthos

Occurrences, abundance and seasonal distribution of the benthic fauna of the mudbank area at Alleppey were investigated. Ihe substratum at the mudbank area being of an unconsolidated and unstable nature due to the fresh supply of sediments and their periodic movement, it was thought that the fauna therein may be of a recent colonisation and a study on the animal- sediment relationship would be of interest. This was well established during the present studies with regard to the occurrence and numerical abundance of species and the benthic population in general

Ecology of mudbanks-Zooplankton

Zooplankton investigations carried out in the region of Alleppey mudbank, commencing with the formation of the mudbank of 1971 and continued through the mudbank of 1972, revealed that the mudbanks are richer in zooplankton in general. The fluctuations of the standing crop as well as of the major individual groups are discussed briefly to show the characteristic of the mudbank