HATCHERY SEED PRODUCTION OF THE ROCK SCALLOP, CRASSADOMA GIGANTEA IN PUGET SOUND, WASHINGTON

Rhee, W.Y.

Abstract:

For over 20 years in the U. S., efforts by academia, government, and

the industry for hatchery seed production of the rock scallop

Crassadoma gigantea remained as a difficult challenge. The

conditioning and spawning of the broodstock, the setting of the

larvae, and growout beyond pediveliger stage remained as bottlenecks

to the hatchery seed production. The application of "traditional

hatchery techniques" of intertidal clams, mussels, and oysters to the

rock scallop, a subtidal species appears to have been the major cause

in hampering the development of a successful rock scallop seed

hatchery. The objective of this study was to apply "nontraditional

techniques" for successful rock scallop hatchery seed production.

Broodstock conditioning was done with lowered temperatures (4 - 7

C) to suppress spawning, spawning of the broodstock was induced

with serotonin (0.2 ml/10^4 M solution), and the pediveligers put

directly into the open ocean for growth after they reached ca 250 u

size. Preliminary results indicate good survival rate of the juveniles in

the open sea. Previously unrecorded dribble spawning in mature rock

scallops and protandric hermaphroditism in 2 year old rock scallops

were also observed in the study.

(The Seafood Advisor, P.O. Box 658, Bedford, MA 01730, USA)

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