Correlation Between Different Physical and Engineering Properties of Tropical Peat Soils from Sarawak

The present paper describes the physical and engineering properties of tropical peat soils from Sarawak, Malaysia. Different physical properties such as organic content (OC), liquid limit (LL), fibre content (FC), specific gravity (Gs) and engineering properties (mainly the standard Proctor test) have been conducted on remoulded peat soil samples. The results show that, the value of LL, FC, Optimum Moisture Content (OMC) increases with an increase in OC. Also the results show that, Gs and MDD decrease with increasing values of OC. Furthermore, the plot of OC against Gs from the current study is compared with other researchers; whereby the correlation shows that R2 values ranges from 0.71 to 0.95. This demonstrates that findings on local peat soils from Sarawak are in good agreement with other researchers as similar trends are observed. Consequently, geotechnical engineers can refer these correlations to comprehend the preliminary behavior of peat soil, where the geotechnical data are not readily available

Population parameters of Rastrelliger kanagurta (Cuvier, 1816) in the Marudu Bay, Sabah, Malaysia

An investigation of the population parameters of Indian mackerel, Rastrelliger kanagurta (Cuvier, 1816) in the Marudu Bay, Sabah, Malaysia was carried out from January to September 2013. The relationship between total length and body weight was estimated as W=0.006TL3.215 or Log W=3.215LogTL – 2.22 (R2=0.946). Monthly length frequency data of R. kanagurta were analyzed by FiSAT software to evaluate the mortality rates and its exploitation level. Asymptotic length (Lµ) and growth co-efficient (K) were estimated at 27.83 cm and 1.50 yr-1, respectively. The growth performance index (φ') was calculated as 3.07. Total mortality (Z), natural mortality (M) and fishing mortality (F) was calculated at 4.44 yr-1, 2.46 yr-1 and 1.98 yr-1, respectively. Exploitation level (E) of R. kanagurta was found to be 0.45. The exploitation level was below the optimum level of exploitation (E=0.50). It is revealed that the stock of R. kanagurta was found to be still under exploited in Marudu Bay

Embryonic and larval development of lemon fin barb hybrid (♂ Hypsibarbus wetmorei × ♀ Barbonymus gonionotus)

Aim: The Lemon fin barb hybrid was developed by crossing Lampam (Barbonymus gonionotus) females with Kerai (Hypsibarbus wetmorei) males as a potential food source for lower income people in Malaysia due to fast growth and ease of culture. For delicious flesh and high market demand, the farming of this hybrid has subsequently expanded rapidly. Many of the basic biological aspects of this hybrid have not yet been investigated and in this study the embryonic and early larval development were examined. Methodology: After injecting the brood-stocks with hormones, the matured eggs and sperms were collected by strip spawning. The developing embryonic stages were subsequently observed at 10 min intervals for the first hour, 20 min intervals at the second hour, 30 min for the next hour, and then hourly intervals up to hatching. After hatching, observations continued at 2 hr intervals for the first day and a minimum of 6 hr intervals for the following days. Results: In the consortium, there was more than 2-fold increase in the maximum algal specific growth rate and a 1.3-fold increase in the maximum bacterial specific growth rate. Furthermore, the maximum ethylene glycol removal efficiency by consortium was 89%, while those by bacteria monoculture was 31%. No apparent removal of ethylene glycol by the C. fusca monoculture was observed. Interpretation: This study represents the first description of the early development stages for Lemon fin barb hybrids that may assist with the establishment of seed production and rearing techniques for aquaculture development in Malaysia

Effects of bottom substratum on survival and growth of early juveniles of blue swimming crab, (Linnaeus, 1758) in captivity

Aim: Cannibalism remains a limiting factor during the nursery culture of crabs. This study was undertaken to improve the rearing techniques by investigating the impact of bottom substratum on crablet survival and growth. The knowledge gained from the research will be useful for the communal seed culture and development of crab farming, which are important factors regarding farmers' job stability in the future. Methodology: Blue swimming crab, Portunus pelagicus (first settled (C1 crabs); initial average weight and SD of 0.02 ± 0.01g) were cultured in glass aquarium (90 x 44 x 34 cm) and their survival and growth were assessed after 22 days of culture in four types of substratum such as control (none), sand, soil, or sand + soil. All treatments had 25 juvenile crabs, each of which was triplicated. Feeding was done twice a day (9 am and 5 pm) to apparent satiation. Results: Survival of early juvenile crabs cultured with sand was substantially higher at 65.33 ± 6.11% than those cultured with soil, sand + soil or control at 29.33 ± 10.07%, 28.00 ± 8.00%, and 21.33 ± 6.11%, respectively. Growth performance (such as final weight, weight gain and specific growth rate) of the early juvenile of P. pelagicus in all treatments were not significantly different (p>0.05). Interpretation: Overall, the best survival was achieved with sand substratum and can be recommended as a mean of reducing cannibalism during the early nursery rearing of blue swimming crab juveniles under captive culture conditions

Size frequency and length-weight relationships of spined anchovy, Stolephorus tri from the coastal waters of Besut, Terengganu, Malaysia

Study on length-weight relationships of anchovy, Stolephorus tri collected from Benting Lintang (Lat. 5°44'33.62 N and Long. 102°39'22.84 E), the coastal waters of Besut, Terengganu was carried out on June and July 2010. Stolephorus tri are important component of marine ecosystems and commercially significant marine food resources in Malaysia. The mean size length of Stolephorus tri was 63.53 mm with a range of 51.0-76.0 mm. The average weight of Stolephorus tri was 1.57 g. The relationship between total length and body weight of Stolephorus tri was Log W = 3.0384 Log TL-5.2923 (W = 0.00001 TL3.0384). It is revealed that the exponent ‘b’ for Stolephorus tri was very close to the isometric value (b = 3). Therefore, the relative growth of Stolephorus tri was isometric in the coastal waters of Besut, Terengganu

Population parameters of Rastrelliger kanagurta (Cuvier, 1816) in the Marudu Bay, Sabah, Malaysia

An investigation of the population parameters of Indian mackerel, Rastrelliger kanagurta (Cuvier, 1816) in the Marudu Bay, Sabah, Malaysia was carried out from January to September 2013. The relationship between total length and body weight was estimated as W=0.006TL3.215 or Log W=3.215LogTL – 2.22 (R2=0.946). Monthly length frequency data of R. kanagurta were analyzed by FiSAT software to evaluate the mortality rates and its exploitation level. Asymptotic length (Lµ) and growth co-efficient (K) were estimated at 27.83 cm and 1.50 yr-1, respectively. The growth performance index (φ') was calculated as 3.07. Total mortality (Z), natural mortality (M) and fishing mortality (F) was calculated at 4.44 yr-1, 2.46 yr-1 and 1.98 yr-1, respectively. Exploitation level (E) of R. kanagurta was found to be 0.45. The exploitation level was below the optimum level of exploitation (E=0.50). It is revealed that the stock of R. kanagurta was found to be still under exploited in Marudu Bay

Embryonic and larval development of endangered Temoleh, Probarbus jullieni (Sauvage)

The present study was carried out to investigate the embryonic and larval development of the endangered Temoleh, Probarbus jullieni in lab-rearing condition. The matured egg and sperm were collected by stripping the bloodstock of Temoleh fish after injecting with ovaprim hormone extract. The samples were collected from hatching tank at every 10 min interval for the first hour, 20 min for the second hour, 30 min for the third hour and then hourly interval up to hatching. After hatching, larvae were observed daily until the complete disappearance of the yolk sacs. The fertilized eggs were spherical, demersal, adhesive and brownish-yellow in colour with a mean diameter of 2316 μm. First cleavage occurred within 10 min post-fertilization at temperature ranged from 26.0 to 28.0°C. Hatching started 22 h post-fertilization and completed within 25 h at the same temperature. The yolk sac was completely absorbed 61 h after hatching. At the same time, the larvae started to swim actively and feed exogenously. This marks the first description on the early life history of P. jullieni. The present study will provide some valuable information on the ontogeny, breeding biology and early larval rearing protocol of P. jullieni which will ultimately be helpful towards the establishment of large scale seed production technique for conservation and aquaculture production