ABSTRACT
Body mass to size relationships of a wide range of specimens of the deep-sea brittle star species Ophiura ljungmani and Ophiomusium lymani, in conjunction with demographic models developed from disc size frequencies in time series of large samples from the Rockall Trough (RE, Atlantic), have been used to estimate rates of secondary production. Ratios of annual somatic production to biomass (Ps /B) were calculated by means of two methods. These yielded quite similar values, and the results overall indicate rates of turnover little different from those known from congeners or closely related species living in shallow water.
