Recruitment in the Holothurian Cucumaria frondosa in the Gulf of Maine

Abstract

Summary The sea cucumber Cucumaria frondosa spawns in the spring, in the Guff of Maine, USA. The larvae remain pelagic for several weeks prior to recruitment to the benthos. In the western Gulf of Maine, a previous study showed that juvenile C. frondosa occur exclusively inside mussel beds; adults are absent from the region. In the present investigation, recruitment and juvenile abundances in the field were examined from 1993–1995. A study conducted in the spring of 1993 in the Maine-New Hampshire coastal waters indicated that recruitment of C. frondosa to mussel beds was high. In the fell of 1994, no recruits were present on the benthos; juveniles were more abundant in coralline algae than in mussel beds or kelp holdfasts. In 1995, recruitment and juvenile abundance monitored over the recruitment season revealed that recruitment was highest in June. Toward the end of June and during early July, recruitment was significantly higher in mussel beds than in coralline algae and kelp holdfasts. In June, a 2-day intensive field study indicated that recruits were significantly more abundant in mussel beds than in kelp holdfasts or coralline algae, while juveniles were significantly more abundant in the mussel beds than coralline algae. Mussel beds may enhance early survival by providing a refuge from predation. A potential predator on new recruits are large nereid worms.