D. Stanwellsmith et A. Clarke, SEASONALITY OF REPRODUCTION IN THE CUSHION STAR ODONTASTER VALIDUS ATSIGNY-ISLAND, ANTARCTICA, Marine Biology, 131(3), 1998, pp. 479-487
The reproductive and larval biology of the common Antarctic cushion-st
ar Odontaster validus Koehler (Echinodermata: Asteroidea) were studied
in a shallow-water population at Signy Island in the maritime Antarct
ic. The gonad index peaked in April/May, and injection with 1-methylad
enine indicated that competence to spawn peaked in May/June. Gastrulae
were first detected in May, and maxima; water-column larval densities
were measured in July. Reproduction was therefore highly seasonal, al
though not ail individuals appeared to spawn each year. The pyloric ca
eca index increased in summer (typically November to March, but variab
le between years) and decreased during winter (June to October), sugge
sting that feeding activity was seasonal. Ail aspects of biology inves
tigated showed significant interannual variability. Comparison with pr
evious studies in the high Antarctic at McMurdo Sound indicated a simi
lar if more pronounced seasonality at Signy. but the warmer seawater t
emperatures in the maritime Antarctic (particularly in late winter/ear
ly spring from September onwards) resulted in faster larval developmen
t at Signy.