Nursery of cultured spats of the taquilla clam, Mulinia edulis, in a suspended system in the sea

Abstract

Spats of Mulinia edulis, produced in a hatchery, were nursered for 40 days in a suspended system in the sea in Bahía Yal (Chiloé), in order to test the feasibility of pre-fattening. Two initial sizes: 2.9 and 6.2 mm and two cultivation densities [1(D1) and 2(D2) spats cm-2] were used in treatments with (TA) and without sand (TSA) with small spats. Additionally, the growth and the survival of small spats in long-line installed both on the periphery and in the center of the farm were tested. In the size experiment, the small spats grew an average of 5.0 mm and the large spats an average of 4.9 mm in TA, and in TSA, 0.9 mm and 0.7 mm, respectively. The spat survival in TA (small= 51.3% and large= 62.3%) was greater than in TSA (small= 18.9% and large= 40.0%). In the density experiment, the largest sizes were reached in the TA, with an average growth of 5.0 mm in D1 and 4.5 mm in D2. The greatest survival was attained in TA (D1= 51.3% and D2= 49.4%) and the lowest in the TSA (D1= 18.9% and D2= 7.1%). The growth of the small spats was greater in the long-line located in the periphery of the farm, nevertheless no differences were observed in the survival. The results show that it is feasible to do large-scale nursering with an initial spat size of 2.9 mm at a density of 2 spat cm2 in a suspended system with sand.