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.
The nursery stages of mud crab, genus Scylla, proceed from the megalopa stage to crablet instar stages. We review the definition and several of the key stages in mud crab nursery activities. The practice of the direct stocking of megalopa into ponds is not recommended due to their sensitivity. Instead, nursery rearing is needed to grow-out mud crabs of a larger size before pond stocking. Individual nursery rearing results in a higher survival rate at the expense of growth and a more complicated maintenance process compared with communal rearing. The nursery of mud crabs can be done both indoors or outdoors with adequate shelter and feed required to obtain a good survival percentage and growth performance. Artemia nauplii are still irreplaceable as nursery feed, particularly at the megalopa stage, while the survival rate may be improved if live feed is combined with artificial feed such as microbound diet formulations. Water quality parameters, identical to those proposed in tiger shrimp cultures, can be implemented in mud crab rearing. The transportation of crablets between different locations can be done with or without water. The provision of monosex seeds from mud crab hatcheries is expected to become commonplace, increasing seed price and thus improving the income of farmers. Numerous aspects of a mud crab nursery including nutrition; feeding strategies; understanding their behaviour, i.e., cannibalism; control of environmental factors and practical rearing techniques still need further improvement.
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.
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.
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.
Population density, growth, survival, water quality and larval stage index of purple mud crab, Scylla tranquebarica at different feeding regimes and the data on ingestion rate of chosen microalgae, survival and larval development of blue swimming crab, Portunus pelagicus are presented. A twenty days of S. tranquebarica larval culture from zoeal 1 until megalopa stage under two different feeding regimes of A) Rotifer, Artemia nauplii and shrimp meat and B) Rotifer, Artemia nauplii and artificial feed is shared. A method on investigation of individual larvae of P. pelagicus capability to catch four different types of microalgae within 24 h is also shared. Direct eye observation, data collected through the larval rearing culture of S. tranquebarica and further statistical analysis were done daily until the crabs reached the megalopa stage. The result obtained from the optimum density of selected microalgae fed by individual larvae of P. pelagicus will be combined with the highest survival rate and larval stage index to develop feeding schedule for crab larvae P. pelagicus. This dataset has not previously been published and is of great potential for further comparison with other - and future investigation of various feeding regimes affected the crab culture. The collected information could be used as a standard feeding regime for nursery and hatchery seed production of others portunids crabs. The data described in this article are available as a supplementary file to this article.
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.
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.
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.
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.
The present datasets were conducted to investigate glucose concentration in hemolymph, energy levels at selected body parts (hepatopancreas, muscle, gonad), and feces among different sexes of crabs cultured at four different water velocities (0, 20, 40, and 60 cm/s) during a 60-day culture period. A total of 102 immature crabs (51 males, and 51 females) were sampled from Kuala Muda, Kedah coastal water, Peninsular Malaysia (5°39'N 100°19'E) from April to November of 2018. Results indicated that glucose concentration was the highest at water velocity of 60 cm/s for both male and female crabs (♂: 3.76 ± 0.08 mmol/L; ♀: 3.63 ± 0.06 mmol/L), whereas at 0 cm/s, the lowest levels of glucose concentration (♂: 0.13 ± 0.08 mmol/L; ♀: 0.19 ± 0.06 mmol/L) were recorded. As for energy analysis in hepatopancreas, results showed that both male and female crabs recorded the highest levels at 0 cm/s (no flow) with 37.919 ± 0.07 KJ/g and 34.636 ± 0.50 KJ/g, respectively. Energy for locomotion (muscle) of male crabs recorded the highest at 0 cm/s (♂: 26.823 ± 0.06 KJ/g), meanwhile for females, the highest was recorded at 20 cm/s (26.607 ± 0.34 KJ/g). Energy for reproduction of males could not be compared due to an insufficient available amount of testes/vas deferens, whereas female crabs recorded the highest energy usage at 20 cm/s water velocity (♀: 37.895 ± 0.08 KJ/g). For feces, both male and female crabs recorded the lowest energy at 60 cm/s (♂: 5.841 ± 0.03 KJ/g; ♀: 5.393 ± 0.01 KJ/g). Glucose assessment showed a direct relationship between increased velocity and glucose secretion in hemolymph at high velocity of 60 cm/s (stress condition) compared to other treatments. Regarding energy analysis, this research improved the mechanism of hepatopancreas, gonad, muscle and feces functions in development and reproduction, while it shed light on the influence of velocity on energy metabolism of S. olivacea.
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
This article investigated how crabs responded to different culture temperatures especially dislocation before molting using a combination of large recording files and computer software. In this novel approach of video recording portunid crab behavioral data, crab culture was recorded at five different acclimation temperatures of 20, 24, 28, 32 and 36 °C. Crabs were reared until the instar stage before being acclimatized for video recording. Large video files (MPEG-TS) were then analyzed using the latest version of Solomon Coder software developed by A. Peter and programmed with Embarcadero® Delphi® XE [1]. Recorded data was analyzed by calculating and marking movements of crabs using the time sequence tool. Additionally, a total movement was counted 30 min before crabs molted from instar stage 8 to instar stage 9. Part of the data is associated with the research article "Thermal tolerance and locomotor activity of blue swimmer crab Portunus pelagicus instar reared at different temperatures" (Azra et al., 2018) [2] and provided here as raw data of Supplementary materials.
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.
Malaysian Mahseer (Tor tambroides) is considered as a good prospect for aquaculture in Malaysia. However, knowledge about Malaysian Mahseer-associated sperm microbiota is still limited, although some studies reported that sperm-related bacteria are a factor in the decline of sperm quality, as sperm may become the carrier of pathogenic bacteria to the egg. The goal of this study was to evaluate the sperm microbiota associated with Malaysian Mahseer from 3 different locations (Universiti Malaysia Terengganu [UMT], Ajil, and Pahang) using polymerase chain reaction denaturing gradient gel electrophoresis (PCR-DGGE) fingerprinting and to compare location differences by cluster analysis. Our results showed that the UMT sample had different sperm microbiota composition and a different trend in its relationship with sperm quality. Correlation analysis showed a relationship between bacterial diversity and sperm quality. Phylogenetic analysis indicated that sperm microbiota was composed of diverse phyla, including Proteobacteria, Firmicutes, and Actinobacteria. Interestingly, bacteria such as Salinisphaera sp., Pelomonas sp., and Staphylococcus spp. were detected in all the locations, suggesting that these bacteria are indigenous bacterial members of the Malaysian Mahseer sperm microbiota, although their function is still unclear.
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.
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.
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.
Aquaponics is known to be a smart way of producing fish and crops simultaneously; however, there is a paucity of information about the extents of this system's efficiency over other conventional methods of food production. Thus, this study was designed to evaluate the performance of a catfish-pumpkin aquaponics system in comparison with recirculatory and static aquaculture systems (for fish performance), as well as irrigated and nonirrigated systems (for pumpkin performance). Results obtained showed that the production of fish in the aquaponics system was 29% and 75% more efficient than recirculatory and static aquaculture systems, respectively. The survival of the fish was also significantly improved probably due to better water quality in the aquaponics system. With respect to pumpkin production, yield in the aquaponics system was about five times the performance in irrigated land and eleven times those in nonirrigated land. This study gives definitive evidence to support the efficiency of the aquaponics system over other conventional food production methods.
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.