Biological Studies On The Chilean Sea-Urchin Loxechinus Albus (Molina) (Echinodermata- Echinoidea) IV.- Maturation Cycle And Seasonal Biochemical Changes In The Gonad

Abstract

In one reproductive cycle of Loxechinus albus in Central Chile it is possible to recognize animals in spawning condition almost the year round. However, the main spawning season is a very restricted period beginning in August in late winter and lasting through to October in spring. During gamete release the protein and the water content of the gonad decreases; these compounds are possibly replaced by the ether extract. To delimit the spawning period, the developmental period of the larvae has also been taken into account, and this is the phase in which they reach metamorphosis which occurs when coastal water temperature are at their most stable. After the spawning season there is a period when some sea-urchins are still in spawning condition. This period is in reality a continuation of maturation which is interrupted by the onset of winter conditions. The accumulated energy is essentially employed to avoid starvation. The reproductive cycle is not a fixed process, and varies both geographically and from one breeding season to another.