Effect of temperature on the population of Emerita asiatica (H. Milne Edwards, 1837) in the Kovalam beach, East coast, Tamilnadu, India.

Effect of temperature on the population of sand crab, Emerita asiatica was studied. Specimens were collected once in a fort night from April 2012 to March 2013 by hand picking method in the intertidal region of Kovalam beach. The temperatures of atmosphere, sea water and wet sand were recorded once in a fortnight. The population presented a smaller incidence of males in relation to females (54.79:45.21); however in September 2012 an inverse pattern occurred (29.50:70.50). Ovigerous females were present in all samples with greater frequencies in September and October 2012 where as the highest juveniles were present in May and August 2012.

Changes in the neurosecretory cells of the brain and thoracic ganglion of male crab, Uca (celuca) lactea annulipes with respect to seasons.

The change in the neurosecretory cells with males with respect to seasons was investigated. The brain is provided with three types of neurosecretory cells namely A, B and C and thoracic ganglion with four types of neurosecretory cells A, B, C and D. They vary in number and neurosecretory activity according to seasons which may be responsible for the increase in the size and development of the reproductive and associated structures.