Blue Swimming Crab Portunus Pelagicus Research Articles

The Availability of Blue Swimming Crab (Portunus pelagicus, Linnaeus, 1758) in seaweed culture area of marine coastal waters

Seaweed cultures in marine coastal waters provide providing microhabitats, shelter, and food sources to fish and invertebrate. The availability of blue swimming crab (Portunus pelagicus) in seaweed culture area was conducted from October to December 2019 in the south coastal waters of Bulukumba Regency, South Sulawesi, Indonesia. The purpose of the study was to assess the catch, size, and sex distribution of the blue swimming crab in the area. The crabs were caught by set bottom gillnets with 4 inches of mesh sizes and 300 m of a length. The carapace width (CW) and sex for each crab individual were recorded. The results of the study show that the total catch of 21 trips during 3-month fishing operation was 539 crabs that consist of 260 male (48.24 %) and 279 females (51.76 %). The (CW) of males ranged from 53.6 to 143.6 mm, while females ranged from 58.3 to 142.8 mm. There were 38 breeding crabs or 13.62 % from the female total. The carapace width of breeding crab ranged from 92.2 to 138.6 mm. Moreover, it needed to study in the area intensively.

Population genetic structure of blue swimming crab (Portunus pelagicus) in the Gulf of Thailand

Abstract. Supmee V, Sawusdee A, Sangthong P, Suppapan J. 2020. Population genetic structure of Blue Swimming Crab (Portunus pelagicus) in the Gulf of Thailand. Biodiversitas 21: 4260-4268. The Blue Swimming Crab (Portunus pelagicus) is an important commercial fishery product in the Gulf of Thailand. To provide a strategy for management, information on genetic features is needed. In our study, the population genetic structure and demographic history of the P. pelagicus living in the Gulf of Thailand were analyzed based on the variation of the nucleotide sequence of the mitochondrial DNA in the control region (mtDNA CR). Ninety-seven samples were collected from 5 sampling sites: Rayong, Chonburi, Chumphon, Surat Thani, and Nakhon Si Thammarat provinces in the Gulf of Thailand. Forty-nine haplotypes were identified and 39 private haplotypes were found. An AMOVA showed no genetic structure among populations. The pairwise FST also indicated no statistically significant difference between all possible regional combinations. The topology of a minimum spanning network revealed a star-like topology that was not separated by geographic structure. The historical demographic analysis revealed a stable population size for a long period and followed by a very recent expansion. An absence of a population structure of the P. pelagicus was possibly caused by a high level of gene flow. The results of this study differ from previous studies that used genetic markers in nuclear DNA. Thus, to clear the genetic structure information of P. pelagicus in the Gulf of Thailand, we suggested that more sensitive markers to detect genetic structure should be used in further analysis.

Spatial and temporal size structure abundance of the blue swimming crab (Portunus pelagicus) in Tiworo Strait, Southeast Sulawesi, Indonesia

This study aimed to analyze spatial and temporal size abundance and sex ratio patterns of blue swimming crab (BSC). It was conducted from June to December 2018. Samples were taken monthly using collapsible pots and gillnets from different habitat characteristics of intertidal (station A), river mouth (station B), seagrass (station C and D), and depth of > 30 m (station E). Each sample was sexed, measured its CW (cm), and weighed its body weight (g). Those were classified according to sex and CW into: < 6.0 cm (juvenile), ≥ 6.0 - 9.0 cm (mature), and ≥ 9.0 cm (adult) and counted to perform abundance and sex ratio of each station and month. Results showed that juveniles were more abundant in station A, while mature abundance has no distribution pattern. Adults tended to be abundant in station E. Those may affect sex ratio in all stations and months. Male juvenile sex ratio preponderated over female in station A, while in other stations have no pattern. On the contrary, mature females preponderated over males in station A, but have no pattern in other stations, while adults showed females preponderated over males in station E. It implies that females of the blue swimming crab (BSC = Portunus pelagicus) prefer deep water having high salinity to release eggs.

Proportion and Total of Commodities Blue Swimming Crab (Portunus pelagicus Linnaeus, 1758) Catches in Gebang Mekar Village, Cirebon Regency, West Java Using Crab Gillnet and Collapsible Crab Trap

Blue swimming crab (Portunus pelagicus) is one of the high economic value commodities which causes increased efforts to catch blue swimming crab in Indonesia. The effort of catching continues to increase the blue swimming crab resources in the nature that has decreased. Cirebon Regency is one of the largest blue swimming crab fishing centers in West Java with a total value of blue swimming crab production in 2017 by 7,347 tons/year. This research was conducted to determine the selecitivity level of the crab gillnet and collapsible crab trap based on the proportion and total of catches obtained in Gebang Mekar Village, Cirebon Regency. Research was conducted in September 2019 – October 2019 in Gebang Mekar Village. For this research we used are primary data; collected directly during the observations includes catch type and weight of the catches and then interviews with several crab gillnet and collapsible crab trap fisherman and secondary data; data from official agencies and some literature. Our research suppose the moonlight phase effect of the blue swimming crab catch. Based on the research, it can be concluded that the crab gillnet with 3.5 inch mesh size and collapsible crab trap that operated in Gebang Mekar Village may be called a selective fishing gears but crab gillnet is more eficient as compared to collapsible crab.

Temporal sex ratio, growth patterns and condition factor of the blue swimming crab (Portunus pelagicus) in Northern of Tiworo Strait waters, Southeast Sulawesi, Indonesia

Blue swimming crabs Portunus pelagicus occupied Tiworo Strait waters has been experiencing heavy pressure due to high exploitation and damaging its habitat caused by conversion to be a port or jetty particularly in the intertidal and subtidal zones closed to mangrove areas and river mouth. Those zones constitute main habitats of BSCs. The study aimed to analyze temporal sex ratio (SR), growth patterns and condition factor (CF) of BSCs in Tiworo Strait waters which was conducted in June–December 2018. The BSC samples were taken monthly using collapsible pot. Each sample taken was identified its sex, measured its CW and weighed its BW. Monthly SR of male and female was counted, while BW–CW relationship was analyzed using a simple linear regression. Growth patterns and CF were derived and analyzed from BW–CW regression. The results of study showed that monthly BSC SR of male and female showed females preponderated over males, except in November. The growth pattern of male and female was negative allometric (b 3). Data of BSCs CF were mostly influenced by growth coefficient (b), namely the higher b the lower CF. This condition is frequent happening in BSC population dominated by juvenile and mature stages. This study showed most BSCs found in this location were juvenile which indicated as their nursery ground in the intertidal zone dominated by sand substrate closed to mangrove forest.

Effect of calcium and enzyme involvement to survival rate and development of the early stage zoea Portunus pelagicus

The early stage of blue swimming crab (Portunus pelagicus) zoea requires calcium for calcification after molting which can be drawn from water and its diet. However, the digestive system of the early stages of the larvae is still not perfect, so the ability to digest food is limited. Calcium and enzyme inclusion in its formulated diet is important to aid the calcification process. Therefore, in this study, the effect of calcium and enzyme inclusion to survival rate and development of the zoea were examined. Zoeas were fed with nauplii Artemia and three levels of calcium Kalzana-D without enzyme Enzyplex inclusion (At, Bt and Ct) and with enzyme Enzyplex inclusion (AtE, BtE and CtE). There were three replicates in each treatment that had 100 zoeas in 2-L plastic tube on 30°C water bath. The result revealed that 50 mg calcium with enzyme involvement supported the early stage of zoea to molt and develop to the next stage. In addition, calcium inclusion with or without enzyme involvement promoted survival rate of the zoea.

Teknologi Penangkapan Rajungan (Portunus pelagicus spp.) Ramah Lingkungan dengan Bubu Kubah di Kabupaten Aceh Barat Provinsi Aceh

Fishermen of West Aceh District is still using a tool of unfriendly for environment namely mini trawl for blue swimming crab (Portunus pelagicus spp) fishing, so that it will impact the ecosytem of the sea and the damage to the fish resources such as blue swimming crab. For that reason, there needs to be an alternative of eco-friendly fishing technology to catching blue swimming crab and replace fishing gear unfriendly for environment i.e. mini trawl and exposing the blue swimming crab fishing is as main activity in West Aceh District where Ujong Baroh Village as pilot projetc location for this activity. The community service program has carried out with IbM activity (Ipteks bagi Masyarakat). The activity was done on February – Agustus 2017, where education, practice and accomponiment was used as methods. IbM program is expected to increase skill and business managerial as well as improving the economic situation of the coastal communities.

STOCK STATUS OF BLUE SWIMMING CRAB (Portunus pelagicus) IN TANAH LAUT, SOUTH KALIMANTAN, AND ITS ADJACENT WATERS

A study on the stock status of blue swimming crab (Portunus pelagicus Linnaeus, 1758) was conducted in Tanah Laut, South Kalimantan waters, based on data collected in March to November 2017. The results showed that the growth pattern of blue swimming crab in Tanah Laut waters was negatively allometric and the sex ratio of males to females was 1.0 : 1.7. The chi-square test indicated that the total males and total females of the blue swimming crab was significantly different. It means that there was an imbalance in numbers between males and females. The estimated length at first capture (Lc) was 127.26 mm (carapace width; CW), smaller than the length at first maturity (Lm) at 133.24 mmCW. The growth parameter of blue swimming crab was 1.1year with a maximum carapace width (L) of 204.3 mmCW. The estimated instantaneous total mortality (Z) and natural mortality (M) were 3.04/year and 1.24/year, respectively. While fishing mortality (F) and exploitation rate (E) were 1.80/year and 0.59/year, respectively, the estimated spawning potential ratio (SPR) was 11.1 %. Therefore, the stock status was categorized as overfishing. In order to ensure the sustainability of the blue swimming crab, a precautionary approach,, such as reducing fishing effort by 18 % of the current situation, is strongly recommended to apply.

The relationship between blue swimming crab (Portunus pelagicus) abundance and environmental parameters in Spermonde Archipelago

Management and conservation of the blue swimming crabs by the marine protected area method require the abundance and environmental parameter information of the blue swimming crab. The aim of this study is to analyze the changes in the relative abundance of the blue swimming crab and its environmental parameters. The study was conducted from March to July 2015, in the waters of Salemo Island, Spermonde Archipelago. The specimens were collected at the three fishing locations around the mangrove, seagrass, and coral reef ecosystems. The variable of relative abundance of the blue swimming crab is determined catch per effort. Samples of environmental parameters such as temperature and current speed are measured in situ. However, for the salinity, dissolved oxygen, ammonia, nitrate, plankton, and chlorophyll-a were analyzed in the laboratory. A comparison of the blue swimming crab abundance in each ecosystem was conducted by One Way ANOVA. Moreover, the relationship between blue swimming crab abundance with environmental parameters was analyzed by multiple regression. The results show that the blue swimming crab is abundant in the seagrass and coral reefs. The environmental parameter that significantly influences the abundance of the blue swimming crab is salinity. The suitable area for blue swimming carb protection based on abundances are seagrass and coral reef ecosystems.

Genetic diversity of blue swimming crab (Portunus pelagicus Linn 1758) from Indonesian waters (Sunda and Sahul Shelf, Wallacea region): Phylogenetic approach

Abstract. Hidayani AA, Fujaya Y, Trijuno DD, Rukminasari N, Alimuddin A. 2020. Genetic diversity of blue swimming crab (Portunus pelagicus Linnaeus 1758) from Indonesian waters (Sunda and Sahul Shelf, Wallacea region): Phylogenetic approach. Biodiversitas 21: 2097-2102. Blue swimming crab is one of the exploited fisheries commodities in Indonesia. This condition has contributed to the decline of their genetic diversity. The information on genetic diversity assumes importance for the conservation and the cultural purposes of species. The study aimed to determine the genetic diversity of blue swimming crabs from Indonesian waters using phylogenetic analysis. We conducted sampling of crab from several Indonesian waters, such the Aceh and Semarang (representing Sunda Shelf), Barru, South Sulawesi, and Maumere, Flores (representing Wallacea region) and Sorong, Raja Ampat and Kaimana (representing Sahul Shelf). Genetic diversity in this study using mitochondrial DNA (mtDNA) by implementing the method of Cytochrome c Oxidase Subunit I (COI). According to the findings, the blue swimming crabs from our study sites had a high genetic diversity variation. Three groups of crabs were determined using phylogenetic tree which formed three different unique clades. There was the same haplotype of crab observed from different locations, barring a sample from the Sahul Shelf which has a unique haplotype. There was no genetic speciation of crab samples from the Sunda Shelf and the Wallacea region were observed, except samples from the Sahul Shelf. Hybridization might occur between species of the crabs due to the finding of a cryptic species.

New record of parasitic isopod (Isopoda: Bopyridae) infecting the branchial chamber of blue swimming crab Portunus pelagicus (Linnaeus, 1758) (Decapoda: Portunidae) in the Philippines

A parasitic disease causing swollen carapace in commercially important blue swimming crab (Portunus pelagicus L.) has not received considerable attention; neither its causative agent is identified nor its seasonality is recorded. This study aimed to identify the parasite in P. pelagicus inhabiting the Manila Bay. Parasite found in the branchial chamber were isolated, preserved in ethanol and examined. A total of 292 crab specimens were examined and ten were found to be infected (3.42% prevalence with 0–2 parasites per host). Infections were only observed in November 2014 and between January and June 2015. The highest prevalence of infection (10.34%) was recorded in January 2015 whereas the greatest intensity of infection (up to two parasites per infected crab individual) was recorded from February to April 2015. The parasite, based on morphology, was identified as Allokepon monodi. This study presents the third record of female and second record of male A. monodi infecting a crab species. It also represents the first record of male A. monodi in P. pelagicus and in the Philippines. We recommend further studies on the impacts and economic implications of the disease.

Identification and prevalence of ectoparasites on the fry of Asian sea bass (Lates calcalifer), white shrimp (Litopenaeus vannamei), and blue swimming crab (Portunus pelagicus)

The study aims to find out the types of ectoparasites infected in the fry of Asian Sea Bass (Lates calcalifer), White Shrimp (Litopenaeus vannamei), and Blue Swimming Crab (Portunus pelagicus), and to know their prevalence. The method used in this study is an examination of fish samples using the wet mount method. The results showed that the parasites found in the fry of Asian Sea Bass were Trichodina sp., Caligus sp., and Dactylogyrus sp., with the prevalence, were 18.85%, 3.28%, and 1.64% respectively. While, the parasites of Vorticella sp., Epistylis sp and Zoothamnium sp. infected on white shrimp with the prevalence respectively were 2.71%, 0.84%, and 0.17%. Furthermore, on the blue swimming crab was found parasite of Vorticella sp. with the prevalence was 16.47% and Epistylis sp. with the prevalence value was 12.54%.

Morphometric character variation of the blue swimming crab (Portunus pelagicus Linnaeus, 1758) population in western and eastern part of Java Sea

The blue swimming crab (Portunus pelagicus Linnaeus, 1758) inhabits coastal waters with sandy or muddy substrates of Southeast Asia. Aquatic environment and fishing intensity might influence the variation in morphometric characters of species as a form of adaptation and might characterize the stock unit as well. This study was aimed to analyze the morphometric variation of the blue swimming crab (BSC) population in western and eastern parts of Java Sea as part of Fisheries Management Area (FMA 712) of Indonesia. The representative crab sample for both males and females were taken randomly from three different locations, i.e. East Lampung, Rembang, and Southern Madura Island. Those samples were analyzed with a method called “conventional morphometric method”. Result of the Kruskal-Wallis test showed that 10 characters were significantly different between male and female crabs. The cluster analysis also showed that the crabs in East Lampung and Rembang had high similarities which tended to be close population, while Southern Madura’s crabs were seemed to be dissimilar. In addition, discriminant analyses also showed that the BSC population in Southern Madura was different from the other two populations, indicating that the BSC population of Southern Madura is a different stock unit.

Growth and Survival of Blue Swimming Crab (Portunus pelagicus L.)In Different Rearing Substrates and Stocking Densities

The study of the growth and survival of blue swimming crabs is important to optimize its production and explore the development of net-cage crab culture as the culture scheme for production of blue swimming crabs. This paper investigates the growth and survival rate of Portunus pelagicus at 15 and 30 days of culture using two rearing substrates (net and sand) and three stocking densities (15, 30 and 45 crabs/m2). Physicochemical parameters such as the dissolved oxygen, salinity, water temperature, and water transparency were also gathered across the days of culture to explain other factors that may influence survival rate of crabs during culture. Results showed no significant differences for both growth rate in terms of carapace width and body weight and survival rate. Significant interaction between the stocking rate and rearing substrates on the growth rate in terms of carapace width during the 15 days of culture were observed. Poor growth and survival rates of the crabs may have been the result of cannibalism and poor quality of bottom substrates like silt and abrupt change of water quality namely salinity and transparency. It is recommended to validate the results in a more favorable rearing environment. Management strategies to control predation may be tested and implemented when culturing blue swimming crabs in cages and pens.

Genome-wide SNP analyses reveal population structure of Portunus pelagicus along Vietnam coastline.

The blue swimming crab (Portunus pelagicus Linnaeus, 1758) is one of the commercially exploited crab fishery resources in Vietnam. This is the first study to provide a broad survey of genetic diversity, population structure and migration patterns of P. pelagicus along the Vietnamese coastline. The crab samples were collected from northern, central and southern Vietnam. Here, we used a panel of single nucleotide polymorphisms (SNPs) generated from restriction site-associated DNA sequencing (RADseq). After removing 32 outlier loci, 306 putatively neutral SNPs from 96 individuals were used to assess fine-scale population structure of blue swimming crab. The mean observed heterozygosity (Ho) and expected heterozygosity (He) per locus was 0.196 and 0.223, respectively. Pairwise Fst and hierarchical AMOVA supported significant differentiation of central and northern from southern populations (P<0.01). Population structure analyses revealed that P. pelagicus in the south is a separate fisheries unit from the north and center. Contemporary migration patterns supported high migration between northern and central populations and restricted genetic exchange within the southern population. In contrast, historic gene flow provides strong evidence for single panmictic population. The results are useful for understanding current status of P. pelagicus in the wild under an environment changing due to natural and anthropogenic stresses, with implications for fisheries management.

The effect of Melastoma malabathricum leaf extract on growth and spawning of blue swimming crab (Portunus pelagicus)

The aim of this study was to evaluate the effect of Melastoma malabathricum leaf extract on growth and spawning of the blue swimming crab Portunus pelagicus. This research was conducted from March to May 2019 at the Hasanuddin University mini hatchery in Barru Regency, South Sulawesi Province, Indonesia. The study used five treatment doses of M malabathricum leaf extract: 0, 5, 10, 15, and 20μg/g of female crab body weight. The extract was dissolved in water and an aliquot of 0.1 mL was injected into each crab. The results showed that there was a decrease in growth in all treatments within the first 10 days after injection, but an increase after the 20th day. Doses of 15 and 20 ug/g resulted in the highest spawning rate, ie 100% after 30 days. Crabs with no extract treatment had the lowest spawning rate, which was only 33%. The conclusion of this study is that an appropriate dose of M. malabathricum leaf extract can be used to stimulate spawning of Portunus pelagicus.

Biological condition and carapace width frequency distribution of blue swimming crabs (Portunus pelagicus) in Gresik and Lamongan, East Java

Crabs, including the blue swimming crab (Portunus pelagicus), are one of the top five Indonesian fisheries export commodities. The blue swimming crab (BSC) is captured by various fishing gears that are indicated to threaten the sustainability of BSC resources. The aims of this study were to determine the biological condition of BSC by fishing gear, especially carapace width and weight relationship; sex composition and berried or non-berried female (BEF/NBEF); and carapace width distribution. BSC samples were randomly collected from four fishing bases in Gresik and Lamongan, East Java, Indonesia, from July to September 2018. The study found allometric and isometric BSC growth patterns at Gresik and Lamongan, respectively. Sex ratio of male and female crabs was balanced (1:1) with 16% of BEF in Gresik, while in Lamongan, there were more females than males (1:1.6) with 20% of BEF. Overall, catches were dominated by the size class with 11-12 cm carapace width and 70-90 g in weight. The carapace width distribution of indicated that catches from traps were dominated by BSC with of carapace width >10 cm (94%), (according to Ministerial Decree of Marine Affairs and Fisheries number 56/2016, >10 cm of carapace width is the legal size for BSC capture). Meanwhile, BSC catches from gillnets and mini trawls comprised 69% and 52% in the legal size class (>10 cm carapace width), respectively. Promoting traps as a BSC fishing gear can support the implementation of the ministerial decree in the field.

META ANALISIS PENGARUH TEKANAN PENANGKAPAN TERHADAP UKURAN RAJUNGAN (Portunus pelagicus) DI TELUK BANTEN

Blue swimming crab (Portunus pelagicus) is an important economical fishery commodity for fishermen in Banten Bay that are caught using gill nets and collapsible traps. The increasing of fishing pressure has highly potential to reduce the quality of the catch as exposed in previous studies. However, the comprehensive, and time series analysis of the previous research results have not been conducted. The purpose of this study is to analyze the variations of blue swimming crab caught in Banten Bay through a combination of meta-analysis techniques, fishing trials and field obser-vations to determine the effect of fishing activities on swimming crab sizes, and evaluate the status of swimming crab fisheries in Banten Bay. Standard mean difference from 10 different studies was used as a meta-analysis parameter. The results of the meta-analysis showed that fishing activities were conducted from 2004 to 2018 had a significant effect on the decreasing of the swimming crab size. The average of swimming crab carapace width caught in 2019 approximately 121.66 mm. The proportion of legal swimming crabs in 2014, 2015 and 2019 was more than 80%, so that the status of swimming crab fisheries in Banten Bay is still environmentally friendly.Keywords: carapace width, meta analysis, fisheries, Portunus pelagicus, blue swimming crab

Population Characteristics, Maturation and Spawning of the Blue Swimmer Crab Portunus pelagicus in Eastern Mediterranean Sea, Egypt

Population Characteristics, Maturation and Spawning of the Blue Swimmer Crab Portunus pelagicus in Eastern Mediterranean Sea, Egypt

Growth performance and survival rate of Portunus pelagicus (Linnaeus, 1758) broodstock females fed varying doses of amaranth extracts

Background: Formulated diets made from food waste enriched with amaranth extract largely determine the level of softshell crab production. The study was carried out to analyze the growth performance and survival rate of blue swimming crab Portunus pelagicus (Linnaeus, 1758) broodstock females fed formulated diets with different doses of amaranth extracts. Methods: The female crab samples were collected from the coastal region of Padang, West Sumatra. The method used in this study was a completely randomized design, with four treatments and five replications of amaranth extract-enriched diets (0, 250, 500, and 750 ng/g crab). Results: The results show that the enrichment of the formulated diet with amaranth extracts significantly affected (P &lt; 0.05) the absolute weight gain (AWG), carapace length (ACL), and carapace width (ACW). Conclusions: A quadratic relationship existed between the amaranth extract dose in the formulated diet and the AWG, ACL and ACW.