scholarly journals BIOLOGI REPRODUKSI TUNA MATA BESAR (Thunnus obesus) YANG TERTANGKAP DI SAMUDERA HINDIA

2017 ◽  
Vol 3 (2) ◽  
pp. 129
Author(s):  
Ria Faizah ◽  
Budi Iskandar Prisantoso
Keyword(s):  
Indian Ocean ◽  
Gonad Development ◽  
Morphological Structure ◽  
Maturity Stage ◽  
Batch Fecundity ◽  
Gonad Maturity ◽  
Thunnus Obesus ◽  
The Indian Ocean ◽  
Index Value ◽  
Somatic Index

Tujuan penelitian ini adalah untuk mendapatkan informasi mengenai aspek reproduksi ikan tuna mata besar (Thunnus obesus) di perairan Samudera Hindia. Sebanyak 42 contoh gonad dari ikan tuna mata besar yang tertangkap perairan Samudera Hindia antara bulan Maret sampai Oktober 2008 digunakan dalam penelitian ini. Pengamatan meliputi struktur morfologi gonad ikan, perkembangan gonad, diameter telur, dan fekunditas. Hasil penelitian ini menunjukan bahwa ikantuna mata besar yang tertangkap memiliki tingkat kematangan gonad I, II, dan IV. Nilai gonado somatic index rata-rata tuna mata besar semakin meningkat seiring dengan meningkatnya tingkat kematangan gonad. Musim pemijahan untuk tuna mata besar diduga terjadi pada bulan Oktober. Tuna mata besarmemiliki fekunditas antara 8.163.715-10.365.317 butir dan memiliki pola pemijahan berganda. The objective of this research is to study the reproductive biology of big eye tuna (Thunnus obesus) from Indian Ocean. A numbers of 42 gonad samples were taken from fresh individuals captured in the Indian Ocean during period of March until October 2008. The observation comprised of morphological structure of gonad, gonad development, oocytes diameter, and batch fecundity. The results showed that the gonad maturity stages of big eye tuna were ranged from immature (the gonad maturity stage of I and II) to mature (the gonad maturity stage of IV), and the gonado somatic index value increase along with increase of gonad maturity. Spawning season for big eye tuna estimated was in October, range of fecundity were 8.163.715-10.365.317 oocytes, and the spawning type waspartial spawned.

scholarly journals KOMPOSISI UKURAN, PERBANDINGAN JENIS KELAMIN, DAN TINGKAT KEMATANGAN GONAD IKAN TODAK BERPARUH PENDEK (Tetrapturus angustirostris) DI SAMUDERAHINDIA

2017 ◽  
Vol 3 (2) ◽  
pp. 123
Author(s):  
Dian Novianto ◽  
Budi Nugraha ◽  
Andi Bahtiar
Keyword(s):  
Indian Ocean ◽  
Sex Ratio ◽  
Size Composition ◽  
Maturity Stage ◽  
Chi Square ◽  
Male And Female ◽  
Level Ii ◽  
Chi Square Test ◽  
The Indian Ocean ◽  
Tuna Longline

Ikan todak berparuh pendek atau ikan tumbuk atau shortbill spearfish (Tetrapturus angustirostris) merupakan salah satu hasil tangkapan sampingan rawai tuna. Informasi mengenai ikan todak berparuh pendek seperti komposisi ukuran, perbandingan kelamin, dan tingkat kematangan gonadsangat terbatas. Tulisan ini bertujuan untuk menyajikan data dan informasi mengenai aspek biologi ikan todak berparuh pendek yang merupakan hasil tangkapan sampingan dari rawai tuna yang beroperasi di Samudera Hindia. Penelitian ini dilakukan pada bulan September sampai Desember 2008 di perairan Samudera Hindia. Hasil penelitian menunjukan bahwa ikan todak berparuh pendek memiliki kisaran panjang tubuh 135-175 cmLJFL dan modus pada kisaran 155-165 cmLJFL.Perbandingan jenis kelamin ikan jantan dan betina 1:13,5, berdasarkan atas hasil uji chi-square menunjukan bahwa rasio ikan jantan dan betina pada periode penelitian ini tidak seimbang. Pada bulan September ikan todak berparuh pendek betina didominansi oleh tingkat kematangan gonad IIsebesar 66,7%, bulan Oktober oleh tingkat kematangan gonad V sebesar 46,2%, bulan Nopember oleh tingkat kematangan gonad II sebesar 53,3%, sedangkan pada bulan Desember oleh tingkat kematangan gonad III sebesar 42,9%. Pada bulan Nopember sampai Desember terlihat bahwa tingkat kematangan gonad V mulai berkurang, hal ini menunjukan bahwa pada bulan Nopember sampai Desember diduga banyak ikan todak berparuh pendek betina yang sudah memijah. Shortbill Spearfish (Tetrapturus angustirostris) is one of bycatch of tuna longline. Information about shortbill spearfish on the size composition, sex ratio, and maturity stage is still very limited. The objective this paper is to present the data and information about shortbill spearfish which is a bycatch of tuna longline that operated in the Indian Ocean. Research was conducted during September until December 2008 in Indian Ocean. The results showed that the shortbill spearfish have body length about 135-175 cmLJFL and modes in 155-165 cmLJFL. Sex ratio of the male and female was 1:13.5. Based on chi-square test showed that the ratio of male and female in the period of the study was not balanced. In September, the female stage maturity was dominated by level II of 66.7%, October by level V of 46.2%, November by level II of 53.3%, and December by level III of 42.9%. During November until December showed that the maturity stage of level V was decreased, this shows that in this time the female of shortbill spearfish was spawned.

scholarly journals Comparison of handline tuna catches in Indian Ocean and Banda Sea waters

2021 ◽  
Vol 322 ◽  
pp. 03004
Author(s):  
Ignatius Tri Hargiyatno ◽  
Regi Fiji Anggawangsa ◽  
Moh. Natsir ◽  
I. Gede Bayu Sedana ◽  
Agustinus Anung Widodo ◽  
...  
Keyword(s):  
Indian Ocean ◽  
Average Length ◽  
Fishing Ground ◽  
Katsuwonus Pelamis ◽  
Thunnus Obesus ◽  
Significant Difference ◽  
Landing Sites ◽  
The Indian Ocean ◽  
Catch Composition ◽  
First Maturity

There are two essential landing sites for handline tuna in Indonesia: Palabuhanratu (in the Indian Ocean) and Kendari (in the Banda Sea). This paper analyzes handline catches from the Indian Ocean and Banda Sea waters as the main fishing ground. The catch composition of the handline tuna landed in Kendari is more varied than Palabuhanratu. Several species commonly caught are yellowfin tuna (Thunnus albacares), skipjack tuna (Katsuwonus pelamis), bigeye tuna (Thunnus obesus) as a target species, and some billfish species as bycatch. Mean CPUE for handline tuna landed in Palabuhanratu is lower than Kendari. A significant difference is based on the monthly mean CPUE variation between Palabuhanratu and Kendari landing sites (p < 0.001). Handline catches in Palabuhanratu had a more comprehensive range of length sizes than Kendari, using a two-sample K-S test showed significant differences (p < 0.001). The fish size landed in Kendari is relatively smaller than Palabuhanratu. The average length of fish caught by handline is smaller than the length at first maturity (Lm) value in both landing sites. The use of large size hook for hand lines is recommended for catching tunas in this area.

Genetic population structure and connectivity in a commercially exploited and wide-ranging deepwater shark, the leafscale gulper (Centrophorus squamosus)

2012 ◽  
Vol 63 (6) ◽  
pp. 505 ◽  
Author(s):  
A. Veríssimo ◽  
J. R. McDowell ◽  
J. E. Graves
Keyword(s):  
Genetic Diversity ◽  
Population Structure ◽  
New Zealand ◽  
Indian Ocean ◽  
Genetic Homogeneity ◽  
Genetic Population Structure ◽  
Maturity Stage ◽  
Genetic Population ◽  
The Indian Ocean ◽  
Nuclear Loci

The leafscale gulper (Centrophorus squamosus) is a wide-ranging deepwater benthopelagic shark threatened by commercial fisheries in parts of its range. Despite concerns about resource sustainability, little is known about the population structure and connectivity between critical habitats of the leafscale gulper. This study investigates the genetic population structure and the migration patterns of C. squamosus using nuclear microsatellites and mitochondrial NADH dehydrogenase subunit 2 (ND2) gene sequences. Genetic diversity was estimated and compared among sample collections from off Ireland, Portugal, the Azores, South Africa and New Zealand. The null hypothesis of genetic homogeneity among all collections was not rejected by the nuclear loci (FST (the overall genetic differentiation among sample collections) = –0.002, P = 0.88), but we found long-term genetic divergence between New Zealand and the remaining collections at the mtDNA ND2 (FCT (genetic differentation among groups of sample collections) = 0.366, P = 0.000). Migration rate estimates indicated limited female dispersal across the Indian Ocean whereas males showed less restricted dispersal. Our results are consistent with a single genetic stock of C. squamosus and the existence of sex-biased dispersal across the Indian Ocean. Widespread genetic homogeneity at nuclear loci minimizes the loss of unique adaptive genetic diversity in the event of localised depletion. However, high local fishing mortality may have far reaching impacts given the marked sex- and maturity-stage-based habitat partitioning previously reported for C. squamosus.

scholarly journals Biologi reproduksi udang mantis Cloridopsis scorpio di ekosistem mangrove Belawan, Sumatera Utara

DEPIK ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 227-334
Author(s):  
Rivo Hasper Dimenta ◽  
Rusdi Machrizal ◽  
Khairul Khairul ◽  
Rosmidah Hasibuan ◽  
Aini Qomariah Manurung ◽  
...  
Keyword(s):  
Random Sampling ◽  
Anthropogenic Activities ◽  
Sampling Period ◽  
Mangrove Ecosystem ◽  
Maturity Stage ◽  
Gonad Maturity ◽  
Mantis Shrimp ◽  
Shrimp Trawl ◽  
Gonad Somatic Index ◽  
Somatic Index

Anthropogenic activities that tend to be exploitative in the mangrove ecosystem of Belawan are thought to have an impact on the biota associated with the ecosystem. One of the impacts is thought to be implied by mantis shrimp Cloridopsis scorpio (Latreile, 1828). The reproductive biology of the shrimp is the main object that needs to be studied in relation to the impacts. This study aims to determine the distribution of gonad maturity stage, gonad somatic index, and the length of the first mature of C. scorpio in the Mangrove Ecosystem of Belawan, North Sumatera. The research was conducted on March to May 2019 with a biweekly sampling period. The purposive random sampling was applied to choose three sampling stations in the research location. Mantis shrimp samples were caught using shrimp trawl. The result showed that the gonad maturity stage of males and females were dominated by Stage I. The gonad somatic index (GSI) range of males were 7.00-10.93 and female were 7.40-11.15. The GSI value of C. scorpio is closely related to its gonad maturity development. The length of the first mature (L50) of males were 205.50±10.65 mmBL and females were 186.0±10.48 mmBL.Keywords: Cloridopsis scorpio, Gonad maturity stage, Gonad somatic indeks, Length of the first mature ABSTRAKAktivitas antropogenik yang cenderung eksploitatif di kawasan ekosistem mangrove Belawan diduga telah berdampak terhadap biota-biota yang berasosiasi dengan ekosistem tersebut. Salah satu dampaknya dialami oleh udang mantis Cloridopsis scorpio (Latreile, 1828). Aspek reproduksi C. scorpio menjadi salah satu objek yang perlu dikaji berkaitan dengan dampak tersebut. Penelitian ini bertujuan untuk menganalisis sebaran tingkat kematangan gonad (TKG), indeks kematangan gonad (IKG), dan ukuran pertama kali matang gonad (L50) dari C. scorpio di ekosistem mangrove Belawan, Sumatera Utara. Penelitian dilakukan pada bulan Maret sampai Mei 2019 dengan periode pengambilan sampel dua mingguan. Metode purposive random sampling digunakan untuk menentukan tiga stasiun pengambilan sampel di lokasi penelitian. Sampel C. scorpio ditangkap menggunakan pukat udang. Hasil penelitian menunjukkan distribusi TKG C. scorpio jantan dan betina didominasi oleh TKG I. Nilai IKG C. scorpio jantan berkisar antara 7,00-10,93 dan C. scorpio betina berkisar antara 7,40-11,15. Nilai IKG C. scorpio berkaitan dengan tahap perkembangan gonadnya. C. scorpio jantan mengalami pertama kali matang gonad (L50) pada ukuran 205,50±10,65 mmBL dan C. scorpio betina pada ukuran 186,00±10,48 mmBL.Kata kunci: Cloridopsis scorpio, TKG, IKG, Ukuran pertama kali matang gonad

scholarly journals DUGAAN MUSIM PEMIJAHAN IKAN CAKALANG (Katsuwonus pelamis) DI PERAIRAN SAMUDRA HINDIA SELATAN JAWA DAN NUSA TENGGARA

2020 ◽  
Vol 12 (1) ◽  
pp. 1
Author(s):  
Yoke Hany Restiangsih ◽  
Anthony Sisco Panggabean ◽  
Erfind Nurdin
Keyword(s):  
Indian Ocean ◽  
Spawning Season ◽  
Katsuwonus Pelamis ◽  
Landing Sites ◽  
The Status ◽  
The Indian Ocean ◽  
Biological Sampling ◽  
Average Size ◽  
First Maturity ◽  
Somatic Index

Sumberdaya ikan cakalang (Katsuwonus pelamis) merupakan ikan ekonomis penting dan utama di Indonesia. Tingginya tingkat pemanfaatan ikan cakalang di Samudra Hindia menjadi hal yang sangat rawan dan perlu kehati-hatian dalam pengelolaannya. Tersedianya data dan informasi tentang musim pemijahan merupakan bagian dari pengetahuan yang diperlukan untuk mengetahui status sumberdaya bagi upaya pengelolaannya. Penelitian ikan cakalang dilakukan berdasarkan pengambilan contoh biologi dibeberapa tempat pendaratan ikan (Palabuhan Ratu, Prigi dan Labuhan Lombok). Penelitian dilaksanakan pada bulan Januari sampai dengan Nopember 2016. Pendugaan musim pemijahan menggunakan pendekatan indeks kematangan gonad (IKG) bulanan. Distribusi ukuran ikan yang tertangkap dengan menggunakan pancing tonda berkisar antara 24 – 66 cm. Ukuran rata-rata pertama kali tertangkap (Lc) pada panjang 41,6 cm, ukuran pertama kali matang gonad (Lm) 42,5 cm. Berdasarkan fluktuasi IKG musim pemijahan ikan diduga berlangsung pada bulan April dan Nopember.Skipjack tuna (Katsuwonus pelamis) are most important and economically fish in Indonesia. The highest exploitation skipjack in the Indian Ocean is very vulnerable are requires caution in its management. The availability of data and information about the spawning season is a part of the knowledge needed to determine the status of resources for management efforts. This research was carried out based on biological sampling at several fish landing sites (Palabuhanratu, Prigi, and Labuhan Lombok). This research was conducted from January until to November 2016. Estimating of the spawning season was used a monthly Gonado Somatic Index (GSI) approach. The range of size distribution from of fish caught using troll line were 24 until 66 cm. The average size of first caught (L50%) at a length was 41.6 cm, the size of the length of first maturity (Lm) was 42,5 cm. Based on the GSI fluctuation, spawning season was done in April and November.

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