Studies on the species composition, abundance and distribution of fish larvae in the survey area identified 186 species of larvae belonging to 112 families. The oblique hauls during pre-SW monsoon were the richest yielding 158 species belonging to 94 families. Based on their ecological characteristics, three basic groups of pelagic, mesopelagic and demersal types of larvae were identified. Larvae of Gobiidae [29.44%], Bregmaceros rarisquamosus [16.26%], Nemipterus sp. [2.86%], Hygophum sp. [2.78%] and Callionymus sp. [2.49%] were the most abundant in the oblique hauls, while Stolephorus sp. [10.49%], Myripristis sp. [8.83%], Holocentrus sp. [8.04%], Upeneus sp. [8.04%] and Gobiidae [5.38%] were abundant in the surface horizontal hauls [Fig. 18]. During the SW monsoon, Gobiidae [32.04%], Bregmaceros rarisquamosus {8.68%], Decapterus sp. [4.74%], Apogon sp. [3.56%], Lutjanus sp. [2.7%], Callionymus sp. [2.57%], Benthosema sp. [2.13%] and Nemipterus sp. [2.12%] were abundant in the oblique hauls, while Sardinella sp. [10.22%], Upeneus sp. [9.74%], Gobiidae [7.6%], Myripristis sp. [6.21%] and Diaphus sp. [5.68%] were common in the surface horizontal hauls [Fig. 19]. Larvae of eight Scombrid genera, Rastrelliger, Scomber, Scomberomorus, Acanthocybium, Euthynnus, Auxis, Katsuwonus and Thunnus were collected during both the cruises. Fish larvae belonging to 107 families of fishes have been recorded from the area during previous studies
Larvae of Sardinella sp. were most abundant at the surface during the SW monsoon
cruise, while Stolephorus sp. predominated during the pre-SW monsoon cruise, and their pedominance at the surface was particularly outstanding in the samples collected during the night and on overcast days, indicating phototactic behavior. 75% of all Gobiid larvae caught were in the oblique hauls, closely followed by Bregmaceros rarisquamosus larvae. Larvae of mesopelagic species, Benthosema sp., Diaphus sp., Hygophum sp., Myctophum sp., Pollicthys sp. and Lampadena sp. were common at the deeper stations. Family Myctophidae with 13 genera, including one specimen each of Centrobranchus sp. and Lobianchia sp., were the most widely represented. Two mesopelagic genera belonging to Argentinidae, Argentina kagoshimae and Glossanodon sp. [only one specimen] were also collected at the deeper stations. Larvae of mesopelagic species were always more common in the oblique hauls because of their phototactic behavior. Larvae of species belonging to Carangidae and Nomeidae were often found clinging to floating debris. Based on the distribution patterns, larvae of Sardinella sp., Stolephorus sp., Myripristis sp., Holocentrus sp., Upeneus sp., Decapterus sp., Euthynnus sp., and Diaphus sp. were found to be pelagic in character, while Gobiidae, Bregmaceros rarisquamosus, Decapterus sp., Apogon sp., Nemipterus sp., Callionymus sp., Hygophum sp., Myctophum sp. and Benthosema sp. were more demersal in character.
Studies on species composition, diversity and distribution of fish species, identified a total of 523 species of fishes belonging to 24 orders and 108 families, out of which 103 economically valuable species were obtained from the trawl catches and 160 species from the landing places and fish markets surveyed. During the pre-SW monsoon cruise, 454 species from 88 families were collected from the trawl samples and 97 species from the local fish
markets. Saurida undosquamis [most abundant], Abalistes stellatus, Synodus hoshinonis, Fistularia petimba, Pentaprion longimanus, Priacanthus macracanthus, Seriolina nigrofasciata, Parupeneus cinabarinus and Nemipterus nemurus were the most widely distributed. 359 species belonging to 87 families were collected during the SW monsoon cruise. Of these, Priacanthus macracanthus [most abundant], Saurida undosquamis, S. micropectoralis, Parupeneus cinabarinus, Gymnocranius griseus, Fistularia petimba, Pentaprion longimanus, Seriolina nigrofasciata and Abalistes stellatus were the most widely distributed. 7 species were common to both the cruises. The coastal waters of Sarawak had the maximum species diversity of up to 70 species per haul. 37 species were collected by handline fishing, of which Lutjanus malabaricus, Gymnocranius griseus, Cephalopholis miniatus, C. sonnerati, Diagramma pictum, Lethrinus lentjan and Arius bilineatus were the most commonly caught. Many more species, caught mainly from coral reefs by small-scale fishing, using traps, gill nets and handlines, and also from offshore trawl catches, were observed at the local fish markets. The third recorded specimen of the rare deep-sea fishes, Hepalogenys analis and Pomadasys auritus from the Southeast Asian waters were collected during the survey.
Most species-rich families were Carangidae with 40 species, Serranidae with 30 species and Nemipteridae with 26 species. Central areas of Sarawak were found to be most rich in terms of species diversity, yielding up to 70 species per haul. Most of the species along the southwest corner of the Sarawak coastline were estuarine, belonging to Ariidae, Clupeidae and Scianidae. Deep-sea species belonging to Moridae, Caproidae and Argentinidae were recorded along the northeastern areas of the Sarawak coast. A total of 2,500 species of bony fishes, belonging to 45 orders and 228 families have previously been reported from the South China Sea region.
