On the egg masses, eggs and embryos of Notocochlis isabelleana (D’Orbigny, 1840) (Gastropoda: Naticidae) from Northern Patagonia

GUIDO PASTORINO; ANDRÉS AVERBUJ; PABLO E. PENCHASZADEH

MALACOLOGIA

INST MALACOL

Año: 2009 vol. 51 p. 395 - 402

0076-2997

Naticids are common predators in sandy bottoms of shallow waters around the world. Probably due to their infaunal habitat, they are hard to find alive, particularly in the Patagonian waters of Argentina. Nevertheless, their presence is confirmed by the typical predation boreholes that can be seen on their bivalve prey along the coast (e.g., Bromley, 1981; Carriker, 1981; Pastorino & Ivanov, 1996; Signorelli et al., 2006). These boreholes record information on predators without actually seeing them. Paleontologists have exploited this field, analyzing the behavior and producing models of predator-prey relationships in ancient and recent communities (Kabat, 1990, and citations herein). Studies on the spawn of naticids are scarce in modern literature, despite its common presence in sandy bottoms. The typical sand collars were recognized several decades ago as belonging to this family. Ankel (1930) and Thorson (1935, 1940, 1946), among others, described these characteristic egg masses from different areas around the world. An accurate account of the morphology of the collar and capsules, including the way the gastropod builds them, was described by Giglioli (1955) and Ziegelmeier (1961). An interesting approach was recently published by Huelsken et al. (2008), who reviewed the naticids from Giglio, an Italian island off the coast of Tuscany. They compared mitochondrial and nuclear gene fragments (COI, 16S, H3, 18S) from adults and embryos from the egg masses, leaving no doubt about the mother species of each egg mass.