Development of sperm cryopreservation protocol for patin buah, Pangasius nasutus

The development of sperm cryopreservation for Pangasius nasutus is necessary in order to serve the growing demand of this species through artificial fertilization and the preservation of valuable strains of male broodstocks. In the present study, the basic protocol of sperm cryopreservation for P. nasutus was established by identifying the optimal conditions for optimum cryoprotectant, toxicity of cryoprotectants, extenders, freezing condition and dilution ratio. Methanol (MeOH) at 10% concentration had the best post-thaw motility (26.3 ± 0.9%) and curvilinear velocity (VCL) compared to dimethyl acetamide and dimethyl sulfoxide. MeOH was the least toxic cryoprotectant; sperm suspended in 5 and 10% MeOH maintained motility up to 50 min. No significant differences were detected between the three types of extenders tested (0.9% sodium chloride, Calcium-free Hanks' Balance salt solution and ringer solution). P. nasutus sperm had a narrow range of optimal cooling rate. Significantly higher post-thaw motility was identified when cooling at 9.23 °C min-1, obtained by freezing at height of 14 cm above liquid nitrogen vapor for 7 min, showing lower cooling rate is suitable for this species. However, when cooling below and above the optimal cooling rate, post-thaw motility dropped drastically. There were no significant differences among the dilution ratios investigated, indicating the volume of cryodiluent at all tested ratios (1:9, 1:19 and 1:49) was sufficient for the protection of cells during the cryopreservation process. The development of the protocol for cryopreserved P. nasutus sperm will assist artificial seed production and provide an important tool for genetic and breeding research.

Ovarian lavage method as an alternative route for hormonal administration and short-term sperm storage in Clarias gariepinus

Ovarian lavage is a term used to describe the injection of fish with a catheter through the oviduct into the ovary. In this study, the efficacy of this technique was evaluated as a route for hormone administration and sperm preservation in the African catfish Clarias gariepinus. Firstly, the effects of hormone injection routes (namely, intramuscular, intraperitoneal, and ovarian lavage) were evaluated on breeding and haematological parameters. In the second study, the fish's spermatozoa were stored in the ovaries for 1, 2, 3, and 4 days before stripping, sperm activation with freshwater, and fertilization. The breeding performance was then compared with eggs fertilized using spermatozoa refrigerated for the same duration. The study showed that the administration of synthetic hormone (ovaprim®) through the ovaries was comparable to the intramuscular route, while those injected intraperitoneally had the least values (P < 0.05) for breeding performance. The trend of the haematological parameters also suggests the intraperitoneal administration procedure elicited more stress compared to intramuscular or ovarian lavage routes (P < 0.05). In the second experiment, the use of sperm stored in the ovaries or refrigerated for 24hr didn't affect (P > 0.05) the fertilization (92-93%) and hatching (81-83%) of the eggs when compared to the control (91% and 82%). Beyond this 24hr threshold, breeding performances were significantly reduced in the ovarian lavage treatments compared to those fertilized with refrigerated sperm (P < 0.05). The loss of fertilizing capacity observed herein was justified by the reduction in sperm quality over time (P < 0.05). It was concluded that ovarian lavage is a viable route for hormonal administration and 24hr sperm storage in C. gariepinus.

Enhancing Reproductive Performance of Freshwater Finfish Species through Dietary Lipids

Dietary lipid manipulation in the feed of commercially cultured finfish is used not only to improve production and culture but also to enhance their reproductive performances. The inclusion of lipid in broodstock diet positively affects growth, immunological responses, gonadogenesis, and larval survival. In this review, existing literature on the importance of freshwater finfish species to aquaculture and the inclusion of dietary lipid compounds in freshwater fish feed to accelerate the reproduction rate is being summarized and discussed. Although lipid compounds have been confirmed to improve reproductive performance, only a few members of the most economically important species have reaped benefits from quantitative and qualitative lipid studies. There is a knowledge gap on the effective inclusion and utilization of dietary lipids on gonad maturation, fecundity, fertilization, egg morphology, hatching rate, and consequently, larval quality contributing to the survival and good performance of freshwater fish culture. This review provides a baseline for potential future research for optimizing dietary lipid inclusion in freshwater broodstock diets.

Isolation and identification of potential host probiotic bacteria from Malaysian mahseer, Tor tambroides for aquaculture practices

Abstract. Hossain MK, Iehata S , Noordin NM, Kader MA, Emilia SN, Sung YY, Abol-Munafi AB. 2022. Isolation and identification of potential host probiotic bacteria from Malaysian mahseer, Tor tambroides for aquaculture practices. Biodiversitas 23: 5423-5430. The digestive tract has been revealed as a reservoir of potential probiotics derived from the host. The goal of this study was to isolate, identify, and characterize putative host-associated probiotic bacteria (HAPs) from the digestive tract of Malaysian mahseer Tor tambroides. To evaluate potential T. tambroides HAPs, in-vitro digestive enzyme activity (such as a cellulolytic, proteolytic, and lipolytic activity) and antibacterial activity against two fish pathogens (Vibrio parahaemolyticus and Aeromonas hydrophila) were utilized. Thirty-seven isolates with digestive enzyme activities were tested for their ability to inhibit pathogenic bacteria growth using an agar well-diffusion assay. Three isolates displayed in-vitro suppression of pathogenic bacteria, with two strains (KT03 and KM07) inhibiting the growth of V. parahaemolyticus and one strain (KT27) suppressing the proliferation of both harmful bacteria (V. parahaemolyticus and A. hydrophila). Strains KT03 and KM07 exhibited the most resemblance to Enterococcus faecalis (strains 2674 and FC11682, respectively) based on 16S rRNA sequences, whereas KT27 had a 97% similarity to Aeromonas sp. A8-29. The study’s findings provide valuable data on the prospective use of these three isolates (KT03, KT27, and KM07) as potential HAPs for better understanding their physiological activities, such as growth and disease resistance on T. tambroides.

Morphological Variation between Hatchery Bred and Wild Caught Anabas testudineus in Malaysia

This study was designed to characterise the cultured and wild populations of Anabas testudineus in Malaysia using morphological parameters. Fish samples from the East and West coast of the country were obtained from fishermen (wild samples) and well-recognised climbing perch farmers in Kedah, Kelantan, Johor and Selangor. The Truss network method was applied to obtain necessary data and analysed to examine phenotypic variation between the cultured and wild stocks. Results obtained suggest that each hatchery population belonged to a distinct stock as revealed by their separate clustering into individual unique groups. However, an extensive overlap was observed in the wild population suggesting similarity of origin. The most important morphological parameters for the discrimination of the two populations are the homologous landmark B (i.e., snout to insertion of the pelvic fin) and C (i.e., above the eye to insertion of the pelvic fin). Genetic characterisation of the A. testudineus is needed to complement the findings of this study and establish a baseline for the development of a selective breeding programme for the fish species in Malaysia.

Genetic Variation between Triploid and Diploid Clarias gariepinus (Burchell, 1822) Using RAPD Markers

This study was designed to examine the use of RAPD markers in discriminating triploid and diploid African catfish Clarias gariepinus (Burchell, 1822). Following a routine technique, triploidy was induced by cold shock and confirm by erythrocyte measurement in C. gariepinus. Thereafter, 80 RAPD markers were screened; out of which, three showed the highest percentage of polymorphism (i.e., OPB 16 = 71.43%; OPC 14 = 61.9%; OPD 12 = 75%). The results obtained showed genotype differences between triploid and diploid without overlapping. However, the development of a Sequence Characterized Amplified Region (SCAR) marker was not achievable because progenies of triploid and diploid C. gariepinus could not be differentiated based on a specific fragment. Consequently, the genetic distance showed high similarities for both treatments and the UPGMA-generated dendrogram could not separate the treatments into two distinct clusters. It was concluded that RAPD makers cannot be used to separate the ploidy status of fishes.

Thermal Tolerance and Physiological Changes in Mud Crab, Scylla paramamosain Crablet at Different Water Temperatures

Simple Summary

The nursery phase of mud crab (Scylla spp.)—from megalopa to several, further crablet stagesneeds to be carried out in optimal environmental conditions, until they reach a larger size suitable to being stocked to a pond. This study observed the behavioral thermoregulation of crablet instar phases, and determined the effects of several levels of water temperature on growth, survival, molting cycle, gill condition, and sex ratio in the nursery phase of S. paramamosain. In this study, optimal temperature for the long-term nursery phase of S. paramamosain, beginning with megalopa stage, was found to be 28 to 30 °C, with the possibility that water temperature could affect the sex ratio of mud crabs. Findings of this study could result in increased crablet production from hatcheries, and assist in realizing potential of monosex seed production of S. paramamosain, through temperature treatment.

Abstract

This study was carried out to determine the physiological changes (survival, growth, molting cycle, sex differentiation, and gill condition) of mud crab, Scylla paramamosain crablet at different water temperatures of 24, 28 and 32 °C, and ambient temperature of 27 to 30 °C. Thermoregulatory behavior, represented by preferred temperature (29.83 ± SD 2.47 °C), critical thermal minimum (17.33 ± SD 0.58 °C), critical thermal maximum (40 ± SD 0.00 °C), and thermal tolerance interval (22.67 ± SD 0.58 °C), were checked for Crablet 1 stage only (with ambient temperature as acclimation temperature).Both low (24 °C) and high (32 °C) temperatures were associated with lower growth performance, and survival rate (p < 0.05), in comparison with both 28 °C and ambient temperature treatments.Male ratio at low temperaturetreatment (24 °C) was higher (80.09 ± SD 18.86%) than for other treatments (p < 0.05), observed as 44.81 ± D 10.50%, 41.94 ± SD 19.44%, and 76.30 ± SD 5.13% for 28 °C, 32 °C and ambient temperature treatments, respectively. However, there was no significant difference observed between 24 °C, 28 °C, and ambient temperature treatments. Anatomical alterations of gill lamellae of S. paramamosain crablet for both 32 °C, and 24 °C treatments, appeared thinner and paler than at both 28 °C, and ambient temperature treatments. Based on this study, temperature of 28 to 30 °C was recommended as the optimal temperature for the long-term nursery phase of S. paramamosain.

Dietary implications of toasted Jatropha curcas kernel on the growth, haematology, and organ histology of Clarias gariepinus fingerlings

The nutritional value of Jatropha curcas kernel (JCK) can be improved through different processing methods; however, when using a thermal treatment, optimization of the process is needed to prevent denaturation of nutrients. In this study, JCK was toasted for varying durations (0, 10, 20, and 30 min) and nutritionally evaluated. The implication of feeding Clarias gariepinus with dietary inclusions (35% CP; 315 kcal g^-1) of the toasted JCK was also reported. The results obtained suggest that prolonged duration of toasting improved the nutritional characteristics of the JCK until the 20th min. Beyond this time, the protein content and essential amino acids are reduced. However, the antinutrients continuously decreased with prolonged processing. The growth, carcass analysis, and haematology of the fish groups fed toasted JCK at varying duration also did better than those fed raw JCK. Importantly, the performance tends to reduce for those fed JCK toasted beyond 20 min. The estimated cost of producing 1 kg of the fish also substantially reduced with feeding the processed JCK than feeding raw JCK. Histological examination of the intestine and liver tissues further revealed fewer signs of histopathological degeneration for fish-fed processed JCK compared to the control. It was concluded that the processing of JCK by toasting should not exceed 20 min to improve the nutritional composition of the feed ingredients and their dietary utilization by fish.

Sexual dimorphism of Malaysian Mahseer, Tor tambroides broodstock reared in captivity: Morphometric measurements dataset

Despite having high economical value and declining wild population, the aquaculture of the Malaysian mahseer (Tor tambroides) is still way behind. Crucial information such as on its sexual dimorphism is scarce thus making its broodstock management in captivity challenging. The first step in studying fish sexual dimorphism is by observing and identifying the morphological differences between each sex. Thus, this article collected and described morphometric measurements data of broodstock reared in captive conditions. The broodstock were reared and raised in captivity for five years since they were bought from a local commercial supplier while they were five-inch fingerlings. Seven conventional and 21 Truss network morphometric measurements were taken from 27 male (TL: 53.88 ± 2.86 cm; W: 1.82 ± 0.23 kg) and 27 female (TL: 53.97 ± 3.62 cm; W: 1.86 ± 0.35 kg) T. tambroides broodstocks using digital image analysis. Photograph of the fish broodstocks were captured and the morphometric measurements were conducted using imageJ freeware. Statistical analysis was later conducted on the morphometric data to identify the morphological differences between the broodstocks. This dataset will not only aid the sex identification of this species but also in stock population studies thus accelerating the development of T. tambroides aquaculture while improving its conservation efforts.

Hydrothermal Processing of Clarias gariepinus (Burchell, 1822) Filets: Insights on the Nutritive Value and Organoleptic Parameters

This study evaluated the effects of cooking for different hydrothermal-treatment durations (10, 20, 30 and 40 min) on the proximate composition, amino acid profile, fatty acid composition and organoleptic parameters of filets of African catfish Clarias gariepinus (Burchell, 1822). Filets of the fish were prepared from market size African catfish with similar breeding history. Parameters of the processed filet under the different hydrothermal durations were also compared against a raw-unprocessed control group except during organoleptic analysis. The results obtained revealed a significant increase in protein, fat and ash content until the 30th minute of hydrothermal processing (p ≤ 0.05). Beyond this processing time, protein and fat significantly reduced while ash remains unaffected. The same trend was observed for most essential/non-essential amino acids isolated as well as the prominent saturated fatty acids, monounsaturated fatty acids and polyunsaturated fatty acids. In all, the raw control group consistently recorded the least values of nutritional components. The perception of assessors was, however, found to be similar (p ≥ 0.05) in terms of organoleptic parameters regardless of the duration of the processing time of the filets. It was concluded that cooking the African catfish filet using the hydrothermal method should not be extended beyond 30 min.

Dataset for the morphological and erythrocytes parameters of Clarias gariepinus, Pangasianodon hypophthalmus, and their reciprocal hybrids

Discrimination of different fishes can be done through different means which includes morphological appearance. When two fishes are successfully hybridized, they produce progenies that have shared morphology between their pure parent, hence, making morphometric characterization an important aspect of hybrid discrimination. However, erythrocyte characterization is also a simpler method for characterization. The dataset presented in this article represents the traditional morphological data, truss network data and erythrocyte data of pure and novel hybrids from reciprocal crosses of African catfish Clarias gariepinus and Asian catfish Pangasianodon hypophthalmus. Breeding of the broodstocks was done to produce pure and hybrid progenies which were maintained for a period of four to six months. Based on the cross combinations and morphotypes, traditional measurement of twenty-five morphological characters and five meristic counts were recorded. Thereafter pictures of the different fish groups were used to determine values of thirty-six distances between ten landmark points. The morphological abnormality of the hybrids at market size is also presented in this data article for the very first time. Blood was then collected from the caudal peduncle of ten fish per group and smeared on a slide for observation under a compound microscope (at 100 × magnification). Data gotten included erythrocytes parameters such as cell major axis, cell minor axis, nucleus major axis, nucleus minor axis cell area, nucleus area, cell volume, and nucleus volume. Data recording was through the Microsoft excel spreadsheet; which was also used to process the data to get the exclusive ranges of values for paired progenies. The data as presented is associated with the research article “Morphological characterization of the progenies of pure and reciprocal crosses of Pangasianodon hypophthalmus (Sauvage, 1878) and Clarias gariepinus (Burchell, 1822)” [1]. The dataset presented in this article can be used for easy identification of the novel hybrid progenies of the African Catfish and Asian Catfish.

Microbiota composition data for wild and captive bluestreak cleaner wrasse Labroides dimidiatus (Valenciennes, 1839)

The Labroides dimidiatus is known as the “doctor fish” because of its role in removing parasites and infectious pathogens from the body of other fishes. This important role played both in wild and captive conditions could represent a novel form of parasitic transmission process mediated by the cleaning activity of the fish. Yet, there is a paucity of data on the microflora associated with this fish which is important for tracking disease infection and generally monitoring the health status of the fish. This article, therefore, represents the first dataset for the microbiota composition of wild and captive L. dimidiatus. Wild fish samples and carriage water were gotten in Terengganu Malaysia around the corals of the Karah Island. The captive sample, however, was obtained from well-known ornamental fish suppliers in Terengganu Malaysia. Thereafter, bacteria present on the skin, in the stomach and the aquarium water were enumerated using culture-independent approaches and Next Generation Sequencing (NGS) technology. Data obtained from the three metagenomic libraries using NGS analysis gave 1,426,740 amplicon sequence reads which are composed of 508 operational taxonomic units (OTUs) for wild samples and 3,238,564 valid reads and 828 OTUs for captive samples. All sequence reads were deposited in the GeneBank (Accession numbers SAMN14260247, SAMN14260248, SAMN14260249, SAMN14260250, SAMN14260251, and SAMN14260252). The dataset presented is associated with the research article “16S rDNA-Based Metagenomic Analysis of Microbial Communities Associated with Wild Labroides dimidiatus From Karah Island, Terengganu, Malaysia” [1]. The microbiota data presented in this article can be used to monitor the health and wellbeing of the ornamental fish, especially under captivity, hence preventing possible cross-infection.

Fatty Acid Composition of Hepatopancreas and Gonads in Both Sexes of Orange Mud Crab, Scylla olivacea Cultured at Various Water Flow Velocities

Nutritional quality of the hepatopancreas and gonads of orange portunid mud crab, Scylla olivacea was evaluated for each gender under four treatment of different water velocities (0, 20, 40 and 60 cm s⁻¹), in terms of nutrient reserve and nutrient for reproduction. About 56 crabs were used in this study in which fatty acids composition was analysed using gas chromatography mass-spectrometry (GC-MS). For hepatopancreas analysis, monounsaturated fatty acids (MUFAs) were present in the highest fatty acids concentration, followed by polyunsaturated fatty acids (PUFAs) and, saturated fatty acids (SFAs). However, long-chain polyunsaturated fatty acids (LC-PUFAs) were displayed in low concentration in the hepatopancreas. Total fatty acid (TFAs) composition was significantly higher at moderate velocity of 20 cm s⁻¹ compared to other water velocity treatments. For gonad analysis, 20 cm s⁻¹ showed the highest TFA concentration of 93.34 mg g⁻¹ while, the lowest concentration of 3.90 mg g⁻¹ occurred at 0 cm s⁻¹. There were significant differences in male and female crab’s fatty acids contents of gonads at all flow velocities challenged (p < 0.05). PUFAs and MUFAs were dominant while, SFAs were observed at low concentration. This study revealed that, concentration of PUFAs increased as gonad maturation increased. The decreasing concentration of hepatopancreas fatty acids over the culture period indicated that nutrient was shifted from the hepatopancreas, to be used as energy reserved to gonads for further growth of eggs and offspring. The linkages between water flow strength, hepatopancreas, and gonad fatty acids concentrations, is fundamental knowledge useful in establishing efficient habitat velocities selection which will improve aquaculture production of mud crabs with high quality broodstock.

Environmental effects on the oxygen consumption rate in juvenile Epinephelus fuscoguttatus (Forsskal, 1775)

This study was designed to optimize the culture conditions of juvenile Epinephelus fuscoguttatus (Forsskål, 1775) under laboratory conditions. To this effect, the rate of oxygen consumption was monitored as an index of stress under different temperature, salinity, pH, photoperiod, and urea concentrations. The result obtained after 12 h of exposure suggests the preference of the juvenile E. fuscoguttatus to a temperature range of 15-25 °C and salinity of 30 ppt. Based on this study, temperature was found to be the most lethal as 100% mortality was observed after 6 h in fish exposure to temperatures above the optimal (≥ 30 °C). However, the oxygen consumption rate was similar under the different pH, photoperiod, and urea concentration tested. It was concluded that water temperature was most critical in terms of respiration physiology of the juvenile E. fuscoguttatus given the range and levels of environmental factors tested in this study.

Data on PCR primer design for glucose 6-phosphate dehydrogenase gene and the effects of dietary carbohydrate levels on its expression in the liver of Malaysian mahseer (Tor tambroides)

The enzyme glucose-6-phosphate dehydrogenase (G6PD) catalyses the metabolite glucose-6-phosphate in producing NADPH during the first phase of pentose-phosphate pathway thus provides reducing power to all cells for cellular growth, antioxidant defence, and biosynthetic reactions in all living organism. The deliberate inclusion of starch as carbohydrate source in commercial feed however may affect the G6PD hepatic activity in cultured fish. We designed a set of primers to target G6PD gene in the popular Malaysian aquaculture species, Tor tambroides. For this dataset, the molecular characteristics of obtained T. tambroides G6PD (TtG6PD) nucleotide sequence was analysed using multiple alignments and phylogenetic analyses of the deduced amino acids. The set of primers obtained were then used in a study to evaluate the effect of different dietary carbohydrate inclusion levels on the hepatic TtG6PD mRNA expression of the T. tambroides fingerlings. Four groups of fish were given a dietary treatment of 15%, 20%, 25% and 30% starch at the optimal inclusion level of 23.4% for 10 weeks. The TtG6PD mRNA transcripts were measured using real-time-PCR assays and its expression normalized against β-actin, which acts as the internal control gene. This article provides supportive data in relation between hepatic TtG6PD mRNA gene expression in T. tambroides and how it is influenced by its dietary carbohydrate intake. These data will also assist in further nutritional genomic studies of carbohydrate and energy utilization for all species in the mahseer family.

Experimental data of phospholipid supplementary in full fishmeal replacement diets on growth indices, whole body nutrient composition, muscle fatty acid composition, haematocrit value and serum lysozyme activity in Malaysian mahseer (Tor tambroides)

The data collection was initiated to evaluate the effects of supplementary phospholipid to non-fishmeal based diet in order to make functional diets for the Malaysian Mahseer, Tor tambroides. Four iso-nitrogenous and iso-lipidic diets were formulated to consist 100% fishmeal (FM100), 0% fishmeal or full fishmeal replacement (FM0), and 0% fishmeal supplemented with 4% phospholipids (FM0+4%PL), 6% phospholipids (FM0+6%PL). A 60-day feeding trial was conducted and data collection was carried out for the following parameters; growth indices, somatic parameters, whole body nutrient composition, muscle fatty acid composition, haematocrit value and serum lysozyme activity. Fish fed FM0 diets showed significantly poor performance (P < 0.05) for all parameters. Fish showed improved growth, better whole body protein content and higher lysozyme activity when fed FM100 and phospholipid supplemented diets. In general, the current study validated that dietary PL supplementation may possibly improve the growth and survival of juvenile T. tambroides fed non-fishmeal based diets. Findings of this research could contribute in the aquaculture development of T. tambroides.

First Report on Successful Triploidy Induction in Clarias gariepinus (Burchell, 1822) Using Electroporation

This study investigated the use of electric-shock in inducing triploidy in African catfish Clarias gariepinus. To achieve this, three voltages (9, 12, 21 V) were applied for different durations (3, 5, 10 min). The shock was initiated approximately three minutes after fertilization followed by incubation in ambient temperature. After incubation, hatchability and survival rates were determined while ploidy status of the treatment fishes was confirmed in one-month-old fingerlings using the exclusive triploid range of the erythrocyte major axis previously reported for the same species (11.9–14.9 μm) and by cytogenetic analysis of the chromosome. The results showed triploidy were achieved in 10 to 85% of the treatment groups. A consistent trend of decrease in hatchability and an increase in triploidy rate was observed with increased electroporation voltages and shock durations. The mean erythrocyte major axis length of triploid progenies (3n = 84) was observed to be between 11.3–14.6 μm and was higher than the range of 7.0–10.5 μm recorded for diploid progenies (2n = 56). It was concluded that electric shock can be used to induce triploidy in African catfish C. gariepinus.

Data on the molting duration and time of hardening of instar crab at different culture temperatures

This data article includes raw and analyze data for molting duration and time of hardening of blue swimming crab, Portunus pelagicus instar at three different temperatures of 24 °C, 28 °C, and 32 °C. Two sets of experimental data are included: first, the recorded on time-lapse video of duration of successful molted crabs (from emergence of swimming legs to chelae); and second, the time interval of shell hardening up to before molting occurred. Shell hardening were calculated in 1 h interval with a unit of x hour molting crab⁻¹, meanwhile the molting duration of the crabs were calculated in x second molting crab⁻¹. Video files were then analyzed using the latest version of Solomon Coder software developed by A. Peter. Relationship between culture temperature and the time of molting and carapace hardening are also included in this article. The dataset is made publicly available to enable critical or extended analyzes.

Experimental data on behavioral, hepatosomatic, gonadosomatic indeces and total lipid of mud crab, Scylla olivacea at different velocity levels

The data collected in the present work correspond to the behavioral, Hepatosomatic Index (HSI), Gonadosomatic Index (GSI) and total lipid analysis between male and female mud crabs, Scylla olivacea at different water velocities. A total of 56 immature male and female crabs were used in this data article. The important criteria for estimating the selective habitat facing by S. olivacea is a considerate of (1) the behavioral range in response to abiotic factors (and how it adapt ontogenetically) and (2) the movement of the crab under wild velocities situations. This work purposes to recognize the performance, locomotion rate and escaping capability of S. olivacea under stagnant and flowing water situations and to discuss the significance of horizontal walking to habitat choice. The collective outcomes clearly show that the locomotor activities and escaping capabilities of S. olivacea were influenced by water flow in the mangrove habitats. For the HSI data, velocities of 20 cm/s were the highest increased mean HSI percentage and highest mean HSI percentage in males and females was recorded on the end of the experiment. For GSI percentage of male and female crabs, 20 cm/s dominates the highest increases mean GSI, followed by 60, 40 and 0 cm/s. For total lipid percentage, the results showed that, the mean total lipid of hepatopancrease, muscle and gonad were increased at the beginning and decreased at the final in each water velocities except for 20 cm/s over a culture period of 60 days. Velocities of 20 cm/s were the highest increased mean total lipid percentage followed by 40, 60, and lastly 0 cm/s. The high flow velocities inhibit the production of hepatopancrease and gonad, in terms of nutrients from food used to endeavor the stress condition faced.

Molecular Characterization and Gene Expression of Glutathione Peroxidase 1 in Tor tambroides Exposed to Temperature Stress

Temperature is an abiotic factor that affects various biological and physiological processes in fish. Temperature stress is known to increase the production of reactive oxygen species (ROS) that subsequently cause oxidative stress. Fish is known to evolve a system of antioxidant enzymes to reduce ROS toxicology. Glutathione peroxidase (GPx) family consists of key enzymes that protect fish from oxidative stress. In this study, full-length GPx1 cDNA (GenBank accession no. KY984468) of Tor tambroides was cloned and characterized by rapid amplification of cDNA ends (RACE). The 899-base-pair (bp) GPx1 cDNA includes a 576-bp open reading frame encoding for 191 amino acids, plus 28 bp of 5'-untranslated region (UTR) and 295 bp of 3'-UTR. Homology analysis revealed that GPx1 of T tambroides (Tor-GPx1) shared high similarity with GPx1 sequences of other fish species. The phylogenetic construction based on the amino acid sequence showed that Tor-GPx1 formed a clade with GPx1 sequences of various fish species. Real-time polymerase chain reaction (PCR) was performed to assess the levels of GPx1 gene expression in the liver and muscle of T tambroides under thermal stress. The results indicated that GPx1 gene expression was down-regulated under decreased temperature. However, there was no significant difference between GPx1 gene expression in fish exposed to high temperature and control. Our study provides the first data regarding GPx gene expression in T tambroides under thermal stress.

Thermal tolerance and locomotor activity of blue swimmer crab Portunus pelagicus instar reared at different temperatures

Owing to its potential market value, the blue swimmer crab Portunus pelagicus is of great economic importance. The temperature of water significantly affects the physiological function and production efficiency of these crabs. The aim of the present study was therefore to examine the critical thermal minimum (CTMin), critical thermal maximum (CTMax), acclimation response ratio (ARR), escaping temperature (Tesc), and locomotor behavior of P. pelagicus instars at 20 °C, 24 °C, 28 °C, 32 °C, and 36 °C. The CTMax ranged from 39.05 °C to 44.38 °C, while the CTMin ranged from 13.05 °C to 19.30 °C, and both increased directly with temperature. The ARR ranged from 0.25 to 0.51. The movement of crabs (walking before molting) correlated positively with the acclimation temperature. These results indicate that the parameters evaluated varied with temperature. Furthermore, the high CTMax indicates the potential of this species to adapt to a wide range of temperatures. In addition, the implications of these findings for portunid crabs behavior and distribution in their natural habitat are also discussed.

Effect of 17α-hydroxyprogesterone and 17α-hydroxypregnenolone on sperm quality and sperm quantity in male mud spiny lobster (Panulirus polyphagus)

The present study aimed to determine the effect of 17α-hydroxyprogesterone (17α-OHP) and 17α-hydroxypregnenolone (17α-OHPL) on sperm quality and sperm quantity in male mud spiny lobster (Panulirus polyphagus). The mean of sperm quality was increased in 17α-OHP and 17α-OHPL treated hormones. In 17α-OHP injected animals, the mean of sperm quantity of dose 0.01 μg g(-1) b.wt. was increased than 17α-OHPL. Meanwhile, 17α-OHP and 17α-OHPL concentrations were lower when injected with the hormones but 17α-OHP was higher at only day 15 (dose 0.01 and 0.1 μg g(-1) b.wt.). For 17α-OHPL, the hormone was a prohormone in the body of P. polyphagus and only required smaller to increase the sperm quantity. Besides, when the higher dose of 17α-OHPL (0.1 μg g(-1) b.wt.) was used in P. polyphagus, the development of P. polyphagus was inhibited and decreased the sperm quantity and 17α-OHPL concentration in hemolymph was lower. Injection of 17α-OHP in P. polyphagus has increased the sperm quality and quantity for both 17α-OHP dosage of 0.01 and 0.1 μg g(-1) b.wt. However, injection of 17α-OHPL in P. polyphagus has decreased the sperm quantity only, also for both dosage of 0.01 and 0.1 μg g(-1) b.wt. and lower on hormone concentration.

Sperm Viability Assessment over elapsing time maintained at 2 degrees C of orange mud crab, Scylla olivacea (Herbst, 1796)

The aim of this study was to evaluate how long the fresh sperm maintained at 2 degrees C would be utilized for fishery management. The study was conducted every 2 h to assess the sperm viability of orange mud crab Scylla olivacea. Evaluations were conducted as 3 treatments; T1, T2 and T3. In T1, the live specimens were sacrificed; for T2, only spermatophores were extracted and for T3 spermatophore extraction followed by homogenization to create a sperm suspension. All samples were stored with ice in an insulated box was keep fresh longer at 2 degrees C. The time '0' referred the immediate collection of sperm after the specimen was sacrificed. Spermatophore viability was determined using the sperm suspension by eosin-nigrosin staining method. Sperm viability for the fresh sample at time zero was 97.36 ± 0.53%. Viability of the sperm significantly decreased in the 2nd h in all treatments, T1 was 44.66 ± 0.54 to 4.2 ± 0.22% at 16 and 18th h, T2 was 36.56 ± 0.5 to 2.69 ± 0.06% at the 12 and 14th h and T3 was 33.69 ± 1.26 to 6.4 ± 0.29% at 8 and 10th h. In comparison, T1 showed significantly higher than other treatments (p < 0.05). Extremely low viability percentages were recorded in T3. This study also proved that the time elapse had significant impact on the percentage of viable sperm count.

Effect of testosterone undecanoate hormone on sperm and its level in the hemolymph of male mud spiny lobster, Panulirus polyphagus

The present study aimed to determine the effect of testosterone undecanoate hormone on sperm quality (sperm viability) and sperm quantity (sperm counts) and its levels in the hemolymph of male mud spiny lobster, Panulirus polyphagus. Male P. polyphagus was injected laterally in fifth abdominal segment of pure hormone, Testosterone Undecanoate (TU) and ethanol at days 1, 8, 15, 22 and 29. Hemolymph of P. polyphagus was taken every two weeks and checked with Enzyme-linked immunosorbent assay (ELISA) to measure hormone levels. The mean sperm quality and quantity were increased due to increase the TU dose and TU levels also increase. The sperm quality, quantity and hormone levels were relevance each others. These findings indicate that TU injection should be evaluated as a practical way of improving sperm quality and quantity in commercial operations.

Application MALDI TOF on protein identification of vitellogenin in giant grouper (Epinephelus lanceolatus)

A new proteomics technology has been implemented to study the protein repertoires of developing oocytes of giant grouper (Epinephelus lanceolatus). Knowledge of the chemical composition and physiochemical properties of vitellogenin (Vtg) is necessary to interpret the functional and biological properties attributed during ovulation. Vtg, as a biomarker indicator in sex determination, has been analyzed to determine the sex and maturational status of fish in the absence of the gonad tissue. A male giant grouper was induced by 2 mg/kg of 17ß-estradiol (E2), and blood was sampled at days 0, 1, 3, 5, and 10. SDS-PAGE 1D electrophoresis was used to analyze Vtg protein, and Vtg identification was done with 4800 Plus MALDI TOF/TOF™ mass spectrophotometer (Applied Biosystems/MDS SCIEX, USA). Meanwhile, MS/MS de novo sequencing identified the proteins by matching sequences of tryptic peptides to the known sequences of other species. Vtg was confirmed by MASCOT at 95% significant level, and molecular mass was 187 kDa. Protein resolved on SDS-PAGE as a double band of approximately the same mass as determined with MALDI-TOF. The N-terminal sequences and identification of Vtg were also determined. The potential of using MS methods to understand the structure and function of Vtg is discussed.

Fecundity, embryonic and ovarian development of blue swimming crab, Portunus pelagicus (Linnaeus, 1758) in coastal water of Johor, Malaysia

Blue swimming crab, Portunus pelagicus is widely study and research throughout the Indo-West Pacific, but little is known of its reproductive biology in Malaysia. The present study describes the fecundity, embryonic development and ovarian development stages of the P. pelagicus from Johor coastal water, Malaysia. Carapace width range of berried crabs sampled was from 9.64 to 13.32 cm, while the body weight range was from 75 to 235 g. The mean number of egg produced by females in different sizes ranged from 105443.333 +/- 35448.075 per eggs batch. Mean egg size during embryonic development at stage 1 was 0.307 +/- 0.037, while 0.386 +/- 0.039 and 0.396 +/- 0.033 for stage 2 and stage 3, respectively. Study showed that there was significant (p < 0.05) relationship between the number of eggs and carapace width/body weight. Mean diameter oocyte during ovarian development at stage 1 was 97.732 +/- 12.391 while for stage 2 was 149.516 +/- 23.287. Stage 3 showed increasingly of size with mean diameter was 158.506 +/- 27.616 and 181.013 +/- 24.339 for stage 4.