Fishes from five streams in Gunung Machinchang and six streams in Gunung Raya areas of Pulau Langkawi were surveyed with the aim to investigate their diversity and distribution. Fish samples were collected from 23rd to 29th November 2007. Samplings took place along the 50 m reach of each of the site using an electrofisher and scoop nets. A total of 619 individuals of fish comprising 27 species and 14 families were recorded. Sixty-six percent from the taxa listed were of the cyprinids and Puntius binotatus was the most abundant species. Carassius auratus auratus was recorded for the first time in Pulau Langkawi. Streams of the Gunung Machinchang area were dominated by secondary freshwater fish species, but in the Gunung Raya area the streams were dominated by primary freshwater fish species. The highest diversity of fish was recorded for Sg. Kubang Badak with Simpson Index Ds = 0.838 and the lowest was for Sg. Perangin with Ds = 0.450. The highest evenness index of fish species was detected for Sg. Temurun with Es = 0.684 and the lowest was for Sg. Perangin with Es = 0.299. Species overlapping between streams of the two areas was 9.6%.
The ornamental fish sector is a widespread and global component of international trade, fisheries,
aqu aculture and developm e nt. The utilization of multiple trade names causes problem in species
identification. Moreover, unmanaged trading could lead to severe threats to biodiversity. In this
regard, DNA barcoding could effectively clarify the divergence of the species. Consider i ng the utility
of DNA barcoding as a comprehensive system for species identification and discovery, this study aims
to investigate the genetic relationship and to construct the phylogenetic tree among those selected fish
species colle cted from selected pe t stores in Seremban, Negeri Sembilan. The 642bp barcode
fragment of the Cytochrome c oxidase I ( COI ) gene was PCR amplified. Results from BLAST
showed all the generated sequence were subjected to high percentage identity index and sim ilarity
between 99% t o 100%. It was then analyzed using MEGA 7.0 through Neighbour Joining (NJ)
clustering and K2P distance based approach. The analysis revealed straightforward identification of
eight specimens into five species with increasing value of g enetic distances from conspecific (0.05%)
to the taxonomic level (20.18%). The phylogenetic analysis consists of own sequences and reference
sequences obtained from the GenBank. All the specimens from different genus was found with high
bootstrap value (n> 90%) through Neighbou r Joining (NJ) and Maximum Likelihood method. Thus,
DNA barcoding reflects the efficacy of the techniques in identifying the genetic assessment in selected
ornamental fishes.
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.