Biological aspects of pink ear emperor, Lethrinus lentjan (Lacepede, 1802) in Bangka and adjacent waters

Coral fish is the one of the important fish resources in Indonesian waters, but the potential and exploitation rate needs to be obtained. Pink ear emperor is one of coral fish that many caught in Bangka. Research was conducted to determine biological aspect of pink ear emperor caught by fish traps, that includes length distribution, length-weight relationship, sex ratio, maturity stage, food habits, and length at first mature. This research was conducted from February 2014 to November 2015 with sampling location in Sungailiat fishing port. The observed aspects included fork length, weight, sex, gonad maturity and fish stomach contents was done monthly. The results showed the growth pattern are allometric negative, folk length ranged from 12 to 58 cm. The condition of sex ratio of males to females was 1:2,06. The gonade maturity stage of males and females were stage I, II, III, and IV for all months of observation. Stomach contained was shellfish, crap, shrimp and fish. Length at first capture(Lc) was 28 cm and length at first maturity(Lm) was 26 cm. Size length at first capture was bigger than the size length at first maturity, so the pink ear emperor at Sungailiat available to maintained the balance of fish stock on population.AbstrakIkan karang merupakan salah satu sumber daya yang penting di perairan Indonesia, namun tingkat potensi dan tingkat pemanfaatannya masih perlu untuk dikaji. Ikan lencam merupakan salah satu ikan karang yang banyak tertangkap di perairan Bangka. Tujuan penelitian ini mengkaji beberapa aspek biologi ikan lencam hasil tangkapan bubu, meliputi sebaran ukuran panjang, pola pertumbuhan, nisbah kelamin, dan ukuran rata-rata pertama kali matang gonad dan kebiasaan makan. Penelitian ini dilaksanankan di PPN Sungailiat pada bulan Februari 2014 – November 2015. Aspek yang diamati meliputi panjang cagak, bobot tubuh ikan, jenis kelamin, kematangan gonad, dan isi lambung ikan. Hasil penelitian menunjukkan pola pertumbuhan ikan lencam bersifat allometrik negatif. Sebaran ukuran panjang berkisar antara 12 – 58 cm. Nisbah kelamin jantan terhadap betina sebagai 1 : 2,06. Pada setiap bulan pengamatan tingkat kematangan gonad jantan dan betina berada pada stadia I, II, III, dan IV. Isi lambung ikan lencam selama pengamatan terdiri dari kerang-kerangan, kepiting, udang, dan hancuran ikan. Panjang pertama kali ikan tertangkap (Lc) sebesar 28 cm dan pertama kali matang gonad (Lm) sebesar 26 cm. Rata-rata ukuran pertama kali tertangkap lebih besar dbandingkan dengan ukuran pertama kali matang gonad sehingga ikan lencam di Perairan Bangka masih dapat mempertahankan keseimbangan stok dalam suatu populasi.

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Biologi reproduksi ikan layur, Trichiurus lepturus Linnaeus, 1758 di perairan pantai Kabupaten Bantul

Jurnal Iktiologi Indonesia ◽

10.32491/jii.v17i2.362 ◽

2018 ◽

Vol 17 (2) ◽

pp. 227

Author(s):

Praditha Novianingrum ◽

Djumanto Djumanto ◽

Murwantoko Murwantoko ◽

Eko Setyobudi

Keyword(s):

Sex Ratio ◽

Length Distribution ◽

Fish Length ◽

Maturity Stage ◽

Oocyte Diameter ◽

Maturity Level ◽

Gonad Maturity ◽

Gonadal Maturity ◽

Trichiurus Lepturus ◽

Fish Samples

Largehead hairtail (Trichiurus lepturus) is one commodity fish catches with high production and value in Yogyakarta. The purpose of this research is to analyse reproductive aspects of this fish in coastal area of Bantul Regency. Yogyakar-ta. Those aspects are gonadal maturity level, fecundity, and the length at the first gonadal maturity. Fish samples are taken from the catch of fisherman using gillnet with a mesh sizes of 1.75 and 2 inches in the coastal fishing port of Depok and Samas. The fish collected from January to April 2016 with at least 30 individuals every two weeks. The samples are identified to find their sex and measured to know the length, weight, and gonadal maturity level (TKG). The data analyzed include length distribution, weight, sex ratio, gonadosmoatic index, length at the first gonadal maturity (Lm), fecundity and oocyte diameter. The result shows the fish length varies between 52.8 and 86.2 cm, and weight 115 and 567.2 g. The sex ratio between male and female was 1:0.6. Gonad maturity stage II and III are found every month observation while gonad maturity stage IV found in April. Oocyte diameter in the stage of gonadal ma-turity IV was 0.35-1.02 mm, there were two distribution modus so that the spawning expected partial spawner with fec-undity of 24.601 eggs with range was 12.873-33.534 eggs. Fecundity increased as parent’s body length with equation F= 0,434L2.60. Hairtail expected reaching the length of the first gonadal maturity in 65.55 cm, higher than the average captured, namely 63.4 cm. AbstrakIkan layur (Trichiurus lepturus) merupakan salah satu komoditas hasil tangkapan ikan di Daerah Istimewa Yogyakarta dengan jumlah produksi dan nilai yang tinggi. Penelitian ini bertujuan untuk mengkaji aspek reproduksi yang meliputi: tingkat kematangan gonad, fekunditas, dan ukuran ikan kali pertama matang gonad layur di perairan pantai Kabupaten Bantul, Daerah Istimewa Yogyakarta. Sampel ikan dikumpulkan dari hasil tangkapan nelayan yang menggunakan jaring insang dengan ukuran mata jaring 1,75 dan 2 inci di Tempat Pelelangan Ikan Depok dan Samas. Pengumpulan sampel ikan dilakukan pada bulan Januari hingga April 2016 setiap dua minggu sekali minimal 30 ekor. Sampel ikan diidentifikasi jenis kelamin, diukur panjang, bobot tubuh, bobot gonad, dan tingkat kematangan gonad (TKG). Data yang dianalisis meliputi sebaran panjang, bobot, nisbah kelamin, indeks kematangan gonad, ukuran ikan kali pertama matang gonad (Lm), fekunditas, dan diameter telur. Hasil pengamatan menunjukkan kisaran panjang ikan 52,8-86,2 cm dan bobot 115-567,2 g, nisbah betina dan jantan sebesar 1 : 0,6. TKG II dan III ditemukan pada setiap bulan pengamat-an sedangkan TKG IV banyak ditemukan pada bulan April. Diameter telur ikan TKG IV berkisar 0,35-1,02 mm, terda-pat dua modus persebaran sehingga pemijahan diduga bertahap dan fekunditas sebanyak 24.601 butir dengan kisaran 12.873-33.534 butir. Fekunditas meningkat seiring panjang tubuh induk dengan persamaan F = 0,434L2,60. Ukuran ikan layur kali pertama matang gonad diperkirakan pada panjang 65,55 cm, lebih panjang daripada ukuran rata-rata tertangkap, yaitu pada 63,4 cm.

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Aspek reproduksi ikan kakap Lutjanus vitta (Quoy & Gainmard, 1824) di Teluk Jakarta dan sekitarnya

Jurnal Iktiologi Indonesia ◽

10.32491/jii.v17i2.360 ◽

2018 ◽

Vol 17 (2) ◽

pp. 215

Author(s):

Selvia Oktaviyani ◽

Wanwan Kurniawan

Keyword(s):

Sex Ratio ◽

Average Length ◽

Fork Length ◽

Immature Stage ◽

Sampling Location ◽

Length Frequency ◽

Gonad Weight ◽

Resources Management ◽

First Maturity ◽

Somatic Index

Study on reproductive aspects of brownstripe red snapper Lutjanus vitta (Quoy & Gainmard, 1824) in Jakarta Bay and its surroundings can obtain important information for fish resources management. The objective of this research is to analyze length frequency distribution, sex ratio, gonadal maturation, gonado somatic index, the length at first maturity (Lm) and the average length of captured (Lc) for this fish. This research was conducted from April 2014 to January 2015 with sampling location in Tanjung Pasir Fishing Port, Tangerang. Fish sampling and of fish that were. The observed aspects included fork length, weight, sex, gonad maturity and gonad weight was done monthly. The result showed that the fork length of this fish ranged between 132-265 mm with the equal sex ratio. The capture fish are dominated by fish with immature stage. The highest of gonado somatic index was on September 2014 (2%). The fork length at first maturity (Lm) were 252 mm (male) and 187 mm (female) while the average fork length of captured (Lc) was 178 mm. This condition can cause a growth overfishing. AbstrakKajian beberapa aspek reproduksi ikan kakap Lutjanus vitta (Quoy & Gainmard, 1824) di Teluk Jakarta dan sekitarnya dapat menghasilkan informasi yang sangat penting dalam rangka pengelolaan sumber daya ikan tersebut. Tujuan pene-litian ini adalah untuk menganalisis sebaran frekuensi panjang, nisbah kelamin, kematangan gonad, indeks kematangan gonad, ukuran kali pertama matang gonad, dan rata-rata panjang tertangkap ikan kakap. Penelitian dilaksanakan pada bulan April 2014 hingga Januari 2015 di Tempat Pelelangan Ikan (TPI) Tanjung Pasir, Tangerang. Aspek yang diamati meliputi panjang cagak dan bobot tubuh ikan, jenis kelamin, kematangan gonad, dan bobot gonad. Hasil penelitian me-nunjukkan bahwa ukuran panjang cagak ikan kakap berkisar antara 132-265 mm dengan nisbah kelamin dalam keadaan seimbang. Ikan kakap yang tertangkap didominasi oleh ikan yang belum matang gonad. Indeks kematangan gonad tertinggi terjadi pada bulan September 2014 yaitu 2%. Ukuran panjang cagak kali pertama ikan matang gonad (Lm) adalah 252 mm (jantan) dan 187 mm (betina), serta panjang cagak rata-rata tertangkap (Lc) adalah 178 mm. Kondisi ini dapat menyebabkan lebih-tangkap yang mengganggu tingkat pertumbuhan ikan kakap.

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BIOLOGI REPRODUKSI IKAN TONGKOL ABU-ABU (Thunnus tonggol) DI PERAIRAN LAUT CINA SELATAN

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.10.1.2018.17-28 ◽

2018 ◽

Vol 10 (1) ◽

pp. 17 ◽

Cited By ~ 1

Author(s):

Thomas Hidayat ◽

Tegoeh Noegroho

Keyword(s):

Sex Ratio ◽

Size Structure ◽

Average Length ◽

Stomach Contents ◽

Management Policy ◽

Maturity Stage ◽

Gonad Somatic Index ◽

First Maturity ◽

Longtail Tuna

Ikan tongkol abu-abu (Thunnus tonggol) tertangkap di Laut Cina Selatan dan bernilai ekonomis penting. Trend produksi berfluktuatif, 2009-2011 meningkat, menurun pada 2013 dan 2015 meningkat kembali. Kondisi fluktuatif juga ditunjukkan dari nilai CPUE jarring insang hanyut. Seiring dengan meningkatnya permintaan, pemanfaatan tongkol abu-abu harus dikelola agar ketersediaannya tetap berkesinambungan. Tujuan penelitian adalah mengkaji biologi reproduksi ikan tongkol abu-abu sebagai bahan kebijakan pengelolaan yang lestari. Kajian yang dilakukan meliputi struktur ukuran, hubungan panjang dan berat, nisbah kelamin, tingkat kematangan gonad (TKG), indeks kematangan gonad (IKG), rata-rata ukuran pertama kali tertangkap dan matang gonad serta kebiasaan makanan. Pengumpulan sampel dilakukan oleh enumerator di PPN Pemangkat, Kalimantan Barat pada Januari sampai November 2014. Data yang dikumpulkan meliputi panjang, berat, jenis kelamin, tingkat kematangan gonad, dan isi lambung. Hasil penelitian menunjukkan sebaran panjang ikan tongkol abu-abu pada kisaran 29-80 cm dan modus 47-49 cm, pertumbuhan bersifat isometrik, nisbah kelamin jantan dan betina menunjukkan kondisi seimbang, ukuran rata-rata pertama kali tertangkap (Lc) pada panjang 47,8 cm, ukuran pertama kali matang gonad (Lm) 41,1 cm. Dari data TKG dan IKG, prediksi musim pemijahan berlangsung pada Mei dan Agustus. Hasil pengamatan isi lambung menunjukkan bahwa ikan tongkol abu-abu tergolong ikan karnivora. Dari hasil penelitian rekomendasi untuk kebijakan pengelolaan adalah penetapan penutupan musim dan daerah penangkapan pada bulan Mei dan Agustus pada wilayah perairan yang diduga sebagai daerah pemijahan, penetapan kuota ukuran tangkapan lebih besar dari Lm 41,1 cm dan alternatif wisata pancing dengan ukuran mata pancing yang hanya menangkap ukuran yang sudah matang gonad. Longtail tuna (Thunnus tonggol) were caught in the South China Sea has important economic value. The catch trend fluctuates, increases from 2009 - 2011, decreases in 2013 and increase in 2015. Fluctuating condition is also showed from CPUE drift gill net. Along with the escalation demand, the utilization longtail tuna should be managed in order to keep it sustainable. The objective of the research was to study the reproductive biology of longtail tuna as suggestion for sustainable management. Studies performed on the size structure, the length and weight relationship, sex ratio, maturity stage, gonad somatic index (GSI), Length at first capture and Length at first maturity and food habits. Sample collection was conducted by enumerators at Pemangkat Fishing Port, West Kalimantan in January to November 2014. Data containing length, weight, sex, maturity stage, and stomach contents. The results showed that the length of longtail tuna in range of 29-80 cm and the mode of 47-49 cm, the growth is isometric, the sex ratio male and female showed a balanced condition, the average Length at first capture (Lc) at 47.8 cm, Length at first maturity (Lm) 41.1 cm. From the Maturity stage and GSI data, the predicted spawning season takes place in May and August. Observations o of the stomach contents showed longtail tuna is carnivorous fish. From results of the research recommendation for the management policy is the determination of the close seasons and close areas in May and August on the location suspected as spawning areas, determination of the legal size is bigger than 41.1 cm and encourage the recreational fishing as alternative with the size of the hook which is only catch the mature size fish.

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BIOLOGI REPRODUKSI IKAN MALALUGIS (Decapterus macarellus) DI TELUK TOMINI

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.9.1.2017.63-72 ◽

2017 ◽

Vol 9 (1) ◽

pp. 63

Author(s):

Heri Widiyastuti ◽

Achmad Zamroni

Keyword(s):

Sex Ratio ◽

Negative Impact ◽

Descriptive Analysis ◽

Fork Length ◽

Maturity Stage ◽

Small Pelagic Fish ◽

Mature Gonad ◽

Gonad Somatic Index ◽

First Maturity ◽

Somatic Index

Ikan Malalugis (Decapterus macarellus) merupakan ikan pelagis kecil yang banyak ditangkap di perairan Teluk Tomini dengan alat tangkap pukat cincin mini. Penangkapan secara terus menerus tanpa upaya pengendalian dikhawatirkan akan mengancam kelestariannya. Tujuannya adalah untuk menggambarkan indikator biologi reproduksi ikan malalugis di Teluk Tomini. Metode yang digunakan pada penelitian ini adalah analisis deskriptif. Penelitian tentang aspek reproduksi meliputi nisbah kelamin, tingkat kematangan gonad, indeks kematangan gonad dan ukuran pertama kali matang gonad dilakukan pada bulan Juni-Agustus dan Nopember 2015 di Pangkalan Pendaratan Ikan Tenda, Gorontalo. Sampling dilakukan terhadap 572 ekor ikan malalugis yang didaratkan. Hasil analisis menunjukkan bahwa rasio jenis kelamin jantan dan betina yaitu 1,06:1 dengan rata-rata panjang cagak (Fork length) adalah 24,75 cm. Sebagian besar ikan jantan dan betina dalam kondisi matang gonad. Musim pemijahan diindikasikan pada bulan Agustus-Nopember. Rata-rata ukuran pertama kali matang gonad ikan malalugis betina pada panjang cagak 26,94 cm dan ikan jantan pada panjang cagak 26,74 cm. Indeks kematangan gonad berkisar antara 0,01-6,15% dengan rata-rata IKG sebesar 2,09%. IKG tertinggi terjadi pada bulan Agustus sedangkan IKG terendah pada bulan November. Mackerel scad (Decapterus macarellus) is one of the major contributor of small pelagic fish in Tomini bay, which is being commercially exploited by mini purse seine. Mackerel scad fishing without regarding sustainability will have negative impact for the sustainability of this fish. The objective is to describe bio-reproduction indicators of the scad fishery in the area. Method used in this research was descriptive analysis. The observations on reproductive aspects include sex ratio, maturity stage, gonad somatic index, and estimate length of first maturity was conducted based on data collected during period of June-August and November 2015 at the landing place (PPI) Tenda, Gorontalo. Total specimens measured was 572 fish. The result shows that sex ratio of male and female is 1,06:1. The average of fork length was 24,75 cm. In general, the fish spawned probably between August-November. The size of the first female and male mature gonad was 26,94 cm FL and 29,74 cm FL. Gonad Somatic Index (GSI) ranged from 0,01 to 6,15%. The average of GSI is 2,09%. The highest GSI was in August and the lower was in November.

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BEBERAPA ASPEK BIOLOGI IKAN TENGGIRI PAPAN (Scomberomorus guttatus) DI PERAIRAN CILACAP DAN SEKITARNYA

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.8.3.2016.191-198 ◽

2017 ◽

Vol 8 (3) ◽

pp. 191

Author(s):

Yoke Hani Restiangsih ◽

Tegoeh Noegoho ◽

Karsono Wagiyo

Keyword(s):

Sex Ratio ◽

Length Distribution ◽

Stage Iv ◽

Mesh Size ◽

Maturity Stage ◽

Biological Aspect ◽

Multiple Spawner ◽

Males And Females ◽

King Mackerel ◽

First Maturity

Tenggiri papan (Scomberomorus guttatus)merupakan ikan yangmemiliki nilai ekonomis penting dan banyak tertangkap dengan gillnet di perairan Cilacap dan sekitarnya. Pada saat ini terdapat kecenderungan ukuran individu yang mengecil. Tujuan Penelitian ini adalah mengetahui beberapa aspek biologi ikan tenggiri papan meliputi sebaran ukuran panjang, hubungan panjang-bobot, nisbah kelamin, tingkat kematangan gonad dan ukuran rata-rata pertama kali matang gonad, berdasarkan hasil tangkapan gillnet yang didaratkan di Pelabuhan Perikanan Samudera Cilacap pada bulan Februari sampai Desember 2013. Hasil penelitian menunjukkan ukuran panjang cagak berkisar antara 11 – 67cm. Pola pertumbuhan ikan tenggiri papan bersifat isometric dimana pertambahan panjang dan bobotnya seimbang. Nisbah kelamin jantan terhadap betina sebagai 1 : 0,7. Panjang pertama kali ikan tertangkap (Lc) dengan gillnet berukuran mata jaring 3 inchi sebesar 32,7 cmFL dan pertama kalimatang gonad (Lm) sebesar 42,34 cmFL. TingkatKematanganGonad (TKG) ikan jantan dan betina didominasi oleh stadia IV terutama pada bulan Februari dan Mei. Hasil penelitian ini menunjukkan dugaan awal masa pemijahan terjadi pada bulan Maret dan Juni, dengan demikian pemijahan dilakukan secara bertahap. Indo-Pasific king mackerel (Scomberomorus guttatus) is one of fish that has an important economic value.The species were many caught by gillnet in Cilacap and adjacent waters. Research was conducted to determine biological aspect of Indo-Pasific king mackerel that includes length distribution, length-weight relationship, sex ratio, maturity stage and length at first mature, based on monthly catches landed at Cilacap fishing port during February to December 2013. The results showed that folk length ranged from 11 to 67 cm. The growth pattern are isometric. The condition of sex ratio ofmales to females was 1 : 0,7. Length at first capture(Lc) by gillnet with mesh size of 3 inches was 32.7 cmFL and length at first maturity(Lm) was 42.34 cmFL. The gonade maturity stage of males and females were dominated by stage IV mainly in Febuary and May. It was indicated that spawning seasons occured in March and June. It was indicated that the fish has multiple spawner.

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Biologi reproduksi ikan layur, Trichiurus lepturus Linnaeus, 1758 di perairan pantai Kabupaten Bantul

Jurnal Iktiologi Indonesia ◽

10.32491/jii.v17i2.361 ◽

2018 ◽

Vol 17 (2) ◽

pp. 227

Author(s):

Praditha Novianingrum ◽

Djumanto Djumanto ◽

Murwantoko Murwantoko ◽

Eko Setyobudi

Keyword(s):

Sex Ratio ◽

Length Distribution ◽

Fish Length ◽

Maturity Stage ◽

Oocyte Diameter ◽

Maturity Level ◽

Gonad Maturity ◽

Gonadal Maturity ◽

Trichiurus Lepturus ◽

Fish Samples

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Estimating reef fish size distributions with a mini remotely operated vehicle-integrated stereo camera system

PLoS ONE ◽

10.1371/journal.pone.0247985 ◽

2021 ◽

Vol 16 (3) ◽

pp. e0247985 ◽

Cited By ~ 1

Author(s):

Steven B. Garner ◽

Aaron M. Olsen ◽

Ryan Caillouet ◽

Matthew D. Campbell ◽

William F. Patterson

Keyword(s):

A Priori ◽

Length Distribution ◽

Fork Length ◽

Fish Length ◽

Angle Of Incidence ◽

Remotely Operated Vehicle ◽

Camera System ◽

Stereo Camera ◽

Fish Model ◽

Study Results

We tested the efficacy of a stereo camera (SC) system adapted for use with a remotely operated vehicle (ROV) to estimate fish length distributions at reef sites in the northern Gulf of Mexico. A pool experiment was conducted to test the effect of distance (1, 2, 3 or 5 m), angle of incidence (AOI; 0° to 40° at 5° increments), and SC baseline distance (BD; BD1 = 406, BD2 = 610, and BD3 = 762 mm camera separation) on the accuracy and precision of fish model length (288, 552, or 890 mm fork length) estimates compared to a red laser scaler (RLS). A field experiment was then conducted at 20 reef sites with SCs positioned at BD1 to compare fish length distribution estimates between the SC and RLS systems under in situ conditions. In the pool experiment, mean percent errors were consistently within the a priori selected threshold of ±5% at AOIs ≤10° at all distances with all four systems. However, SCs produced accurate estimates at AOIs up to 30° at all distances tested; 2–3 m was optimal. During reef site surveys, SCs collected 10.4 times as many length estimates from 4.3 times as many species compared to the RLS. Study results demonstrate that, compared to laser scalers, ROV-based SC systems can substantially increase the number of available fish length estimates by producing accurate length estimates at a wider range of target orientations while also enabling measurements from a greater portion of the cameras’ field of view.

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BIOLOGI REPRODUKSI IKAN SELAR BENTONG (Selar crumenophthalmus Bloch, 1793) DI PERAIRAN NATUNA, LAUT CINA SELATAN

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.10.2.2018.105-117 ◽

2018 ◽

Vol 10 (2) ◽

pp. 105

Author(s):

Moh Fauzi ◽

Isdradjad Setyobudiandi ◽

Ali Suman

Keyword(s):

Sex Ratio ◽

Spawning Season ◽

Maturity Stage ◽

Biological Aspect ◽

Population Decrease ◽

Intensive Exploitation ◽

Males And Females ◽

Biological Reproduction ◽

First Maturity ◽

In The Beginning

Ikan selar bentong (Selar crumenophthalmus) merupakan salah satu jenis ikan pelagis kecil yang cukup dominan tertangkap di perairan Natuna, Laut Cina Selatan. Pemanfaatan yang semakin intensif oleh perikanan pukat cincin dikhawatirkan akan mengakibatkan penurunan populasinya. Pengetahuan tentang biologi ikan selar bentong penting sebagai dasar pertimbangan pengelolaannya. Penelitian ini bertujuan menganalisis karakter biologi reproduksi ikan selar bentong di perairan Natuna, meliputi nisbah kelamin, ukuran rata-rata pertama kali matang gonad, ukuran rata-rata tertangkap (L50%), tingkat kematangan gonad dan dugaaan musim pemijahan. Penelitian dilakukan dengan mengumpulkan ikan contoh hasil tangkapan pukat cincin yang didaratkan di PPN Pemangkat Kalimantan Barat selama 5 tahun (2012-2016). Hasil penelitian menunjukkan Nisbah kelamin ikan jantan dan betina adalah 1:1.05. Sebagian besar ikan dalam stadium pematangan (ripening, TKG 3). Ikan bentong mengalami dua musim pemijahan yakni pada awalmusim timur (Juni-Juli) dan awal musim barat (Desember-Januari). Ukuran rata-rata tertangkap (L50%) sebesar 18 cm FL lebih kecil dari nilai pertama kali matang gonad (Lm) yakni 20,2 cm FL. Nilai Lc yang lebih kecil daripada nilai Lm mengindikasikan terjadinya growth overfishing.Bigeye scad (Selar crumenophthalmus) dominantly caught by fishers in the Natuna watersof South China Sea. The intensive exploitation rate of this species by purse seiner led to population decrease. The understanding on biological aspect of bigeye scad is important as a consideration on arranging a proper management. This study aims to analyze biological reproduction of bigeye scad in the Natuna waters, such as sex ratio, length at first maturity, length at first capture, gonad maturity stage and the estimation of spawning season. This research is conducted by sampling the fishes that caught by purse seine fleets which is landed in AFP Pemangkat, West Borneo for 5 years (2012 to 2016). The result showed that sex ratio of males and females were balance by 1:1,05. It dominated by fish that are ripening stage. Spawning season happens twice per year which are in the beginning of east season on June to July and at the beginning of west season on December to January. Length at first capture (L50%) is 18 cmFL lower than length at first maturity (Lm = 20,2 cmFL) this condition indicated growth overfishing occurred in this fishery.

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BIOLOGI REPRODUKSI IKAN CAKALANG (Katsuwonus pelamis) DI SAMUDERA HINDIA BAGIAN TIMUR

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.7.2.2015.87-94 ◽

2015 ◽

Vol 7 (2) ◽

pp. 87

Author(s):

Irwan Jatmiko ◽

Hety Hartaty ◽

Andi Bahtiar

Keyword(s):

Indian Ocean ◽

Histological Analysis ◽

Gonadosomatic Index ◽

Fork Length ◽

Maturity Stage ◽

Skipjack Tuna ◽

Katsuwonus Pelamis ◽

The Indian Ocean ◽

The One ◽

First Maturity

Cakalang (Katsuwonus pelamis) adalah salah satu hasil tangkapan penting bagi nelayan di Samudera Hindia. Penelitian ini bertujuan untuk mengetahui perkembangan gonad dan panjang pertama kalimatang gonad cakalang di Samudera Hindia. Sampel cakalang dikumpulkan dari beberapa tempat di Pantai Selatan Jawa yaitu: Palabuhanratu, Cilacap, Pacitan, Sendang Biru, Kedonganan, Tanjung Luar, Labuhan Lombok dan Oeba dari bulan April 2012 sampai November 2013. Panjang cagak dari 136 sampel berkisar antara 35-68 cm. Tingkat kematangan gonad (TKG) diamati secara histologi dan analisis Gonadosomatic index (GSI). Hasil penelitian ini menunjukkan bahwa TKGcakalang didominasi oleh TKGIV sebesar 43%, diikuti dengan TKG III (21%), TKG I (17%), TKG II (16%) dan TKG V (2%). Panjang pertama kali matang gonad terjadi pada ukuran 42,9 cm. Skipjack tuna (Katsuwonus pelamis) is the one of the important catch for fishermen in the Indian Ocean. The objectives of this research are to investigate gonad maturity and length at first maturity for female cakalang in Indian Ocean. Skipjack tuna were sampled from several places in South Coast of Java i.e.: Palabuhanratu, Cilacap, Pacitan, Sendang Biru, Kedonganan, Tanjung Luar, Labuhan Lombok and Oeba from April 2012 to November 2013. Fork length of the sampled 136 fish ranged from 35 to 68 cm.Maturity stage (TKG) investigate using histological analysis and Gonadosomatic index (GSI) calculation. The results showed that maturity stage of skipjacktuna dominated by TKG IV with 43%, followed by TKG III (21%), TKG I (17%), TKG II (16%) dan TKG V (2%). Length at first maturity occurred at 42.9 cm.

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BEBERAPAASPEKBIOLOGI IKANKUNIRAN (Upeneus sulphureus) DI PERAIRANTEGALDANSEKITARNYA

BAWAL Widya Riset Perikanan Tangkap ◽

10.15578/bawal.3.4.2011.261-267 ◽

2017 ◽

Vol 3 (4) ◽

pp. 261

Author(s):

Duranta Diandria Kembaren ◽

Tri Ernawati

Keyword(s):

Sex Ratio ◽

Frequency Distribution ◽

Condition Factor ◽

Growth Characteristic ◽

Demersal Fish ◽

Maturity Stage ◽

Gonad Maturity ◽

Level 3 ◽

Biological Aspects ◽

First Maturity

Ikan kuniran (Upeneus sulphureus)merupakan salah satu ikan demersal dari familiMullidae banyak tertangkap di perairan Laut Jawa. Penelitian ini tentang beberapa aspek biologi ikan kuniran di perairan Tegal dan sekitarnya dilakukan pada bulan Maret, April, dan Agustus 2009. Penelitian ini bertujuan untuk mengkaji beberapa aspek biologi ikan kuniran, seperti nisbah kelamin, sebaran frekuensi panjang, hubungan panjang dan bobot, tingkat kematangan gonad, panjang pertama kali matang gonad (length at first maturity), dan faktor kondisi. Ikan yangdiamati 358 ekor yang terdiri atas 170 jantan dan 188 betina. Perbandingan jumlah ikan jantan dan betinamenunjukanrasio kelamin yang tidak seimbang. Berdasarkan atas sebaran frekuensi panjang, ikan dengan panjang 9 cmFL mendominansi hasil tangkapan pada bulan Maret dan April dan pada bulan Agustus didominansi ikan dengan panjang 11 cmFL. Pertumbuhan ikan kuniran pada bulan Maret bersifat allometrik negatif, sedangkan pada bulan April danAgustus bersifat isometrik.Analisis tingkat kematangan gonad menunjukan bahwa pada bulan Agustus banyak ditemukan tingkat kematangan gonad I dan II dan pada bulanMaret banyak ditemukan tingkat kematangan gonad III dan IV. Ikan kuniran diduga pertama kali matang gonad pada ukuran panjang 9,87 cmFL. Faktor kondisi menunjukan tidak ada perbedaan antara bulan Maret, April, dan Agustus. The silver goatfish (Upeneus sulphureus) is demersal fish which caught excessively in the Java Sea and taxonomically belong to the family Mullidae. Some biological aspects of the silver goatfish in Tegal and adjacent waters were studied on March, April, and August in 2009. The objective of this research were to know some biological aspects, i.e. sex ratio, length frequency distribution, length weight relationship, gonad maturity stage, length at first maturity, and condition factor. A total of 358 fishes that consisted of 170 males and 188 females were examinated their biological aspects. The composition of male and female showed an unequal sex ratio. According to the lenght frequency distribution, the fishes of 9 cmFL were dominant onMarch and April, while on August was dominated by the fishes of 11 cmFL. The growth characteristic of the silver goatfish were allometric negative on March and isometric on April and August. Gonad maturity stage level 1 and 2 were dominant on August and level 3 and 4 onMarch. Lenght at first maturity (Lm) of silver goatfish were 9,87 cmFL. The condition factor showed that there is no difference on March, April, and August.

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