Journal of the Marine Biological Association of India

Larval rearing, spat production and juvenile growth of the blood clam Anadara granosa

Volume 34 Issue 1&2

P. Muthiah, K. A. Narasimham, C. P. Gopinathan and D. Sundrarajan

Abstract

The blood clam Anadara granosa spawned in the Shellfish Hatchery Laboratory, Tuticorin on two occasions. The fertilised eggs measured 50-60fi in diameter, morula larvae developed in 3-4 hrs and the trochophore stage was reached in 5 hrs. The straight hinge stage was attained in 20-26 hrs after fertilization and these larvae measured 83µ length and 65.5µheight. Advanced umbo stage was reached on day 12 (size 155.3 x 140.5µ) and on day 16, majority of the larvae were in pediveliger stage with an average size of 182.7 x 162.9µ. Settlement began on day 16 and majority of the larvae were set on day 18. The growth of the spat in the hatchery is described by the exponential equation L = 0.0002739 D ^2.2623 where L is length in mm and D, days. On day 59, the spat attained an average size of 2.42 x 1.70 mm. A total of 8090 spat were produced. During the nursery rearing in the field, the seed clam attained 20 mm average length in the following 5 months. In India, A. granosa seed were produced for the first time. The significance of this study for the mass production of the blood clam seed in the hatchery and its relevance to undertake blood clam culture are highlighted.

Date : 31-10-1992