• Fisheries and Aquatic Sciences
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• v.26 no.10
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• pp.617-627
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• 2023

Harvest control rules have been recently developed for some fisheries in Indonesia, including grouper fisheries, and are expected to reverse the trend of declining stocks. One of the proposed options of the harvest control rules is to implement the catch size limit. The catch size limit approach, however, is challenging, unless it is supported also with strong fisheries surveillance, law enforcement, and innovation. The catch size limit approach can be done by implementing changes in fishing methods and gear, including the application of different hook sizes in the hook and line fishing gear. This study examines the impact of different hook sizes on the length at first capture (Lc) and on the bell-shaped maximum selectivity using various selectivity models of the two targeted grouper species (Plectropomus leopardus and Plectropomus maculatus) in the Saleh bay, West Nusa Tenggara, Indonesia. We found that increasing hook size influences the grouper's catch size, increasing the Lc and the bell-shaped maximum selectivity of both species. Based on our findings, hook size can be used as one of the practical tools for grouper management measures, as part of harvest control rules to improve grouper stock in Indonesia.

• Korean Journal of Environmental Biology
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• v.38 no.1
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• pp.40-46
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• 2020

Hybrid grouper(Epinephelus fuscoguttatus ♀×E. lanceolatus ♂) (mean weight 25.7±3.5g, mean length 11.2±0.9cm) were exposed to different ammonia concentrations of 0, 5, 10, 20, and 40mg L^-1 for 96 hours. The hematological hematocrit and hemoglobin parameters of the hybrid grouper were significantly decreased by 20 mg L^-1 ammonia exposure. In the organic plasma components, calcium was significantly decreased, whereas there was no change in magnesium. In the organic plasma components, the glucose and cholesterol values of the hybrid grouper were significantly increased by ammonia exposure. In the enzymatic plasma components, the ALP(Alkaline phosphatase) value of the hybrid grouper was also significantly increased by ammonia exposure. The results of this study demonstrate that acute ammonia exposure to hybrid grouper induced changes in hematological parameters and plasma components. Therefore, acute ammonia exposure over 20 mg L^-1 appears to be toxic to hybrid grouper and the results can be used as a major indicator in breeding hybrid grouper.

• Development and Reproduction
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• v.19 no.1
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• pp.19-24
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• 2015

This study was conducted to determine the stress response [ethological (operculum movement number (OMN)), hematological (hematocrit and hemoglobin), biochemical (glucose, cortisol and glutamic oxaloacetic transaminase (GOT))] in red spotted grouper, Epinephelus akaara during exposure of different water temperature in winter season. This species (Total length, $18.56{\pm}0.34cm$) previously maintained in water temperature of $15^{\circ}C$ were transferred to 15, 20 and $25^{\circ}C$. During experimental period (7 days), OMN, hematocrit (Ht), glucose and GOT values were significantly high in $15^{\circ}C$ when compared to 20 and $25^{\circ}C$. Hemoglobin value was also increased at $15^{\circ}C$, but no significant differences. There was no differences in cortisol levels among the temperature groups. No fish mortality was observed during the experimental period. From these results, $15^{\circ}C$ is likely more stressful to red spotted grouper than $20^{\circ}C$ and $25^{\circ}C$. These observations confirm that red spotted grouper adapts better to temperatures between 20 and $25^{\circ}C$ during the winter season.

• Fisheries and Aquatic Sciences
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• v.24 no.5
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• pp.181-190
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• 2021

Grouper is one of the most economically important fishes with various morphological forms and characteristics, meaning it is often difficult to identify species and distinguish between life stages, sometimes leading to morphological misidentification. Therefore, identification using a molecular deoxyribose nucleic acid (DNA) approach was needed as an alternative means to identify closely related species. This study aims to determine the molecular phylogeny of grouper from the northern part of the Bird's Head Seascape of Papua. The DNA sequence of each cytochrome oxidase I (COI) gene was used to study the molecular relationship among closely related species of grouper. The results showed that there were 16 Epinephelinae that have been compared to a gene bank (National Centre for Biotechnology Information, NCBI) in the sequence length of 623 base pairs. The closest genetic distance was found between Cephalopholis miniata and Cephalopholis sexmaculata (0.036), while the furthest genetic distance was observed between Plectropomus laevis and Cephalopholis spiloparaea (0.247). This finding was further reinforced by the morphological characters of each species. This finding highlighted that five genera were represented as a monophyletic group (clade), i.e., Epinephelus, Cephalopholis, Plectropomus, Saloptia and Variola.

• The Journal of Fisheries Business Administration
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• v.36 no.2 s.68
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• pp.121-134
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• 2005

In order to evaluate the effectiveness of management measures and to provide policy suggestions for the allocation of total allowable catch between recreational and commercial sectors, the economic value of red grouper recreational fishery in the United States Gulf of Mexico was estimated using a Travel Cost Method(TCM), Due to the characteristic of count data, a Poisson model(PM) and a Negative binomial model(NBM) were used in the TCM. Results of models showed that the NBM was statistically more suitable than the PM since the overdispersion problem occurred in the PM. Results also indicated all signs of the estimated parameters were as expected and were significant, except for a Boat parameter in both models. Based on the results of NBM, the total economic value of the recreational red grouper fishery was estimated to be $\$698.6$ and the value per trip was $\$179.5$. In addition, the total changes in expected consumer surplus due to changes in catch rates was $ \$42.3$.

• Parasites, Hosts and Diseases
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• v.46 no.2
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• pp.77-82
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• 2008

Fishborne zoonotic metacercariae have not been reported from brackish water and marine fish from Vietnam waters although these parasites are common in the country's freshwater fish. Both wild-caught and cultured grouper (Epinephelus coioides and Epinephelus bleekeri), and mullet (Mugil cephalus) from brackish and marine waters located in Khanh Hoa province in central coastal Vietnam were examined, and found positive for zoonotic trematode metacercariae. From grouper, Heterophyopsis continua and Procerovum varium were recovered. The prevalence of H. continua ranged from 2.0 to 6.0% and that for P. varium ranged from 11.6 to 15.8%. Mullet were infected with Pygidiopsis summa and H. continua; both of these species are new records for Vietnam. The prevalence of P. summa in mullet was generally high, ranging from 17.6 to 75.5%, and was significantly higher than the prevalence of H. continua (2.5 to 32.4%). There were no significant differences in the prevalence of metacercariae between grouper from natural or cultured habitats, indicating that the highest risk of infection occurs in the wild-caught state prior to their placement in culture. Further, there was no difference in metacercarial prevalence between the 2 species of grouper. Infected wild-caught seed were only observed from January to October. Monthly variation in prevalence suggests seasonal variation in mullet infections occurs in this region with the highest transmission taking place from October to December. Basic investigations on the ecology and epidemiology of these intestinal flukes need to be carried out to determine their significance as a public health problem and the aspects of their biology that may be vulnerable to control interventions.

• Journal of Aquaculture
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• v.16 no.2
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• pp.110-117
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• 2003

We have cloned and sequenced the cDNA encoding growth hormone (GH) from pituitary poly(A)$^{+}$ RNA of red-spotted grouper (Epinephelus akaara). The cDNA of red-spotted grouper GH is 883 base pairs (bp) consisting of 21 bp of 5'untranslated region (UTR), 615 Up of an open reading frame (ORF) and 247 Up of 3'UTR. The polyadenylation signal, AATAAA, was 20 bp upsteam of polyadenylation site. Based on the nucleotide sequences, the deduced putative polypeptide contains 204 amino acids (aa), representing 17 aa of a signal and 187 aa of a mature polypeptide. The putative GH cDNA encodes a polypeptide with four cysteine residues and only one N-gly- cosylation site. Comparative sequence alignment shows that red-spotted grouper GH exhibits high similarity with its corresponding other Perciformes species GH cDNAs.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.2
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• pp.129-136
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• 2022

The nutrient composition of the muscle of the hybrid grouper (Epinephelus fuscoguttatus×E. lanceolatus, HG) and the hybrid longtooth grouper (E. moara×E. lanceolatus, HLG) was measured as a function of body weight in this study. The crude protein and lipid levels in HG were 21.0-21.2 g/100 g and 1.9-3.4 g/100 g, respectively. HLG contained 20.6-20.7 g/100 g protein, and 3.9-5.5 g/100 g crude lipid. The total amino acid contents of HG were 18,829.7-18,980.2 mg/100 g and that of HLG was 17,793.7-19,293.7 mg/100 g. The mean saturated fatty acid content was 0.61-1.09 g/100 g for HG and 1.27-1.77 g/100 g for HLG. Monounsaturated and polyunsaturated fatty acid levels were 0.59-1.02 g/100 g (Monoene), 0.67-1.11 g/100 g (Polyene) in HG, which were lower than the 1.21-1.78 (Monoene), 1.22-1.69 g/100 g (Polyene) found in HLG. The highest mineral content (K and P) of HG was 510.13-517.05 mg/100g and 231.59-247.67 mg/100 g, while that of HLG was 518.81-523.59 mg/100 g and 257.51-248.84 mg/100 g, respectively. In conclusion, there is potential for expanding the commercial utilization of HG and HLG as food resources as they are both nutrient-rich.

• Journal of fish pathology
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• v.4 no.2
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• pp.87-94
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• 1991

In the late summer of 1990 and 1991, mass mortality occured among cage-cultured grouper, Epinephelus septemfasciatus in south cost of Korea. The moribund fish didn't feed and became pale or dark chestnut colour and irregularly swimmed due to the loss of equilibrium, finally the diseased fish fell down side away on the bottom or the surface of cage showing the bent of body and died. The diseased fish showed the extensive hemorrahge in brain, the swelling of spleen and bile duct as the specific syptoms of internal organs. So the gill, skin and other organs of the diseased fish were examined for the presence of pathogenic parasites and bacteria. The parasitic Trichodina sp. were detected only from the gill lamella of the diseased fish, but these parasites seemed to be not a direct causative agents that induced the gross mortality of the cultured grouper. because these parasites were also observed in normal grouper, yellowtail, red seabream and rock bream co-cultured with the diseased grouper in same or near cages. In the viral examination, although isolation of the causative agent by the use of estabilshed cell Lines, RTG-2 and CHSE-214, was not succeed, the normal grouper inoculated intramuscularly with the filtered homogenate of the organs of the diseased fish showed the same external and internal signs with the naturally infected grouper. They died within a week. By using the naturally and the artificially infected fishes, electron microscopic observation revealed numerous hexagonal or polygonal particles in the cytoplasm of liver cells. Based on the these results, we suggest that the mass mortality of the cultured grouper would be occurred by the infection of a viral agent.

• Journal of Veterinary Clinics
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• v.27 no.5
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• pp.618-621
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• 2010

A giant grouper (Epinephelus lanceolatus) that was reared for public exhibition in a private commercial aquarium in Seoul, Korea, was recently found dead. The fish had evidenced symptoms including anorexia, lethargy, and depression persisting for two weeks. A bacterial pathogen from fish organs (kidney, liver, spleen) was cultured, identified and confirmed as Photobacterium damselae subsp. damselae, using a Vitek System 2, API 20E test, multiplex PCR, and 16S rRNA gene sequencing. In this paper, we have described the isolation and identification of Photobacterium damselae subsp. damselae from a giant grouper reared in a private aquarium in Korea.