The calcified egg capsule of the Patagonian neogastropod Odontocymbiola magellanica: Behavioral, morphological, and mineralogic correlates.

BIGATTI, G.; GIRAUD-BILLOUD, M.; VEGA, I.A.; CASTRO-VAZQUEZ, A.; PENCHASZADEH, P.E.

JOURNAL OF MOLLUSCAN STUDIES

OXFORD UNIV PRESS

Año: 2010 vol. 76 p. 279 - 288

0260-1230

Odontocymbiola magellanica is the only known South American volutid depositing calcareous egg capsules. The spawn is moulded and fixed to flat or convex surfaces by the female’s ventral pedal gland, during an hours long process in which the female adopts a stereotyped posture while it appears non-reactive to most external stimuli. Microscopically, the ventral pedal gland has a three layered epithelium whose different cells show features suggesting their participation in the secretion of both the organic matrix and the calcium component of the calcareous layer. The latter is mainly formed by numerous spherulites which are packed together around cylindrical, membranous septated spaces which traverse the spherulitic layer and attach to the membranous layers surrounding the capsule cavity. These septated spaces should ensure permeability of the capsule wall, which is needed for embryonic respiration and excretion. Notably, the calcareous layer is made of high-magnesium calcite, a calcium carbonate polymorph in which Ca is partially substituted by Mg in the calcite lattice. Mg substitution is thought to confer a greater stability to the Ca mineral, it is commonly found in many invertebrates, but apparently has not been reported before in molluscs. O. magellanica is a long-lived species, heavily investing in its egg capsules, and is a vulnerable, though commercially exploitable snail whose interesting morphological, behavioural and ecophysiological features deserve future study. and is a vulnerable, though commercially exploitable snail whose interesting morphological, behavioural and ecophysiological features deserve future study. molluscs. O. magellanica is a long-lived species, heavily investing in its egg capsules, and is a vulnerable, though commercially exploitable snail whose interesting morphological, behavioural and ecophysiological features deserve future study. and is a vulnerable, though commercially exploitable snail whose interesting morphological, behavioural and ecophysiological features deserve future study. excretion. Notably, the calcareous layer is made of high-magnesium calcite, a calcium carbonate polymorph in which Ca is partially substituted by Mg in the calcite lattice. Mg substitution is thought to confer a greater stability to the Ca mineral, it is commonly found in many invertebrates, but apparently has not been reported before in molluscs. O. magellanica is a long-lived species, heavily investing in its egg capsules, and is a vulnerable, though commercially exploitable snail whose interesting morphological, behavioural and ecophysiological features deserve future study. and is a vulnerable, though commercially exploitable snail whose interesting morphological, behavioural and ecophysiological features deserve future study. molluscs. O. magellanica is a long-lived species, heavily investing in its egg capsules, and is a vulnerable, though commercially exploitable snail whose interesting morphological, behavioural and ecophysiological features deserve future study. and is a vulnerable, though commercially exploitable snail whose interesting morphological, behavioural and ecophysiological features deserve future study. cells show features suggesting their participation in the secretion of both the organic matrix and the calcium component of the calcareous layer. The latter is mainly formed by numerous spherulites which are packed together around cylindrical, membranous septated spaces which traverse the spherulitic layer and attach to the membranous layers surrounding the capsule cavity. These septated spaces should ensure permeability of the capsule wall, which is needed for embryonic respiration and excretion. Notably, the calcareous layer is made of high-magnesium calcite, a calcium carbonate polymorph in which Ca is partially substituted by Mg in the calcite lattice. Mg substitution is thought to confer a greater stability to the Ca mineral, it is commonly found in many invertebrates, but apparently has not been reported before in molluscs. O. magellanica is a long-lived species, heavily investing in its egg capsules, and is a vulnerable, though commercially exploitable snail whose interesting morphological, behavioural and ecophysiological features deserve future study. and is a vulnerable, though commercially exploitable snail whose interesting morp