Norhafizah Osman

Growth, mortality and recruitment of the sergestid shrimps Lucifer intermedius, collected from the Sungai Pulai seagrass area in Johor, Peninsular Malaysia was investigated between April 2007 and December 2007 using monthly length-frequency data. The shrimps were collected during the day by subsurface towing of a Bongo net with a mesh size of 500 μm for 30 minutes. Total length was measured monthly for 50 individuals and the estimated extreme length was 10.42 mm. The von Bertalanffy growth parameters, K and L∞ were estimated as 1.40 yr-1 and 11.10 mm, respectively. The growth performance index (φ’) was 2.237 while total mortality (Z) was calculated at 5.32 yr-1. The natural and fishing mortality was 2.99 yr-1 and 2.33 yr-1, respectively. The recruitment pattern of L. intermedius was continuous throughout the year with two major peaks. The exploitation rate (E) was estimated at 0.44. This indicates that fishery status of L. intermedius in the Sungai Pulai sea grass area of Johor Stra...

Information on the relations between phytoplankton communities and the environment is limited for the man-made lakes in Malaysia. This paper presents the results of a study on the diversity and seasonal succession of phytoplankton in Seri Serdang Lake and Faculty of Engineering Lake conducted between November 2013 and February 2014. A total of 27 species from four phyla (Chlorophyta, Euglenophyta, Cyanobacteria, Bacillariophyta) and 33 species belonging to Cyanobacteria, Chlorophyta, Bacillariophyta, Euglenophyta and Dinophyta were identified from Seri Serdang Lake and the Faculty of Engineering Lake, respectively. Chlorophyta were most dominant in both lakes. Highest number of species recorded was Monoraphidium sp. in Seri Serdang Lake and Pediastrum tetras in Faculty of Engineering Lake. Seri Serdang Lake had lower phytoplankton density (20 cells ml–1 to 396 cells ml–1) as compared to the Faculty of Engineering Lake (250 cells ml–1 to 300 cells ml–1). Although the distance between...

Microalgae has been getting broad attention of researchers and investors lately, especially when discussing on healthy food and energy sources for the future. In this study, twelve samples of mixed microalgae from outdoor ponds were analyzed for their fatty acid compositions. The potential of microalgae to solve variety of world’s problems was not realized because of bottleneck in microalgal supplies at reasonable cost. Therefore, the objective of this study is to determine fatty acid profiles of mixed microalgae from tilapia fish ponds. The study was conducted in Tapak Ternakan Ikan, Taman Pertanian Universiti and Department of Biology, Faculty of Science, Universiti Putra Malaysia. Mixed microalgae were extracted for their lipids with methanol: chloroform mixture and after transesterification, the fatty acid methyl ester were analyzed using gas chromatography equipped with flame ionization detector. Results showed that saturated was the major constituent fatty acids. The average p...