科研之友
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摘要
We examined habitat, population size-structure, colour dimorphism, reproductive behaviour, arm loss and the relation between arm regeneration to pyloric caeca indices in populations at Whitford Rock (WR) and Port Beach (PB) in January 2009. The sediment was fine sand at WR and a mix of larger particles at PB. Individuals at PB were predominantly orange and more uniform in colour than those at WR, which were predominantly grey. Body size and pyloric caeca index of individuals at WR were greater than those of individuals at PB, indicating the nutritional condition was better at WR. This suggests the quantity or quality of food at WR was better. Organic matter of the pyloric caeca and body wall of intact and regenerating individuals at both sites were similar, indicating loss of an arm did not affect gross proximate composition of the organs. Sea stars with regenerating arms made up 5.4 and 8.4 % of the populations observed. Despite the very small size of the gonads, some individuals were in the pseudocopulatory position, indicating this behaviour occurs even when gametes are not present. In every case observed, the male of the pseudocopulating pair was situated above the female. Given the abundance of this species in nearshore habitats dominated by sediment, it is likely to be ecologically important. However much of the biology and ecology of the species, even its diet, remain unknown. This together with its unusual mode of reproductive behaviour involving pseudocopulation, which is only known from two other species of asteroids, underscore the need for more research on Archaster angulatus.
- 出版日期2011-12
- 单位CSIRO
