The Use Of Water- And Pocket-Pulse Amplitude Modulation In Investigating Photophysiology And Nutrient Limitations In Microalgae

Investigating photosynthesis and nutrient limitations of microalgae allow for insight into how cells will respond to different environmental or physical stressors particularly nutrients. Advances in chlorophyll fluorescence techniques have provided a means for rapid and non-invasive measurement of microalgal ecophysiology. Furthermore, available Pulse Amplitude Modulation (PAM) fluorometers in the market present different technical characteristics and configuration which may lead to different photosynthetic parameters output. Here the photosynthetic activities of microalgae were observed using both Water-PAM and Pocket-PAM to validate the differences between these two fluorometers

A CHECKLIST OF FREE-LIVING MARINE NEMATODES AT DIFFERENT ECOSYSTEM IN NORTHERN STRAITS OF MALACCA, MALAYSIA

Nematodes present in all substrates and sediment types with an enormous number of species. The studies on free-living marine nematodes are still limited in Malaysia. The present study provides general information on genus checklist of free-living marine nematodes in the northern part of Peninsular Malaysia in a different ecosystem which are intertidal zones of estuarine, sandy beach and mangrove ecosystems.  Samples were randomly collected at three stations in each ecosystem. A total of 34 genera (22 families and ten suborders) were recorded in three ecosystems. Each ecosystem had common genera which also commonly found worldwide. Viscosia genus was observed in all three ecosystems. The nematode genera of Estuary and mangrove ecosystems had greater similarities than those in the sandy beach

The Abundance and Spatial Distribution of Soft Sediment Communities in Tanjung Bungah, Malaysia: A Preliminary Study

Abstract: Benthic faunal communities are important components in the intertidal zones. The diversity and abundance of the benthic communities are subjected to different natural and anthropogenic disturbances. The study was conducted as one off sampling on 6th November 2013 (1) to investigate the abundance and distribution of soft sediment communities in relation to environmental variables and (2) investigate the changes of population structure and diversity using spatial scales of 1 m, 10 m, and 100 m. Results indicated a total of 110 individuals of macrobenthos consisting of 7 different groups (Annelida, Bivalvia, Crustacea, Gastropoda, Nematoda, Nemertea, Polychaeta) and 4 different groups of meiobenthos (Copepoda, Nematoda, Ostracoda, Polychaeta) consisting 920 individuals were recorded. Dissolved oxygen played the most significant role in affecting the distribution of soft sediment communities while ammonia concentrations only affected marcobenthic organisms. However, sediment grain size did not show significant correlation (p>0.05) on soft sediment communities. Hence, understanding how different properties of benthos respond to changes in environmental variables is crucial in determining how the impacts on the sediment are tolerated by the benthic organisms

PRELIMINARY OBSERVATION OF TROPICAL DIATOM <em>Thalassiosira</em> spp. FROM TELUK BAHANG, PENANG

This study describes the morphological structure of Thalassiosira spp. found in coastal water and intertidal area of Teluk Bahang, Penang. Examination of the samples collected from January 2015 to June 2016 showed that these species were the common genera in both benthic and surface seawater at Teluk Bahang. To obtain phytoplankton samples, five liters of seawater were filtered through the plankton net (35 µm). While for benthic samples, the samples were collected at sediment surface of 1 mm depth. Samples of Thalassiosira spp. were obtained from both phytoplankton and benthic samples. Scanning electron microscope (SEM) was used to study the morphology of Thalassiosira spp. Results from the SEM showed distinct differences in areolae pattern, sizes, position and number of processes among Thalassiosira spp. (Thalassiosira nanolineata, Thalassiosira densannula, and Thalassiosira gravida). Thalassiosira densannula and Thalassiosira nanolineata were found in both habitats, coastal and benthic area while Thalassiosira gravida was found only in coastal water. Thalassiosira spp. contribute approximately 15% of the total benthic community and approximately 35% of the total phytoplankton community