Abstract

GONZALEZ-VALLEJO, Norma Emilia  and  LEON-GONZALEZ, Jesús Ángel de. New ecological and taxonomic remarks on Sabinella troglodytes and Nanobalcis worsfoldi (Gastropoda: Eulimidae) living on the “slate-pencil sea urchin” from the Mexican Caribbean region. Rev. Mex. Biodiv. [online]. 2018, vol.89, n.1, pp.123-133. ISSN 2007-8706.  https://doi.org/10.22201/ib.20078706e.2018.1.2185.

Eulimidae is one of the most diversified families among marine parasitic gastropods. They are usually reported associated with echinoderms, but for most described species the host is unknown, and few biological aspects of the symbiosis are known. As part of a larger study on eulimids, 300 sea urchins were collected in shallow water reef lagoons. Some were kept alive in the laboratory for 1 week and photographed and filmed under stereomicroscopes. Nanobalcis worsfoldi lives around and at the base of primary spines of the sea urchin Eucidaris tribuloides and is very abundant, whereas Sabinella troglodytes lives attached inside a gall that it builds from primary spines, and is uncommon. A complete characterization of the shells and morphology data for both eulimids are included. The comparison of our specimens with type and non-type material indicates several noteworthy features. We found higher and wider whorls, variation in position of growth scars and total number of whorls. We suggest that there is a species complex for Sabinella troglodytes. Mantle pigmentation patterns, mode of attachment, live displacement, and other ecological observations on the host are presented for the first time for both species from the Mexican Caribbean Sea.

Keywords : Ectoparasites; Echinoderms; Eucidaris; Shallow water; Symbiosis.

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