Search

With the ongoing climate change affecting the ocean, there is a need to understand and predict the future distributions of marine species in order to assess the sustainability of marine ecosystem. In this study, remotely-sensed satellite oceanographic data together with Indian mackerel (Rastrelliger kanagurta) fishery dataset were used to predict potential fishing grounds in the Exclusive Economic Zone (EEZ) of Peninsular Malaysia using boosted regression trees (BRT) model. The model was developed using three years (2008–2010) fish catch data and environmental variables of chlorophyll-a (chl-a), sea surface temperature (SST) and sea surface height (SSH). Result indicated that potential fishing grounds were closely associated with SSH, followed by SST and chl-a. The performance of the BRT model indicated acceptable fishing grounds prediction accuracy (AUC value of 0.749). Seasonal variability in fishing grounds was related to favorable environmental conditions of SSH (1.1–1.3 m), SST (29–32 °C) and chl-a (0.3–0.6 mg/m3). The projection of increases in SST due to climate change according to IPCC-AR5-RCPs was observed to influence the spatial and temporal distributions R. kanagurta. Increased temperature at 1.80 °C resulted in high potential catch areas for R. kanagurta in the EEZ. Meanwhile, elevated temperature at 2.60 °C and 3.30 °C showed decreased in potential catch areas for R. kanagurta in the EEZ. Most of the future fishing grounds area were projected to decline, and it was observed to shift outside the EEZ off South China Sea. Hence, by understanding these relationships, this analysis identifies where strategies can be adapted to face the ecological impacts under changing environmental conditions.

This study reports the discovery of the exclusive predation of sea turtle hatchlings by several juvenile blacktip reef sharks (Carcharhinus melanopterus) in Chagar Hutang bay on Redang Island, Malaysia, in the South China Sea. Three dead specimens of C. melanopterus were retrieved from ghost nets, and the entire digestive tracts of these sharks solely contained the partially digested bodies of sea turtle hatchlings, with no evidence of the remains of any other prey. Thus, juvenile C. melanopterus may opportunistically feed primarily on turtle hatchlings during times when hatchling abundance is high.

The effects of temperatures (22, 26, 30 and 34 °C) and diets (commercial pellet and shrimp) on the growth properties and gastric emptying time (GET) of the tiger grouper × giant grouper (TGGG) hybrid were analyzed over a 30 day experimental period under controlled laboratory conditions. Food consumption (FC), food conversion rate (FCR), specific growth rate (SGR) and GET were significantly influenced by temperature and diet type. The highest mean SGR (1.00% BM day−1, p 0.05) were observed between any of the groups at 22 and 34 °C fed on either the shrimp or the pellet diet. The lowest statistically significant (p

In this study we aimed to analyze the effects of water temperature and diet on the length-weight relationship and condition of juvenile Malabar blood snapper Lutjanus malabaricus over a 30-d experimental period. The experiment was conducted in the laboratory using a flow-through-sea-water system. The fish were subjected to four different temperatures (22, 26, 30, and 34 °C) and two diets (commercial pellet and natural shrimp). Fish were fed twice daily. L. malabaricus exhibited negative allometric growth (b3) at 30 °C fed with shrimp diet, which indicated that fish weight increases faster than their length. The rest of the temperatures represented negative allometric growth (b

The sampling programme was conducted to determine the diversity and abundance in fish assemblages from June 2011 to July 2012 using gill and trawl nets and traps. A total of 13,132 individuals of fishes comprising 116 species and 50 families were recorded. Family Siganidae had the highest family abundance recorded with 43.0%. Siganus javus was determined as the most abundant species with a percentage value of 38.8%. Ninety species were caught and considered to be commercially valuable. Four species were recorded as vulnerable in the IUCN Red List, which were Hippocampus spinosissimus, Hippocampus trimaculatus , Himantura uarnak, and Pegasus laternarius; while Himantura walga, Favonigobius melanobranchus, Favonigobius rechei. Epinephelus coioides , and Epinephelus diachanthus were listed as near threatened. Overall values of diversity, richness and evenness indices were found to be 2.60, 12.12 and 0.55, respectively. Estimates from these indices were an indication of high fish species composition, richness, and evenness in the population of fishes in Setiu wetlands. It is recommended that government should gazette the Setiu Wetlands as a state park in Terengganu for future planning.

Trace metals (Cu, Zn, Cd and Pb) concentrations in muscles, livers and gills of three important marine fishes, Torpedo Scad (Megalaspis cordyla), Sea Catfish (Arius thalassinus) and Belangeri Croaker (Johnius belangeri) were studied using the Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The samples were collected from Mersing the eastern coastal waters of Peninsular Malaysia. The estimated ranges of Cu, Zn, Cd and Pb concentrations in the muscles, livers and gills of the three fish species were 1.51-3.48, 17.54-28.34, 0.02-0.12 and 0.12-0.15; 15.8-26.0, 80.58-365.1, 2.32-6.14 and 0.57-1.54; 3.04-5.51, 61.63-259.3, 0.03-0.12 and 0.14-2.03 μg g-1 dry weight, respectively. Metal concentrations in the edible parts of the fish were assessed for human consumption according to the Provisional Tolerable Weekly Intake (PTWI) and Provisional Tolerable Daily Intake (PTDI). Generally, levels of metal in muscles were lower than those in livers and gills. Zinc concentration was found to be the highest among the tested metals in all three species. The estimated weekly and daily intakes for the studied metals were far below the PTWI and PTDI limits. Present study reveals that consumption of these fishes from the study area does not pose a risk to human health.

Larval stage of marine fishes, habitat characteristics, nursery and feeding ecology has been discussed in this review. Identification of fish larvae is difficult and that is why limited research is available on biology of fish larvae in the Indo-Pacific coastal region. Estuaries play a vital role in energy transfer between a river and a sea, which is especially important for many commercial coastal fishes whose larvae and juveniles are dependent on the estuary as a nursery and feeding grounds. Many coral reef fish species use mangrove and seagrass beds as nursery habitats. Diet composition of the family Clupeidae were made up of seven major categories to include phytoplankton, plant-like matter, debris, fragment of copepod, algae and unidentified food items. The most predominant food item in the gut of clupeids was phytoplankton (82.53%).

Morphometnc data of six dominant families of fish larvae were examined to observe the degree of similarity among the six families. The experiment was conducted in the seagrass-mangrove ecosystems of Gelang Patah, Johor Strait, Peninsular Malaysia. Samples of fish larvae were collected by using bongo net through 30 min subsurface tow. The six dominant families (Terapontidae, Gobndae, Sillaginidae, Nemipteridae, Blenniidae and Leiognathidae) were selected for the morphometric analysis using one-way ANOVA by SPSS and PRIMER 5 software for cluster analysis. All the morphometric characters, total length, standard length, body depth, snout length, head length, eye diameter and pre anal length of the six dominant families of the order Perciformes were found to be significantly different (p

Reproductive biology of the introduced sailfin cat fish Pterygoplichthys pardalis in the Langat River of peninsular Malaysia was studied. Fish samples were collected monthly from Langat River during March 2003 - June 2004. The sex ratio observed for P. pardalis was female-biased with 1: 2. Gonadal maturity stage is achieved at 12.5 cm standard length (SL) for males and 13.0 cm SL for females. This species appeared to have continuous spawning that peaked when water levels were high between September and January. Egg sizes were found to reach as large as 3.3 mm in dia in the ovary; suggesting that they spawn in batches. Fecundity varied from 1297 to 18791 numbers per brood, proportional to individual size. Data obtained from this study indicate that the introduced sailfin cat fish has successfully colonised in Langat River in Malaysia.

Water temperature can influence the metabolic rate of ectothermal animal such as, fish. This study aims to investigate the gastric emptying time (GET) of malabar blood snapper (L. malabaricus) at different temperature (22, 26, 30, 34°C) fed with commercial diet pellet. The gastric emptying times at different temperatures were determined X-radiographically, using barium sulfate (BaSO4) as a contrast medium food marker. The food marker and X-radiography showed that initial voidance of fecal matter began 4-8 h after feeding at all temperature. The fastest GET (18 h) was obsereved at 30°C, whereas the longest (28 h) GET was seen at 22°C. GET was increased with increasing temperature up to 30°C whereas decreased at extreme (34°C) and stress temperature (22°C). The findings of this study suggest to culture L. malabaricus at 26-30°C with commercial diet pellet as this temperature ranges escalate the faster digestion process which may contribute faster growth rate of this commercially important fish species. Overall, the data obtained from this study may have important consequences for optimization of commercial production of malabar blood snapper.

Laevistrombus canarium Linnaeus, 1758 is one of the important edible sea snail within the western Johor Straits, Malaysia. In this study, the impact of temperature on oxygen consumption (MO2) of L. canarium based on their ontogenetic changes (juvenile and adult) was measured in the laboratory condition at 22.0, 26.0, 30.0 and 34.0°C. Measurement of MO2 were taken every 1 s for 60 min on 4.20 – 34.00 g dog conch using respirometry chamber. All experiments were carried out in static conditions in five replicates with one snail per chambers. The results of oxygen consumption showed that juvenile dog conch respired at the rate of 0.163 ml h−1 and adult respired at the rate of 0.119 ml h−1. Consequently, the oxygen consumption in juvenile and adult dog conch was expressed as a total energy spends. The results indicates that total energy spend for oxygen consumed (ml h−1) of L. canarium at different temperature regimes (22.0 to 34.0°C) slightly increased over time period (0.63 ± 0.12 to 3.24 ± 0.05 J h−1) respectively. This finding of the present study suggested L. canarium is well adapted for life in high temperature environment.

Knowledge of fish gastric emptying time is a necessary component for understanding the fish feeding rates, energy budgets and commercial production of fishes in aquaculture. The hybrid grouper Epinephelus spp. is getting popular as a culture species in Malaysia for their faster growth rate compared to commonly cultured grouper species (giant grouper Epinephelus lanceolatus and tiger grouper Epinephelus fuscoguttatus). There are data suggests that elevated sea water temperature affects gastric emptying time (GET) of fishes. Hence, this study aims to study the GET of hybrid grouper at different temperature (22, 26, 30, 34°C) in laboratory condition with commercial diet pellet. The gastric emptying times (GETs) at different temperatures were determined X-radiographically, using barium sulfate (BaSO4) as a contrast medium food marker. The food marker and X-radiography showed that initial voidance of fecal matter began 4-6 h after feeding at all temperature. The fastest GET (13 h) was obsereved in the 30°C gro...

Macrobenthos are very useful organisms for monitoring marine environmental and widely use in marine ecology research. They are able to monitor the difference phase in the recovery stage of disturbed sites by appear different species macrobenthos after the cessation of the impact. Univariate and multivariate methods were use to study the macrobenthos community within Sungai Pulai estuary, Johor, Malaysia. Five sub-samples were taken at each sampling sites by using 10 cm diameter corer. Crustaceans were the most abundant at Tanjung Adang (St. 1) and the station of non-seagrass area (St. 2) while polychaetes were the most abundant at Merambong Shoal (St. 3). Higher density of macrobenthos was found at St.3 followed by St. 1 and St. 2. The commonly used population indices such as diversity, richness, evenness and dominance were employed to determine the differences in diversity and abundance of macrobenthos. The diversity, richness and evenness index values showed slight increment from Station 1 to Station 3, while the dominance index decreasing trend from Station 1 to Station 3. A total 21 polychaete families were collected in Sungai Pulai estuary, which was dominated by the Spionidae, Capitellidae and Glyceridae. Cluster (Bray-Curtis similarities) analyses revealed that the Tanjung Adang and Merambong Shoal population were clearly separated from the station non-seagrass. For the time being factors that influence the pattern of distribution of the macrobenthos cannot be determined and subjected to further studies.

The volutid, Cymbiola nobilis Lightfoot, 1786, is a gastropods molluscs that inhabit deep seas and traditionally harvested by locals for food and hence fetch a high market value. The objective is to study the development of volutid and larval production as an effort to restore depleted natural population of this species. Egg masses used in this study was collected while still underneath spawning females, and embryonic and post-hatching larval development was observed in the laboratory. The larvae were reared in 50 × 100 cm aquarium with 0.22 μm filtered seawater medium at a salinity of 30 ± 1 PSU. Fecundity was estimated at 29 eggs/egg mass (n=10). The juvenile hatching was exactly the same as the adult. Base on this study the morphological features of Cymbiola nobilis can be assigned to eight different development stages beginning from egg described in this paper. The metamorphosis stage were took place in the egg and it is about 7 days before become pre-hatching juvenile. They showed a short period of metamorphic competence and morphological changes also described.

Megalaspis cordyla popularly known as hard-tail scad or torpedo scad is a commercially important fish in Malaysia. The present study describes the length-weight relationship and trophic level of M. cordyla collected from the coastal waters of Tanjung Sepat, Selangor, Malaysia from December 2010 to November 2011. A total of 375 specimens ranging from 17.3-37.5 cm total length and 52.40-451.12 g body weight were analysed in this study. The growth form meant that the allometric coefficient b of the length-weight relationships was less than three, suggesting negative allometric growth for males (b = 2.65), females (b = 2.77), and combined sex (b = 2.64). The regression coefficient was not significantly different between the sexes. Stomach content analysis revealed that both males and females fed mostly on teleost (90%, 88%) followed by crustaceans (7%, 8%) and molluscs (4%, 4%), respectively. The estimated mean trophic level for the males and females were 3.67 0.04 and 3.84 0.05, respectively, indicating that they are largely carnivorous. In this study we found less diverse diets compared to previous reports, which might be indicative of anthropogenic disturbance to their food chain and ecosystem.