scholarly journals SIZE, SEX AND LENGTH AT MATURITY OF FOUR COMMON SHARKS CAUGHT FROM WESTERN INDONESIA

2007 ◽  
Vol 32 (1) ◽  
pp. 7-19 ◽  
Author(s):  
Fahmi ◽  
Kurnaen Sumadhiharga
Keyword(s):  
Conservation Status ◽  
Shark Species ◽  
Sex Composition ◽  
Sphyrna Lewini ◽  
Scalloped Hammerhead ◽  
Landing Sites ◽  
Silky Shark ◽  
Carcharhinus Falciformis

A study on four common shark species in Indonesia, the spinner shark Carcharhinus brevipinna (Muller and Henle, 1839), silky shark Carcharhinus falciformis (Bibron, 1839), spot-tail shark Carcharhinus sorrah (Valenciennes, 1839) and scalloped hammerhead Sphyrna lewini (Griffith and Smith, 1834) was conducted at several shark landing sites in western Indonesia from March 2002 to December 2004. Data were collected from the surveyed areas including the length of frequency, sex composition and length at maturity. In general, they were caught at size smaller than their maturity size. The proportion of immature C. brevipinna, C. falciformis, C. sorrah and S. lewini to their total number recorded at the surveyed area during the study were about 87%, 50%, 80% and 65%, respectively. According to the length at maturity, females generally attained their maturity in larger size than males. Some factors contributing the catches in immature size and conservation status of those four species were also discussed.

scholarly journals Jenis, performa, dan nisbah kelamin ikan hiu yang didaratkan di Pelabuhan Perikanan Samudra Cilacap

2018 ◽  
Vol 17 (2) ◽  
pp. 185 ◽  
Author(s):  
Dian Bhagawati ◽  
Tri Nurani ◽  
Muh. Nadjmi Abulias
Keyword(s):  
Conservation Status ◽  
Sampling Technique ◽  
Total Body Length ◽  
Species Number ◽  
Shark Species ◽  
Female Fish ◽  
Sphyrna Lewini ◽  
Isurus Oxyrinchus ◽  
Carcharhinus Falciformis ◽  
Total Body

Shark fisheries in Indonesia are still relying on the natural catch. Several shark species are important fisheries commo-dities and are highly collected. Although there are several rules to control catch, usage, and conservation status, in practice, fishermen are less submissive. This study was conducted to obtain information about species diversity, per-formance, and sex ratio of sharks which were found in Cilacap Port in October to November 2015. The method used was purposive random sampling technique. Samples were taken four times with two weeks interval for each observation. The parameters were species number, total body length, body weight, morphometry and sex. Data were analyzed descriptively. Thirty six sharks were recorded during the sampling which consisted of 14 species. Among 36 individuals, 7 individuals were juveniles, 3 individuals were adolescence, and 26 individuals were adults. Alopias superciliosus (321 cm) was the longest species, while the shortest was Sphyrna lewini (59 cm); Isurus oxyrinchus was the heaviest (100 kg) species and the lightest species was Carcharhinus falciformis (1 kg). In general, female fish were obtained more than the males. AbstrakProduksi ikan hiu di Indonesia masih mengandalkan hasil tangkapan dari alam. Meskipun sudah terdapat beberapa per-aturan yang mengatur tentang penangkapan, pemanfaatan dan status perlindungannya, namun dalam prakteknya kurang dipatuhi. Penelitian ini dilakukan untuk mendapatkan informasi tentang keragaman spesies, performa, dan nisbah kela-min ikan hiu yang didaratkan di Pelabuhan Perikanan Samudra Cilacap pada periode Oktober sampai dengan November 2015. Sampel dipilih dengan persyaratan tertentu dan identifikasi dengan teknik photo ID (Photo-Identiûcation). Para-meter yang diamati adalah jumlah jenis, panjang total, bobot tubuh, morfometrik, dan jenis kelamin. Data yang diper-oleh dianalisis secara deskriptif. Selama pengambilan sampel diperoleh 36 ekor ikan hiu, yang terdiri atas 14 jenis, dan tergolong yuwana sebanyak 7 ekor, 3 remaja, dan 26 dewasa. Ikan yang tertangkap dan memiliki ukuran tubuh terpan-jang adalah Alopias superciliosus (321cm), terpendek Sphyrna lewini (59cm); terberat Isurus oxyrinchus (100kg) dan teringan adalah Carcharhinus falciformis (1kg). Secara umum ikan betina lebih banyak tertangkap daripada ikan jantan.

scholarly journals Population structure and reproductive characteristics of the silky shark Carcharhinus falciformis (Müller & Henle, 1839) (Carcharhiniformes: Carcharhinidae) off the coast of Oaxaca, Mexico

2017 ◽  
Vol 44 (3) ◽  
pp. 513-524
Author(s):  
María del Carmen Alejo-Plata ◽  
Miguel Ángel Ahumada-Sempoal ◽  
José Luis Gómez-Márquez ◽  
Adrián González-Acosta
Keyword(s):  
Population Structure ◽  
Sex Ratio ◽  
Seasonal Changes ◽  
Sexual Maturity ◽  
Size Structure ◽  
Landing Sites ◽  
Silky Shark ◽  
Oceanic Species ◽  
Carcharhinus Falciformis ◽  
Gravid Females

Carcharhinus falciformis is an abundant oceanic species, which occurs in equatorial and tropical zones, with an important catch in the Atlantic and Pacific coasts of Mexico. Samples were taken from December 2000 to December 2007 in four landing sites of the artisanal fleet on the coast of Oaxaca. During the period of study 1236 specimens (602 females and 634 males) of C. falciformis were registered. Total length (TL) ranged from 49 to 217 cm for females (mean = 111.3 cm) and from 59 to 265 cm for males (mean = 111.7 cm). The sex ratio of females to males was 1:1 ( 2 0.05 = 0.78, P > 0.05). The present data suggest a size at first sexual maturity of about 184.8 cm TL for females and 178.5 cm TL for males. The catches were composed mainly of young. In the 52 gravid females examined, the average number of embryos per female was seven; with a range of 3-14 embryos. Mean TL of embryos ranged from 10 to 66 cm with evidence of seasonal changes in the size structure. Results obtained showed that C. falciformis gives birth most of the year, with the highest proportion of births during the rainy season (May to October).

scholarly journals KOMPOSISI DAN FLUKTUASI HASIL TANGKAPAN IKAN CUCUT DOMINAN YANG TERTANGKAP RAWAI TUNA PERMUKAAN

2017 ◽  
Vol 14 (4) ◽  
pp. 371
Author(s):  
Dharmadi Dharmadi ◽  
Suprapto Suprapto ◽  
Agustinus Anung Widodo
Keyword(s):  
Indian Ocean ◽  
Total Catch ◽  
Fishing Activity ◽  
Prionace Glauca ◽  
Long Line ◽  
Landing Sites ◽  
Silky Shark ◽  
The Indian Ocean ◽  
Carcharhinus Falciformis ◽  
Catch Composition

Perikanan rawai tuna memiliki kontribusi cukup besar terhadap hasil tangkapan ikan cucut (Requiem shark sp.) di perairan Samudera Hindia. Hasil tangkapan rawai tuna sebagian besar didaratkan di 2 pendaratan ikan utama yaitu Pelabuhan Perikanan Pelabuhan Ratu dan Pelabuhan Perikanan Samudera Cilacap. Kegiatan penelitian untuk mengetahui komposisi dan fluktuasi hasil tangkapan ikan cucut (Requiem shark sp.) dominan pada rawai tuna permukaan berbasis di 2 lokasi pendaratan ikan tersebut dilakukan pada tahun 2004. Hasil penelitian menunjukkan bahwa komposisi hasil tangkapan cucut (Requiem shark sp.) pada rawai tuna permukaan didominansi oleh jenis ikan cucut karet atau selendang (Prionace glauca) antara 40 sampai dengan 90%, sedangkan komposisi jenis ikan cucut lain seperti ikan cucut lanjaman (Carcharhinus falciformis dan Carcharhinus sorrah), cucut paitan (Alopias superciliosus), cucut tikusan (Alopias pelagicus), dan cucut mako (Isurus sp.) antara 3 sampai dengan 30%. Hasil tangkapan ikan cucut (Requiem shark sp.) terhadap hasil tangkapan total rawai tuna permukaan antara 5 sampai dengan 25% pada tahun 2004 dari rata-rata 85 unit kapal rawai tuna yang beroperasi di perairan Samudera Hindia. Hasil tangkapan ikan cucut (Requiem shark sp.) tertinggi terjadi pada bulan Juli sampai dengan Agustus. Hasil tangkapan ini berkaitan dengan kondisi cuaca (Requiem shark sp.) pada saat nelayan melakukan penangkapan ikan di laut. Tuna long lines fisheries have more contributed on the catch of shark (Requiem shark sp.) in the Indian Ocean. Most of catch from tuna long lines landed at two main landing sites of tuna long line which operated in the Indian Ocean were Pelabuhan Ratu and Cilacap. This study was conducted at that two landing sites during 2004. The result showed that shark (Requiemshark sp.) catch composition on tuna long line was dominated by blue shark, Prionace glauca (40 to 90%), while other sharks i.e. silky shark (Carcharhinus falciformis), spot tail shark (Carcharhinus sorrah), big eye thresher (Alopias superciliosus), pelagic thresher (Alopias pelagicus), and mako shark (Isurus sp.) between 3 to 30% from the total catch of shark (Requiem shark sp.). Percentage catch of sharks (Requiem shark sp.) againts total catch of tuna surface long line during 2004 was ranging 5 to 25% from everage of 85 unit of tuna long line boat that operated in the Indian Ocean. Catch fluctuation related with the weather conditon when the fishers are fishing activity at sea. The high catch of shark (Requiem shark sp.) was occur on July until August.

scholarly journals CARACTERIZACIÓN DE LA PESCA DEL TIBURÓN MARTILLO SPHYRNA LEWINI , EN LA PARTE EXTERNA DEL GOLFO DE NICOYA, COSTA RICA

2009 ◽  
Vol 1 ◽  
pp. 175 ◽  
Author(s):  
Ilena Zanella ◽  
Andrés López ◽  
Rándall Arauz
Keyword(s):  
Costa Rica ◽  
Outer Part ◽  
Shark Species ◽  
Central Pacific ◽  
Sphyrna Lewini ◽  
Hammerhead Shark ◽  
Total Length ◽  
Management Actions ◽  
Scalloped Hammerhead ◽  
Gulf Of Nicoya

En el ámbito nivel mundial, el tiburón martillo (Sphyrna lewini) es una de las especies más afectadas por la sobrepesca y el aleteo. Recientemente se incorporó a la Lista Roja de la UICN como especie en peligro de extinción. El presente estudio pretendió caracterizar la pesca y la distribución de S. lewini en la parte externa del Golfo de Nicoya. Para lograr este propósito, se realizaron muestreos entre marzo del 2006 y mayo del 2007 y se analizaron los tiburones martillo capturados por pescadores artesanales afiliados a la Cooperativa artesanales de Pescadores de Tárcoles (CoopeTárcoles R. L.), que faenan en la parte externa del Golfo de Nicoya. Para cada tiburón, se determinó la longitud total, la zona de pesca donde se capturó y el arte utilizado. En total se analizaron 273 tiburones. Se identificó un área de crianza primaria en el Peñón y se determinó que existe una relación lineal positiva entre la longitud total y la profundidad de la zona de pesca (R2 = 0.4296; p ‹ 0.0001), y la longitud total y la distancia de la zona de pesca de la desembocadura del río Grande de Tárcoles (R2 = 0.4052; p ‹ 0.0001). Los tiburones de menor tamaño (crías) se encontraron en la zona del Peñón, donde las aguas son poco profundas, turbias y productivas, ofreciendo a las crías alimento y protección de los depredadores. Por lo cual, se recomienda proteger esta zona, en particular en marzo, abril y mayo, época de nacimiento de las crías.The scalloped hammerhead shark (Sphyrna lewini) is one of the shark species most impacted by overfishing, and is currently listed by the IUCN Red List as an Endangered.  This research sought to characterize the distribution of S. lewini in the external area of Gulf of Nicoya, central Pacific coast of Costa Rica, based on observations from a coastal artisanal fishery. From March 2006 to May 2007, we analyzed scalloped hammerhead shark landings by members of the Tarcoles Artisanal Fishermen's Cooperative (CoopeTárcoles R. L.), who operate in the outer part of the Gulf of Nicoya. We measured the total length of each shark, recorded the reported location of capture, and the gear used. In total, we recorded data for 273 sharks landed. We determined that total length holds a positive linear relationship with the depth of the fishing area (R2 = 0.4296, *** p <.0001) as well as with the distance from the mouth of the Tárcoles River (R2 = 0.4052, *** p <.0001). The smaller sharks (pups) were caught in a fishing site known as Peñon, slightly north of the mouth of the Tarcoles River, where the waters are shallow, turbid and highly productive, providing food and shelter for the pups.  As pups mature and attain larger sizes, they move towards deeper waters away from the Tarcoles River, out of the Gulf of Nicoya. We identify Peñon as a primary nursery for scalloped hammerhead sharks, and recommend management actions that seek to reduce fishing effort between March and May, when pups are born.

scholarly journals Intraspecific demography of the silky shark (Carcharhinus falciformis): implications for fisheries management

2019 ◽  
Author(s):  
Michael I Grant ◽  
Jonathan J Smart ◽  
Cassandra L Rigby ◽  
William T White ◽  
Andrew Chin ◽  
...  
Keyword(s):  
Life History ◽  
Fisheries Management ◽  
Life Stage ◽  
Leslie Matrix ◽  
Parameter Estimates ◽  
Shark Species ◽  
Life History Parameter ◽  
Silky Shark ◽  
Carcharhinus Falciformis ◽  
Management Approaches

Abstract The silky shark (Carcharhinus falciformis) is one of the most heavily fished tropical shark species globally, and currently there is increasing concern for its conservation status. However, large differences and ambiguity in life history parameter estimates among regions complicates its conservation and fisheries management. Using a Leslie matrix model that incorporated stochastic effects, we analysed the intraspecific demography of C. falciformis using available life history data from seven regions. Among regions, large differences were observed in generation time and age-specific reproductive contributions. Carcharhinus falciformis generally had low resilience to fishing mortality (F) throughout its distribution. Age-at-first-capture and age-at-last-capture management approaches resulted in substantial differences among regions. This was largely influenced by age-at-maturity. However, in scrutinizing some regional life history studies, it is likely that sampling design and methodological differences among regions have resulted in inaccuracies in life history parameter estimates and subsequent demographic attributes. This implies that age and life-stage-dependent management approaches using these possibly inaccurate life history parameters may be inappropriate. We suggest that a greater emphasis needs to be placed on eliminating human sources of error in elasmobranch life history studies to ensure management for wide-ranging species, such as C. falciformis, is most effective.

scholarly journals Availability of vulnerable elasmobranches in the marine water of Bangladesh

2013 ◽  
Vol 40 (2) ◽  
pp. 221-229 ◽  
Author(s):  
Roy Bikram Jit ◽  
Nripendra Kumar Singha ◽  
SM Hasan Ali ◽  
Md Gaziur Rhaman
Keyword(s):  
Marine Water ◽  
Shark Species ◽  
Total Catch ◽  
Percentage Contribution ◽  
Percentage Composition ◽  
Average Percentage ◽  
Silky Shark ◽  
Carcharhinus Falciformis

A study was conducted about vulnerable shark and ray species availability and their percentage composition in two fish landing centers at Fishery ghat, Chittagong and BFDC fish harbor, Cox’s Bazar district during April 2006 through March 2012. A total of 35 species (11 shark and 24 ray species) was identified within these six years. Out of 35 species, only one vulnerable shark species, the silky shark Carcharhinus falciformis (Muller and Henle, 1839), was not abundant all the year round and three were vulnerable ray species, Javanese cow ray Rhinoptera javanica (Muller and Henle, 1841), banded eagle ray Aetomylaeus nichofii (Bloch and Schneider, 1801) and white spotted shovelnose ray Rhynchobatus laevis (Bloch and Schneider 1801) were found throughout the year during the study period. The average percentage composition by weight of C. falciformis was 1.38 and the availability of average number was 3202. The average percentage contribution and the landed average number of vulnerable R. javanica, A. nichofii and R. laevis species were 1.46% (948 numbers), 0.61% (554 numbers) and 0.54% (298 numbers), respectively of the total catch. DOI: http://dx.doi.org/10.3329/bjz.v40i2.14316 Bangladesh J. Zool. 40(2): 221-229, 2012

scholarly journals CATCH COMPOSITION AND SOME BIOLOGICAL ASPECTS OF SHARKS IN WESTERN SUMATERA WATERS OF INDONESIA

2017 ◽  
Vol 22 (2) ◽  
pp. 99 ◽  
Author(s):  
Dharmadi Dharmadi ◽  
Mahiswara Mahiswara ◽  
Kamaluddin Kasim
Keyword(s):  
Size Composition ◽  
Tiger Shark ◽  
Scalloped Hammerhead ◽  
Ratio Size ◽  
Landing Sites ◽  
Target Fish ◽  
Silky Shark ◽  
Catch Composition ◽  
First Maturity ◽  
Banda Aceh

This study was conducted in western Sumatera and since October 2013 to June 2014. The sampling locations in Banda Aceh and Sibolga-North Sumatera which were the largest base of fisheries in western Sumatera region. Shark landing recorded by enumerators was used  as sampling data daily . This research aim to describ sex ratio, size composition, catch composition of sharks, and length at first maturity. In Banda Aceh, the sharks as target fish collected by  sorting the bycatch from tuna longlines and tuna handlines. In Sibolga, sharks  is bycatch from fish net, bottom gillnet and purse seine. Overall, there were 20 species of shark caught in west Indian Ocean and landed at those fish landing sites, dominated by Spot tail shark (23%) and Silky shark (13%), whereas Hammerhead shark contributed about 10% and  Oceanic whitetip shark was only less than 1%. Almost of Spot tail shark, Silky shark, and Scalloped hammerhead that caught in that area were  immature, while for the almost part of Tiger shark and Pelagic thresher were  matured. The sex ratios for Spot tail shark, Silky shark, Tiger shark, Pelagic thresher, and Scalloped hammerhead caught and landed at Lampulo and Sibolga fish landing sites were not balance. The length at first maturity for Spot tail shark was Lm=87,1 cm and Lm = 213,2 cm total length for Tiger shark. 

scholarly journals Monitoring of the status of eleven bony and cartilaginous fish populations in the Malpelo Sanctuary of Fauna and Flora, Colombian Pacific

2021 ◽  
Vol 50 (1) ◽  
pp. 105-120
Author(s):  
Felipe Ladino ◽  
Sandra Martínez ◽  
María Duarte ◽  
Natalia Vélez ◽  
Sandra Bessudo
Keyword(s):  
Management Plan ◽  
Cartilaginous Fish ◽  
Tropical Eastern Pacific ◽  
Sphyrna Lewini ◽  
Hammerhead Shark ◽  
Scalloped Hammerhead ◽  
The Status ◽  
Silky Shark ◽  
Spotted Eagle Ray ◽  
Over Time

To determine trends over time in the relative abundance of species prioritized in the Malpelo Fauna and Flroa Sanctuary Management Plan, underwater visual censuses were done from April 2009 to August 2019. Data were collected for five species of bonefish: bluefin trevally (Caranx melampygus), longfin yellowtail (Seriola rivoliana), yellowfin tuna (Thunnus albacares), leather bass (Dermatolepis dermatolepis) and sailfin grouper (Mycteroperca olfax), and six cartilaginous fish: spotted eagle ray (Aetobatus laticeps), silky shark (Carcharhinus falciformis), Galapagos shark (Carcharhinus galapagensis), whitetip reef shark (Triaenodon obesus), whale shark (Rhincodon typus) and scalloped hammerhead shark (Sphyrna lewini). A negative non-significant trend in abundance through time was observed for most of the evaluated species, except A. laticeps and T. obesus, which showed positive non-significant trends. The hammerhead shark (S. lewini) was the only species that showed a statistically significant decrease in abundance over time. The results of this study highlight the urgent need to establish more effective fisheries management and regulation measures that promote the conservation of important fish species, not just inside the sanctuary but also within the Tropical Eastern Pacific.

scholarly journals PARAMETER POPULASI HIU MARTIL (Sphyrna lewini Griffith & Smith, 1834) DI PERAIRAN SELATAN NUSA TENGGARA

2017 ◽  
Vol 22 (4) ◽  
pp. 253
Author(s):  
Agus Arifin Sentosa ◽  
Dharmadi Dharmadi ◽  
Didik Wahju Hendro Tjahjo
Keyword(s):  
Conservation Status ◽  
Landing Site ◽  
Fish Length ◽  
Population Parameters ◽  
Sphyrna Lewini ◽  
Hammerhead Shark ◽  
Scalloped Hammerhead ◽  
Main Target ◽  
Juvenile Sharks ◽  
Target Fishing

Hiu martil (Sphyrna lewini Griffith & Smith, 1834) merupakan salah satu target tangkapan bagi perikanan artisanal di Indonesia. Dengan status konservasi masuk dalam Appendix II CITES, pengelolaan terhadap hiu martil telah menjadi perhatian khusus di bidang perikanan tangkap. Penelitian ini bertujuan untuk mengkaji beberapa aspek parameter populasi hiu martil yang tertangkap di perairan selatan Nusa Tenggara pada periode Januari – Desember 2015. Data ukuran panjang dan jenis kelamin diperoleh di Tempat Pendaratan Ikan Tanjung Luar, Lombok Timur, Nusa Tenggara Barat. Analisis dilakukan secara deskriptif menggunakan perangkat lunak FiSAT II. Hasil penelitian menunjukkan bahwa dari 634 ekor hiu martil yang tertangkap didominasi oleh jenis kelamin betina dengan sebaran ukuran panjang total berkisar antara 81 – 320 cm (rerata 211,2 cm) dan jenis kelamin jantan berkisar antara 91 – 310 cm (rerata 176,9 cm). Dominasi kelompok hiu muda yang belum matang kelamin berpotensi terjadinya recruitment overfishing. Hiu martil mampu mencapai panjang asimtot 399 cm. Laju pertumbuhan dan mortalitas jenis hiu jantan lebih tinggi dibandingkan jenis betina. Populasi hiu martil telah mengalami kondisi tangkap lebih sehingga perlu adanya regulasi dan pengelolaan agar pemanfaatannya tetap lestari. The scalloped hammerhead sharks (Sphyrna lewini Griffith & Smith, 1834) is one of the main target fishing for artisanal shark fisheries in Indonesia. By the conservation status of Appendix II CITES, its management had been concerned in capture fisheries. This research aimed to assess some aspects of scalloped hammerhead shark population parameters caught in the southern of Nusa Tenggara in the period from January to December 2015. Fish length and sex was obtained in Tanjung Luar landing site, East Lombok, West Nusa Tenggara. The analysis was done descriptively used FiSAT II software. The results showed that 634 individuals of hammerhead shark caught dominated by female with a total length size distribution ranging between 81-320 cm (mean 211.2 cm) and male ranged between 91-310 cm (mean 176.9 cm). The dominance catch of juvenile sharks with immature was potential to recruitment overfishing. Sphyrna lewini was capable of reaching 399 cm asymptotic length. The growth rate and mortality of male sharks was higher than female. The population of S. lewini had been overfished so that the regulation and management are needed in order to maintain their sustainability of the population.

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