Resumen

MUNOZ, GABRIELA. Different life histories of two species of bopyrid isopods (Isopoda, Epicaridea), parasites of the ghost shrimp Neotrypaea uncinata (H. Milne Edwards, 1837) (Decapoda: Thalassinidea). Rev. chil. hist. nat. [online]. 2001, vol.74, n.4, pp. 755-761. ISSN 0716-078X.  doi: 10.4067/S0716-078X2001000400003.

On coastal habitats near Concepción city, Chile, there are two isopod species Ione ovata Shiino, 1964, and Ionella agassizi Bonnier, 1900 both occupying the gill chambers of the ghost shrimp Neotrypaea uncinata (H. Milne Edwards, 1837). However, in I. ovata, the prevalence is smaller, there is a low frequency of coupled isopods in the same gill chamber, and is less host specific than I. agassizi. These observations suggest that both isopod species have different life histories. To improve the understanding of the causes of these differences some life history traits of isopods species (fecundity, egg size and reproductive investment and the capability of individual males isopods to survive in uninfested ghost shrimps) are examined and compared. Ione agassizi has lower fecundity but larger eggs than I. ovata. However, there were neither differences in reproductive investment nor in relation to their body size between the two species. Experimental infestation of ghost shrimps by males of both species of isopods showed that only males of I. ovata could remain on the hosts for a few weeks and metamorphose into females. It would be necessary to estimate survival of isopods during the total life cycle, in order to improve the interpretation of these results

Palabras clave : bopyrid isopods; reproductive strategies; fecundity; egg size; metamorphosis; ghost shrimps; crustaceans.