scholarly journals ASPEK BIOLOGI RAJUNGAN (Portunus pelagicus) DI TELUK BANTEN, INDONESIA

2021 ◽  
Vol 2 (2) ◽  
pp. 83
Author(s):  
Muhammad Fadil Mursyid ◽  
Pulung Adhi Prabowo ◽  
Isnendar Prakasa Sudrajat ◽  
Novira Farhandika ◽  
Diah Puspa ◽  
...  

Rajungan (Portunus Pelagicus ) merupakan salah  satu  sumberdaya  perikanan  yang   penting   di wilayah  Perairan Teluk  Banten. dan  minim informasi mengenai  populasi  dan  status stok. Tujuan  penelitian  ini  adalah  mengkaji  Aspek biologi  (Portunus Pelagicus) berdasarkan  laju eksploitasi  dan  rasio  potensi pemijahan  di Perairan Teluk Banten,  penelitian ini dilakukan pada bulan maret-april 2019. Penelitian ini menggunakan metode market survey (Observasi pada pengepul Rajungan) dan data langsung  di lapangan sebagai data primer serta data sekunder.  Penelitian ini bertujuan untuk mengetahui  aspek biologi rajungan meliputi: jumlah stok hasil tangkapan selama kurang lebih 40 hari, ukuran pertama tangkapan kali (Lc), menganalisa  hubungan  panjang  dan berat,  hasil pertama  kali  matang  gonad (Lm) dan sex ratio rajungan.  Hasil  penelitian diharapkan dapat memberikan informasi  mengenai  perikanan  rajungan dalam pengelolaan berkelanjutan sumberdaya rajungan di perairan teluk banten. Hasil  analisa jumlah stok hasil  tangkapan rajungan di  teluk banten berjumlah 476 (302 jantan dan 174 betina),  Untuk hasi l analisa  ukuran pertama  kali tertangkap (Lc) diperoleh nilai Lc jantan = 10.47cm  dan Lc betina 13.50 cm ,  Hasil  analisa   hubungan lebar-bobot diperoleh  nilai  b jantan = 11.7810 (allometrik positif), sedangakan b betina = 10.6747 (allometrik positif) , Ukuran pertama kali matang gonad (Lm) jantan sebesar 11.82 cm dan betina 9.30 cm,  Perbandingan sex ratio sebesar 1.73 : 1 lebih dominan rajungan jantan.

2020 ◽  
Vol 2 (1) ◽  
pp. 49
Author(s):  
Meuthia Maharani Kanedi ◽  
Priyanto Rahardjo ◽  
Mira Maulita

Abstrak Salah satu potensi perikanan laut adalah rajungan (Portunus pelagicus). Rajungan (Portunus pelagicus) merupakan komoditas yang penting karena mempunyai nilai ekonomi tinggi dan permintaan pasar baik di dalam maupun luar negeri masih tinggi. Tujuan dilaksanakan praktik integrasi ini adalah untuk Menganalisis beberapa aspek biologi untuk mengetahui pola pertumbuhan sebagai acuan kajian stok rajungan di Pesisir Kabupaten Lampung Timur, Provinsi Lampung dan Mengetahui aspek perikanan di Pesisir Kabupaten Lampung Timur, Provinsi Lampung. Metode yang digunakan dalam penelitian ini adalah metode penelitian deskriptif.  Pengambilan data praktik meliputi penentuan hubungan lebar bobot karapas, nisbah kelamin, tingkat kematangan gonad, ukuran pertama kali tertangkap dan ukuran pertama kali matang gonad. Hasil praktik menunjukkan rajungan yang ada di pesisir Kabupaten Lampung Timur diperoleh dari hasil pengukuran sampel lebar-bobot rajungan sebanyak 1013 spesies dengan pola pertumbuhan alometrik negatif. Hasil nisbah kelamin P. pelagicus memperlihatkan bahwa 544 rajungan jantan (54%) dan 469 rajungan betina (46%) memiliki sex ratio 1:0.862. Persentase Tingkat kematangan gonad jantan (46%) dan betina (54%). Ukuran morfometrik nilai standar length at first maturity (Lm) yaitu 12.48 cm. Dari hasil perhitungan diperoleh nilai Lc Total sebesar 13.23 cm. Rajungan di Pesisir Kabupaten Lampung Timur biasanya ditangkap menggunakan alat tangkap Jaring Rajungan dan Bubu.Kata Kunci : Rajungan; Lampung Timur, Alat Tangkap


2016 ◽  
Vol 21 (1) ◽  
pp. 17 ◽  
Author(s):  
Muh. Saleh Nurdin ◽  
Syamsu Alam Ali ◽  
Dewi Yanuarita Satari

Blue swimming crab (Portunuspelagicus) is aeconomical valuable fisheries importantcommodity  due to the high demand and availability jobs created for the fishermen. Due to their high demand blue swimming crab heavily exploited from Salemo Island. This study aimed at comparing the sex ratio and the size at first maturity of blue swimming crab caught in mangrove ecosystems, coral reefs, and seagrass. Sex ratio was analyzed using chi square test and the size at first maturity was analyzed using the Spearman-Karber formula. The results showed the sex ratio ofmales and femalessmall crab caught in every ecosystem is balanced. The size at first maturity of blue swimming crab caught in mangrove, seagrass and coral reefs, each to the male 81,08 mm, 102,36 mm and 102,87 mm in width and size of female 94,54 mm, 83,35 mm, 98,31 mm width. In a reference to government regulations, the blue male swimming crab caught in the coral reef and seagrass ecosystems have yet to size at first maturity is allowed to be captured. Keywords: blue swimming crab, sex ratio,size at first maturity, Salemo Island


Author(s):  
Insaniah Rahimah ◽  
Vincentius Siregar ◽  
Syamsul Agus

The blue swimming crab in the waters of Lancang Island is indicated as being overfished. Hence, the major challenge is managing its utilization in a proper manner. The purpose of this study is to explore the water's characteristics which is suitable for blue swimming crab fishing. Accordingly, the potential fishing ground around Lancang Island waters can be mapped spatially as an initial effort for species preservation. Geospatial analysis was applied to assess the physical parameters of the existing habitat. The results show that parameters such as MPT, TDS, brightness, phosphate, nitrate, depth and substrate types were remarkably suitable to support the growth of blue swimming crabs. Meanwhile, parameters such as salinity, DO, and temperature show lower quality which implied that the habitat is less suitable. However, the result of weighting and reclassification conclude that Lancang island waters is a decent habitat for blue swimming crab. Catch data show that 40% blue swimming crabs have small carapace size (7-11.83 cm) which is undersized and prohibited by law. Furthermore, about 68% of catch are quite light (30-147 gr) and the sex ratio of males to females was 1:2. It was also revealed that approximately 35% of female species were carrying eggs (BEF/barried female). Keywords: geospatial, fishing ground, suitability, Lancang Island, blue swimming crab.


2019 ◽  
Vol 25 (2) ◽  
pp. 79
Author(s):  
Karsono Wagiyo ◽  
Tirtadanu Tirtadanu ◽  
Tri Ernawati

Teluk Jakarta merupakan salah satu daerah penangkapan dan habitat rajungan (Portunus pelagicus) di Indonesia. Permintaan pasar yang terus meningkat dan bersamaan dengan penurunan kualitas perairan mengakibatkan stok rajungan mengalami tekanan eksploitasi dan degradasi habitat. Agar pengelolaan sumberdaya rajungan di Teluk Jakarta tetap lestari, maka diperlukan penelitian mengenai perikanan dan dinamika populasi. Tujuan penelitian memperoleh data dan informasi mengenai daerah tangkapan, alat dan musim penangkapan, indeks kelimpahan, produksi dan komposisi, struktur ukuran, nisbah kelamin, kematangan gonad, musim pemijahan, ukuran panjang pertama tertangkap, ukuran panjang pertama matang gonad, laju pertumbuhan, laju kematian dan laju eksploitasi. Data dan informasi diperoleh dengan eksplorasi, observasi, enumerasi, wawancara dan perunutan pada tempat pendaratan ikan dan instansi lain yang terkait dengan perikanan, selama tahun 2016. Hasil penelitian didapatkan karakteritik daerah penangkapan rajungan; substrat lumpur berpasir dengan perairan dasar yang mempunyai salinitas 30,5-32 ppt, oksigen 6,5-6,9 ml/l, pH 7,5-8,01, kecepatan arus 0,08-0,24 m/dt. Alat tangkap utama berupa jaring insang dasar bermata 3-3,5 inchi, musim penangkapan Mei-Agustus dan paceklik November-Januari. CPUE rajungan tahun 2016 sebesar 7,2 kg/tarik/trip/hari dan mengalami penurunan 55,22 % tahun 2007. Rajungan berkontribusi 69,11 % terhadap hasil tangkapan jaring insang dasar, sumberdaya ikan lainnya 30,89 %. Modus lebar karapas 85-90 mmCW, lebar karapas pada perairan dekat pantai 84,3 mm dan kearah lepas pantai 99,4 mm. Rajungan di Teluk Jakarta mempunyai tipe pertumbuhan alometrik negatif. Nisbah kelamin jantan : betina = 1 : 0,83, betina dominan pada perairan kearah lepas pantai dan jantan dominan kearah pantai (salinitas rendah). Musim pemijahan rajungan di Teluk Jakarta sepanjang tahun, mempunyai dua puncak pada bulan Maret dan September dengan pusat sebaran gonad ovigerous di sekitar perairan P. Damar. Rata-rata ukuran pertama tertangkap (Lc) = 93,87 mmCW lebih besar dari rata-rata ukuran pertama matang gonad (Lm) = 68,8 mmCW. Laju pertumbuhan (K) = 1,08 mmCW/tahun dengan lebar karapas maksimal (L”) = 142,5 mmCW. Laju kematian total (Z)= 4,87/tahun, penangkapan (F) = 3,63/tahun, alami (M) = 1,24/tahun dan laju pengusahaan (E) = 0,75/tahun. Jakarta Bay is one of the fishing areas and habitat of blue swimmer crabs (Portunus pelagicus) in Indonesia. Market demand that continues to increase and along with the decline in water quality results in crab stocks experiencing pressure from exploitation and habitat degradation. So that the management of crab resources in the Jakarta Bay remains sustainable, research on fisheries and population dynamics is needed. The purpose of the study was to obtain data and information; fishing ground, fishing season and main gears, abundance index, production and composition of catch, size structure, sex ratio, gonad maturity, spawning season, first length of catch, length of first gonad maturity, growth rate, mortality rate and exploitation rate. Data and information were obtained by exploration, observation, enumeration, interviews and tracing at fish landing sites and other institutions related to fisheries, during 2016. The results of the study obtained the characteristics of the crab fishing ground; sandy mud substrate with bottom waters which have a salinity of 30.5-32 ppt, oxygen 6.5-6.9 ml / l, pH 7.5-8.01, flow velocity 0.08-0.24 m / sec. The main gears are bottom gill nets with mesh size 3-3.5-inch, the fishing season in May-August and famine in the November-January. CPUE of blue swimmer crabs in the 2016 was 7.2 kg / pull / trip / day decreased 55.22% in 2007. The blue swimmer crabs contributed 69.11% to the catch of bottom gill nets, other fish resources 30.89%. Carapace width frequency have mode is 85-90 mmCW, carapace width in waters near the coast is 84.3 mm and offshore is 99.4 mm. The blue swimmer crabs in Jakarta Bay has a negative allometric growth type. Sex ratio male: female = 1: 0.83, female dominant in offshore and male dominant direction towards in shore and (low salinity). The spawning season of blue swimmer crabs in Jakarta Bay has two peaks in March and September with an ovigerous gonad distribution center around the waters of P. Damar. The average size of the length first catch (Lc) = 93.87 mmCW is greater than the average size of the length first gonad maturity (Lm) = 68.8 mmCW. Growth rate (K) = 1.08 mmCW / year with length infinity of carapace width (L”) = 142.5 mmCW. Maturity rate are total (Z) = 4.87/year, capture (F) = 3.63/year, natural (M) = 1.24/year and explotation rate (E) = 0.75/year.


2021 ◽  
Vol 24 (1) ◽  
pp. 133-140
Author(s):  
Sri Redjeki ◽  
Muhammad Zainuri ◽  
Ita Widowati ◽  
Ambariyanto Ambariyanto ◽  
Rudhi Pribadi ◽  
...  

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. 


2020 ◽  
Vol 9 (1) ◽  
pp. 65-74
Author(s):  
Muhammad Juli Hendra Putra ◽  
Subagiyo Subagiyo ◽  
Ria Azizah Tri Nuraini

ABSTRAK : Rajungan (Portunus pelagicus) memiliki nilai ekonomi tinggi, berbanding lurus dengan penangkapan yang meningkat. Tingkat pemanfaatan yang tidak konservatif akan mempengaruhi  ukuran dan kondisi rajungan di suatu populasi, serta stok rajungan di suatu perairan. Penelitian bertujuan untuk mengetahui kajian konservasi rajungan (Portunus pelagicus) berdasarkan morfometri dan sex ratio yang didaratkan oleh nelayan  di Perairan Desa Gegunung Wetan, Kecamatan Rembang, Kabupaten Rembang. Metode yang digunakan dalam penelitian bersifat deskriptif. Pengamatan rajungan dilakukan pada salah satu pengepul di Desa. Rajungan di amati berdasarkan morfometri dan sex rasio selama 30 hari. Hasil Informasi dapat dijadikan pedoman dalam menentukan kebijakan mengenai pengelolaan perikanan rajungan yang berkelanjutan dan bersifat konservatif. Hasil dari penelitian diketahui bahwa kelimpahan rajungan jantan sebesar 46% (1379 ekor) rajungan betina 56% (1621 ekor) dari 3000 ekor sampel rajungan. Rasio perbandingan jantan dan betina 1:1,18. Berdasarkan distribusi ukuran lebar karapas rajungan di perairan Rembang adalah berkisar anatara 72–167  mm dan distribusi berat sebesar 40–303 gram. Distribusi tingkat kematangan gonad pada perairan Rembang adalah 608 ekor pada TKG 1; 658 ekor pada TKG 2; dan 355 pada TKG 3. Data menunjukan bahwa pola pertumbuhan rajungan yang ada di perairan Rembang adalah allometrik negatif  baik rajungan jantan maupun rajungan betina. Abstract: Blue swimming crab (Portunus pelagicus) has a high economic value, directly proportional to the increased catch. The level of non-conservation utilization will affect the size and condition of the blue swimming crab in a population, as well as the blue swimming crab stock in a waters. This study is aimed to determine the blue swimming crab conservation study (Portunus pelagicus) based on morphometry and sex ratio brought by fishermen in the waters of Gegunung Wetan Village, Rembang District, Rembang Regency. The method used in this study is descriptive. Observation of blue swimming crab samples was carried out in one of the collectors in the village. Blue swimming crab was observed based on morphometry and sex ratio for 30 days. Informative results can be used as a guide in determining policies regarding sustainable and conservation management of blue swimming crab fisheries. The results of the study revealed that the abundance of male blue swimming crab was 46% (1379 male blue swimming crab) and the abundance of the female blue swimming crab was 56%  (1621 female blue swimming crab) of 3000 blue swimming crab samples. The ratio of male and female  is 1:1.18. Based on the size distribution of the width of the blue swimming crab carapace in the waters of Getanung Wetan it ranges from 72-167 mm and the distribution of weight is 40-303 grams. 13.8% (413 blue swimming crab) sized≤10 cm and 86.2% (2587 blue swimming crab) sized ≥10 cm. The distribution of gonad maturity level in the waters of Gegunung Wetan is 608 female blue swimming crab at TKG 1; 658 female blue swimming crab at TKG 2; and 355 female blue swimming crab at TKG 3. There were 355 female blue swimming crab (22%) of the total female blue swimming crab laying eggs. The data showed that the blue swimming crab growth pattern in Gegunung Wetan waters was negative allometric both male and female blue swimming crab.


2020 ◽  
Vol 5 (2) ◽  
pp. 104-111
Author(s):  
Oce Astuti ◽  
Naslina Alimina ◽  
Safilu Safilu ◽  
Emiyarti Emiyarti ◽  
La Sara ◽  
...  

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.


2019 ◽  
Vol 8 (3) ◽  
pp. 223-228
Author(s):  
Ulfah Nur Hidayah ◽  
Ibnu Partikto ◽  
Irwani Irwani

Rajungan (Portunus pelagicus) merupakan salah satu komoditi perikanan yang memiliki nilai ekonomis tinggi yaitu Rp. 70.000 – 90.000 /kg dan banyak diminati oleh masyarakat baik di dalam maupun luar negeri. Penurunan potensi sumberdaya rajungan (Portunus pelagicus) di beberapa perairan Indonesia mulai memprihatinkan. Hal tersebut dapat dihindari dengan memahami faktor-faktor internal dan eksternal yang berpengaruh pada sumberdaya rajungan. Penelitian ini bertujuan untuk mengetahui distribusi ukuran, nisbah kelamin dan tingkat kematangan gonad, hubungan panjang berat dan faktor kondisi, serta tingkat pertumbuhan rajungan berdasarkan fase bulan baru dan bulan purnama di Perairan Teluk Awur Jepara. Hasil penelitian distribusi ukuran lebar rajungan rata-rata 12,65 ± 1,335 pada bulan purnama dan 12,64 ± 1,259 cm pada bulan baru. Distribusi berat rata-rata 147,28 ±53,85 gram pada bulan purnama dan 146,65 ± 53,31 gram pada bulan baru. Distribusi tingkat kematangan gonad rajungan betina yaitu TKG 1 sebanyak 126 ekor, TKG 2 sebanyak 77 ekor, dan TKG 3 sebanyak 112 ekor sedangkan rajungan betina yang belum matang gonad 225 ekor. Nisbah kelamin rajungan jantan dan betina di Teluk Awur yaitu 0,9 : 1. Pola pertumbuhan rajungan di Teluk Awur yaitu bersifat allometrik negatif dimana pertumbuhan panjang karapas lebih dominan daripada pertumbuhan bobot tubuhnya. Sedangkan tingkat pertumbuhan rajungan untuk mencapai panjang maksimal yaitu 8,16 cm dengan koefisien pertumbuhan 0,6 per tahun. Blue Swimming Crab (Portunus pelagicus) is one of the fisheries commodity which has high economic value Rp. 70.000 – 90.000 /kg and is much in demand by the both domestic and foreign societies. The decrease of blue swimming crab (Portunus pelagicus) resource potential in some Indonesian waters is starting to apprehensive, that can be avoided by understanding the internal and external factors that influence the blue swimming crab resources. This research aimed to determine the size distribution, sex ratio and gonad maturity level, the relationship of length of weight and condition factor, and blue swimming crab growth rates according to the phase of the new moon and full moon in the Jepara Teluk Awur Waters. The results of the research of the width distribution of most crab in the full moon 12,65 ± 1,335  cm and 12,64 ± 1,259 in the new moon. The distribution of weight are 147,28 ±53,85 grams in the full moon and 146,65 ± 53,31 in the new moon phases. The distribution of maturity levels of female blue swimming crab gonads that is TKG 1 amounted 126 crabs, TKG 2 amounted 77 crabs, and TKG 3 amounted 112 crabs. While the female immature blue swimming crab were gonads 225. The sex ratio of male and female blue swimming crab in Teluk Awur is 0,9 : 1. The blue swimming crab growth pattern in Teluk Awur is negative allometric where the growth of carapace length is more dominant than the growth of its body weight. While the blue swimming crab growth rate to reach the maximum length is 8.16 cm with a growth coefficient of 0.6 per year. 


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