The paper details the observations made on the natural spawning of honeycomb grouper (Epinephelus
merra) achieved at the Regional Centre of Central Marine Fisheries Research Institute (CMFRI), Mandapam
Camp. The construction details of indoor maturation and spawning system developed for the captive
maturation and natural spawning of small sized groupers are given. Sub-adults of this species were collected,
maintained, developed into brood stock and transferred to indoor maturation tank for observations on natural
spawning. The natural spawning occurred between August and October 2004 and corresponded to the lunar
phase of each month. Number of eggs, percentage fertilization and hatching, the water quality parameters,
feeding protocol adopted for sub-adults and brood stock are detailed. Disease occurrence and their control,
importance of PUFA enriched feed are also discussed.

Natural spawning, captive condition, honeycomb grouper