The biosynthesis of long-chain polyunsaturated fatty acids (LC-PUFA), a process to convert C18 polyunsaturated fatty acids into eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or arachidonic acid (ARA), requires the concerted activities of two enzymes, the fatty acyl desaturase (Fads) and elongase (Elovl). This study highlights the cloning, functional characterisation and tissue expression pattern of a Fads and an Elovl from the Boddart's goggle-eyed goby (Boleophthalmus boddarti), a mudskipper species widely distributed in the Indo-Pacific region. Phylogenetic analysis revealed that the cloned fads and elovl are clustered with other teleost orthologs, respectively. The investigation of the genome of several mudskipper species, namely Boleophthalmus pectinirostris, Periophthalmus schlosseri and Periophthalmus magnuspinnatus, revealed a single Fads2 and two elongases, Elovl5 and Elovl4 for each respective species. A heterologous yeast assay indicated that the B. boddarti Fads2 possessed low desaturation activity on C18 PUFA and no desaturation on C20 and C22 PUFA substrates. In comparison, the Elovl5 showed a wide range of substrate specificity, with a capacity to elongate C18, C20 and C22 PUFA substrates. An amino acid residue that affects the capacity to elongate C22:5n-3 was identified in the B. boddarti Elovl5. Both genes are highly expressed in brain tissue. Among all tissues, DHA is highly concentrated in neuron-rich tissues, whereas EPA is highly deposited in gills. Taken together, the results showed that due to the inability to perform desaturation steps, B. boddarti is unable to biosynthesise LC-PUFA, relying on dietary intake to acquire these nutrients.

This research was conducted to determine the abundance and diversity status of the sea stars from the central South China Sea. An account is given of the species collected during The Research on the Seas and Islands of Malaysia (ROSES) Expedition 2004 from Archipelago of Beting Patinggi Ali to Pulau Layang-Layang, South China Sea. Fifteen reefs were surveyed in Malaysian waters. Surveys for sea star abundance and diversity were done using SCUBA diving and reef walks at low tide. High abundance and species richness was observed. In total, 6 families, 12 genera and 20 species of sea stars were recorded at the study sites. The most dominant family was Ophidiasteridae (12 species) and the most common genus was Linckia spp. (four species). Terumbu Siput (Erica Reef) exhibited the highest diversity of sea stars amongst all the reefs surveyed in this expedition. Ten colour patterns and variations of Culcita novaeguineae were observed and specific to each sampling location. Entire sea star species observed in this study was first time recorded in Central South China Sea. Most of the species (18 species) observed during this expedition have been recorded elsewhere in the Indo-Pacific, an indication of the successful larval dispersal along the waters of the South China Sea meanwhile two species are new in South China Sea records, namely Fromia sp. and Leiaster sp.

Land reclamation in Penang began two decades ago and is still rampant with large reclamation projects planned to be executed in the near future. The present study provides the first information on effects of land reclamation in Penang towards the coastal macroinvertebrates. This study assessed the abundance, diversity, and evenness of coastal invertebrates assumed to be the foremost affected when land is reclaimed. Three kinds of areas were focused on: reclaimed, unclaimed (adjacent to reclaimed), and undisturbed. A total of 53 species of macroinvertebrates from 10 classes (Gastropoda, Bivalvia, Polychaeta, Malacostraca, Maxillopoda, Echinoidea, Polyplacophora, Branchiopoda, Scaphopoda, and Holothuroidea) were sampled. Reclaimed areas were moderately rich in species averaging 11 species compared to 7 species in adjacent and 14 in undisturbed areas. Species richness was the highest in Teluk Aling (an undisturbed area) with 22 species, and was the lowest in Gurney Drive (an adjacent area) with 2 species. The average species diversity and evenness on reclaimed land was the lowest with values of 1.9974 and 0.5787, respectively. The diversity was higher by 5.07% in adjacent areas and by 22.92% in undisturbed areas compared to reclaimed areas. Species evenness was 29.75% higher in unreclaimed areas and 17.87% higher in undisturbed areas compared to reclaimed areas. Land reclamation reduces species diversity and evenness, and to a lesser extent, species richness.

No abstract

AbstractLong-chain polyunsaturated fatty acid biosynthesis, a process to convert C18 polyunsaturated fatty acids to eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA) or arachidonic acid (ARA) requires the concerted activities of two enzymes, the fatty acyl desaturase (Fads) and elongase (Elovl). This study highlights the cloning, functional characterisation and tissue expression pattern of a Fads and Elovl from the Boddart’s goggle-eyed goby (Boleophthalmus boddarti), a mudskipper species widely distributed in the Indo-Pacific region. Phylogenetic analysis revealed that the cloned Fads and Elovl are clustered with other teleost Fads2 and Elovl5 orthologs, respectively. Interrogation of the genome of several mudskipper species, namely B. pectinirostris, Periophthalmus schlosseri and P. magnuspinnatus revealed a single Fads2 for each respective species while two elongases, Elovl5 and Elovl4 were detected. Using a heterologous yeast assay, the B. boddarti Fads2 was shown to possess low desaturation activity on C18 PUFA. In addition, there was no desaturation of C20 and C22 substrates. In comparison, the Elovl5 showed a wide range of substrate specificity, with capacity to elongate C18, C20 and C22 PUFA substrates. We identified an amino acid residue in the B. boddarti Elovl5 that affect the capacity to bind C22 PUFA substrate. Both genes are highly expressed in brain tissue. Among all tissues, DHA is highly concentrated in neuron-rich tissues while EPA is highly deposited in gills. Taken together, the results showed that due to disability of desaturation steps, B. boddarti is unable to biosynthesis LC-PUFA, relying on dietary intake to acquire these nutrients.