Cs. Gallardo, REPRODUCTIVE HABITS AND LIFE-CYCLE OF THE SMALL CLAM KINGIELLA-CHILENICA (BIVALVIA, CYAMIIDAE) IN AN ESTUARINE SAND FLAT FROM THE SOUTH OF CHILE, Marine Biology, 115(4), 1993, pp. 595-603
A population of the small clam Kingiella chilenica Soot Ryen 1959 was
studied from March 1986 to December 1988 in an intertidal flat at Queu
le River, in the south of Chile. The life cycle and life history patte
rn of the bivalve were established contrasting population structure an
d dynamics to its reproductive habits. Individuals are gonochoristic a
nd semelparous, presenting a typical annual life cycle. The species is
a sequential brooder whose embryos undergo direct development. After
the brooding season (summer through autumn), the adults disappear grad
ually (autumn through winter). Recruited juveniles overwinter during a
relatively long period. undergoing rapid growth during the spring to
attain the adult stage during the summer. The number of brooded embryo
s increases in proportion to adult length cubed. Life history traits o
f this bivalve are compared to those reported for other small brooder
clams. Some basic tendencies become apparent when traits for semelparo
us versus iteroparous species are contrasted. As in other semelparous
sequential brooders (Transennella tantilla, Gaimardia bahamondei), the
relationship between brood size and shell length observed in K. chile
nica does not fit the allometry hypothesis for marine brooding inverte
brates that allometric constraints on the brooding space limit the fec
undity of larger individuals. Also contrary to theoretical predictions
, small body size does not limit the diversity of a clam's development
al patterns. Possible explanations for this finding are discussed.