Relative importance of parental and larval nutrition on larval developmentand metamorphosis of the sea urchin Strongylocentrotus droebachiensis

We examined the relative importance of parental nutritional condition and l arval food ration on the rates of development, growth and metamorphosis of larvae of Strongylocentrotus droebachiensis (Muller) in a laboratory experi ment. Parents were reared for 22 months on either a high ration of kelp (La minaria spp., 6 days week(-1)) supplemented with mussel flesh (Mytilus spp. , 1 day week(-1)) (KM), or a low ration of kelp (1 day week(-1)) (KL). Larv ae were fed either a high ration (5000 cells ml(-1)) or a low ration (500 c ells ml(-1)) of microalgae (Dunaliella tertiolecta). Larval food ration had a strong effect on the rates of development, growth, and metamorphosis, wh ich were all significantly greater in larvae fed the high ration. Test diam eter of settlers also was significantly greater in the high than the low ra tion. Parental nutritional condition had little or no effect on the rates o f development and growth, and no effect on settler size. The rate of metamo rphosis was significantly higher in larvae from the KM than the KL treatmen t in the high but not the low ration (where rates of metamorphosis were sim ilar). Although parental condition generally had a small effect on larval d evelopment, our results suggest that when planktonic food is abundant, larv ae of adults from nutritionally rich habitats (such as kelp beds) may metam orphose sooner than those of adults from nutritionally poor habitats (such as barrens). (C) 1999 Elsevier Science B.V. All rights reserved.