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

ZABALA, SOLEDAD; TESO, S.V.; PENCHASZADEH, PABLO E.; AVERBUJ, A.

Invertebrate Biology

John Wiley and Sons Inc

Año: 2024 vol. 143

Olivancillaria carcellesi occurs in shallow sandy shores from north Patagonia, in intertidaland subtidal sandy bottoms. Females of O. carcellesi exhibited a remarkablespecificity for spawning on the shells of living males and females, indiscriminately, ofthe buccinanopsid Buccinastrum deforme, measuring 26.9 ± 4.7 mm in shell length.The egg capsule was semispherical and attached to B. deforme shells by a small ellipticaland wide base. The capsule was translucid when spawned, with a thick and semirigidwall and a hatching aperture of 1.8 ± 0.1 mm (n = 111) in diameter. Each eggcapsule contained a single egg that measured 1367 ± 34 μm (n = 5) in diameterbefore cleavage. The embryo developed a small bilobed velum and an operculum,which were both lost before hatching as a crawling juvenile of 1762 ± 47 μm(n = 28) in shell length. As in other species in the genus, the eggs of O. carcellesi areamong the largest in the caenogastropods with direct development. The time fromoviposition to hatching is estimated to be approximately 6 months.