Analisis Sebaran Lebar Karapas dan Proporsi Rajungan Betina Bertelur yang Tertangkap di Perairan Demak

ABSTRAK : Rajungan merupakan komoditas perikanan bernilai ekonomis penting dan memiliki nilai komersial yang cukup tinggi. Salah satu desa yang memproduksi rajungan adalah Desa Betahwalang. Sebagian besar rajungan hasil tangkapan di perairan Betahwalang dikirim untuk di ekspor ke luar negeri. Tingginya permintaan pasar terhadap komoditas perikanan rajungan memicu eksploitasi yang berlebihan sehingga dapat berdampak terhadap kelestarian sumber daya rajungan. Tujuan penelitian ini adalah untuk menganalisis sebaran lebar karapas dan proporsi EBF (egg berried female) rajungan di Desa Betahwalang, Demak terkait dengan upaya pengelolaan rajungan secara berkelanjutan sesuai dengan Peraturan Menteri Kelautan dan Perikanan no. 1 tahun 2015. Penelitian ini dilaksanakan pada bulan Februari – Maret 2019 di Desa Betahwalang, Demak menggunakan metode random sampling. Pengukuran rajungan dilakukan di bakul yang ada di Desa Betahwalang, Demak. Hasil penelitian menunjukkan bahwa 1003 ekor rajungan (83%) yang tertangkap berukuran >10 cm dari total 1203 rajungan tertangkap. Nisbah kelamin di Desa Betahwalang menunjukkan bahwa antara jantan dan betina seimbang (1:1,06). Sedangkan untuk betina bertelur yang tertangkap (EBF) berjumlah 81 ekor rajungan (13%). ABSTRACT : Blue Swimming Crab is one of fisheries commodity with highly important economical and commerce value. One of the village that produce blue crab is Betahwalang. Most of the crabs are exported. With high demand of blue crab resulting in over exploitation that affects the population of blue crab. The purpose of this research is to analyze the spread of carapace width and the proportion of EBF (Egg Berried Female of the blue swimming crab in Desa Betahwalang, Demak that are related with the continuous management effort of blue crab consistent with Peraturan Menteri Kelautan dan Perikanan No 1 Tahun 2015. This research was conducted on February – March 2019 at Desa Betahwalang, Demak using random sampling method. The measurement of blue crab was done on the buyer at Desa Betahwalang, Demak. The results show that 1003 blue crab (83%) that were caught had carapace width more than 10 cm from 1203 blue crab caught. The ratio of male and female crab show that male and female were equal (1:1,06). For the egg berried female (EBF) that were caught shows 81 blue crab caught (13%).

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Kajian Tingkat Kerentanan Rajungan (Portunus pelagicus) di Perairan Desa Tunggulsari Kabupaten Rembang

Journal of Marine Research ◽

10.14710/jmr.v10i1.28247 ◽

2021 ◽

Vol 10 (1) ◽

pp. 147-157

Author(s):

Parameswari Iccha Nirmalabuddhi Wishnuputri ◽

Sri Redjeki ◽

Retno Hartati

Keyword(s):

Water Quality ◽

Growth Pattern ◽

Economic Value ◽

Quality Parameters ◽

Swimming Crab ◽

Portunus Pelagicus ◽

Male And Female ◽

Over Exploitation ◽

The Village ◽

Swimming Crabs

Rajungan (Portunus pelagicus) adalah salah satu sumber daya hayati laut Indonesia. Rajungan merupakan komoditas utama perikanan di Indonesa, baik untuk lokal maupun ekspor. Nilai ekonomis rajungan yang tergolong tinggi mengakibatkan penangkapan rajungan dilakukan secara besar-besar dan dapat memicu terjadinya kepunahan. Penelitian bertujuan untuk mengetahui tingkat kerentanan rajungan di Perairan Desa Tunggulsari dan mengetahui karakteristik morfometri dari rajungan yang ditangkap pada lokasi tersebut. Metode yang digunakan dalam penelitian ini adalah metode Productivity and Susceptibility Analysis (PSA). Wawancara dilakukan kepada 60 nelayan di Desa Tunggulsari. Pengukuran parameter kualitas perairan meliputi suhu, oksigen terlarut, salinitas, dan pH. Pengukuran morfometri dilakukan pada salah satu pengepul di desa. Hasil dari wawancara diketahui bahwa nelayan di Desa Tunggulsari menggunakan 2 macam alat tangkap yaitu bubu lipat dan jaring insang dasar. Penilaian atribut produktivitas rajungan masuk dalam kategori tinggi, sedangkan penilaian atribut kerentanan tergolong pada resiko rendah untuk penggunaan kedua alat tersebut. Nilai MSC untuk alat tangkap bubu lipat adalah 96,0 dan 98,2 untuk alat tangkap jaring insang dasar. Nilai MSC > 80 menunjukkan bahwa tingkat kerentanan rajungan pada lokasi tersebut masuk pada kategori rendah. Selanjutnya, pola pertumbuhan rajungan di Desa Tunggulsari adalah allometrik negatif baik untuk rajungan jantan maupun betina. Hal ini menunjukkan pertumbuhan panjang dan lebar karapas lebih cepat dibandingkan penambahan berat rajungan. The blue swimming crab (Portunus pelagicus) is one of the Indonesian marine biological resources. The blue swimming crab is a main commodity of fisheries in Indonesia, both for local and export. Economic value of blue swimming crab classified as high involve over-exploitation of blue swimming crab and can lead to extinction. This research is aimed to determine level of vulnerability of blue swimming crab in Tunggulsari waters and to discover morphometry characteristic of blue swimming crab that caught at that location. The method used in this research is Productivity and Susceptibility (PSA) method. Interviews were conducted with 6 fishermen in the village of Tunggulsari. Measurement of water quality parameters including temperature, dissolved oxygen, salinity, and pH. Morphometry measurement was carried out in one of the collectors in the village. The results of the interview revealed that fishermen in the village of Tunggulsari used 2 fishing tools namely bubu lipat and bottom set gillnet. Assessment of blue swimming crab productivity attributes is included in the high category, while the assessment of vulnerability attributes is classified as low risk for the use of both tools. The MSC value for bubu lipat is 96,0 and 98,2 for bottom set gillnet. The MSC value is more than 80 indicates that the level of blue swimming crab vulnerability at that location is in the low category. Further, blue swimming crab growth pattern in the village of Tunggulsari are negative allometrics for both male and female blue swimming crabs. This shows the growth in length and width carapace is faster than the addition of blue swimming crab weight.

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ASPEK BIOLOGI, DINAMIKA POPULASI DAN TINGKAT PEMANFAATAN RAJUNGAN (Portunus pelagicus Linnaeus, 1758) DI PERAIRAN KOTABARU, KALIMANTAN SELATAN

Jurnal Penelitian Perikanan Indonesia ◽

10.15578/jppi.23.3.2017.205-214 ◽

2018 ◽

Vol 23 (3) ◽

pp. 205

Author(s):

Tirtadanu Tirtadanu ◽

Ali Suman

Keyword(s):

Population Dynamic ◽

Random Sampling ◽

Sampling Method ◽

Carapace Width ◽

Landing Site ◽

Fishing Effort ◽

Biological Study ◽

Female Crab ◽

Portunus Pelagicus ◽

Biological Aspects

Penangkapan rajungan yang intensif di perairan Kotabaru memerlukan kajian biologi dan dinamika populasi sebagai dasar dalam menentukan pengelolaan yang tepat. Penelitian ini bertujuan untuk mengkaji aspek biologi, dinamika populasi dan tingkat pemanfaatan sumberdaya rajungan di perairan Kotabaru. Penelitian dilakukan pada Januari – November 2016 di daerah pendaratan rajungan di Kotabaru. Pengambilan sampel dilakukan tiap bulan berbasis enumerator dengan metode random sampling. Analisis dinamika populasi dilakukan dengan model analitik berdasarkan pergeseran modus struktur ukuran lebar karapas. Hasil penelitian menunjukkan modus ukuran rajungan tertangkap adalah 110 mmCW pada jantan dan 120 mmCW pada betina. Pertumbuhan bobot rajungan jantan lebih tinggi dibandingkan betina. Nisbah kelamin rajungan tidak seimbang dengan perbandingan jantan dan betina adalah 1,7 : 1. Ukuran rata-rata pertama kali matang gonad (Lm) rajungan betina adalah 110,25 mmCW. Lebar karapas asimptotik (CW) rajungan adalah 179,2 mmCW pada jantan dan 183,6 mmCW pada betina. Laju pertumbuhan rajungan (K) adalah 1,36 per tahun pada jantan dan 1,11 per tahun pada betina. Laju eksploitasi (E) rajungan sebesar 0,68 pada jantan dan 0,77 pada betina menunjukkan tingkat pemanfaatan lebih tangkap (overfishing). Pengelolaan yang disarankan adalah mengurangi upaya penangkapan sekitar 54% dari 4.190 unit armada jaring rajungan, penentuan ukuran minimum rajungan yang boleh tertangkap sebesar 110 mmCW sebagai masukan bila ada revisi terhadap peraturan tentang penangkapan rajungan dan dilakukan penutupan penangkapan pada beberapa daerah asuhan. Intensive fishing on blue swimming crab (Portunus pelagicus Linnaeus, 1758) in Kotabaru waters requires biological study and population dynamic as bases to determine proper management. The current research aims to study biological aspects, population dynamic and exploitation rate of crab in Kotabaru waters. The research was conducted on January-November 2016 at landing site of crab in Kotabaru. Samples were collected every month by enumerator with random sampling method. Population dynamic was analysed by analytical model. Results show that the mode of carapace width was 110 mmCW in males and 120 mmCW in females. The growth in weight of male was greater than female. Sex ratio of male and female crabs was (1.7:1). Length at first (Lm) of female crab was 110.25 mmCW. The asymptotic carapace width (CW) of crab was 179.2 mmCW for male and 183.6 mmCW for female. The growth rate of crab (K) was 1.36 year-1 for male and 1.11 year-1 for female. The explotation rate (E) of crab was 0.68 for males and 0.77 for female so that the exploitation was overfished. From the results obtained, it suggests that the fishing effort should be reduced to 54% of 4.190 gillnet fleet and the minimum legal size would be at 110 mmCW as input for regulation if is needed and it should be determined the closure of fishing activities in some nursery grounds.

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ANALISIS KAJIAN SOSIAL EKONOMI PEMBANGUNAN DAN PERLUASAN TOSERBA “ X ”

Jurnal Ilmiah Manajemen Ekonomi & Akuntansi (MEA) ◽

10.31955/jimea.vol2.iss2.pp66-89 ◽

2018 ◽

Vol 2 (2) ◽

pp. 66-89

Author(s):

Desfitriady Desfitriady ◽

Tatang Kusmayadi

Keyword(s):

Random Sampling ◽

Research Method ◽

Sampling Method ◽

Secondary Data ◽

Simple Random Sampling ◽

Research Data ◽

Qualitative And Quantitative ◽

The Government ◽

The Village ◽

Descriptive Method

The purpose of this study is to know and understand the community in the Village Sayati Margahayu District Bandung regency with the development and extension of department store (Convenience Store) "X". The research method is descriptive method using qualitative and quantitative approach as the basis of analysis and interpretation. Sample determination technique used is cluster with simple random sampling method and purposive sampling, which means that the sample used in accordance with the purpose of research. Data which is primary and secondary data. The results showed that people responded positively and variedly about the decision to the extension of the "X" Stores, and only a small portion would be used, but it was only up to the government.

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ANALISIS PEMASARAN KOPI ARABIKA ( Caffea arabica ) (Studikasus: Desa SitinjoII, Kecamatan Sitinjo, Kabupaten Dairi)

Jurnal Agriuma ◽

10.31289/agr.v1i2.2840 ◽

2019 ◽

Vol 1 (2) ◽

pp. 36

Author(s):

Ester Megawati Boang Manalu ◽

Khairul Saleh ◽

Faoeza Hafiz Saragih

Keyword(s):

Random Sampling ◽

Sampling Method ◽

Marketing Channel ◽

Clear Picture ◽

Stratified Random Sampling ◽

Arabica Coffee ◽

Purposive Sampling ◽

Marketing Efficiency ◽

The Village ◽

Final Consumer

<pre>ABSTRACT</pre><pre> Considering the importance of arabica coffee commodity for farmers, a clear picture of arabica coffee marketing channel from producer farmer to final consumer (Merchant) is needed so that the profit can be equally distributed. This study aims to determine the marketing channel, margin, marketing efficiency of arabica coffee in the village of Sitinjo II, Sitinjo Subdistrict, Dairi Regency. The method used is proportionate stratified random sampling as much as 50 farmers while collecting merchant samples taken by census method that is as much as 5 traders and for the factory is taken as many as 2 factories with Purposive sampling method. The results showed that there are two channels of arabica coffee marketing at the location of research that is, the first channel starts from the farmer to the factory in the village Sitinjo II Sitinjo District. The second channel starts from the farmers, the collecting merchant proceeds to the factory in the village of Sitinjo II, Sitinjo Subdistrict. The biggest marketing margin is RP.4.000 found on channel II and the more efficient channel is on channel I with an efficiency value of 7.51%.</pre>

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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.

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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.

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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.

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KAJIAN PENGELOLAAN USAHATANI KELAPA DI DESA TOLOMBUKAN KECAMATAN PASAN KABUPATEN MINAHASA TENGGARA

AGRI-SOSIOEKONOMI ◽

10.35791/agrsosek.7.2.2011.90 ◽

2011 ◽

Vol 7 (2) ◽

pp. 39 ◽

Cited By ~ 1

Author(s):

Eyverson Ruauw ◽

Jenny Baroleh ◽

Devison Powa

Keyword(s):

Random Sampling ◽

Sampling Method ◽

Secondary Data ◽

Simple Random Sampling ◽

Primary Data ◽

Land Area ◽

Average Income ◽

Average Area ◽

One Year ◽

The Village

This study aims to assess the management of coconut farms in village of Tolombukan district of Pasanmainly include land area, production, revenue, and marketing. The results could be input materials andinformation for farmers in increasing production and income of coconut farmers in of Tolombukan districtPasan.The research was carried on in the of Tolombukan district of Pasan which lasted from June 2010 untilAugust 2010. Data taken in this study are primary data that was obtained through interviews to farmersbased on a list of questions and secondary data obtained from agencies - agencies. Sampling method usedin this study is simple random sampling method with a sample size of 20 farmer respondents. Data is presentedin tables and is explained descriptively. The data are mainly in the form of costs, income, and revenue.Results showed that coconut farmers harvest pass once in 3 months so that in one year there are 4times the harvest with an average area of 1.59 ha. The other results of thisr studies are outlined below.The results of the average oil production in the village of Tolombukan district of Pasan of 2375.9 kg ofcopra per year with an average income of Rp4.891.948, 78 per year. In addition to plant coconut, farmersalso planted cloves between the coconut that provide an income of Rp11.734.695, 84 per two years orRp5.867.000 per year. The product of copra and cloves sold at traders in the village Tolombukan own.

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Community study of dragon’s blood palm (Daemonorops spp.) in Harapan Rainforest, Sumatra

Biodiversitas Journal of Biological Diversity ◽

10.13057/biodiv/d201223 ◽

2019 ◽

Vol 20 (12) ◽

Author(s):

Revis Asra ◽

JOKO RIDHO WITONO ◽

IZUANDRY FIJRIDIYANTO ◽

ELVA ◽

STEFAN SCHEU

Keyword(s):

Random Sampling ◽

National Park ◽

Sampling Method ◽

Economic Value ◽

Community Study ◽

Income Source ◽

Male And Female ◽

Dragon’S Blood ◽

Fruit Skin ◽

Harvesting Method

Abstract. Asra R, Witono JR, Fijridiyanto I, Elva, Scheu S. 2019. Community study of dragon’s blood palm (Daemonorops spp.) in Harapan Rainforest, Sumatra. Biodiversitas 20: 3632-3640. Dragon's blood palms are rattan species that produce red-colored exudate on its fruit skin, popularly called exudates 'dragon's blood'. It has a high economic value and plays an important role as an income source for indigenous tribes in Jambi, such as in Bukit Duabelas National Park who live Anak Dalam Tribe and Semerantihan Village live Talang Mamak Tribe. However, overexploitation and unsustainable harvesting method have caused its decline in its population in natural forest. This study aims to make an inventory and map distribution of Dragon's blood palms in Harapan Rainforest, at the boundary between Jambi and South Sumatra Provinces, Indonesia; to determine its sex ratio and identify environmental factors that influence sex of Dragon's blood palms. This research used purposive random sampling method at three areas in Harapan Rainforest, i.e.: Hamparan Bato, Hamparan Batang Kapas, and Hamparan between Block A and B. The results showed that three species of Daemonorops were found in Harapan Rainforest, namely Daemonorops didymophylla, D. draco, and D. longipes. D. longipes has the highest population (18 clumps). The highest number of clumps were found in Hamparan Bato (17 clumps)and Hamparan Batang Kapas (17 clumps) areas. The ratio of male and female plants of D. longipes is 1: 1.84, D. draco is 1: 2 and D. didymophylla is 2.2: 1. Most clumps of Daemonorops species in Harapan Rainforest grow on the river banks which have low organic matters. Soil chemical variables that most contribute to the growth of Daemonorops spp. in Harapan Forest are N, C and pH.

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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.

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