Reproductive biology and population dynamics of Ophiura Ijungmani were studied by measuring disk diameters and by examining oocyte size-frequencies and fecundity from a sequential seasonal series of large samples from a 2900 m deep Permanent Station in the Rockall Trough (Northeast Atlantic). Egg size (max. 90 !lm) and fecundity (up to 57000 eggs per individual) suggests indirect planktotrophic development, while a clear annual cycle in gametogenesis, with probably synchronous spawning in JanuaryFebruary, confirms a marked seasonality that is also seen as an annual, summertime set of postlarvae on to the bottom. Analysis of size structure of the population indicates annually discrete year classes with a maximum longevitv of around 10 years. lndividuals... |