Aspek Morfometri Dan Tingkat Kematangan Gonad Rajungan (Portunus pelagicus) Linnaeus, 1758 (Malacostraca:Portunidae) di Perairan Betahwalang Demak

ABSTRAK: Rajungan (P. pelagicus, Linnaeus, 1758) adalah salah satu hasil perikanan utama di Betahwalang, Demak. Penangkapan rajungan diduga dilakukan secara intensif oleh nelayan di Des Betahwalang, maka diperlukan langkah pengelolaan yang tepat untuk menjaga kelestarian dan konservasi rajungan. Informasi aspek morfometri rajungan bias digunakan sebagai salah satu acuan dalam pengelolaan rajungan berkelanjutan. Tujuan penelitian adalah untuk mengkaji tingkat kematangan gonad dan morfometri rajungan yang dilaksanakan pada bulan Juli – September 2019 di Desa Betahwalang, Demak. Penelitian menggunakan metode survey dengan analisis yang bersifat deskriptif yang dilakukan secara “time-series”. Pengamatan sampel rajungan sebesar 10% dari hasil tangkapan yang didaratkan oleh setiap nelayan di pengepul rajungan. Total rajungan yang diamati 5.480 ekor terdiri dari betina 2.960 ekor dan jantan 2.388 ekor. Hasil penelitian menunjukkan pertumbuhan rajungan jantan bersifat allometrik positif, sedangkan rajungan betina cenderung bersifat allometrik negatif dengan seks rasio relatif seimbang. Rajungan betina diduga mengalami pertama kali matang gonad pada selang kelas lebar karapas 70 – 79 mm. Sampel pengamatan fekunditas dan kematangan telur pada 126 ekor rajungan betina bertelur. Kematangan telur dilihat dari pigmen warnanya secara berurutan mulai pigmen warna kuning, orange, coklat dan hitam, serta berdasarkan ukuran diameter telur. Fekunditas telur memiliki korelasi yang sangat kuat terhadap lebar karapas yang berarti semakin besar ukuran rajungan, maka jumlah telur semakin banyak. Selama penelitian masih ditemukan rajungan “undersize” sebesar 18% (981 ekor) dan rajungan betina bertelur sebesar 24% (716 ekor), yang berarti nelayan di Desa Betahwalang belum menerapkan kriteria dan ukuran layak tangkap sesuai dengan peraturan yang berlaku.ABSTRACT: Blue swimming crab (P. pelagicus, Linnaeus, 1758) is one of main fisheries products in Betahwalang, Demak. High-intensity levels of catching the blue swimmer crab by fisherman may need sustainable management to protect and conserve the population. The purpose of this study was to determine about gonad maturity level and morphometrical aspect of blue swimming crab started from July – September 2019. There’s a descriptive survey method used in this study with time-series observations. The sample size is about 10% of the total number landed crab from each fisherman. The total sample are 5.348 that consist of 2.960 female crabs and 2.388 male crabs. The results showed the male crabs has a positive allometric on growth parameters, but the females have an allometric positive and negative growth parameters, and balanced sex-ratio. Female crabs may reach the first matured gonad level between 70 – 79 mm of carapace width. Fecundity and egg’s maturity observation used 126 berried female crabs. The egg’s maturity based on the pigment color started from yellow, became orange, brown and black also by egg diameter increase. The analysis showed that female crab fecundity has a strong correlation to the increase of carapace width, which means carapace width increase followed by egg’s amount increasing. During the study, it was found about 18% (981 crabs) the undersize crabs (<100 mm) and 24% (716 crabs) the berried female crabs, which means the Betahwalang fisherman hasn’t applied the rule yet.

Download Full-text

Kajian Morfometri dan Tingkat Kematangan Gonad Rajungan di Perairan Betahwalang, Demak

Journal of Marine Research ◽

10.14710/jmr.v10i2.29247 ◽

2021 ◽

Vol 10 (2) ◽

pp. 175-183

Author(s):

Iqbal Maulana ◽

Irwani Irwani ◽

Sri Redjeki

Keyword(s):

Time Series ◽

Size Structure ◽

Growth Parameters ◽

Carapace Width ◽

Economic Value ◽

Survey Method ◽

Swimming Crab ◽

Female Crab ◽

Portunus Pelagicus ◽

Gonad Maturity

Rajungan (Portunus pelagicus) merupakan komoditas laut yang memiliki nilai ekonomis yang tinggi, dimana berbanding lurus dengan penangkapan yang terus meningkat. Tingkat pemanfaatan yang tidak mengindahkan ukuran dan kondisi rajungan dapat mempengaruhi struktur ukuran dan stok rajungan di suatu perairan. Penelitian ini bertujuan untuk mengetahui distribusi ukuran, hubungan lebar dan berat rajungan serta distribusi tingkat kematangan gonad (TKG) di perairan Betahwalang, Demak. Penelitian menggunakan metode survey dengan analisis yang bersifat deskriptif yang dilakukan secara “time-series”. Pengamatan sampel rajungan sebesar 10% dari hasil tangkapan yang didaratkan oleh setiap nelayan di pengepul rajungan.. Hasil dari penelitian ini menujukkan dari 3030 ekor rajungan yang diamati diketahui distribusi lebar karapas rajungan berkisar antara 35 – 185 mm dan kisaran berat sebesar 10 – 350 gram. Rajungan yang terdapat di perairan Betahwalang memiliki pertumbuhan yang bersifat allometrik positif pada rajungan jantan dan betina pada bulan Januari serta Februari. Hasil nilai b sebesar 3,29 dan 3,08 (Januari & Februari) pada rajungan jantan. Nilai b sebesar 3,10 dan 3,15 pada rajungan betina (Januari & Februari) serta nilai b sebesar 3,14 pada keseluruhan rajungan. Sehingga diketahui pertumbuhan lebar karapas lebih cepat dibandingkan bobot rajungan. Sedangkan distribusi tingkat kematangan gonad rajungan betina adalah 21% pada TKG 1; 63% pada TKG 2; serta 16% pada TKG 3, dengan ukuran pertama kali matang gonad adalah 141,51 mm. Blue swimming crab (Portunus pelagicus) is a marine commodity has a high economic value , which is causing the crab catch to rise as well. The catch rate that does not consider the size and maturity of sea crab can affect the size structure and population stock of sea crab in waters. This study aims to determine the size distribution,the relationship of width and weight of Blue swimming crab and distribution of gonad maturity in Betahwalang, Demak. There’s a descriptive survey method used in this study with time-series observations. The sample size is about 10% of the total number landed crab from each fisherman. The results of this study showed that from 3030 crabs observed, the distribution of crab carapace width ranged from 35 – 185 mm and the weight range at 10 – 350 gram. The results showed the all crabs has a positive allometric on growth parameters. The value of b 3,29 and 3,08 (January & February) in male blue swimming crab, 3.10 and 3.15 (January & February) on female sea crabs, and 3.14 on whole sea crabs. So it is known that the growth of carapid width is faster than the weight of crab. While the distribution of female crab gonad maturity level is 21% in level 1; 63% in level 2; and 16% in level 3, with the first size of mature gonad at 141,51 mm.

Download Full-text

Biologi Rajungan Portunus pelagicus Linnaeus, 1758 (Crustacea: Portunidae) Ditinjau Dari Aspek Distribusi Ukuran Dan Parameter Pertumbuhan Di Perairan Rembang, Jawa Tengah

Journal of Marine Research ◽

10.14710/jmr.v8i4.24539 ◽

2019 ◽

Vol 8 (4) ◽

pp. 402-408

Author(s):

Nathanael Ganang Anindityo Wibowo ◽

Chrisna Adhi Suryono ◽

Ibnu Pratikto

Keyword(s):

Size Structure ◽

Carapace Width ◽

Growth Parameter ◽

Survey Method ◽

Average Weight ◽

Swimming Crab ◽

Female Crab ◽

Potential Yield ◽

Portunus Pelagicus ◽

Male Crab

Rembang merupakan salah satu kabupaten di Jawa Tengah yang dikenal sebagai daerah penghasil sumberdaya rajungan yang cukup tinggi permintaannya dan terus meningkat setiap tahunnya. Hal tersebut dapat menyebabkan terjadinya penurunan potensi hasil rajungan akibat intensifnya penangkapan di Perairan Rembang. Kajian tentang kondisi stok sumberdaya rajungan terkait sebaran dan dinamika populasi ini sangat diperlukan dalam pengelolaan potensi rajungan. Tujuan dari penelitian ini adalah untuk menganalisis struktur ukuran dan parameter pertumbuhan rajungan di Perairan Rembang. Penelitian ini dilaksanakan pada bulan Maret – Juni 2019 di Perairan Rembang, dengan menggunakan metode survei yang bersifat deskriptif. Total sampel rajungan selama penelitian adalah 1200 ekor yang terdiri dari 574 ekor jantan dan 624 ekor betina. Hasil penelitian menunjukkan kelas ukuran lebar karapas rajungan didominasi oleh rajungan muda, dengan rata – rata 105.01 ± 11.99 mm untuk jantan dan 107.73 ± 10.68 untuk betina. Berat rata – rata rajungan jantan yaitu sebesar 95.2 ± 27.1 gram dan rajungan betina sebesar 97.9 ± 23.1 gram, sehingga menunjukkan rajungan jantan lebih kecil dibandingkan dengan rajungan betina. Pola pertumbuhan rajungan di Perairan Rembang bersifat allometrik negatif. Laju pertumbuhan rajungan di Perairan Rembang yang didapatkan adalah berupa nilai panjang asimptotik (L∞) sebesar 71.4 mm dengan koefisien pertumbuhan (K) sebesar 1.5/tahun.Rembang is a coastal region in Central Java which known as to producer of blue swimming crab resources that are in high demand and continues to increase every year. It will because decreasing the potential yield of blue swimming crab due to intensive fishing in Rembang Waters. Study on the stock condition of the blue swimming crab resource related to the distribution and dynamics of the population is required for the management of the blue swimming crab potential. The current research aims to assess the size structure and growth parameter of blue swimming crab in the Rembang Waters. The research was conducted from March to June 2019 in Rembang Waters, using a descriptive survey method. The total number of crab samples during the study was 1200 animals consisting of 574 male and 624 female. The results showed that the size of the crab carapace width class was dominated by young crabs, with an average of 105.01 ± 11.99 mm for males and 107.73 ± 10.68 for females. The average weight of male crab is 95.2 ± 27.1 gram and female crab is 97.9 ± 23.1 gram, indicates that male crab is smaller than female crab. The crab’s growth in Rembang Waters is allometric negative. The growth rate of crab in the Rembang Waters obtained is in the form of asymptotic length (L∞) was 71.4 mm with a growth coefficient (K) 1.5/year.

Download Full-text

DISTRIBUSI UKURAN DAN POLA MUSIM PENANGKAPAN RAJUNGAN (Portunus pelagicus) DI PERAIRAN KABUPATEN PANGKEP

Marine Fisheries Journal of Marine Fisheries Technology and Management ◽

10.29244/jmf.9.1.77-87 ◽

2018 ◽

Vol 9 (1) ◽

pp. 77

Author(s):

. Ihsan

Keyword(s):

Time Series ◽

Fishing Effort ◽

Survey Method ◽

Dominant Male ◽

Distribution Analysis ◽

Swimming Crab ◽

Female Crab ◽

Portunus Pelagicus ◽

Fishing Season ◽

Dominant Female

The swimming crab potential is a resource that has high economic value. Therefore the utilization needs to be done continuously and to achieve this is by conducting an important research focussed on the size and the fishing season pattern of the swimming crab by studying the pattern of the catching season, it is expected to improve the efficiency and effectiveness of the catching time. The objective of this research is to 1. Map the distribution of the frequency and size of crab and 2. Determine the pattern of fishing season in Pangkep waters. The research is conducted from March to November 2016. It is located in Pangkep waters regency, South Sulawesi Province. The data is collected through survey method consisted of primary and secondary data. The data were analyzed using frequency distribution analysis approach and time series analysis technique toward catch (kg) of fishing effort. The results obtained showed that the dominant female crab caught with a size > 10.0 cm, as well as dominant male crabs caught with a size > 10 cm. The fishing gear used is trap and gillnet. In addition the catching season is in May, June, July, September, October and November. The peak season of catching season takes place in June and September.Keywords: Size distribution, Season pattern, swimming crab, at Pangkep District ABSTRAKPotensi sumberdaya rajungan, merupakan komoditas sumberdaya yang memiliki nilai ekonomis penting, sehingga pemanfaatannya perlu dilakukan secara berkelanjutan. Untuk mencapai hal tersebut maka ukuran hasil tangkapan dan pola musim penangkapan rajungan menjadi penting untuk diteliti. Adanya informasi pola musim penangkapan, diharapkan dapat meningkatkan efesiensi dan efektifitas waktu penangkapan rajungan. Penelitian ini bertujuan untuk 1) memetakan distribusi frekuensi dan ukuran rajungan yang tertangkap, dan 2) menentukan pola musim hasil tangkapan rajungan di perairan Kabupaten Pangkep. Pelaksanaan penelitian dilaksanakan mulai bulan Maret sampai bulan November 2016, di perairan Kabupaten Pangkep Propinsi Sulawesi Selatan. Metode pengumpulan data dalam penelitian ini adalah dengan metode survei. Data yang dikumpulkan terdiri dari data hasil tangkapan rajungan per hari; panjang dan lebar (cm) karapas dan berat (gram/kg) rajungan. Data dianalisis dengan menggunakan pendekatan analisis distribusi frekuensi dan teknik analisis deret waktu (time series) terhadap hasil tangkapan (kg) persatuan upaya penangkapan. Hasil penelitian yang diperoleh menunjukkan bahwa distribusi frekuensi rajungan betina, tertangkap berukuran < 10,0 cm, lebih sedikit dibandingkan yang tertangkap di atas ukuran > 10,0 cm. Demikian juga rajungan jantan ukuran < 10,0 cm jumlahnya lebih sedikit dan ukuran rajungan > 10,0 cm lebih dominan tertangkap. Alat tangkap yang digunakan adalah bubu lipat, dan gillnet rajungan. Pola musim penangkapan rajungan di perairan Kabupaten Pangkep terjadi pada bulan Mei, Juni, Juli, September, Oktober dan November dan puncak musim berlangsung pada bulan Juni dan September.Kata kunci: distribusi ukuran, pola musim, rajungan, Kabupaten Pangkep

Download Full-text

Studies on Biological Test of Formulated Diets Supplementation of Vitamin E for the Broodstock of Females Blue Swimming Crab, Portunus pelagicus (Linnaeus, 1758)

F1000Research ◽

10.12688/f1000research.15885.1 ◽

2018 ◽

Vol 7 ◽

pp. 1780 ◽

Cited By ~ 2

Author(s):

Efrizal Efrizal ◽

Indra Junaidi Zakaria ◽

Rusnam Rusnam ◽

Suryati Suryati ◽

Nofa Yolanda

Keyword(s):

Vitamin E ◽

Carapace Width ◽

Coastal Region ◽

Mass Scale ◽

Dietary Vitamin ◽

Swimming Crab ◽

Female Crab ◽

Portunus Pelagicus ◽

Formulated Diets ◽

Formulated Diet

Background: Currently, great progress in the artificial propagation of commercially important portunid crabs of the genus Portunus has been achieved, and various methods have been adopted in mass-scale hatchery activities. This study analyzed the biological testing of formulated diets with different dose supplementations of vitamin E for the broodstock of female blue swimming crabs, P. pelagicus (Linnaeus, 1758) Methods: Female crab samples were collected from the coastal region of Padang, West Sumatra. The method used in this study was completely randomized design, with four treatment regimens (n=5 crabs each) of dietary vitamin E (0, 300, 600, and 900 IU/kg formulated diets). Results: The results show that the supplementation of vitamin E in the formulated diet had a significant effect (P <0.05) on the absolute weight growth, carapace length and carapace width. Conclusions: Supplementation of vitamin E on in formulated diet causes broodstock blue swimming crab molting, with a percentage value of 40–80% on day 20 and 20% on day 30, with a 100% survival rate.

Download Full-text

Studies on Biological Test of Formulated Diets Supplementation of Vitamin E for the Broodstock of Females Blue Swimming Crab, Portunus pelagicus (Linnaeus, 1758)

F1000Research ◽

10.12688/f1000research.15885.2 ◽

2019 ◽

Vol 7 ◽

pp. 1780 ◽

Cited By ~ 1

Author(s):

Efrizal Efrizal ◽

Indra Junaidi Zakaria ◽

Rusnam Rusnam ◽

Suryati Suryati ◽

Nofa Yolanda

Keyword(s):

Vitamin E ◽

Carapace Width ◽

Coastal Region ◽

Mass Scale ◽

Dietary Vitamin ◽

Swimming Crab ◽

Female Crab ◽

Portunus Pelagicus ◽

Formulated Diets ◽

Formulated Diet

Download Full-text

Distribution and Size of Crab (Portunus pelagicus) in Betahwalang Waters, Demak, Central JavaSex Ratio, Size Distribution and Length-Weight Relationship of Portunus pelagicus Linnaeus, 1758 (Malacostraca : Portunidae) in Betahwalang, Demak, Central Java

Jurnal Kelautan Tropis ◽

10.14710/jkt.v24i1.10467 ◽

2021 ◽

Vol 24 (1) ◽

pp. 133-140

Author(s):

Sri Redjeki ◽

Muhammad Zainuri ◽

Ita Widowati ◽

Ambariyanto Ambariyanto ◽

Rudhi Pribadi ◽

...

Keyword(s):

Body Weight ◽

Body Size ◽

Sex Ratio ◽

Size Distribution ◽

Growth Parameters ◽

Carapace Width ◽

The Body ◽

Swimming Crab ◽

Portunus Pelagicus ◽

Male And Female

Blue Swimming Crab (P. pelagicus, Linnaeus, 1758) is the main fisheries product from Betahwalang peoples. Fishing activity of Blue Swimming Crab by the fisherman almost every day in Betahwalang waters. Distribution and body size data of Blue Swimming Crab can be used for sustain management reference. The purpose of this study was to determine distribution pattern and body size of Blue Swimming Crab, started from July to November 2018 in Betahwalang waters, Demak. The data analyze consist of sex ratio, carapace width distribution and relationship between carapace width and body weight. 11790 samples Blue Swimming crab from Betahwalang waters consist of 7070 female crabs and 4720 male crabs. The result showed that sex-ratio between male and female crabs are balanced (1.0:1.37), with the most female crabs found at July and August. Body size distribution of male and female crabs are dominated in class 103-111 mm carapace width. Male and female crabs have a positive allometric on growth parameters, that means growth of the body weight is faster than carapace width. The result showed that Blue Swimming Crab in Betahwalang waters are support for sustainable fisheries.

Download Full-text

BIOLOGI POPULASI RAJUNGAN(Portunus pelagicus) DI PERAIRANSEKITARWILAYAHPATI, JAWATENGAH

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.6.1.2014.31-40 ◽

2015 ◽

Vol 6 (1) ◽

pp. 31

Author(s):

Tri Ernawati ◽

Mennofatria Boer ◽

Yonvitner Yonvitner

Keyword(s):

Growth Characteristic ◽

Carapace Width ◽

Biological Data ◽

Spawning Season ◽

Maturity Stage ◽

Swimming Crab ◽

Female Crab ◽

Portunus Pelagicus ◽

Mean Size ◽

The Mean

Rajungan (Portunus pelagicus) adalah salah satu komoditas perikanan yang sudah banyak dieksploitasi oleh nelayan tradisional. Penangkapan yang berlebihan merupakan salah satu penyebab menurunnya populasi alamidari rajungan. Kondisi tersebut dikhawatirkan akanmengancamkelestarian dan keberlanjutan pemanfaatannya, sehingga perlu dilakukan penelitian tentang aspek biologi populasi rajungan untuk tujuan pengelolaan yang rasional di wilayah Pati. Penelitian dilakukan di perairan Pati dan sekitarnya sejak bulan Januari 2012 sampai dengan Maret 2013. Tujuan penelitian adalah untuk mengetahui rata-rata ukuran pertama kali tertangkap (Lc) dan matang gonad (Lm), sifat pertumbuhan, musim pemijahan dan jumlah telur individu betina rajungan. Data biologi rajungan yang dikumpulkan terdiri dari: ukuran lebar karapas, berat, jenis kelamin dan tingkat kematangan gonad betina. Hasil penelitian diperoleh bahwa sebaran hasil tangkapan pada substrat yang berbeda relatif sama (ñ > 0.05). Ukuran rata-rata lebar karapas rajungan pertama kali tertangkap (Lc) oleh bubu lipat adalah 108 mm. Ukuran rata-rata lebar karapas rajungan pertama kali matang gonad (Lm) adalah 107 mm. Sifat pertumbuhanrajungan jantan dan betina adalah lebih cepat pertambahan bobot dibandingkan lebar karapasnya.Nisbah kelamin pada musim barat relatif seimbang (ñ < 0.05). Nisbah kelamin pada musim timur relatif tidak seimbang (ñ < 0.05). Reproduks terjadi sepanjang tahun. Jumlah total telur individu betina berkisar antara 351.214 sampai 1.347.029 butir dengan rata-rata 957.196 butir.Blue Swimming crab (Portunus pelagicus) was one of fisheries commodity, intensively exploited by artisanal fisheries. Overfishing was caused of declining natural populations of crabs. Its was feared to threaten the preservation and sustainability of utilization. So it was necessary doing research on biological aspects of crab populations for the purpose of rational management in the region Pati. The study was conducted in Pati and surrounding waters from January 2012 toMarch 2013. The research were aimed to determine the mean size at first capture (Lc) and mean size at gonad maturity (Lm), growth characteristic, spawning season and fecundity of individual females crabs. Collecting crab biological data consists of: carapace width, weight, sex and maturity stage female gonads. The result showed that catch distribution on different substrates was not different (ñ>0,05). The mean size of crabs’s carapace width at first capture (Lc) by collapsible traps was 108 mm. The meansize at first mature of female crabs (Lm) was 107 mm. The growth type of male and female crab were positive allometric. Its means that gain of weight was rapidly than carapace width of crabs. Sex ratio between male andfemale inWest season was relative balanced but in East season was not balanced (ñ < 0.05). Spawning season of blue swimming crab is throughout the year. The total fecundity ranged from 351,214 – 1,347,029 eggs whichmean 957,196 eggs.

Download Full-text

Studi Kerentanan Rajungan (Portunus pelagicus) di Desa Paciran Kecamatan Paciran Kabupaten Lamongan Sebagai Upaya Konservasi Berkelanjutan

Journal of Marine Research ◽

10.14710/jmr.v9i4.27891 ◽

2020 ◽

Vol 9 (4) ◽

pp. 509-516

Author(s):

Aninda Putri Amelia ◽

Irwani Irwani ◽

Ali Djunaedi

Keyword(s):

Growth Characteristic ◽

Carapace Width ◽

Economic Value ◽

Growth Patterns ◽

Average Weight ◽

Swimming Crab ◽

Female Crab ◽

Portunus Pelagicus ◽

Average Width ◽

A Value

Rajungan (Portunus pelagicus) adalah hewan bercangkang keras seperti kepiting yang memiliki habitat alami hidup di laut dan biasa disebut sebagai Blue Swimming Crab. Rajungan menjadi salah satu komoditas perikanan yang memiliki nilai ekonomis yang tinggi di Indonesia. Tujuan dilakukannya penelitian ini untuk mengkaji tingkat kerentanan Rajungan (Portunus pelagicus) akibat adanya kegiatan penangkapan di Desa Paciran Kecamatan Paciran Kabupaten Lamongan, Jawa Timur. Metode yang digunakan dalam penelitian ini adalah metode Analisis PSA (Productivity and Susceptibility Analysis). Hasil analisa parameter produktivitas didapatkan dari literatur, sedangkan parameter kerentanan didapatkan dari hasil wawancara dengan nelayan setempat. Nilai PSA yang didapatkan sebesar 2,01 yang menunjukkan bahwa tingkat kerentanan masih tergolong rendah, sehingga tekanan aktivitas penangkapan belum berdampak serius terhadap potensi keberlanjutan Rajungan (Portunus pelagicus) sementara hasil pola pertumbuhan menunjukkan pola pertumbuhan allometrik negatif baik jantan dan betina. Hubungan lebar karapas dengan berat rajungan menghasilkan nilai b sebesar 2,37 untuk rajungan jantan dan 2,33 untuk rajungan betina. Sifat pertumbuhan ini menunjukkan bahwa pertumbuhan lebar karapas lebih cepat dibandingkan pertumbuhan berat rajungan. Rata rata lebar karapas yang ditemukan dilokasi penelitian 128 mm pada Rajungan jantan dan 111 mm pada Rajungan betina serta memiliki rata rata ukuran berat 115 gr baik pada Rajungan jantan dan betina. Blue Swimming Crab (Portunus pelagicus) is a hard-shelled animal like a crab that naturally lives in the sea and is commonly referred to as the Blue Swimming Crab. The Blue Swimming Crab is one of the fishery commodities with high economic value in Indonesia. This research aimed to examine the vulnerability rate of Blue Swimming Crab (Portunus pelagicus) due to the fishing activities in Paciran Village, Paciran, Lamongan, East Java. The method used in this study is the PSA (Productivity and Vulnerability Analysis) method. The analysis of productivity parameters’ was obtained from literature, while the vulnerability parameters are obtained from interviews with local fisherman. The PSA value was (2,01). The results indicated that the level of vulnerability is still relatively low, therefore the pressure of fishing activities has not seriously affected the potential sustainability of the Blue Swimming Crab (Portunus pelagicus) and the results of the Blue Swimming Crab growth pattern shows negative allometric growth patterns for both males and females.The relationship between carapace width and crab weight had a value of b of 2,37 for male crabs and 2,33 for female crabs. This growth characteristic showed that carapace width growth is faster than the growth of crab weight. The average width of the carapace was found in the study location 128 mm for male, and 111 mm for female crab and has an average weight size of 115 gr for both males and females.

Download Full-text

Stock Status of Blue Swimming Crab (Portunus pelagicus Linnaeus, 1758) in Tiworo Strait Waters, Southeast Sulawesi, Indonesia

ILMU KELAUTAN Indonesian Journal of Marine Sciences ◽

10.14710/ik.ijms.25.2.85-90 ◽

2020 ◽

Vol 25 (2) ◽

pp. 85-90

Author(s):

Yustika Permatahati Intan Permatahati ◽

Nila Nikmatia Bugis ◽

La Sara ◽

Tezza Fauzan Hasuba Hasuba

Keyword(s):

Carapace Width ◽

Growth Patterns ◽

Fishing Ground ◽

Swimming Crab ◽

Portunus Pelagicus ◽

Male And Female ◽

Gonad Maturity ◽

Stock Status ◽

Spawning Potential Ratio ◽

Very High

The blue swimming crab (BSC) fishery in Tiworo Strait has been heavily exploited since two decades ago when its worldwide demand and price was very high. Study on population aspects of this organism in this waters is limited. The aim of present study was to investigate growth patterns, population stock status, and size at first gonad maturity of Portunus pelagicus. One of the main fishing ground of BSC around Tiworo Strait waters is at Bangko and Gala Islands. Samples of BSC were taken monthly using gillnet and collapsible trap. Each sample taken was identified its sex, measured its carapace width, and weighed. Data collected from fishing ground of BSC were analyzed to find out growth patterns, population stock status using spawning potential ratio (SPR) method, and the first gonad maturity (CW50). The results of study showed that growth patterns of BSC male and female following isometric growth patterns (b=0) (P<0.05). It was found out that SPR of BSC from both fishing ground was 22.46% and 23.71%, respectively which indicates that population stock status of BSC in Tiworo strait waters is “moderate level” (SPR > 20%). The size at first gonad maturity (CW50) was attained at carapace width of 9.16 cm for male and 10.16 cm for female. Those imply that BSCs allowed to be caught should be >10 cm.

Download Full-text

VARIABILITY OF CARAPACE WIDTH SIZE AND ABUNDANCE OF BLUE SWIMMING CRABS (Portunus pelagicus Linnaeus) IN PATI WATERS

Jurnal Ilmu dan Teknologi Kelautan Tropis ◽

10.28930/jitkt.v7i2.10996 ◽

2016 ◽

Vol 7 (2) ◽

Author(s):

Dyah Ika Nugraheni ◽

Achmad Fahrudin ◽

. Yonvitner

Keyword(s):

Coastal Waters ◽

Accretion Rate ◽

Carapace Width ◽

Management Strategies ◽

Fishing Effort ◽

Swimming Crab ◽

Nearshore Zone ◽

Portunus Pelagicus ◽

Males And Females ◽

Swimming Crabs

Fishing effort enhancement would put pressure on blue swimming crab resources and its ecosystem. The objective of this study was to determine the spatial distribution based on the size of the carapace width (CW), abundance, temperature, salinity, depth, and fishing intensity in Pati waters which was divided into two zones (zones 1=nearshore, zone 2=offshore). The result showed that the average of carapace width in zone 1 to zone 2 was significantly different (p <0.05), as well as between males and females. Average number of individual (abundance) was significantly different according to fishing areas and sex (p <0.05). The average of water temperature in zone 1 was higher than in zone 2, salinity in zone 1 was smaller than in zone 2, and the water depth in zone 1 was shallower than in zone 2. The higher the crab catch intensity leaded to the smaller the abundance and size of carapace width. Alternative management strategies were proposed such as to divert fishing grounds from coastal waters to offshore during low productivity season, to uphold rules on minimum legal size for catching (Lm = 107 mm), to release of berried females catch, and to reduce accretion rate of gear and fishing fleet mainly in the coastal zone waters.Keywords: blue swimming crab, carapace widht (CW), abundance, intensity of fishing

Download Full-text