Spawn and development of the olivid gastropod Olivancillaria carcellesi from Patagonia, Argentina

AVERBUJ, A.; ZABALA S.; TESO V; PENCHASZADEH P. E.

INVERTEBRATE BIOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Lugar: Londres; Año: 2024

1077-8306

Olivancillaria carcellesi occurs in shallow sandy shores from North Patagonia, in intertidal and subtidal bottoms. Females of O. carcellesi exhibit a remarkable specificity for spawning (up to 41 egg capsules) on the shells of living males and females, indistinctly, of the nassariid Buccinastrum deforme, measuring 26.9  4.7 mm in shell length. The egg capsule is semispherical and attached to B. deforme shells by a small elliptical base. The capsule is thin, translucid when spawned, with a rigid wall and a hatching aperture of 1.79  0.13 mm in diameter. Each egg capsule contained a single egg that measured 1367.40  33.64 µm in diameter before cleavage. The embryo developed a small bilobed velum which is completely reabsorbed, as it is an operculum, before hatching as a crawling juvenile of 1761.95  46.76 µm in shell length. As in other species in the genus, the eggs of O. carcellesi are among the largest in the caenogastropods, through a long developmental period of ~6 month, with direct development.