Publication Date:
2022-03-01
Description:
The egg-masses in many cirripedes take the form of two compact lamellae occupying much of the adult mantle cavity in which they are incubated until the ripe embryos are hatched. Under optimal conditions, this period of incubation in a typical warm water species, may be quite short (10-15 days) as one brood follows another in rapid succession. By contrast, incubation in some arctic or boreo-arctic species may occupy several months. For example, in the Arctic, the eggs of Balanus balanoides are fertilized in the late summer and remain in the mantle cavity until the following June-July; during much of this time the animals may be frozen under the ice foot. Further south, for example, at Millport, Scotland, the embryos are retained from November to the following spring. At Woods Hole, Mass., U.S.A., where planktonic conditions are somewhat atypical for a north temperate coastal region (FISH, 1925), incubation may last only from October to December (BARNES 1958; BARNES and BARNEs, 1959a). In view of these facts the respiratory activity of the egg-masses of two intertidal. cirripedes namely B. balanoides (L.) and Pollicipes polymerus J.B Sowerby has been investigated The former, common on both sides of the Atlantic and recorded from the Alaskan coast, is a typical boreo-arctic operculate and the latter, common on the Pacific coast of both North and South America, a temperate and possibly sub-tropical pedunculate.
Type:
Article
,
NonPeerReviewed
Format:
text
