New Zealand Journal of Marine and Freshwater Research abstracts
Effects of protandric sex change on radula, pedal morphology, and mobility
in Crepidula fecunda (Gastropoda: Calyptraeidae)
O. R. CHAPARRO
S. V. PEREDA
I. BAHAMONDES-ROJAS
Instituto de Biología Marina Dr Jurgen Winter
Universidad Austral de Chile
Casilla 567, Valdivia
Chile
email: ochaparr@mercurio.uach.cl
Abstract Protandrism was confirmed in
Crepidula
fecunda Gallardo 1979 by histological analysis of the gonad. Individuals
were classified as immature (12 mm or less in shell length), male
(13-26 mm), intersex (25-28 mm), and female (over 26 mm). There
was an evident loss of mobility with growth--large females became completely
sessile. The presence of epithelial glands in mobile individuals was associated
with the need for lubrication during crawling, whereas the proliferation of
subepithelial glands in sessile females was associated with adhesion. Mobility
of immature and male individuals was related to grazing activities on biofilms,
and in males was also associated with copulation. Grazing activity of motile
individuals was carried out so that the radula teeth did not come into direct
contact with the substratum, but rather harvested the biofilm surface. Sessile
females used the radula to rasp the area under their shells, thus cleaning the
substratum in preparation for oviposition. Since this process required that the
radula enter into direct contact with the substratum, it suffered abrasion of
radular teeth and loss of radular denticles, producing important alterations in
its appearance in mature females. A complex interaction was observed between
size, mobility, histological changes in the foot, activity, and tooth-wear of
the radula, which have been related to the sessile habit, sex change, and the
oviposition process in this species.
Keywords Crepidula fecunda; hermaphroditism; foot
glands; slipper limpet; radula; motility
New Zealand Journal of Marine and Freshwater Research, 2001, Vol. 35
M00082
Received 20 November 2000; accepted 23 May 2001
PDF file of entire paper: medium quality (1565K); (scanned from paper original: notes about this process)
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