Growth of Cerithidea (Cerithideopsilla) cingulata (Gmelin) in Vellar Estuary, estimated based on the length frequency method was 13, 22, 28 and 32 nun in the first, second, third and fourth years respectively. The actual growth was 13 mm (at the rate of 1.08 mm per month), 9 mm (0.75 mm/month), 6 mm (0.5 mm/month) and 4 mm (0.33 mm/month) during the four year period. Slowing down of growth rate was noticed from 19 ram onwards, probably due to attainment of maturity and subsequent breeding activity.

Growth estimated by probability plot method was 9.5 mm to 9.75 mm in the first year, 18.5 to 19.0 mm in the second year, 26.5 to 26.75 mm in the third year and 30.5 to 32.25 mm in the fourth year. Growth observed by marking experiments was 6 mm in 5 months.

Von Bertalanffy's growth equation for estimating the Lt at the age of t is:

L_t =39.99 [1 ^{-e -o-4054 (t-0.00971})]

Morphometric studies indicated that growth of various body parts in relation to length was linear and isometric. Length-weight relationship of both total and flesh-weight varied between juveniles and adults and therefore two equations have been derived separately:

Total weight                Juveniles : -0.0106 +1.9646 log 1

             Adults : -0.6646 + 2.6575 log I

Flesh weight                  Juveniles : :-2.3215 + 3.2525 log 1

 Adults ; -1.6383+2.7151 log 1

Population was composed of 0, 1, 2 and 3 year classes mainly, of which 0-year class was dominant. There was no apparent limiting influence of environmental factors such as food, season, salinity and overcrowding on the growth of C (C) cingulata in the Vellar Estuary, during the period of study.