Gonadal cycle of Pseudechinus magellanicus (Philippi, 1857) (Echinoidea: Temnopleuridae) from Patagonia, Argentina

BIGATTI, G.; MARZINELLI, E. M.; CLEDÓN, M. & PENCHASZADEH, P. E

Echinoderms: München- Heinzeller & Nebelsick (eds)

Balkema

Lugar: London; Año: 2004; p. 11 - 14

Pseudechinus magellanicus is one of the most abundant echinoids in Argentinean waters, it occurs at depths ranging from 5 to over 150 m. It is distributed along the South American coast, from off Rio de la Plata in the Atlantic Ocean, to Puerto Montt, Chile in the Pacific Ocean; the species is also found in islands of the Antarctic Sea. It lives in a variety of habitats like tide pools, mixed bottoms of gravel and sand, Macrocystis blades and Mytilus beds. The reproductive cycle of this sea urchin was examined from September 2000 to March 2003. Specimens were collected monthly by scuba diving from depths of 6-10 m in Golfo Nuevo, Puerto Madryn. Changes in relative gonadal size (gonad index) were analyzed monthly. There are two reproductive peaks and partial spawning events throughout the year. Major spawning were recorded in early spring, corresponding to an increase from the minimum winter water temperature (8 oC – 9oC) in 1 or 2 oC, and in late summer, corresponding to the higher water temperature value (18 oC). These observations were corroborated by analysis of microscopic changes in the gonad tissue.