Performance of triploid oysters in Louisiana

Triploid oysters (Crassostrea virginica [Gmelin]) were evaluated as a potential summer-crop for increasing shucked meat yield. Triploid and diploid sibling broods were reared identically until planting size ( approximately equal to 20 mm) in June-July, 1994 and distributed on bottom on separate halves of a one-acre reef plot. Mean shell height, wet meat weight, ploidy and survival were measured bimonthly for two years. Percent triploidy decreased from 85% to 56%; post-planting spatfall became indistinguishable from the triploid brood. Mean triploid shell height and wet meat weight were significantly greater than mean diploid values during November, 1994, 1995 and July, 1996. Final meat yield was determined during July, 1996 by weighing individual meats from two sacks (i.e., 270 oysters) harvested from the triploid half-acre and 1 sack from diploid half-acre. Triploid oysters, verified by flow cytometry, had a 0.45 kg meat yield increase per sack over diploids.