Laboratory development of &lt;em&gt;Capitella&lt;/em&gt; sp. A (Annelida: Capitellidae) from a NW Mediterranean fish farm reared under different organic enrichment conditions

Nuria Méndez

doi:10.3989/scimar.04450.08b

Abstract

The polychaete Capitella sp. A, collected in a NW Mediterranean fish farm (Les Cases d’Alcanar, Tarragona, Spain), was cultured for the first time under experimental conditions with different organically enriched sediments to study the differences in development and growth. The species proved to be dioecious and had lecithotrophic development. Sizes of individuals and duration of the developmental stages varied widely, as in most known species of Capitella. In organically enriched sediments, the juveniles were seen one day after hatching and immature females (i.e. with yellow ovaries) after 52 days. Females may reach maturity (i.e. show white intra-coelomic oocytes) at about 64 days old, and the species had a life span of 167 days. According to its development, Capitella sp. A differs from all known lecithotrophic species of the genus. The results also proved that organically enrichment enhanced growth and survival, whereas lowering food can cause morphological alterations such as reduced size in male genital spines.

Highlights

The Capitella capitata (Fabricius, 1780) speciescomplex (Annelida: Capitellidae) consists of at least 50 non-interbreeding but morphologically similar sibling species
The C. capitata sibling species have been distinguished based on allozyme and general protein patterns, ecophysiological characteristics and reproductive modes, and using genes and, classical morphological characters
A was revealed to be a dioecious species with lecithotrophic development and shows a wide variability in size and in duration of the different developmental stages, as previously reported for other species of the complex (Méndez et al 2000, Méndez 2002, 2006)

Summary

Introduction

The Capitella capitata (Fabricius, 1780) speciescomplex (Annelida: Capitellidae) consists of at least 50 non-interbreeding but morphologically similar sibling species. Méndez ber of species within the complex, only a few have been described in detail. Developmental modes (i.e. planktotrophic, lecithotrophic or direct development, poecilogony, hermaphroditism, size and duration of the stages, number of brooded embryos, ciliation in metatrochophores) have been used to distinguish some species of the complex, which were named according to their size or to the collection locality. L (large) (Gamenick 1997); Capitella sp. K, from the Kilmelford salmon farm in Scotland; Capitella sp. From the Cranford salmon farm in Ireland (Méndez et al 2000); Capitella sp. B, from Barcelona in Spain (Méndez 2002); Capitella sp. Y, from Estero del Yugo in Mazatlán, Mexico (Méndez 2006); Capitella sp. A, from the fish farm Les Cases d’Alcanar, Tarragona, Spain (Méndez and Barata 2015)

Methods

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Discussion

Conclusion