Reproduction of the sea urchin Pseudechinus magellanicus (Echinoidea: Temnopleuridae) from Golfo Nuevo, Argentina

EZEQUIEL M. MARZINELLI, GREGORIO BIGATTI, JULIANA GIMENEZ AND PABLO E. PENCHASZADEH

Bulletin of Marine Science

Año: 2006

Abstract Pseudechinus magellanicus is a common and abundant sea urchin along the Argentinean coast. Gonad index cycle was studied for this species in Golfo Nuevo, Patagonia, from May 2001 to March 2003. Comparative studies of gonad index and gonad histology were performed for the year 2002. Gonad index reflects gonadal stages, showing two spawning peaks for the studied period. Major spawning occurred in winter and a second spawning event occurred during summer. Male and female individuals spawned synchronically. Male gonads recover faster than females after spawning, suggesting that females tend to invest more time and energy in gametogenesis. Gonad resorption was observed for males and females. Comparisons with the same genus in other localities are given. Statistical analyses showed a negative correlation between gonad index and photoperiod, and between gonad index and water temperature with a lag period of three months. Mean fresh oocyte diameter observed was 130 mm, which corresponds to a planktotrophic larval development.