3356 research outputs found
Sort by
Assessment of growth and mortality parameters and exploitation rate to monitor the population status of wild catfish, Pangasius nasutus (Bleeker, 1863) in Pahang River, Malaysia
No full textPangasius nasutus is one of the popular freshwater fish species in Pahang River,
Malaysia because of its economic value, however, the high exploitation rate, occurrence of invasive
alien species in the same ecosystem, and habitat modification threatened its population sustainability.
This study aimed to enhance the existing information database of a species that has limited data
availability and to monitor its population status. The monthly samplings were conducted from the
upstream to the downstream of the Pahang River for 12 consecutive months from May 2021 to April
2022. The FiSAT II software was used to analyse population parameters from the length frequency
data. The results revealed the asymptotic length (L?) = 661.50 mm, growth coefficient (K) = 0.18
year-1, growth performance index (??) = 4.90, the maximum age (Tmax) = 16.67, total mortality (Z)
= 0.61 year-1, natural mortality (M) = 0.25 year-1, fishing mortality (F) = 0.36 year-1 and exploitation
rate (E) = 0.59 year-1. The results also showed that P. nasutus exhibits a slow growth rate, rendering
it more susceptible to overfishing. This study also indicated that the current level of exploitation of
P. nasutus population in the Pahang River appears to be appropriate. However, it is recommended
that a precautionary strategy be adopted to mitigate the risk of overexploitation
Aquaculture in an Offshore Ship: An On-Site Test of Large Yellow Croaker (Larimichthys crocea)
No full textShip aquaculture platforms are expected to become a meaningful way to expand offshore
farming. The growth performance and nutritional composition of the large yellow croaker reared
in an offshore ship aquaculture system and nearshore traditional cage system was evaluated in this
study. The results showed that the aquaculture ship could effectively avoid the harsh environment
such as typhoons and red tides. The test large yellow croaker adapted to the ship culture system in a
short time. No serious stress events occurred during the whole rearing process. During the culture
experimental period, the fish fed normally, and disease was controlled. The aquaculture ship has
good environment conditions during breeding with a water temperature of 21.5?28.5 C, salinity
20.7?31.8?, pH 7.6?8.4, dissolved oxygen 7.2?12.8 mg/L, ammonia nitrogen < 0.08 mg/L, and the
number of bacteria and vibrio in water were 1.2 103?1.6 103 CFU/mL and 1.2 102?1.8 102
CFU/mL, respectively. The survival, weight gain rate, and monthly weight gain of the large yellow
croaker in the ship were 99.02%, 41.48%, and 67.52 g, respectively, which were significantly higher
than those of cage culture. The crude protein content of the large yellow croaker raised in the ship
was significantly higher than that in the cage group, and the crude fat content was significantly lower
than that in the cage group. These results indicated that the growth performance and nutritional
composition of the large yellow croaker reared in offshore ship were better than those of the fish in
the cage. These findings enhanced our understanding of an offshore ship aquaculture model of large
yellow croaker
COMPARATIVE ANALYSIS OF PRISMA HYPERSPECTRAL AND SENTINEL-2 MULTISPECTRAL IMAGES FOR CHLOROPHYLL-A AND TURBIDITY MAPPING OF TAAL LAKE
No full textFreshwater bodies like Taal Lake play a pivotal role in providing essential resources like fresh drinking water and in supporting local livelihoods. This study aimed to examine the environmental conditions of Taal Lake by quantifying chlorophyll-a (chl-a) and turbidity levels with Water Colour Simulator (WASI) and water quality indices, specifically with Sentinel-2 and PRISMA imagery. The results from the satellite image-derived data revealed discernible variations in chlorophyll-a and turbidity concentrations across different regions of Taal Lake. Higher chlorophyll-a was consistently observed in the western regions (1.3-5.9 ?g/L for Sentinel-2; 1.4-5.4 ?g/L for PRISMA), while lower concentrations were found in the south (1.7-3.4 ?g/L for Sentinel-2; 1.9-3.3 ?g/L for PRISMA). Meanwhile, turbidity values were higher in the eastern and northeastern parts (0.15-0.59 mg/L for Sentinel-2; 0.13-0.51 mg/L for PRISMA). Water quality indices (NDTI & NDCI) also supported these findings. The findings of this comparative analysis between PRISMA hyperspectral and Sentinel-2 multispectral imagery demonstrate the potential of both satellite systems in providing valuable insights into the spatial distribution of water quality parameters in Taal Lake. Nonetheless, discrepancies observed in the scatter plots and inversion failures in PRISMA underscore the need for further research and refinement in utilizing PRISMA data with the WASI model. This study highlights the significance of freshwater bodies and the importance of monitoring their health for the well-being of communities and the environment
Metabolic scaling variation as a constitutive adaptation to tide level in Mytilus galloprovincialis
No full textUnderstanding how allometric exponents vary in the different biologically
determined patterns turns out to be fundamental for the development of a
unifying hypothesis that intends to explain most of the variation among taxa and
physiological states. The aims of this study were (i) to analyze the scaling
exponents of oxygen consumption at different metabolic rates in Mytilus
galloprovincialis according to different seasons, habitat, and acclimation to
laboratory conditions and (ii) to examine the variation in shell morphology
depending on habitat or seasonal environmental hazards. The allometric
exponent for standard metabolic rate (b value) did not vary across seasons or
tide level, presenting a consistent value of 0.644. However, the mass-specific
standard oxygen consumption (a value), i.e. metabolic level, was lower in
intertidal mussels (subtidal mussels: a = - 1.364; intertidal mussels: a = -
1.634). The allometric exponent for routine metabolic rate changed
significantly with tide level: lower allometric exponents for intertidal mussels (b
= 0.673) than for subtidal mussels (b = 0.871). This differential response did not
change for at least two months after the environmental cue was removed. We
suggest that this is the result of intertidal mussels investing fundamentally in
surface-dependent organs (gill and shell), with the exception of the slightly
higher values obtained in May as a likely consequence of gonadal tissue
development. Subtidal mussels, on the contrary, are probably in constant
demand for volume-related resources, which makes them consistently obtain
an allometric exponent of around 0.87
Effect of coconut (Cocos nucifera) water, and aqueous extract of Mung bean (Vigna radiata) sprouts and Moringa (Moringa oleifera) leaf on the growth and nutrition of Caulerpa racemosa
No full textCaulerpa racemosa, or sea grape, has a high nutritional content and offers many health
benefits to humans. The problem faced in cultivating sea grapes is growth, which affects production. This study aimed to determine the effect of different times of soaking C. racemosa in (Cocosnucifera) water, and aqueous extract of Mung bean (Vigna radiata) sprouts and Moringa (Moringaoleifera) leaf on its morphology and growth performance. Fifty grams of C. racemosa was soaked in coconut water and an aqueous extract of moringa leaves and mung bean sprouts at different times and was cultivated for 30 days. This study used a complete randomized design (CRD) with four treatments and three replicates: A (without soaking), B (extracts of Mung bean sprouts and Moringa leaves soaked for 2 hours), C (crude extracts of Mung bean sprouts and Moringa leaves soaked for 4 hours), D (coconut water soaked for 40 minutes), and E (coconut water soaked for 50 minutes). The results showed that the soaking process of C. racemosa in coconut water and aqueous extract of moringa and mung bean sprouts significantly affected the growth and nutrition of C. racemosa. Caulerpa racemosa soaked in coconut water for 40 minutes showed the highest absolute growth (206.66?7.96 g), specific growth (5.45?0.10 %/day), protein (9.11?0.29%), and fiber (1.02?0.20). The morphology of C. racemosa showed that the ramulli, rhizoid, fronds, and stolon were fresh, healthy, and clean. Soaking sea grape seeds in natural PGRs can increase the growth, production, and
nutritional content. Further research can be conducted, such as identifying the bioactive substance and its amount in coconut water
ANALISIS KESILAPAN TATABAHASA DALAM TAJUK FILEM HAUSA DALAM BAHASA INGGERIS: PENDEKATAN LINGUISTIK
No full text
