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Community-wide understanding of food web dynamics in species-rich tropical estuaries are generally lacking, exacerbating the challenges of managing these valuable coastal habitats. To address this gap, trophic guilds and dietary patterns were elucidated for 39 species of a juvenile-dominated demersal estuarine fish community in the Matang Mangrove Forest Reserve, an Important Marine Mammal Area. Fishes were sampled monthly for a year using otter trawl, and stomach contents were analyzed. Of the seven trophic guilds identified from clustering analysis, the three most speciose ones were shrimp feeders (12 species), zooplanktivores (9), and generalist crustacivores (7). Copepods occurred in diets of 50% of all fish species and were the most important food item volumetrically for specialist zooplanktivores. Diverse shrimp and prawn taxa, including commercially valuable Acetes and juvenile penaeids, showed highest frequency of occurrence in stomachs and supported the shrimp feeder and crustacivore guilds that contained relatively more diet generalists. Biomass-dominant annelidivore guild members are known to be a vital food resource for highly threatened coastal cetaceans. Ontogenetic diet shift, wide intra-guild diet breadth, seasonality in major resource use, and prevalence of detritus in diet were feeding strategies that reduced niche overlap and competition among fish species sharing common food resources. Future fisheries management must consider the bottom-up trophic impacts from excessive removal of valuable prey resources such as shrimps on equally valuable fish consumers that depend on them.

Information regarding the vagile fish fauna and their use of rare polychaete reefs as habitat or feeding area is almost unheard of in the tropics. Of great interest is whether the construction of such biogenic reefs in an otherwise featureless habitat such as a mudflat increases structural complexity thereby enhancing fish abundance and ecological functioning. The Jeram polychaete reef (Straits of Malacca) is unique and recurrent; on the mudflat, it emerges, grows, and decimates within a year. We tested the hypothesis that the enhanced reef resources (prey) modify the reef ichthyofauna in terms of community structure and trophodynamics. The largely juvenile fish that visited the reef totaled 69 species from a 9-month study. Although sharing 57 common species, the reef fish assemblages had less species and diversity than the mudflat (90 species) and also lower abundance and biomass. Temporal variability in the reef’s fish community structure appeared to be tied to the reef dynamics, food availability, and environment. Stable isotope (C and N) results suggest a food web of five trophic levels emanating from phytoplankton and benthic diatoms as basal sources, similar to the mudflat. The enhanced prey resources modified the ichthyofauna, but did not impact reef fish trophodynamics in terms of feeding guild, trophic level, and dietary carbon. Although the polychaete feeding guild was distinct in the reef, most reef fishes as well as mudflat fishes were generalist predators. The reef supports local fisheries, functioning as a feeding and habitat area for 58 fish species of commercial importance.

Despite worldwide efforts to restore degraded mangrove forests in the past decades, defining and tracking restoration success remains a major challenge. In this study, we used a multi-isotope approach to trace ecosystem responses to forest clearing and replanting in a tropical mangrove forest reserve at Matang, Malaysia. We measured δ2H or δD deuterium, δ13C and δ15N (HCN isotopes) in common macroinvertebrate consumers (barnacles, prawns, gastropods, and crabs) across a 70-year chronosequence of mangroves. Functional food web recovery was indicated by a decrease in δ13C and δ15N and increase in δD for gastropod and crab consumers in older forests. Timing of this shift in food web isotopic signals took place between 5 and 15 years post-clearing of mangroves. These changes in food web function paralleled changes in crab community composition, but also reflected changes in physicochemical conditions within the forest, such as increased tree cover and shading, which resulted in a shift of the food web base from microalgal-derived to mangrove-derived organic matter. Prawns and barnacles from tidal waters adjacent to the mangrove forests were estimated to derive 17 to 25% of their nutrition from mangroves, primarily from a microbial loop that was processing localised dissolved and particulate organic matter exported from mangrove marshes. The top-down mixing model approach using combined HCN isotope measurements clearly separated inputs from mangroves versus microalgae for the first time in estuarine food web studies, and tracked ecological mangrove ecosystem recovery. This combination of tracers is recommended for future studies of mangrove conservation and restoration.

This research was supported by funding from the University of Malaya Research Programme grant no. RP001F-13SUS, University of Malaya Postgraduate Research Fund no. PG040-2013B, and an Ocean Park Conservation Foundation Hong Kong grant (MM03-1314). The paucity of baseline data on coastal cetaceans due to a lack of research in developing countries frequently precludes assessment of their status and informed management actions for conservation. This study provides the first abundance estimates of Indo-Pacific humpback dolphins, Irrawaddy dolphins, and Indo-Pacific finless porpoises in the coastal waters of Matang, Peninsular Malaysia. Boat-based surveys covering 1,152 km2 of coastal waters with 4,108 km of survey effort were conducted between 2013 and 2016 to collect data for line transect analysis of Irrawaddy dolphins and finless porpoises. Photo-identification data of humpback dolphins were concurrently collected for mark-recapture analysis. Estimates of abundance from four sampling strata totalled 763 Irrawaddy dolphins (CV = 13%, 95% confidence interval (CI) [588, 990]) and 600 Indo-Pacific finless porpoises (CV = 27%, 95% CI [354, 1,016]). The annual abundance estimates of humpback dolphins ranged between 171 (95% CI [148, 208]) in 2014?2015 and 81 (95% CI [67, 98]) in 2015?2016, likely due to the presence of offshore individuals that moved in and out of the study area. The estuarine strata were inhabited by 68 (95% CI [63, 73]) inshore humpback dolphins in 2013?2014 to 87 (95% CI [78, 97]) dolphins in 2014?2015. As an International Union for Conservation of Nature important marine mammal area, the productive coastal waters of Matang are shown to support a high density of small coastal cetaceans, and the results serve as an important baseline for future studies to identify population trends for conservation management plans. Postprint

Coastal cetaceans in Southeast Asia are poorly studied and are particularly vulnerable to anthropogenic threats, especially in intensive fishing grounds. To investigate the distribution and habitat characteristics of cetaceans in the productive coastal waters of Matang, Perak, Malaysia, boat‐based line transect surveys were conducted between 2013 and 2016. The Irrawaddy dolphin (Orcaella brevirostris) was most frequently encountered at 3.87 sightings per 100 km, followed by the Indo‐Pacific finless porpoise (Neophocaena phocaenoides) at 1.72 sightings per 100 km, and the Indo‐Pacific humpback dolphin (Sousa chinensis) at 0.66 sightings per 100 km. The mean group size was largest for humpback dolphins (8.4 individuals), followed by Irrawaddy dolphins (6.4 individuals), and finless porpoises (2.8 individuals). Humpback dolphins exhibited a clustered distribution concentrated mainly in shallow estuarine waters ( 15 km from river mouths). The spatial distribution of the three cetaceans overlapped minimally, and this is likely to reflect the distribution of preferred prey resources, species interactions, and their differential responses to anthropogenic activities and species dominance. The results from our study serve as baseline information for future research, conservation, and habitat management of these vulnerable and endangered coastal cetaceans. Conservation actions are recommended for the Matang area.

Unvegetated, open mudflat areas are a dominant feature of tropical coastlines, relatively productive and known to support high ichthyofaunal diversity. However, the mudflat’s food web is poorly characterized, especially the primary production that supports it and the degree of dependence on adjacent mangroves. In this study, we investigated the trophodynamics of vagile fish fauna utilizing a large tropical intertidal mudflat area during high tide in Klang, Malaysia, using stomach content and stable isotope (carbon and nitrogen) approaches. Cluster analysis revealed that 53 major fish species using the mudflats, which comprised mainly of juveniles, can be grouped into eight dietary guilds implying a variable degree of food resource partitioning among species. The dominant guild of “shrimp feeders” and all other guilds prey on shrimps of the families Penaeidae and Sergestidae to varying degrees. These abundant crustaceans constitute the prevalent shared prey resource, ecologically important to the co-existence of many mudflat fishes. Stable isotope analysis revealed four to five trophic levels in a relatively complex food web fueled not only by microphytobenthos but also phytoplankton in highly turbid waters. Close pelagic–benthic coupling due to shallow waters and strong tidal mixing probably sustains the mudflat’s primary production and relatively high number of trophic levels despite the transitory and highly dynamic environment. The mudflat’s autochthonous production and diverse prey resources highlight the importance of this often overlooked coastal habitat especially in supporting the early life stage of diverse fish species and, thus, coastal fisheries.

Seagrass meadows are highly productive habitats that support commercially and ecologically important fishes and invertebrates. However, evidence of fish-habitat relationships are seldom drawn from forereef seagrass meadows that are structurally simple in terms of species richness and relative size and, consequently, their role as habitats is unclear. In this study, fish-habitat relationships were examined in such meadows in the forereef seagrasses of Tinggi Island and Babi Besar Island, Malaysia, by documenting habitat complexity attributes (canopy height, shoot density and percent cover), distance to adjacent coral reefs, and water depth within 2×2 m quadrats. Fish assemblages were recorded using the Remote Underwater Video Station method. A total of 1166 individuals from 86 taxa were found and enumerated. This study showed that (1) fish density and species richness were significantly associated with seagrass percent cover alone; (2) commercially important carnivores formed the majority of the fish populations in the meadows, and (3) fish density and species richness were positively correlated with distance to the nearest adjacent coral reef, indicating the need to account for the effects of neighboring habitats in studies of this nature. Thus, structurally simple seagrass meadows are still important fish habitats, especially as feeding grounds for commercially significant carnivores.

Periodic fish ingressions into intertidal areas during high tide are known to occur on tropical mudflats. This study aimed to elucidate the feeding ground function of coastal mudflats for three common stingray species in the Klang Strait, Malaysia. Stingrays (disc width range from 5.65–54.50 cm) sampled over 17 months using a large barrier net (~2 ha enclosure) at two sampling sites were examined for their diet composition, prey frequency and prey volume according to predator species and maturity. The index of relative importance and Schoener's index of diet overlap were calculated. The three stingray species fed on relatively similar prey items which varied in size and contribution. Brevitrygon heterura fed on the widest range of prey taxa (28) whereas Hemitrygon bennetti (22) and Telatrygon biasa (17) showed higher prey specialization. The Penaeidae (dominantly Metapenaeus brevicornis and M. affinis) were the most important food item in the stingray diet which also included Actinopterygii, Amphipoda, Brachyura and Calanoida. The stingray diet showed an ontogenetic shift, with young stingrays tending to be generalists whereas the more mature stingrays (except H. bennetti) become more specialized in their feeding habits. This shift in feeding strategy reflects the diversity of prey taxa abundantly available to young stingrays on the mudflats, while the larger stingrays adapt to feed on larger prey once they enter deeper waters.

Offsetting carbon (C) emissions and reducing nitrogen (N) pollution have been goals of mangrove restoration programs around the world. There is a common, yet dubious expectation that mangrove restoration will result in immediate and perpetual delivery of ecosystem services. There are expected time lags between mangrove clearing and C and N losses, and between restoration and C and N gains. Obtaining accurate rates of losses and gains requires frequent and long-term sampling, which is expensive and time consuming. To address this knowledge gap, we used a chronosequence of mangrove forests in mangroves in Matang Mangrove Forest Reserve (MMFR) in Malaysia, a region with one of the most C dense forests in the world. In this site, we assessed the ecosystem C and N stocks, including soil, downed wood, downed litter, and trees. The objective was to measure C and N changes through time. After mangrove clearing, C and N losses in soil and downed wood were rapid, with stocks halved after just one year. In the first 10 years after replantation, the forest recovered quickly, with rates of C accumulation of 9.5 Mg C ha−1 yr−1. After ten years, the rate of accumulation decreased to 2.8 Mg C ha−1 yr−1. However, 40 years after replantation, mangroves were still about 26% lower in C and 15% lower in N compared to our reference forest. The trajectory of recovery of C and N stocks in these forests was different among mangrove components: forest litter recovered rapidly, but downed wood and soil recovered much slower. Programs aimed at reducing C emissions and N pollution should consider that there are temporal lags and ecosystem trade-offs when assessing the effectiveness of mangrove protection and restoration as climate change mitigation strategies.

In stable isotope analysis, the estimation of proportional contribution of carbon and nitrogen from mangrove to benthic invertebrates requires knowledge of the food-consumer trophic discrimination factor (∆ δ13C and ∆ δ15N). This study tested the hypothesis that the mangrove gastropod Ellobium aurisjudae can assimilate low quality refractory mangrove litter and aimed to determine the trophic discrimination values (TDV) of C and N isotopes between gastropod and the mangrove producer. The mean ∆ δ13C for gastropods fed senescent leaves of the mangrove Bruguiera parviflora (Roxb) Wight & Arn and decomposing mangrove (unknown species from the same site) wood were estimated at 5.3 ± 0.3‰ and 3.2 ± 0.5‰ respectively, whereas for ∆ δ15N, these values were 4.2 ± 0.2‰ and 6.0 ± 0.2‰ respectively. The gastropod assimilated refractory carbon from mangrove leaf and wood litter with 49% and 18% efficiency respectively. Rearing experiment of gastropods (n = 25) fed only mangrove wood litter over 5months in the laboratory, showed mean weight increments of 14.8–74.4% depending on the initial animal weight. Significant deviation of the TDVs for E. aurisjudae from the generalized discrimination values for herbivory underscores the need to use specific TDV for the detritivory link.

Despite the growing concern of scyphozoan jellyfish blooms and their associated threats, there is an acute lack of baseline knowledge regarding the trophic ecology of scyphozoans in tropical waters where blooms of several species sometimes occur at once or successively. Therefore, this study was conducted from June 2010 to December 2011 in the Klang Strait (Malaysia) to elucidate the trophic ecology of eight sympatric species of scyphozoan that occurred in a conjoint mangrove-mudflat habitat. The species diet, trophic position and the relative contribution of primary producers to their nutrition were determined by integrating stomach content examination with stable isotope analysis. Scyphozoans in the Klang Strait are principally carnivores and can be grouped into three major trophic guilds: specialized copepod feeder, copepod and macrozooplankton feeder, and mixed plankton feeder. Bayesian mixing model of δ13C isotope values indicates that the scyphozoans mainly derived their basal carbon source from microphytobenthos and phytoplankton. Analysis of δ15N isotope values reveals that all species are positioned at the third trophic level after mixed zooplankton groups (second) and primary producers (first) in the food web. Scyphozoans thus represent an important trophic link coupling benthic and pelagic primary production to higher-level predators and humans, and are important carbon exporters from nearshore to neritic and offshore waters.

Changes in larval fish assemblages were studied before (1985–86) and after (2013–2014) rapid coastal development in the Klang Strait, Malaysia, based on a Before-After-Control-Impact (BACI) experimental design. Fish larvae were sampled by bongo-nets along an 18-km transect from the impact station at the Kapar power station (KPS) to four control stations in increasingly offshore waters. Families Gobiidae, Clupeidae, Sciaenidae and Engraulidae were most abundant at both sampling periods, demonstrating their adaptability and resilience to the natural and anthropogenic disturbances. Coastal development has reduced larval fish abundance at KPS, inevitably shifting higher larval abundance to the control stations. This shift is related to lower sea surface temperature and higher pH. Despite the coastal disturbances, there was an overall increase in total larval fish abundance attributed to the preflexion stage of the Gobiidae, Sciaenidae, Engraulidae, Cynoglossidae and Callionymidae, and the yolk-sac and preflexion larvae of unidentified taxa.

The ellobiid Ellobium scheepmakeri (Petit de la Saussaye, 1850) is reported from the banks of the Selangor River estuary, 57 years after it was first collected in Peninsular Malaysia. It was found ...

The polychaete (sabellariid-spionid) reefs at Jeram shore (Malaysia) grow up on soft-bottom mudflats and appear short-lived. It is postulated that such reef building results from the succession of polychaete species in response to the changing environment modulated by the extreme hydrometeorological events. To elucidate the biological succession of the reef cycle in relation to the environment, two reef patches on the intertidal mudflat were studied, both spatially (horizontal and vertical community structure) and temporally (June 2012 to January 2014). The Jeram polychaete reef cycles through four phases within a year: pre-settlement phase (March–May), growth phase comprising primary (May–November) and secondary (October–January) successional stages, stagnation phase (December–January), and destruction phase (January–March). The reef dynamics appear to be linked to the regional monsoon climate and local hydrological conditions. At the onset of the southwest monsoon (May), strong erosive forces initiate the reef’s primary succession of the growth phase where the dominant polychaete Sabellaria jeramae colonize and rapidly grow on the exposed lag deposits of shells. During the northeast monsoon (November–March), stronger depositional forces cover the developed reef with fine sediments that are colonized by another polychaete, the spionid Polydora cavitensis during the reef’s secondary succession of the growth phase. On the muddy substrate surrounding the reef clumps, mudflat polychaetes were the most abundant macrobenthos followed by anomurans, gastropods, carideans, and brachyurans. However, these mudflat macrobenthos play no obvious or direct role in initiating the growth of the reef which is likely the result of settlement of dispersed polychaete larvae from unknown offshore reefs. On the other hand, the reef presence has a positive effect on the presence or abundance of surrounding mudflat macrobenthos such as mudflat polychaetes, shrimps, crabs, and gastropods.

Previous studies have found positive correlations between mangrove forest extent and fisheries yield but none of these univariate relationships provide a reliable estimate of yield from mangrove area. This study tests the hypothesis that the nursery ground value or natural production of fish and shrimps is related to the hydrogeomorphology settings of mangrove forests by using multivariate redundancy analysis (RDA). The hydrogeomorphological metrics of five mangrove forests imaged by satellite were measured using Geographical Information System (GIS). The RDA indicated that the metrics, including mangrove area, multiple waterways and creeks, mangrove-river interface, waterway surface area and sediment organic matter, influenced the diversity and abundance of fish and shrimps. Larger values of these metrics increase the abundance of economically important fish species of the families Lutjanidae, Haemulidae, Serranidae and economically-important penaeid shrimps. Sediment organic matter also significantly correlates with the distribution and abundance of fish that feed off the bottom such as the Leiognathidae, Clupeidae and Mullidae. Mangrove forests with combinations of large mangrove area, river surface area, high stream ordering and longest mangrove-river interface will provide greater role as nursery grounds for fish and shrimps.

The alligator pipefish, Syngnathoides biaculeatus, is a cryptic species commonly found in seagrass meadows. The fish is shy and slow, and it is unknown how the predaceous fish hunts its mobile prey...

We aimed to clarify and quantify the abundance of palynomorphs of tropical coastal marine shallow-water sediments collected from Oman, Malaysia, Okinawa and also the Sanriku region of Japan for making a comparison with temperate areas. Palynomorphs in these samples contained phototrophic and heterotrophic dinoflagellate cysts, acritarchs, resting cells of Prasinophyceae and Chrysophyceae, tintinnomorphs, microforaminiferal linings, testate amoebae and resting eggs and body fragments of copepods. The sediment samples from Malaysia, Oman, and Okinawa were characterized by dominance of heterotrophic marine palynomorphs, in particular microforaminiferal linings and heterotrophic dinoflagellate cysts, while the samples from Sanriku were different and dominated by phototrophic and heterotrophic dinoflagellate cysts. In addition subtropical-tropical assemblages were characterized by low cell/grain concentrations, especially phototrophic dinoflagellate cysts. These characteristics of marine palynomorphs...

Brain size varies greatly at all taxonomic levels. Feeding ecology, life history and sexual selection have been proposed as key components in generating contemporary diversity in brain size across vertebrates. Analyses of brain size evolution have, however, been limited to lineages where males predominantly compete for mating and females choose mates. Here, we present the first original data set of brain sizes in pipefishes and seahorses (Syngnathidae) a group in which intense female mating competition occurs in many species. After controlling for the effect of shared ancestry and overall body size, brain size was positively correlated with relative snout length. Moreover, we found that females, on average, had 4.3% heavier brains than males and that polyandrous species demonstrated more pronounced (11.7%) female-biased brain size dimorphism. Our results suggest that adaptations for feeding on mobile prey items and sexual selection in females are important factors in brain size evolution of pipefishes and seahorses. Most importantly, our study supports the idea that sexual selection plays a major role in brain size evolution, regardless of on which sex sexual selection acts stronger.

Larval descriptions of tropical marine and coastal fishes are very few, and this taxonomic problem is further exacerbated by the high diversity of fish species in these waters. Nonetheless, accurate larval identification in ecological and early life history studies of larval fishes is crucial for fishery management and habitat protection. The present study aimed to evaluate the usefulness of DNA barcodes to support larval fish identification since conventional dichotomous keys based on morphological traits are not efficient due to the lack of larval traits and the rapid morphological changes during ontogeny. Our molecular analysis uncovered a total of 48 taxa (21 families) from the larval samples collected from the Klang Strait waters encompassing both spawning and nursery grounds of marine and estuarine fishes. Thirty-two (67%) of the larval taxa were identified at the species level, two taxa (4%) at the genus level, and 14 taxa (29%) at family level. The relatively low rate of species-level identification is not necessarily due to the DNA barcoding method per se, but a general lack of reference sequences for speciose and non- commercial fish families such as Gobiidae, Blenniidae, and Callionymidae. Larval morphology remains important in species diagnoses when molecular matches are ambiguous. A lower ethanol percentage (50%) for larva preservation is also useful to keep the body of larvae intact for morphological identification, and to preserve DNA for subsequent molecular analyses. The 10% Chelex resin used to extract DNA is also cost- effective for long term monitoring of larval fishes. Hence, the DNA barcoding method is an effective and easy way to aid the identification of estuarine larval fishes at the species level.

Despite the significant impacts of scyphozoan jellyfish blooms and fishery to human welfare, scientific knowledge pertaining to the scyphozoans particularly in the tropics have not been progressive due to high species diversity and unresolved taxonomic issues. Previous works in Malaysian waters have exemplified these problems. Here, we provide the most up-to-date collation of research data on scyphozoan jellyfish from Malaysian waters pertaining to their valid species names, distribution and habitat through field surveys and examination of past records. We further examined the threats and positive impacts of the local scyphozoan blooms to human welfare. Twenty identified and verified species, nine unidentified species (i.e. to the genus level only) and five unverified species of scyphozoan from the orders of Rhizostomeae, Semaeostomeae and Coronatae in the Malaysian waters are reported. Versuriga anadyomene is a first record for the Malaysian region, while the edible Lobonemoides robustus is a first record in the eastern waters of Peninsular Malaysia. Species richness was the highest in southern Peninsular Malaysia (19 species), with the mangrove–mudflat habitats having more species (nine species) than the other coastal habitats. Chrysaora chinensis was generally more abundant than other species in the sandy-beach areas. Some species appear to be habitat-specific; Acromitus hardenbergi was only found in the Perak River and Sungei Buloh mangrove-estuary while Cassiopea, Cephea and Netrostoma species were only recorded in the island waters of the eastern and southern Peninsular Malaysia. Nine species were identified as threats to the fishing industry, marine aquaculture, power plant operation, coastal tourism or human health, while eight species are providing economic benefits to the jellyfish fishery and aquarium trade.

Combined multiple 2D views (proximal, anterior and ventral aspects) of the sagittal otolith are proposed here as a method to capture shape information for fish classification. Classification performance of single view compared with combined 2D views show improved classification accuracy of the latter, for nine species of Sciaenidae. The effects of shape description methods (shape indices, Procrustes analysis and elliptical Fourier analysis) on classification performance were evaluated. Procrustes analysis and elliptical Fourier analysis perform better than shape indices when single view is considered, but all perform equally well with combined views. A generic content-based image retrieval (CBIR) system that ranks dissimilarity (Procrustes distance) of otolith images was built to search query images without the need for detailed information of side (left or right), aspect (proximal or distal) and direction (positive or negative) of the otolith. Methods for the development of this automated classification system are discussed.

Marine spatial planning (msp) has been gaining traction in environmental policy debates and in emerging state practice as an effective tool for adaptive and multi-scale management, providing mechanisms for the resolution of jurisdictional conflicts between actors in the marine environment. This article reviews its essential characteristics and then assesses its acceptance within the international community, particularly in the European Union and the developed world, as a major tool for environmental protection. Then, taking Malaysia as a case-study, the article considers the advantages of developing msp to resolve multi-sectoral and inter-jurisdictional conflicts amongst the States of the Federation and multiple actors to achieve its economic and environmental objectives.

Often seen as nonvegetated unutilized wastelands, mudflats pose the least resistance to land claim for coastal development. Here, we studied the large Klang mudflat (Straits of Malacca) from September 2011 to September 2014 to determine the fish species that utilize it and the abiotic factors that influence species composition and abundance, to evaluate the ecological role of the mudflat in support of coastal fisheries. The spatial and temporal assemblage of fish species and their abundance was examined at two sites, during two monsoon seasons, and under the effect of period (wet/dry), moon phase (full/new moon), and diel cycle (day/night). Fish were sampled during ebb tide by a stationary large barrier net that enclosed a calculable area of sampling. A total of 119 species belonging to 46 families of mainly small-sized and juvenile fish made regular ingressions into the mudflat throughout the year. Fish abundance varied spatially and temporally, suggesting site preference and variability in juvenile recruitment. Higher fish abundance due to recruitment occurred during the northeast monsoon season (NEM), as compared to the southwest monsoon. Fish composition but not total fish abundance during the NEM differed between wet/dry periods and diel cycles. Ariidae and Sciaenidae were dominant families during the wet period, whereas Engraulidae dominated during the dry period. Predatory fish species (e.g., Lagocephalus lunaris, Otolithes ruber, and Hexanematichthys sagor) were recorded during the daytime, whereas planktivorous and detrivorous species (e.g., Ambassis gymnocephalus and Liza subviridis) were more abundant during the night.

This study aims to address the potential effects of environmental factors, competition and predation among cohabiting macrobenthos, and in particular on the cultured blood cockles (Tegillarca granosa). Macrobenthos and environmental variables were sampled from culture beds close to the harvesting period at two sites (BNO, BSB) in Selangor and one (KSB) in Perak (Malaysia). A total of 79 taxa were recorded mostly belonging to three taxonomic groups, Mollusca (27 taxa), Crustacea (26) and Actinopterygii (18). Redundancy analysis revealed close associations among the common scavenging/grazing gastropods (Nassarius bellulus and N. jacksonianus), predatory gastropods (Notocochlis tigrina and Indothais malayensis) and various macrobenthic species suggesting competition and predation risk to the cultured bivalves. The biomass of sediment chlorophyll-a (highest at BNO) was correlated with higher T. granosa and macrobenthic density. The higher ammonia level at BSB and KSB may explain the lower macrobenthic density and reduced competition allowing the venerid bivalve, Pelecyora cf. gouldii to proliferate at the expense of T. granosa. This study identified two abiotic factors (nutrient enrichment, ammonia) and two biotic factors (food limitation and predation) that potentially affect the production of densely-stocked T. granosa on the mudflat.

Heat shock response (HSR), in terms of transcription regulation of two heat shock proteins genes hsp70 and hsp90), was analysed in a widespread tropical copepod Pseudodiaptomus annandalei. The mRNA transcripts of both genes were quantified after copepods at a salinity of 20 underwent an acclimation process involving an initial acclimation temperature of 29 °C, followed by gradual thermal ramping to the target exposure temperature range of 24-36 °C. The respective cellular HSR and organismal metabolism, measured by respiratory activity at exposure temperatures, were compared. The fold change in mRNA expression for both hsp70 and hsp90 (8-9 fold) peaks at 32 °C, which is very close to 32.4 °C, the upper thermal optimum for respiration in the species. Unexpectedly, the modelled HSR curves peak at only 3 °C (hsp90) and 3.5 °C (hsp70) above the mean water temperature (29.32 °C) of the copepod in the field. We propose that copepods in tropical waters adopt a preparative HSR strategy, early at the upper limit of its thermal optimum, due to the narrow thermal range of its habitat thus precluding substantial energy demand at higher temperatures. However, the model suggests that the species could survive to at least 36 °C with short acclimation time. Nevertheless, the significant overlap between its thermal range of hsp synthesis and the narrow temperature range of its habitat also suggests that any unprecedented rise in sea temperature would have a detrimental effect on the species.

The present and commonly used batch culture system (BCS) as adopted by many small-scale tropical hatcheries is beset by poor rotifer production and sudden crashes. This study aimed to produce nutritive rotifers and evaluate their performance based on the BCS by using phototrophic bacteria (PB) that can be easily and cheaply cultured from palm oil mill effluent (POME), an agro-industrial byproduct usually discarded as waste. Brachionus rotundiformis given a sole diet of POME-grown PB (Rhodovulum sulfidophilum) grew as well as on the commercially produced microalgae, Nannochloropsis. Production, growth rate and fecundity of rotifers fed condensed bacterial cells (bPB) and culture broth of bacteria grown in POME (cPB) were evaluated. The best performance in terms of the stated parameters was obtained for rotifers fed 200 mL of cPB in 3 L of culture water; this media sustained a mean rotifer density of 600–900 individuals mL−1 after 3–6 days of culture. The biochemical composition of rotifers fed PB was comparable to those fed microalgae, except that the former contained more polyunsaturated fatty acids.

Fish stocking density, feed quality, and tank color were evaluated for their effects on survival of larval Marble Goby Oxyeleotris marmorata reared at 5-g/L salinity for 30 d. Feed quality was examined in terms of proximate composition and fatty acid profile. Fish larvae were given rotifers and brine shrimp Artemia spp. nauplii (R-A) that were fed condensed cells of the phototrophic bacterium Rhodovulum sulfidophilum (bPB) cultured in palm oil mill effluent (POME); under this feeding regime, fish stocked at a density of 15 larvae/L had significantly higher survival (42.0%) than those stocked at 20 larvae/L (33.5%) or 30 larvae/L (9.9%). At the best stocking density of 15 larvae/L, fish survival and growth were further improved when the larvae received either R-A that were fed the whole culture broth of unsettled bacteria (cPB; survival = 60.9%) or R-A that were fed POME (survival = 58.6%). Under similar rearing conditions, larvae reared in gray-colored tanks showed still further significant improv...

The versatile hermit crabs, Diogenes moosai and Diogenes lopochir, are hypothesised to utilise multiple primary sources of energy in the coastal mudflat. Stable carbon and nitrogen isotopes were analysed to determine the primary sources of nutrition (mangrove, benthic microalgae and phytoplankton) and trophic contribution of mudflat hermit crabs to fish predators in Matang mangrove estuary, Peninsular Malaysia. Stable isotope analysis in R showed that benthic microalgae are the major contributor of the total carbon assimilated by diogenid hermit crabs, followed by phytoplankton and mangrove. Interestingly, hermit crabs are one of the few marine organisms that can digest and assimilate lignocellulosic carbon of the mangrove. However, the relative contribution of the primary sources is site dependent and varies along the estuarine gradient with increasing dependency on mangrove-derived carbon by hermit crabs from offshore waters to estuary. The Sciaenidae is the major group of predatory fish of hermit crabs; the implication is that the dense population of hermit crabs with their versatile feeding habits channels energy from three basal sources to support coastal fish production.

Three sympatric species of mud lobsters are spatially distributed along the mangrove shore of Langat estuary, occurring in combinations of Thalassina anomala with either Thalassina kelanang or Thalassina gracilis . The aim of the study was to investigate how these species are distributed in relation to the environmental variables. Environmental and biotic samplings were made from the lower to upper shore at three study sites located on the coast and upper estuary. Spatial partitioning of these species is strongly driven by environmental factors such as tidal inundation, salinity and substrate characteristics. Competitive exclusion is hypothesized with the more aggressive species T. kelanang on the lower shore and T. anomala on the upper shore. T. gracilis genetically closest to T. kelanang is spatially partitioned from the former by its greater tolerance to high salinity fluctuations in the mid-estuary where it occupies a similar elevation as T. kelanang , and similarly coexisting with T. anomala living on higher ground. T. anomala may prefer more silty and organically rich substrates. This preference and its physiological requirements to survive in drier exposed substrates may explain T. anomala 's simpler and deeper burrow to reach the water table, while the frequent need to feed on less organically rich, sandy-mud substrates by T. kelanang and T. gracilis results in more complex network of burrows near the surface.

Shield length-weight relationship (LWR) and relative growth were studied in three tropical hermit crab species, Diogenes moosai Rahayu & Forest, 1995, Diogenes lopochir Morgan, 1989, and Clibanarius infraspinatus (Hilgendorf, 1869). Overall, the length exponent (b) for LWR ranged between 2.67 to 3.28 with males of both Diogenes species showing positive allometry () and females showing negative allometry (), whereas that of both sexes of C. infraspinatus showed negative allometry. Males had larger b values than females in all species, indicating that males are heavier than females of equal shield length. In all species, relative growth of cheliped and chela exhibited positive allometry () with distinct sexual dimorphism whereby males bear longer chelipeds and chelae compared to females of equal shield lengths. Intra- and interspecific variations in growth of body and cheliped among the three sympatric hermit crab species allow for the resource partitioning of their vital shell resources.

Two-hourly zooplankton samplings encompassing tidal (semi-diurnal), diel (24 h), and lunar (4 phases) cycles during the dry (July 2003) and wet (November 2003) monsoon periods were conducted in the Matang estuary to investigate the vertical distribution and behavior of five different groups of copepods (estuarine, euryhaline, marine euryhaline, stenohaline and nocturnal pontellids) in response to the tidal and light regime. Diel vertical migration (DVM) was evident for all copepod groups but the observed patterns differed among species and sampling period (wet or dry and neap or spring tide). Tidally-induced vertical migration (TVM), superimposed by DVM, was observed for estuarine, marine euryhaline and stenohaline copepods but not for euryhaline and nocturnal pontellid copepods. Estuarine copepods tended to ascend during night-flood tide and descent to the bottom during day-ebb tide; this suggests a selective mechanism to penetrate upstream and maintain position in the estuary. In contrast, the marine euryhaline and stenohaline copepods remained at the bottom especially during day-flood tide and ascended into the water column during night-ebb tide; this suggests a selective mechanism to avoid upstream transport. Euryhaline copepods did not respond to tidal advection probably due to their wide range of salinity tolerance, while the large nocturnal pontellid copepods have strong swimming ability. Adaptive vertical migration appears to be a major factor structuring the copepod community in tropical estuaries, and its occurrence in most copepods suggests that neritic marine zooplankton tidally-advected into estuaries and nearshore waters can survive better than previously thought.

Two seahorse species, Hippocampus spinosissimus and Hippocampus trimaculatus, sampled in east and west coastal waters of Peninsular Malaysia, fed mostly on crustacean prey; small caridean shrimps and amphipods as adults (both species), and copepods and larval meroplankton as juveniles (for H. trimaculatus only). The similar short relative gut length (~0.4) of both species is consistent with a carnivorous diet. Both species are considered specialists in prey selection, focusing on slow-moving epibenthic, hyperbenthic and canopy-dwelling crustaceans that dwell on the mud-sand seabed, or are associated with seagrass or mangrove areas. In this light, seahorses with their juveniles in shallow waters are vulnerable to coastal reclamation and development.

Amphibalanus amphitrite is a common fouling barnacle distributed globally in tropical and subtropical waters. In the present study, the genetic (mitochondrial cytochrome oxidase subunit I) and morphological differentiation in A. amphitrite from 25 localities around the world were investigated. The results revealed three clades within A. amphitrite with a genetic divergence of ~ 4% among clades, whereas there were no diagnostic morphological differences among clades. Clade 1 is widely distributed in both temperate and tropical waters, whereas Clade 3 is currently restricted to the tropical region. The deep divergence among clades suggests historical isolation within A. amphitrite; thus, the present geographical overlaps are possibly a result of the combined effects of rising sea level and human-mediated dispersals. This study highlights the genetic differentiation that exists in a common, widely distributed fouling organism with great dispersal potential; future antifouling research should take into account the choice of lineages.

Life-history variables for three incidentally captured species of seahorse (Kellogg's seahorse Hippocampus kelloggi, the hedgehog seahorse Hippocampus spinosissimus and the three-spot seahorse Hippocampus trimaculatus) were established using specimens obtained from 33 fisheries landing sites in Peninsular Malaysia. When samples were pooled by species across the peninsula, sex ratios were not significantly different from unity, and height and mass relationships were significant for all species. For two of these species, height at physical maturity (HM ) was smaller than the height at which reproductive activity (HR ) commenced: H. spinosissimus (HM = 99·6 mm, HR = 123·2 mm) and H. trimaculatus (HM = 90·5 mm, HR = 121·8 mm). For H. kelloggi, HM could not be estimated as all individuals were physically mature, while HR = 167·4 mm. It appears that all three Hippocampus spp. were, on average, caught before reproducing; height at 50% capture (HC ) was ≥HM but ≤HR . The results from this study probe the effectiveness of assessment techniques for data-poor fisheries that rely heavily on estimates of length at maturity, especially if maturity is poorly defined. Findings also question the sustainability of H. trimaculatus catches in the south-west region of Peninsular Malaysia, where landed specimens had a notably smaller mean height (86·2 mm) and markedly skewed sex ratio (6% males) compared with samples from the south-east and north-west of the peninsula.

Life science ontologies play an important role in semantic web. In the fish and fisheries research field, it is imperative to have an ontology that can automatically provide information for biological objects annotations and links to relevant data pieces. As such, we introduce the Fish Ontology (FO), an automated classification architecture of existing fish taxa which provides taxonomic information of unknown fish based on metadata restrictions. It is designed to support knowledge discovery, providing semantic annotation of fish and fisheries resources, data integration, and information retrieval. The automated classification for unknown specimen is a feature not existing in other known ontologies covering fish species profiling and fisheries data. Examples of automated classification for major groups of fish are demonstrated, showing the inferred information by introducing several restrictions at the species or specimen level. The current version of FO has 1830 classes, includes widely used fisheries terminology, and models major aspects of fish taxonomy, grouping, and character. With more than 30,000 known fish species globally, the FO will be an indispensable tool for fish scientists and other interested users.

Although there have been extensive studies on the larval adhesion of acorn barnacles over the past few decades, little is known about stalked barnacles. For the first time, we describe the larval adhesive systems in the stalked barnacle, Octolasmis angulata and the findings differ from previous reports of the temporary (antennulary) and cement glands in thoracican barnacles. We have found that the temporary adhesives of cyprid are produced by the clustered temporary adhesive glands located within the mantle, instead of the specialised hypodermal glands in the second antennular segment as reported in the acorn barnacles. The temporary adhesive secretory vesicles (TASV) are released from the gland cells into the antennule via the neck extensions of the glands, and surrounded with microtubules in the attachment disc. Cement glands undergo a morphological transition as the cyprid grows. Synthesis of the permanent adhesives only occurs during the early cyprid stage, and is terminated once the cement glands reach maximum size. Evidence of the epithelial invaginations on the cement glands supports the involvement of exocytosis in the secretion of the permanent adhesives. This study provides new insight into the larval adhesives system of thoracican barnacles.

The deltaic estuarine system of the Matang Mangrove Forest Reserve of Malaysia is a site where several human settlements and brackish water aquaculture have been established. Here, we evaluated the level of fecal indicator bacteria (FIB) and the presence of potentially pathogenic bacteria in the surface water and sediments. Higher levels of FIB were detected at downstream sampling sites from the fishing village, indicating it as a possible source of anthropogenic pollution to the estuary. Enterococci levels in the estuarine sediments were higher than in the surface water, while total coliforms and E. coli in the estuarine sediments were not detected in all samples. Also, various types of potentially pathogenic bacteria, including Klebsiella pneumoniae, Serratia marcescens and Enterobacter cloacae were isolated. The results indicate that the Matang estuarine system is contaminated with various types of potential human bacterial pathogens which might pose a health risk to the public.

Shell use and partitioning of two sympatric hermit crab species ( Diogenes moosai and Diogenes lopochir ), as determined by shell shape, size and availability, were examined from August 2009 to March 2011 in a tropical mudflat (Malaysia). Shells of 14 gastropod species were used but > 85% comprised shells of Cerithidea cingulata , Nassarius cf. olivaceus , Nassarius jacksonianus , and Thais malayensis . Shell partitioning between hermit crab species, sexes, and developmental stages was evident from occupied shells of different species, shapes, and sizes. Extreme bias in shell use pattern by male and female of both species of hermit crabs suggests that shell shape, which depends on shell species, is the major determinant of shell use. The hermit crab must however fit well into the shell so that compatibility between crab size and shell size becomes crucial. Although shell availability possibly influenced shell use and hermit crab distribution, this is not critical in a tropical setting of high gastropod diversity and abundance.

Extensive cockle culture on coastal intertidal mudfl ats which function as productive feeding grounds for fi sh and shrimp may affect mudfl at productivity and disturb feeding activity. The aim of the present study is to examine fi sh ingressions into two adjacent coastal mudfl at areas, one with cockle culture and the other without cockle culture, especially to compare their diversity and abundance. Two sampling sites were selected at Bagan Sungai Buloh (BSB: with cockle bed) and BaganPasir (BP: without cockle bed) in the Kuala Selangor mudfl at area. Monthly samplings were carried out on spring tide using an enclosure trap (belat lengkung). In six months of samplings, 63 identifi ed species of fi shes and eight species of prawns were recorded. Both mudfl ats differed in their fi sh species richness, with 59 species in BSB and 41 species in BP. However, the BP m udfl at had signifi cantly higher fi sh biomass (142.2 ±148.7 kg/ha) than BSB mudfl at (43.6 ±41.2 kg/ha) (t-test, p

Las relaciones filogeneticas de 43 especies pertenecientes a 11 generos, representando cuatro subfamilias de la familia Lutjanidae y dos generos de la familia Caesionidae, fueron inferidas a partir del gen mitocondrial citocromo c oxidasa subunidad I (COI). Ademas, se uso la region control (RC) del ADN mitocondrial para inferir la filogenia entre los tipos de Lutjanus russellii del oceano Indico y el Pacifico occidental recolectados en las costas de la peninsula de Malasia. Se generaron secuencias de COI (11 especies) y RC (12 especies). Los clados generados concuerdan con las agrupaciones propuestas anteriormente basadas en la morfologia y biogeografia de las especies. La relacion filogenetica cercana entre Pinjalo pinjalo y los pargos rojos Lutjanus malabaricus y Lutjanus sebae justifica la revision taxonomica de los mismos ya que los caracteres morfologicos empleados para diferenciar ambos generos son ambiguos. La divergencia de las secuencias (4.2%) entre los dos tipos de L. russellii (Indico y Pacifico occidental), asi como la caracterizacion morfologica y la informacion biogeografica permiten sugerir que son dos especies distintas