Settlement, growth and reproduction in the deep-sea wood-boring bivalve mollusc Xylophaga depalmai

Abstract

Experimental panels of spruce and oak deployed at 3 and 6 mo intervals over a period of several years at ca. 500 m depth in the NE Tongue of the Ocean, Bahamas, were rapidly colonised by the wood-boring bivalve Xylophaga depalmai Turner, 2002. Colonisation of the wood occurred year-round but there was evidence that it was more intense in the summer months. The population structure of X. depalmai was the same for spruce and oak, although there was evidence that the female population structure in each wood type differs significantly from the male population structure. X. depalmai grew at a mean rate of ca. 0.03 mm d-1. Gametogenesis was initiated in individuals of X. depalmai in all deployments and was active by Day 59. Egg size was ca. 40 μm diameter and fecundity was high. Once initiated, gametogenesis was quasi-continuous and gamete density suggested that spawning was periodic. There was no difference in gametogenesis in individuals from different wood types. © Inter-Research 2007.