Alternate Title

Population Structure, Distribution, Life Cycle and Reproductive Strategy of Spilocuma watlingi Omholt and Heard, 1979 and S. salomani Watling, 1977 (Cumacea: Bodotriidae) from Coastal Waters of the Gulf of Mexico


Populations of S. watlingi and S. salomani in Gulf of Mexico coastal waters south of Dauphin Island, Alabama were systematically sampled from July 1984 to June 1985. Spilocuma watlingi inhabited protected estuarine water of Pelican Bay, while S. salomani was only found seaward of the barrier bar-island system that separated Pelican Bay from the Gulf of Mexico. Both species were present throughout the year. Spilocuma watlingi was most abundant in autumn and winter and had a single winter reproductive peak, but fecundity was low. Abundance and reproductive peaks for S. salomani were not determined because samples were not collected during the winter months and, when collected, too few specimens were obtained. Mature males in both populations were the smallest individuals. Intermediate in size between mature males and females was a non-sexually dimorphic stage. Preparatory and gravid females were the largest individuals and their numbers were at least twice that of males. A protandrous reproductive strategy Is proposed where small mature males metamorphose Into intersex stages which then become females.