Meeting Abstract

S5.3  Tuesday, Jan. 5  Costs of arm loss and regeneration in stellate echinoderms LAWRENCE, J.M.; Univ. of South Florida lawr@cas.usf.edu

The cost of regeneration is greater in asteroids than in crinoids and ophiuroids because of greater development of the body wall and presence of gonads and pyloric caeca. In addition, arm loss occurs at locations along the entire length of arm in extant crinoids and ophiuroids but usually only at the disc in asteroids. The cost of regeneration of organic matter in an arm can be estimated from analysis of intact arms. This does not include the cost of anabolism of organic compounds or energy required for deposition of calcium carbonate. A major consequence of arm loss that affects regeneration is loss of feeding structures and decrease in food consumption. Cost of regeneration has the potential to affect growth of small individuals and reproduction of adults because nutrients in food consumed can be diverted to regeneration. Whether this occurs depends on the quantity and quality of food consumed. The effect of nutrition on regeneration is difficult to demonstrate in the field because of the variability in quantity and quality of food available and the amount consumed. These can be controlled in laboratory studies to evaluate the role of nutrition on cost of regeneration. In addition, growth factors can be added to formulated feeds to evaluate their effect on regeneration. Asteroids appear to be a good model to study the role of nutrition on the cost of regeneration because it is possible to control the quantity and quality of food consumed. Considering life-history strategies, ruderal and competitive species have a greater capacity for production and regeneration than stress-tolerant species.