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A study was conducted at nine sites around Pulau Mertang using point intercept transect method to determine the coral community of the islands. The results showed the reefs around Pulau Mertang were in good condition with an average live coral cover of 51.0 + 2.35%, which is higher than the average live coral cover for Malaysia (42.5%). Hard corals were found monopolizing the benthic fauna along all transects. A total of 25 different genera from 12 families of scleractinian coral were observed during this survey. The dominant genera found at Pulau Mertang are Acropora (41.26 + 20.88%) and Montipora (14.24 + 21.57%), while other sessile life form was dominated by zoanthids (7.59 + 11.92%). The percentage cover of the abiotic component of transect was dominated by dead corals (15.19 + 2.26%) . Coral genus diversity was highest at Pulau Mertang Barat (H' = 2.24), followed by Pulau Mertang Timur (H' =1.71) and Pulau Mertang Tengah (H'=1.56). Most reefs in Pulau Mertang are classified as C4 categories and all islands show low values of mortality index (MI = 0.23). High coral live cover, diversity (H'), conservation class (C4) and low mortality index and domination by branching and tabularAcropora are attributes of a healthy reef. Therefore, it is concluded that the reefs around Pulau Mertang were still in good condition and healthy. From an ecological point of view, it is the closest representation of an undisturbed reef of a non-marine park island in Johor. Thus, this study forms an initial step in understanding the reef community and provides a basis for future observations on the marine ecosystem of Pulau Mertang.

This study aims to elucidate the gastric emptying process of clownfish fed on artificial diet using two gastric evacuation models and to determine the pepsin activity in the digestion process in relation to feeding time. Regression analysis was used to evaluate the adequacy of 2 models; Anderson's [S t in describing the gastric emptying rate. Grove's model provided a better fit with higher r 2 value, with the calculated parameters of maximum meal size at time 0 (S 0 ) = 0.195 g and gastric emptying rate (K) = 0.0165 g h -1 . There was no initial delay phase as predicted and the evacuation followed a curve. Pepsin activity in the stomach showed rapid responses to food intake, where activity was detected at 1 h after feeding and reached its peak at 2 h after feeding. Pepsin activity decreased since then until the 12th h after feeding where it reached the lowest point. An increase of pepsin activity was detected later, where a small boost was detected at 24 h after feeding to digest the remaining food item in the stomach before the pepsin secretion decreased and maintained at pre-feeding level. Fast response of digestive enzyme in stomach implied that clownfish is equipped to utilize infrequent and irregular meals effectively. ABSTRAK Kajian ini bertujuan untuk menjelaskan proses pengosongan perut ikan badut yang diberi diet buatan dengan menggunakan dua model pengosongan gastrik dan untuk menentukan hubungan antara aktiviti enzim pepsin dalam proses pencernaan dengan masa selepas makan. Analisis regresi digunakan untuk menentukan ketepatan dua model; model Anderson [S t = S o (1-S o (α-1) ρ(1-α)t) 1/(1-α) + ξ] dan model Grove [S t = (S oα -αKt) 1/α ], dalam penentuan kadar pengosongan perut selepas makan. Model Grove lebih sesuai kerana mempunyai nilai r yang lebih tinggi dengan parameter yang dikira merupakan saiz hidangan maksimum pada masa 0(S 0 ) = 0.195 g dan kadar pengosongan perut (K) = 0.0165 g per jam. Tiada fasa lewat pada permulaan proses penghadaman seperti yang dianggarkan dan pengosongan perut adalah sejajar dengan lengkungan. Aktiviti enzim pepsin dalam perut menunjukkan tindak balas yang pantas terhadap pengambilan makanan dengan aktiviti pepsin dikesan seawal 1 jam selepas makan dan mencapai kemuncaknya pada masa 2 jam selepas makan. Aktiviti pepsin kemudiannya semakin menurun sehingga mencapai tahap terendahnya pada jam 12 selepas makan. Selepas itu, aktiviti pepsin meningkat semula dan terdapat rangsangan kecil dalam rembesan enzim yang dikesan pada 24 jam selepas makan. Aktiviti pepsin kemudiannya menurun semula kepada tahap sebelum makan. Tindak balas yang cepat terhadap pengambilan makanan menunjukkan ikan badut mampu menghadapi keadaan pembekalan makanan yang tidak menentu dengan berkesan.

Development of broodstock, spawning, and early rearing of the hybrid clownfish, Amphiprion ephippium (♂) × Amphiprion melanopus (♀), was studied under captive conditions. The fishes were successfully paired after being together for over a year. Spawning occurred between 0700 to 1000 hours every 3 weeks. More than 200 eggs were spawned each time, with an egg size of 1.5 ± 0.5mm. Fertilized eggs turned from bright orange to black to silvery before hatching after being incubated for 7–9 days. Out of 20 batches of eggs spawned, 5 batches were successfully hatched, with only 2 batches surviving to adulthood. The average survival rate for all the batches hatched was 21.16%. Newborn larvae measured about 3–4 mm long, with transparent fins that fused, forming a single fin fold. Larvae underwent metamorphosis on day 10 post hatched, where the fins started to separate, form, and develop body colorations. Two clear and thick bands were observed on the body (head and middle) as early as 14-day post hatched to 90-day post-hatched, where the banding reached its peak. The middle band then began fading as the juveniles grew. By 130-day post-hatched, the juveniles became adults with unique coloration featuring a headband and a black blotch, reaching the maximum size of 34 mm. The hybrid clownfish underwent metamorphosis earlier and reached marketable size much sooner compared to its parent species, making it a suitable candidate for ornamental fish culture. It is the first documentation on the production of hybrid clownfish A. ephippium and A. melanopus both in Malaysia and worldwide.