Strain experienced by eggs of Pseudechinus magellanicus during spawning

MARZINELLI, EZEQUIEL M.; BIGATTI, GREGORIO; PENCHASZADEH, PABLO E.; BRÖGGER, MARTÍN I.

Melbourne, Estados Unidos

Congreso; Fifth North American Echinoderm Conference; 2008

Sea urchins spawn large numbers of eggs to the water column where fertilization takes place. In some species, the size of the eggs is greater than the size of the gonopores. Eggs experience strain resulting from compression during spawning, which can affect fertilization. Pseudechinus magellanicus is an abundant urchin off the coast of Patagonia. In Golfo Nuevo, Argentina, major spawning occurs in winter. Mean fresh egg diameter was 122 microns with a jelly coat of 49 microns. There was a positive correlation between test diameter and gonopore size, but egg size did not vary with test diameter. Egg strain was 0.47-0; small mature individuals (less than 15 mm test diameter) were the most affected by this strain. The presence of jelly coat on eggs of this species may, however, reduce the effect of strain forces and prevent damage of the eggs during spawning.