CONICET | Buscador de Institutos y Recursos Humanos

Allostichaster capensis is a fissiparous sea star that displays an annual sexual and asexual reproductive cycle. After fission, organisms spend the rest of the year regenerating the missing arms. Hence, the sea stars should have adaptive responses to allow both reproductive strategies. We conducted three experiments with sea stars in different stages of regeneration: regenerating almost completely regenerated and recently split. Three were three different treatments of food availability and regeneration (high, intermediate and low) from each experiment. Both food availability and regeneration state had an important effect on feeding rates, lipid storage in the pyloric caeca and gonad reproduction. Recently split individuals showed the lowest values of feeding rate, amount of lipid in the pyloric caeca and gonad production, regardless of the food treatment. Regenerating individuals had the highest feeding rate, allocation of resources to lipid production in the pyloric caeca and gametogenesis. Individuals with nearly completely regenerated arms showed an intermediate feeding rate and no deposition of lipid in the pyloric caeca. These individuals spawned during the experiment, indicating the gonads were mature. Low food treatment produced the lowest feeding rates regardless of the regeneration stage. Regenerating individuals died only in the low food treatment. No death was observed in individuals with nearly completely regenerated rays. On the other hand, individuals that had recently undergone fission died regardless the level of food. Since fission and regeneration are part of life history of A. capensis, the sea star has strategies to regenerate and produce gametes. High feeding rate allows regenerating individuals to achieve a good nutritional state to support regeneration, gamete production and survival fission.

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