The study on composition, abundance and diversity of larval fish was conducted with the aim to attain information on larval fish breeding ground and made easy for fishery management. Larval fish were collected during September 2015 from mangrove areas of Pekan Pahang, Pendas Johor, Matang Perak and Setiu Terengganu using a bongo net, towed at a depth of about 0.5 m from the surface for 5 min against the tidal flow. A total of 354 larval fish were collected, representing 21 families and 51 species. The top 3 families were Gobiidae (39.26%), Engraulidae (14.97%) and Clupeidae (14.40%), occurred in all sampling areas except in Setiu. The most abundant 11 species formed about 50% of all collected larval fish. Gobiidae spp. were the most abundant, making up 17.8% of the total catch, followed by Clupeidae spp. (12.7%), Engraulidae spp. (8.2%), Ambassis dusumieri (6.5%), Thryssa kammalensis (4.8%), Pseudogobius masago (both 4.8%), Sillaginidae spp. (4.2%), Ambassidae spp. (3.4%), Pseudogobius sp. (3.4%), Blenniidae spp. (2.8%), and Hemigobius hoevenii (2.5%). The highest diversity of larval fish was recorded for Pendas, Johor with Shannon Wiener index Hs = 2.699, and the lowest was Setiu, Terengganu (Hs = 0.832). The highest evenness index of larval fish species was recorded for Pekan, Pahang with Es = 0.815 and the lowest for Setiu Terengganu with Es = 0.465, indicating high single-species dominance. Species overlapping was the highest between Pendas and Setiu at 14.3%, and zero similarity of fish composition was recorded between Matang and Setiu according to Jaccard coefficient. Findings from surveillance of larval fish species provide valuable information for future biodiversity studies and allow better management of biodiversity resources in the mangrove ecosystem of Malaysia.
This study examined the genetic characteristics of twenty-six microsatellite primers developed from three cyprinid fishes (Cyprinus carpio Linnaeus, Barbus barbus Linnaeus and Barbonymus gonionotus Bleeker) in two indigenous mahseer. The Tor douronensis Valenciennes were randomly collected from two locations in Sarawak (N=52), while Tor tambroides Bleeker were obtained from Peninsular Malaysia (N=56). A total of ten and twelve primers were successfully amplified producing four and five polymorphic loci in T. douronensis and T. tambroides, respectively. The number of alleles per locus ranging from 2 to 5 in T. douronensis and 2 to 7 in T. tambroides. A significant deviation from Hardy-Weinberg equilibrium (HWE) was observed at three loci (Barb37, Barb59 and Barb62) in one or more populations in T. tambroides while two loci (Barb37 and Barb62) were deviated in T. douronensis population of Batang Ai. Population structure analysis showed low level of inter-population genetic differentiation in both mahseer. Overall, the identified microsatellite loci should be useful in analysing T. douronensis and T. tambroides natural populations.