ABSTRACT
Observations of the reproductive and population biology of Cuowmaria ferrari near McMurdo Station, Antarctica indicate that this species broods its embryos (up to 100 per adult female) within 3 pouches of the body wall located at the base of the feeding tentacles. A small pore in the epidermis of the brood pouch permits release following development into a juvenile (3.5–4.5 mm body length). Mean ± 1.S.D. egg diameter is 2.05 ± 0.11 (n = 30). As brooded juveniles are larger than eggs it is unlikely there is sufficient energy and materials in eggs to support development. Additional nutrients may be acquired by DOM uptake. Maximum population densities occur in dense patches of the colonial hydroid Halecium sp. with up to 70 individuals per 0.25 m2. This habitat appears to be optimal as individuals may perch on hydroid stolons to filter feed. Population size structure analysis indicates at least 3–4 distinct cohorts are present. Supported by NSF grant DPP-9118864 to J.B.M.
