Abstract:
Additiona l data on artificial fertilization and rearing
o f the larvae o f Cerastoderma lamarcki (Reeve) are
presented. Temperature shock was used to stimulate
ripe cockles to release large quantities of viable
gametes. Hig h rates of fertilization (>80fo) were
recorded in salinities ranging from 15 to 35%o .
However, the best salinity for quick embryonic
development and larva l hatching success seems to be
25-30% o . No larva l hatching was recorded in salinities
below 15%o .
Crowdin g of eggs had little effect on fertilization
success, but satisfactory embryonic development and
larva l hatching occurred at densities lower than c700
eggs/cm^. Th e sizes o f the newly hatched D-larva e
decreased with increasing egg density in the size range
111.0-120.7 pm.
O f the five different micro-algal food organisms
tested on the larvae, Isochrysis aff. galbana (clone
T-ISO ) (see Ewart & Epifanio , 1981) produced the
best growth rate and minimum mortality.
This wor k shows C. lamarcki to be well adapted to
bivalve hatchery procedures. Th e relative ease o f
maintainin g its laborator y culture s strengthens
previous claims that it would be a better choice for
controlled commercial production than its sibling
species C. edule (L.) .
