Retention of Marks and Their Effects on Growth, Behavior, and Migrations of the American lobster, Homarus americanus

Abstract

Abstract Laboratory and field experiments were conducted with the lobster, Homarus americanus, to test the retention through molting of three primary marks—the back tag, elbow tag, and brand. Relatively more back tags were retained through the molt than elbow tags or brands. Molestation among tagged lobsters contributed significantly to tag loss. In November 1965 and July 1966, a total of 1776 lobsters were tagged and released at Monhegan Island, Maine. Lobsters were given a primary mark plus a secondary mark of amputated abdominal scutes and spines. The secondary mark was retained through 2 molts and permitted recognition of a lobster that had lost its primary mark. The recapture of marked lobsters through June 1968 yielded information on tag retention and the effects of marks on growth and behavior. Lobsters marked with the back tags had an 88% retention rate through a molt compared with 55% for brands and 16% for elbow tags. By June 1968 approximately 98% and 77% of the November release of back-tagged ...