scholarly journals Morphometric Aspects of Scad Decapterus macrosoma Bleeker, 1851 in Cape of Salonggar Regency

2018 ◽  
Vol 6 (1) ◽  
pp. 61 ◽  
Author(s):  
Mediyanto Samuel Panaha ◽  
Fransine B Manginsela ◽  
Meiske S. Salaki
Keyword(s):  
Sex Ratio ◽  
Allometric Growth ◽  
Maturity Level ◽  
Female Fish ◽  
Growth Type ◽  
Male Fish ◽  
Total Size ◽  
Gonadal Maturity ◽  
Length Increase ◽  
Immature Fish

This study aims to determine the biological appearance of globe fish that includes size distribution, growth pattern, sex ratio and maturity level of gonad (TKG) in Tanjung Salonggar Melonguane waters of Talaud Islands Regency. Sampling was conducted from May to July 2017. Decapterus macrosoma has found during the study were 268 with total size of 150 - 244 mm and the weight ranged from 34 to 142 grams. Kite fish caught in Tanjung Salonggar has a negative allometric growth type that is the length increase faster than weight gain (b <3). The sex ratio of male fish and female fish is equal to 1: 1, with maturity level of Gonad (TKG) I up to TKG V. The highest gonadal maturity level is found in June and July, both male and female fish, while in May fish which is caught predominantly by an immature fish gonad. Keywords: Biological appearance, Decapterus macrosoma, growth pattern.AbstrakPenelitian ini bertujuan untuk mengetahui tampilan biologis ikan layang yang meliputi sebaran ukuran, pola pertumbuhan, rasio kelamin dan tingkat kematangan gonad (TKG) di Perairan Tanjung Salonggar Melonguane Kabupaten Kepulauan Talaud. Pengambilan sampel dilakukan pada bulan Mei sampai bulan Juli 2017. Ikan layang Decapterus macrosoma yang diperoleh selama penelitian sebanyak 268 ekor dengan Sebaran ukuran panjang total 150 – 244 mm dan berat berkisar 34 – 142 gram. Ikan layang yang tertangkap di Tanjung Salonggar memiliki tipe pertumbuhan allometrik negatif yaitu pertambahan panjang lebih cepat dari pertambahan berat (b < 3). Rasio kelamin ikan jantan dan ikan betina adalah seimbang  yaitu 1 : 1, dengan Tingkat Kematangan Gonad  (TKG ) I sampai dengan TKG V. Tingkat kematangan gonad tertinggi ditemukan pada bulan Juni dan Juli, baik ikan jantan maupun ikan betina, sementara pada bulan Mei ikan yang tertangkap didominasi oleh ikan yang belum matang gonad.Kata kunci : Tampilan biologis, Decapterus macrosoma, Pola pertumbuhan.

scholarly journals ANALISA ASPEK REPRODUKSI IKAN TOMAN (Channa micropeltes) DI SUNGAI BELIDA KABUPATEN MUARA ENIM

2020 ◽  
Vol 8 (1) ◽  
pp. 12-21
Author(s):  
Danang Yonarta ◽  
Yulisman Yulisman ◽  
Riswandi Riswandi
Keyword(s):  
Sex Ratio ◽  
Time Interval ◽  
Maturity Level ◽  
Female Fish ◽  
Natural Conditions ◽  
Male And Female ◽  
Gonad Maturity ◽  
Fish Resources ◽  
Gonadal Maturity ◽  
Abundant Population

Management of snakehead fish resources in swamp waters need to be done to anticipate a decline in stock in the waters. At this time the area where snakehead fish still have an abundant population is in southern sumatera, precisely in the Belida River, Muara Enim Regency. Until now there has been no information regarding the reproductive aspects of snakehead fish, their location and spawning season. The purpose of this study was to obtain information about the reproductive aspect of snakehead fish which includes sex ratio, gonad maturity level. Gonad maturity index and egg fecundity. The research was conducted in September-December 2019. The location was determined based on the natural conditions of the Belida River and human activities. Fish sampels were caught using experimental gill nets with ½ mash net size. Sampling of fish is done every 4 months with a time interval of once a month. The resuls of study in the male and female fish ratio 1,6:1. This ratio consisted of 109 fish (62,3%) and 66 female fish (37,7%). Gonadal maturity indeks  for male snakehead fish ranged from 0,21 to 0,86, while female snakehead fish ranged from 1,18 to 2,30. snakehead fish egg fecundity were 24.786 eggs with a diameter of 2,20 – 2,51

scholarly journals Aspek Biologi Ikan Layang (Decapterus russelli) di Perairan Latuhalat, Kecamatan Nusaniwe, Pulau Ambon

Omni-Akuatika ◽  
2016 ◽  
Vol 12 (3) ◽  
Author(s):  
Ong T.S Ongkers ◽  
Jesaja A Pattikawa ◽  
Frederick Rijoly
Keyword(s):  
Sex Ratio ◽  
Size Distribution ◽  
Growth Pattern ◽  
Sex Ratios ◽  
Purse Seine ◽  
Allometric Growth ◽  
Maturity Level ◽  
Gonad Maturity ◽  
Fish Samples ◽  
Biological Aspects

This research was carried out in the waters of Latulahalat, Ambon Island from June to August 2016. The objectives of the research were to study some biological aspects namely sex ratio, gonad maturity level, size distribution and growth pattern of scad mackerel, Decaterus russelli. Fish samples were collected every month at fish landing from purse seine fishers. Sex ratios of scad mackerel in the area were equal i.e. 1:1 with the male dominated gonad maturity levels I and IV while female dominated gonad maturity levels II, III and V.  In general, male fishes were smaller than female ones in term of length and weight. Scad mackerel in the area showed positive allometric growth except for male on August which showed isometric growth Keywords: Decaterus russelli, sex ratio, .gonad maturity level, growth pattern 

scholarly journals Potential of sustainable and biological aspect of sting ray (Dasyatis sp.) as catch fisheries status overview in Java Sea

2018 ◽  
Vol 47 ◽  
pp. 03003
Author(s):  
Arif Mahdiana ◽  
Norman Arie Prayogo ◽  
Isdy Sulistyo
Keyword(s):  
Sex Ratio ◽  
Demersal Fish ◽  
Production Method ◽  
Maximum Sustainable Yield ◽  
Primary Data ◽  
Biological Aspect ◽  
Male Fish ◽  
Surplus Production ◽  
Java Sea ◽  
Immature Fish

Stingray fish is a demersal fish commodity in Indonesian waters which decreasing in catch. The purpose of this research is to know the potential of sustainable and some aspects of Stingray fish biology by using the Maximum Sustainable Yield (MSY) indicator as the fishing status in Java Sea. Data of catch and effort taken from production data of year 2006-2015 and primary data to know some aspect of biology is taken at TPI port of Cirebon and Tegal Specification data of fish catching tools Pari obtained from fisherman interview. The data of the catch in the analysis using Surplus Production Method (Schaefer) and observed aspects of stingray biology include: sex ratio and distribution of length of Stingray fish. The results showed the MSY value of Stingray fish was 894.275 tons / year and fMSY value of 34.716 ships / year. The sex ratio of male Stingray fish with female Stingray fish is still balanced, which is 1: 1.34 and the size of long frequency entered into the category of immature fish gonad and fish which first ripe gonad, which ranges between length 16-22 cm both male fish or female. Based on the research results can be concluded that Stingray fish catchment in Java sea still in sustainable condition.

scholarly journals Length-Weight Relationship and Gonad Maturity of Marble sleeper Oxyeleotris marmorata (Bleeker, 1852) in Tondano Lake North Sulawesi

2020 ◽  
Vol 11 (1) ◽  
pp. 23
Author(s):  
Ikky Ahdian Umage ◽  
Nego E. Bataragoa ◽  
Jety K. Rangan ◽  
Anneke V. Lohoo ◽  
Janny D. Kusen ◽  
...  
Keyword(s):  
Condition Factor ◽  
Growth Patterns ◽  
Mature Male ◽  
Allometric Growth ◽  
Female Fish ◽  
Male Fish ◽  
Gonad Maturity ◽  
Weight Relationship ◽  
North Sulawesi ◽  
Fish Samples

The purpose of this study was to determine the length-weight relationship and gonad maturity of Betutu fish (Oxyeleotris marmorata) in Lake Tondano. Fish samples were caught using gill nets and lift nets in Lake Tondano. Total catches of 240 individuals. The legth-weight relation of male fish is W = 0.0094 L3.14 positive allometric growth pattern. Female female fish obtained W = 0.0104 L3.11 positive allometric growth patterns. The condition factor for male fish is 1.46 male and 1.47 female respectively. All levels of gonad maturity (I, II, III, IV and V) were found in each sample both in August and September. The size of the first mature male male fish is 219 ± 3 mm (range in size 216-222 mm) and female fish 171 ± 3 (range in size 169-174 mm).Keywords: Length-Weight, gonad maturity, Tondano Lake ABSTRAKTujuan penelitian ini untuk mengetahui hubungan panjang-berat dan kematangan gonad ikan Betutu (Oxyeleotris marmorata) yang ada di danau Tondano. Sampel ikan  ditangkap menggunakan jaring insang dan jaring angkat di danau Tondano. Total hasil tangkapan  240 individu. Hubungan panjang-berat ikan betutu jantan yaitu W = 0,0094L3,1394 pola pertumbuhan allometrik positif. Ikan betutu betina didapatkan W = 0,0104L3,1137 pola pertumbuhan allometrik positif. Faktor kondisi ikan betutu jantan masing-masing sebesar  1,46 ikan jantan dan  1,47 ikan betina. Seluruh tingkat  kematangan gonad (I, II, III, IV dan V) ditemukan pada setiap sampel baik pada bulan agustus maupun bulan September.  Ukuran pertama kali matang ikan betutu jantan yaitu   219 ±3 mm (kisaran ukuran 216-222 mm) dan ikan betina  171±3  (kisaran ukuran 169-174 mm)Kata Kunci: Panjang-berat, kematangan gonad, Danau Tondano

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

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.

scholarly journals Characteristics of Reproduction of Yellowstripe Scad Selaroides leptolepis (Cuvier, 1833) In Manado Bay Waters

2018 ◽  
Vol 6 (2) ◽  
pp. 46
Author(s):  
Febrina Sinaga ◽  
Ferdinand F Tilaar ◽  
Nego E Bataragoa
Keyword(s):  
Sex Ratio ◽  
Growth Pattern ◽  
Maturity Level ◽  
Female Fish ◽  
Chi Square ◽  
Male And Female ◽  
Random Draw ◽  
First Maturity ◽  
First Time ◽  
Size At First Maturity

The waters of Manado Bay are areas that have a lot of biological resources. One of these resources is Yellowstripe scad (Selaroides leptolepis). The research was aimed to find out the reproduction characteristics of  Yellowstripe scad (Selaroides leptolepis) by looking at male and female sex ratio, growth pattern with male and female condition factor, maturity level of gonad (TKG), gonad maturity index (IKG), size at first maturity, and fecundity. The location of fish sampling is taken from the catch of fishermen in Manado Bay waters in not April-May 2018. Fish sampling using random draw method withdrawal. The number of samples is 200, taken four times in two months (April to May 2018). The sex ratio of Yellowstripe scad (Selaroides leptolepis) in the waters of Manado Bay is balanced. The growth pattern of male is positive allometric, while females is isometric. The condition of male and female fish are 0.9 and 1.3 respectively.  The Yellowstripe scad breeding season in Manado Bay waters takes place after the fourth week in April. The size of the first time ripe gonad Yellowstripe scad male and female 189 mm. The fecundity ranged from 1,960 - 29,145 with an average of 11,716 ± 6,088.Keywords: Yellowstripe scad, reproductive biology, Manado Bay ABSTRAKPerairan Teluk Manado adalah perairan  yang memiliki sumberdaya hayati cukup banyak. Salah satu sumberdaya di perairan tersebut yaitu ikan Selarkuning (Selaroides leptolepis). Penelitian itu bertujuan untuk mengetahui karakteristik reproduksi ikan Selarkuning (Selaroides leptolepis) dengan melihat dari rasio kelamin jantan dan betina, pola pertumbuhan dengan faktor kondisi pada jantan dan betina, tingkat kematangan gonad (TKG), indeks kematangan gonad (IKG), ukuran pertama kali matang gonad, dan fekunditas.       Sampel ikan diambil dari hasil tangkapan nelayan di perairan Teluk Manado pada bulan April-Mei 2018. Pengambilan sampel ikan menggunakan metode penarikan secara acak berlapis.  Jumlah sampel sebanyak 200 ekor, diambil empat kali dalam dua bulan. Berdasarkan uji Chi-square, rasio kelamin ikan Selarkuning (Selaroides leptolepis) di perairan Teluk Manado adalah seimbang. Pola pertumbuhan ikan Selarkuning yaitu bersifat allometrik positif, sedangkan betina bersifat isometrik dengan rata-rata faktor kondisi ikan jantan dan betina mencapai 0,9 dan 1,3. Musim pemijahan ikan Selarkuning di perairan Teluk Manado berlangsung setelah minggu keempat pada bulan April. Ukuran pertama kali matang gonad ikan Selarkuning jantan dan betina 189 mm. Fekunditas ikan Selarkuning berkisar antara 1.960 – 29.145 butir dengan rata-rata 11.716 ± 6.088.Kata kunci: ikan Selarkuning,biologi reproduksi, Teluk Manado

scholarly journals Biological Aspects of Waanders’s Hard-lipped Barbs (Osteochilus waandersii) in Tambatan River, North Sumatera, Indonesia

BIOEDUSCIENCE ◽  
2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Siti Jurniah Nasution ◽  
Rivo Hasper Dimenta
Keyword(s):  
Sampling Method ◽  
Growth Patterns ◽  
Maturity Stage ◽  
Maturity Level ◽  
Female Fish ◽  
Male Fish ◽  
Gonad Maturity ◽  
The Family ◽  
Biological Aspects

Background: Waanders’s hard-lipped barbs or scientifically known as Osteochilus waandersii belong to the family Cyprinidae with the potamodromous category. This fish can be found in the Tambatan river. It has the potential for commercial consumption or ornamental fish. Methods: This study was conducted in the Tambatan river from November to January 2021. The determination of three research stations was carried out using a purposive sampling method. Sampling was undertaken using cast nets. Furthermore, data analyzed were growth patterns, condition factors, and gonad maturity levels. Results: The growth patterns of male (1.944) and female (2.379) Osteochilus waandersii were in a negative allometric category. Besides, The Fulton's condition factor for male fish ranged from 0.42 - 3.43 with an average of 1.05, while that for female fish ranged from 0.59 - 3.67 with an average of 1.47. The result of the observation on the gonad maturity level for male and female O. waandersii in the Tambatan river indicated that they were dominated by fish with gonad maturity stage I (immature). Conclusions: Waanders’s hard-lipped barbs O. waandersii found were in the stage towards the mature level.

scholarly journals EFFECT OF SALINITY ACCLIMATISATION AND ADMINISTRATION OF HORMONES ON OOCYTE MATURATION, OVULATION AND SPAWNING OF GOLDSPOT MULLET LIZA PARSIA (HAMILTON, 1822) REARED IN BRACKISHWATER POND

2020 ◽  
Vol 67 (1) ◽  
Author(s):  
Prem Kumar ◽  
G. Biswas ◽  
T.K. Ghoshal ◽  
L. Christina ◽  
P. Behera ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Oocyte Maturation ◽  
Dopamine Antagonist ◽  
Oocyte Diameter ◽  
Female Fish ◽  
Male Fish ◽  
Oocyte Growth ◽  
Before And After ◽  
Males And Females ◽  
Brackishwater Pond

In this study, anTwo separate experiments were conducted to evaluate the effect of salinity acclimatisation and administration of hormones on oocyte growth of Liza parsia (Hamilton, 1822). In the first experiment, broodstock fishes in the sex ratio of 2:1 (male:female) were acclimatised to 30 ppt salinity (which is the desired salinity for breeding L. parsia) in 24, 48 and 72 h of duration (n=6). Oocyte diameter from the experimental fishes were measured before and after salinity acclimatisation. The results showed that the acclimatisation to breeding salinity reduced oocyte diameter (p<0.05) in female fish and increased sperm relative mortality (p<0.05) in male fish. In the second experiment, males and females in the similar sex ratio (2:1) were acclimatised to the desired salinity of 30 ppt in 24 h. Subsequently, carp pituitary gland extract (PGE), human chorionic gonadotropin (HCG), combination of PGE+HCG and luteinising hormone releasing hormone analogue (LHRHa) with dopamine antagonist (DA) metoclopramide were injected intramuscularly, The dosages used were: PGE- 0.01 and 0.02 mg g-1; HCG - 20 and 40 IU g-1, LHRHa - 10 and 20 µg kg-1 as primary and secondary doses, respectively. Metoclopramide was injected at the dose of 15 mg kg-1 along with LHRHa. Results of the second experiment indicated that the administration of PGE or PGE+HCG is essential for final oocyte maturation and ovulation in salinity acclimatised L. parsia.

scholarly journals The sex ratio, Gonadosomatic Index and Fecundity of the Copper Mahaseer, Neolissochilus hexagonolepis (Mc Clelland, 1839) from Tamor river, Nepal

2015 ◽  
Vol 5 (1) ◽  
pp. 48-55
Author(s):  
S. Subba ◽  
V. K. Mahaseth
Keyword(s):  
Sex Ratio ◽  
Gonadosomatic Index ◽  
Total Weight ◽  
Strong Positive Correlation ◽  
Female Fish ◽  
Male Fish ◽  
Positive Correlation ◽  
Total Length ◽  
Male To Female ◽  
Somatic Index

The sex ratio, Gonado Somatic Index and fecundity of the Copper Mahseer, Neolissochilus hexagonolepis were investigated. The sex ratio was 1:1.2 (Male to female). The gonado-somatic index ranged from 0.084 % to 16.47 % for female fish and 0.086% to 5.81 % for male fish. The highest mean GSI 9.037 % was recorded in July for female fishes and the highest 2.838 % was recorded in September for male fishes.  The total weight and total length of the fishes had strong positive correlation. Also, the correlation between the weight of gonad and GSI was positively correlated.  Absolute fecundity ranged from to 11424. Fecundity had strong positive correlation with total length (r = 0.98), total weight (r= 0.9) and total length (r= 0.88).

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

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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