Spawning behaviors of northeast Pacific sea cucumbers (Holothuroidea: Echinodermata)

Spawning behaviors observed from May 1981 through August 1983 in the laboratory and field are described and compared for twelve species of northeast Pacific holothuroids collected from waters of the San Juan Archipelago, Washington. For many species, elevation of the anterior end, stretching of the introvert, tentacle waving, and swaying are behaviors commonly associated with gamete release. Less common activities include waving of introvert podia, waves of body wall contractions, errant males, aggregations, and pseudocopulation. Positively buoyant eggs of four species Psolus chitonoides Clark, Cucumaria miniata (Brandt), C. piperata (Stimpson), and C. fallax (Ludwig)] were packaged in pellets, ropes, or strands and released passively; a female Molpadia intermedia (Ludwig) discharged negatively buoyant eggs in a single explosive burst. Two externally brooding sea cucumbers C. lubrica (Clark) and C. pseudocurata Deichmann] produced strands of dilution-resistant sperm that were carried by currents to nearby females. Three species commonly sympatric P. chitonoides, C. miniata, and Eupentacta quinquesemita (Selenka)] in high-current rocky habitats have overlapping spring breeding seasons, but spawn at different hours of the day.Please address all requests for reprints to Dr. McEuen at the Harbor Branch Oceanographic Institution