Study of Neurosecretory Cells of Freshwater Bivalve: Lamellidens Corrianus (Lea)

Abstract

The food and feeding habits of Schizothorax plagiostomus in river Lidder was studied by eIn the freshwater bivalve like Lamellidens corrianus neurosecretory cells have been detected in the cerebral, pedal and visceral ganglia. The number of functions of hormones/neurohormones of freshwater bivalves known at the moment is still rather small. In contrast the basic mechanism of some type of neurosecretory cells of gastropods are known in great detail, this is especially due to the fact that in some gastropods these neurons like their conventional neurons are giant cells. For this reason they are highly suitable for neurophysiological studies. The great progress made in this field and the importance of this work for neuroendocrinology in general. To extend the knowledge in this field, the present work has been undertaken on the freshwater bivalve species Lamellidens corrianus which is abundantly distributed along the banks of Godavari river at Jayakwadi backwaters (Nath sagar) near Paithan in Aurangabad district. The histological details of neurosecretory cells (NSCs) in cerebral, pedal and visceral ganglia have been studied which reveals the presence of Type A & Type B cell (with nucleus, nucleolus and axon) predominantly secrete neurosecretory material. The results are converse in illumination of neurosecretory changes.xamining 500 guts collected throughout the year. The fish samples used in the present study was within the range of 25.5cm to 40.33cm in total length and weight ranging from 250g to 580g in weight and the sampling duration was from July, 2013 to June, 2014. During the analysis of food and feeding habits of S. plagiostomus it was concluded that the fish is benthic herbivorous. Its food mainly consists of plant matter 62.02%. A good amount of miscellaneous food items i.e. mud, sand and detritus 31.01% was also present in the gut of fish along with small quantity of animal food 6.97%. Overall it was concluded that diatoms formed an important constituent of food of S. plagiostomus in all months of the year and the presence of detritus, mud and sand indicates that the fish is a detrivorous, bottom feeder. The gastrosomatic index in case of females ranged from 3.88±0.30 to 7.30±2.128 with minimum in July and maximum GaSI in October and 3.37±0.75 to 7.82±2.22 in males with minimum in July and maximum in December.