A NEW LILJEBORGIID AMPHIPOD (CRUSTACEA) FROM KERALA, INDIA

A new gammaridean amphipod, Listriella similis is described in detail. This species shows resemblance to L. picta (Norman), L. diffusa J. L. Barnard and L. eriopisa J. L. Barnard, but can be easily distinguished by the shape of the third pleon epimeron and the appearance of the sixth segment of gnathopods 1 and 2. In the light of the present study, the observations of J. L. Barnard (1959) on the family Liljeborgiidae are critically examined. It is found that the three characters mentioned by him for distinguishing the three existing genera of the family, do not go together. Further, it is suggested that the 2-segmented accessory flagellum of antenna 1 in Listriella may serve as an additional character, differentiating it from Liljeborgia. A brief summary of the annual sequence in the salinity fluctuations of the Kayamkulam lake, where from the present species was obtained, is given. It is probable that the association of the animal with the algal communities of the bar mouth region of the lake affords some protection to it in the intertidal.