Habitat and Ecology
This species can be found in the shallow subtidal zone down to 250m, it is found on various types of substrata and various current regimes, however, it is most abundant in areas with moderate currents over cobbles, boulders, shells, sand, crevassed bedrock and algae. It appears to avoids mud bottoms and areas with freshwater runoff (Zhou and Shirley 1996, Woodby et al. 2000, Bruckner 2006, Hamel and Mercier 2008). A preference for harder substrates has been observed (Woodby et al. 2000).
It is a slow moving deposit feeder which collects organic matter and associated micro-organisms (Cameron and Fankboner 1989). This species ceases feeding and becomes dormant between September and early March (Lambert 1997). Adults undergo fluctuations in body mass, body wall thickness, and muscle weight during their annual cycle as they reabsorb and regenerate their internal organs (Fankboner and Cameron 1985, DFO 2002).This sea cucumber has an annual reproductive cycle and spawning occurs between June and August, and seems to be correlated with bright sunshine days and high phytoplankton productivity (Hamel and Mercier 2008). Recruitment is sporadic in this species and adults have a relatively high natural mortality (Hamel and Mercier 2008).
The larvae feed on plankton and remain in the water column for a period of 35 to 52 days (Lambert 1997). However, Cameron and Fankboner (1989) observed that the pelagic phase could be as long as 65 to 125 days just to reach the auricularia stage and another 2 days were necessary for the pentactula to develop. This suggests that the spawning stock may be quite far from where the larvae settle and grow (Muse 1998). Settlement was observed in dense mats of filamentous red algae, algae holdfast, under rocks or in crevices (Cameron and Fankboner 1989, DFO 2002). The recruitment is sporadic and a high natural mortality rate is suspected (Rogers-Bennett and Ono 2001, Bruckner 2006). Juvenile growth is slow, reaching 0.5 to 2cm after a year and 4 to 10cm after two years (DFO 2002). Sexual maturity is reached after 4 years (Cameron and Fankboner 1989, Lambert 1997). Based on an analysis of length frequency data for the first three years of growth, commercialâsized specimens were estimated to be at least 4 years old; the oldest animals could be around 12 years of age (Cameron and Fankboner 1989).