MORPHOLOGICAL AND BEHAVIOURAL CHANGES OF F2 HYBRID TIGER GROUPER Epinephelus fuscoguttatus x GIANT GROUPER E.lanceolatus LARVAE AT EARLY STAGE.

Azaharie B. Anuar*, Ching Fui Fui, and Shigeharu Senoo.
Borneo Marine Research Institute, Universiti Malaysia Sabah, Jln Ums, 88400, Kota Kinabalu Sabah
Azaharie@ums.edu.my

The F2 Hybrid Tiger Grouper Epinephelus fuscoguttatus x Giant Grouper E. lanceoloatus known as Tiger GG (TGG) was produced in Fish Hatchery of Borneo Marine Research Institute, Universiti Malaysia Sabah. The F1 hybrid TGG had spawned naturally in captivity since February 2016. Total 25,000 fertilized eggs were kept in 1 tonne rounded fibre glass tank (temperature 28.5-29°C; Salinity 30ppt) and morphological and behavioural changes of the larvae were observed. Developments of morphological during the early larvae stage are relatively similar compared to other groupers. The development of newly hatched larvae was started with unpigmented eye, undeveloped mouth, closed anus, and the yolk sac volume decreased as the larvae grow. Cranial development and orbit pigmentation started at 12 hours after hatched (hAH).  At 24 hAH, eyes lenses formed and the presence of cupula and free neuromas was observed. The eyes are fully pigmented, while the pectoral fin buds, melanophores and anus are formed at 50 hAH. Lower jaw was actively moved at 60 hAH. The swimming behaviour of the newly hatched larvae was motion less and transformed to vertical swimming at 1 day after hatched (dAH). Horizontal swimming was observed at 2 dAH and the head was moving actively as the larvae reached 3 dAH. Overall, the morphological and behavioural changes showed by the F2 hybrid TGG is as almost similar as the F1 hybrid TGG.