REPRODUCTIVE CYCLE OF THE SEA URCHIN Arbacia dufresnii (Blainville, 1825)

MARTIN IGNACIO BROGGER; MARIANO IGNACIO MARTINEZ; PABLO ENRIQUE PENCHASZADEH

Munich

Conferencia; The 11th International Echinoderm Conference 2003.; 2003

The reproductive biology of the echinoid Arbacia dufresnii was studied. Monthly samplings were taken by scuba diving from September 2000 through March 2003, in Puerto Madryn, Patagonia, in shallow waters (5-10 m). Sea urchins were fixed in Bouin´s fluid over two days and then preserved in 70% alcohol. Animals were weighed, measured and sexed according to gonad colour. Gonad Index was determined. Samples of gonadal tissues were dehydrated, embedded, sectioned and stained for histological examination. Results indicate that A. dufresnii has an annual reproductive cycle with a short spawning season in October-November (austral spring) and a subsequent larger one in January-February (summer). Variation in gonad index within months was found, and the lowest values were observed from April to June. Spawning seasons, sexual rest and reabsorption were confirmed by gonad histology.Arbacia dufresnii was studied. Monthly samplings were taken by scuba diving from September 2000 through March 2003, in Puerto Madryn, Patagonia, in shallow waters (5-10 m). Sea urchins were fixed in Bouin´s fluid over two days and then preserved in 70% alcohol. Animals were weighed, measured and sexed according to gonad colour. Gonad Index was determined. Samples of gonadal tissues were dehydrated, embedded, sectioned and stained for histological examination. Results indicate that A. dufresnii has an annual reproductive cycle with a short spawning season in October-November (austral spring) and a subsequent larger one in January-February (summer). Variation in gonad index within months was found, and the lowest values were observed from April to June. Spawning seasons, sexual rest and reabsorption were confirmed by gonad histology.