IMPROVED METHOD OF DETERMINING THE SEX OF THE MARINE TOPSHELL, TROCHUS-NILOTICUS (MOLLUSCA, GASTROPODA) FOR SPAWNING

Determining the sex of Trochus niloticus for induced spawning is extre mely difficult. A quick and simple method for therefore developed thro ugh a process involving cutting a 'window' in the shell until the nacr e layer was revealed. Through the window, the color of the gonad could be seen and the sex of the animal determined - dark green in the case of a female and creamy white in the case of a male. The method did no t appear to inflict obvious stress nor mortality on the treated animal s. Successful spawning inductions were achieved by using this method o f determining the sex of the broodstock.