13 research outputs found
Taxonomic composition and abundance of zooplankton Copepoda in the coastal waters of Bintulu, Sarawak, Malaysia
The abundance and composition of copepod was carried out in the coastal waters of Bintulu, Sarawak, Malaysia on March 2005. Samples were collected using conical plankton net with the mesh size of 153 μm. Copepod identified comprised of four orders namely, Calanoida, Cyclopoida, Harpacticoida and Poecilostomatoida. A total of 49 species belonging to 26 genera were identified. Nine most abundant species were Paracalanus crassirostris, Paracalanus elegans, Temora stylifera, Temora turbinata, Oncaea venusta, Corycaeus andrewsi, Corycaeus subtilis, Paracalanus parvus and Paracalanus denudatus. The first four species mentioned were the most abundant species and they accounted for over 50% of the total numbers of identified copepods. Copepod species which were rare and low in abundance included Delius nudus, Acrocalanus gracilis, Tortanus forcipatus, Centropages orsini, Corycaeus dahlia, Copilia mirabilis, Labidocera minuta, Microstetella rosea and Cosmocalanus darwini. Cosmocalanus darwini is new record to Malaysian waters. Species richness and diversity tends to increase towards the offshore while abundance increased towards the inshore stations
Checklist and habitat descriptions of edible gastropods from Sarawak, Malaysia
Sarawak comprises of vast areas of wetland which is the habitat of huge number of edible gastropods. Among the wetland faunal composition, the edible gastropod is one of the important sources of animal protein for the local communities. This diversity of edible gastropod was studied from seven Divisions of Sarawak namely Kuching, Sibu, Mukah, Bintulu, Miri, Limbang and Lawas. Samples were collected from the wet market and catches from local fishermen. A total of 21 species representing 11 families and 16 genera of edible gastropods were identified from Sarawak. Cerithidea spp. was represented by three species while both Nerita and Pomacea were made up of three and two species each. Others were each represented by one single species. Six edible gastropod species belonged to the freshwater habitat while seven and eight species were recorded from brackish and marine habitats, respectively. Cerithidea and Pomacea showed wide geography amongst the Division and also highly distributed. Edible gastropods have high market value in the state of Sarawak and contribute significantly to the livelihoods of the certain indigenous communities in the state
Inner shell as variation key of local hard clam Meretrix spp.
The morphology and 12 shell morphometric features proportionate to shell length were analysed between local hard clam; Meretrix lyrata, M. meretrix and M. lusoria from Sarawak, Malaysia. Meretrix spp. was observed to comprise a unique feature of a pallial sinus scar for each species. Analysis of variance revealed significant differences among Meretrix spp. using proportion ratios of SL for SW; LL; AL; LCT; AW; PW and PS (p<0.05). Cluster analysis among morphometric features of M. lyrata, M. meretrix and M. lusoria were discriminated at 98.5% similarities and supported by the principal component analysis. The present study suggests that pallial sinus scar shape, together with interior and exterior morphometric features, were suitable as identification keys for Meretrix spp. Hence, the present study emphasizes on the application of interior, rather than exterior morphology and morphometric features in hard clam identification before further investigation can be performed through genetic identification means
Effects of salinity on physiological, biochemical and gene expression parameters of Black Tiger Shrimp (Penaeus monodon): potential for farming in low-salinity environments
Salinity is one of the most important abiotic factors affecting growth, metabolism, immunity and survival of aquatic species in farming environments. As a euryhaline species, the black tiger shrimp (Penaeus monodon) can tolerate a wide range of salinity levels and is farmed between brackish to marine water conditions. The current study tested the effects of six different salinity levels (0‰, 2.5‰, 5‰, 10‰, 20‰ and 30‰) on the selected physiological, biochemical and genetic markers (individual changes in the expression pattern of selected candidate genes) in the black tiger shrimp. Experimental salinity levels significantly affected growth and survival performance (p < 0.05); the highest levels of growth and survival performance were observed at the control (20‰) salinity. Salinity reductions significantly increased free fatty acid (FFA), but reduced free amino acid (FAA) levels. Lower salinity treatments (0–10‰) significantly reduced hemolymph osmolality levels while 30‰ significantly increased osmolality levels. The five different salinity treatments increased the expression of osmoregulatory and hemolymph regulatory genes by 1.2–8-fold. In contrast, 1.2–1.6-fold lower expression levels were observed at the five salinity treatments for growth (alpha amylase) and immunity (toll-like receptor) genes. O2 consumption, glucose and serotonin levels, and expression of osmoregulatory genes showed rapid increase initially with salinity change, followed by reducing trend and stable patterns from the 5th day to the end. Hemocyte counts, expression of growth and immunity related genes showed initial decreasing trends, followed by an increasing trend and finally stability from 20th day to the end. Results indicate the farming potential of P. monodon at low salinity environments (possibly at freshwater) by proper acclimation prior to stocking with minimal effects on production performance
SYMBIOTICALLY SNAPPER SHRIMP ANCHISTUS CUSTOIDES BRUCE, 1977 (DECAPODA: PALAEMONIDAE) INHABITING THE MANTLE CAVITY OF THE PEN SHELL (BIVALVIA: PINNIDAE)
Snapper shrimp is a symbiotic organism usually hidden under the rocks,
sponges and pen shells in the seagrass and coral habitats. The relationship study within
snapper shrimp and pen shell was conducted from Merambong shoal, one of the biggest
seagrass beds in peninsular Malaysia. A total of 40 individual pen shells were collected
randomly and four species of pen shells were identified. 40 Anchistus custoides were found
inhabiting symbiotically in the mantle cavity of the pen shell as solitary males and females
and heterosexual pairs. Pen shell, Pinna bicolor and Atrina vexillum recorded the highest
average SH 217.79±53.15 mm, SV 2.62±1.36 dm3 and SH 164.10-224.78 mm with the SV
1.18±0.43 dm3, respectively compared to the other species. The size of Anchistus custoides
ranged from 15.00 to 20.00 mm in length and it was determined to be female due to the
presence of eggs in the pleopods. The length of the cephalothorax and its length were
highly related (rs=0.563, p≤0.01, N=40) and found wider in females. A little difference
in size between the left and right chela in males of identical length was noticed, although
the left chela is much bigger than the right. The significant relationship (rs=0.450, p≤0.01,
N=40) between the pen shell length and shrimp (male-female) length revealed that the size
of the shell is important to be hosted the snapper shrimp in the shell cavity
Distribution of zooplankton community in Toli shad (Tenualosa toli) habitats, Sarawak, Malaysia
The river ecosystems of Sarawak has been identified as important-spawning ground for economically important Toli shad (Tenualosa toli) fisheries. In these river ecosystems, zooplankton serves as a secondary producer to the different types of fish larvae including Toli shad. The productivity and biomass of zooplankton are important factors to control the production of higher trophic level organisms like fish larvae and fishes in different stages including T. toli larvae. In this viewpoint, the composition and abundance of zooplankton were investigated at 5 (five) sampling stations (considered to be spawning and nursing areas of Toli shad) at Batang Lupar and Batang Sadong estuaries from July 2016 to June 2017. A total of 29 zooplankton taxa were recorded that belong to 14 major groups comprised of Copepoda (Arthropoda), Crustacean nauplii (Arthropoda), Fish larvae (Chordata), Mollusca (Mollusca), Luciferidae (Arthropoda), Cnidaria (Cnidaria), Ostracoda (Arthropoda), Cirripedia (Arthropoda), Polychaete larvae (Annelida), Chaetognatha (Chaetognatha), Appendicularia (Chordata), Amphipoda (Arthropoda), Echinodermata larvae (Echinodermata) and Cladoceran (Arthropoda). Copepod was dominant group of zooplankton (82.40-94.41%) at all stations, contributing 477.37-25921.89 ind/m3 and 88.38% of total abundance. The second highest was crustacean larvae (2.45-9.38%) in all stations, contributing 0-2391.7 ind/m3 and 5.88% of total abundance. Zooplankton abundance was higher at downstream station 1 (8460.72 ind/m³) followed by station 2 (5479.80 indi/m³), station 3 (4571.95 ind/m³), station 4 (4394.20 ind/m³) and upstream station 5 (4156.73 ind/m³). Canonical Correspondence Analysis showed that the abundance of copepods was highly influenced by total turbidity and nitrate in the riverine and estuarine ecosystems. Abundance of zooplankton was relatively higher (9549.31 ind/m³) during the post-monsoon and lower (3534.56 ind/m³) during the southwest monsoon
Towards nationally curated data archives for clinical radiology image analysis at scale: Learnings from national data collection in response to a pandemic
The prevalence of the coronavirus SARS-CoV-2 disease has resulted in the unprecedented collection of health data to support research. Historically, coordinating the collation of such datasets on a national scale has been challenging to execute for several reasons, including issues with data privacy, the lack of data reporting standards, interoperable technologies, and distribution methods. The coronavirus SARS-CoV-2 disease pandemic has highlighted the importance of collaboration between government bodies, healthcare institutions, academic researchers and commercial companies in overcoming these issues during times of urgency. The National COVID-19 Chest Imaging Database, led by NHSX, British Society of Thoracic Imaging, Royal Surrey NHS Foundation Trust and Faculty, is an example of such a national initiative. Here, we summarise the experiences and challenges of setting up the National COVID-19 Chest Imaging Database, and the implications for future ambitions of national data curation in medical imaging to advance the safe adoption of artificial intelligence in healthcare.</p