RAJA AMPAT, WISATA BAHARI TERBAIK DI DUNIA

Kamis, 31 Maret 2011
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Mancing Gembira: Giant TrevallyKabupaten Raja Ampat letaknya terpencil di Papua Barat. Kawasan ini menyimpan sejuta keindahan bawah laut. Wisata bahari Raja Ampat dikenal sebagai salah satu dari 10 wisata menyelam terbaik di dunia.

Pesona dan kekayaan alam bawah laut, menjadi andalan Kabupaten Raja Ampat menembus persaingan dunia pariwisata di Indonesia dan dunia. Kawasan ini dikenal sebagai pusat sumber daya alam tropis terkaya di dunia.

"Kita ingin memperkenalkan Raja Ampat ke dunia. Wisata bahari Raja Ampat mempunyai potensi dan peluang menjadi yang utama dalam pentas dunia," kata Bupati Raja Ampat Marcus Wanma saat pembukaan Pusat Informasi Wisata Raja Ampat di Jl By Pass Sanur, Denpasar, Kamis (15/4/2010).

Untuk memperkenalkannya ke dunia, Raja Ampat membuka pusat informasi di Bali. Alasannya, Bali sebagai destinasi utama kunjungan wisatawan asing ke Indonesia.

"Melalui Bali kita memperkenalkan dan mengundang investor dunia ke Raja Ampat," kata Marcus.Mancing Gembira: Diving Soft Coral Raja Ampat

Raja Ampat adalah kabupaten baru di Indonesia. Wilayah yang terletak terpencil di Papua Barat ini baru berusia tujuh tahun. Bahkan, infrastrukturnya belum memadai. Untuk mencapai Raja Ampat, wisatawan harus terbang ke Sorong kemudian menyusuri laut sejauh 71 km untuk tiba di Raja Ampat.

Meskipun masih berusia dini, Raja Ampat mampu menyedot wisatawan mancanegara sebanyak 5 ribu orang per tahun pada 2009. Targetnya, kunjungan wisatawan mancanegara mencapai 6 ribu di tahun 2010. (gds/djo)
Sumber: detik.com, Edited By MG
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KAIL NENEK MOYANG KITA DAHULU

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Mancing adalah aktivitas kuno yang sudah berjalan sejak jaman Paleolithic yang berawal kira-kira 40.000 tahun lalu. Dengan memancing mereka bisa memenuhi kebutuhan pangan mereka yang nantinya berguna untuk kelangsungan hibup mereka. Perkembangan teknologi membawa perkembangan teknik mancing dan peralatan pancing yang digunakan saat ini. Kita mungkin sering bertanya-tanya bagaimanakah cara nenek moyang kita jaman dahulu memancing? Kail seperti apakah yang dulu digunakan sebelum jaman logam?

Kali ini mancing gembira mencoba menggambarkan kail yang digunakan nenek moyang kita dahulu sebelum mereka menggunakan logam sebagai kail. Berikut ini beberapa contoh kail yang mereka buat, diantaranya yang terbuat dari tulang, tanduk, duri tanaman, kayu dan lain2. Bisa kita bayangkan, dengan kail sederhana seperti ini nenek moyang kita dapat menangkap ikan untuk konsumsi mereka.

Kail dari tulang:
Kail dari duri tanaman:
Kail besar dari kayu/tulang:

Seiring dengan perkembangan teknologi, ditemukan metode pemanfaatan logam, maka kail jaman sekarang terbuat dari logam, tidak menggunakan tulang, kayu, duri, tanduk dll. Walau demikian teknologi kuno nenek moyang kita ini masih bisa digunakan untuk survival.
Kail jaman sekarang:
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TENTANG IUU FISHING

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Mancing Gembira: IUU FishingSelama ini kita sering mendengar kata-kata IUU Fishing. Sebenarnya apa yang dimaksud dari IUU Fishing itu? Mancing Gembira mengutip penjelasan tentang IUU fishing dari http://www.stopiuufishing.com sebagai berikut:


DEFINISI IUU
Penangkapan Ikan yang dilakukan secara ilegal, tidak dilaporkan atau yang belum dan tidak diatur (Illegal, Unreported, Unregulated Fishing) di Wilayah Pengelolaan Perikanan Republik Indonesia.

Illegal :
Kegiatan penangkapan ikan yang dilakukan oleh orang atau kapal perikanan berbendera asing atau berbendera Indonesia di WPP-RI tanpa izin atau bertentangan dengan peraturan perundang-undangan yang berlaku.

Unreported :
Kegiatan penangkapan ikan yang tidak pernah dilaporkan atau dilaporkan secara tidak benar kepada instansi yang berwenang, tidak sesuai dengan peraturan perundang-undangan nasional.

Unregulated :
Kegiatan penangkapan ikan pada suatu area penangkapan atau stok ikan di WPP-RI:
  1. Yang belum diterapkan ketentuan pelestarian dan pengelolaan,
  2. Dilaksanakan dengan cara yang tidak sesuai dengan tanggung-jawab negara untuk pelestarian dan pengelolaan sumberdaya ikan sesuai hukum internasional.

Kerugian akibat illegal fishing :
  1. Subsidi BBM dinikmati oleh kapal-kapal yang tidak berhak;
  2. Pengurangan Penerimaan Negara Bukan Pajak (PNBP);
  3. Peluang kerja nelayan Indonesia (lokal) berkurang, karena kapal-kapal illegal adalah kapal-kapal asing yang menggunakan ABK asing;
  4. Hasil tangkapan umumnya dibawa langsung ke luar negeri (negara asal kapal), sehingga mengakibatkan: (a) hilangnya sebagian devisa negara dan (b) berkurangnya peluang nilai tambah dari industri pengolahan;
  5. Ancaman terhadap kelestarian sumberdaya ikan karena hasil tangkapan tidak terdeteksi, baik jenis, ukuran maupun jumlahnya;
  6. Merusak citra Indonesia pada kancah International karena IUU fishing yang dilakukan oleh kapal asing berbendera Indonesia maupun kapal milik warga negara Indonesia. Hal ini juga dapat berdampak ancaman embargo terhadap hasil perikanan Indonesia yang dipasarkan di luar negeri.

PELUNCURAN PORTAL "STOP IUU FISHING"

Mancing Gembira: Freddy NumberiManado (ANTARA News) - Menteri Kelautan dan Perikanan Freddy Numberi meluncurkan portal "Stop Illegal, Unreported, Unregulated (IUU) Fishing" pada rangkaian Sail Bunaken 2009.

Peluncuran website yang bertujuan untuk melawan praktik pencurian ikan tersebut dilakukan bersamaan dengan pembukaan seminar internasional tentang "Intersifying Action to Minimize Illegal Fishing" di Manado, Minggu.

Dirjen Pengawasan dan Pengendalian Pengendalian Sumber Daya Kelautan, Aji Sularso sebagai pemilik ide mengatakan bahwa pembuatan website tersebut bertujuan meningkatkan kepedulian dan merangkul lebih luas masyarakat untuk memerangi IUU Fishing secara global.

Sementara Chief Operating Officer PT One System Solution, Rizka A Putranto, sebagai pembuat website mengatakan bahwa sejauh ini belum ada pengerahan melawan "IUU Fishing" melalui dunia maya.

"Ini menjadi embrio untuk memerangi pencurian ikan melalui dunia maya dalam jangka panjang," ujar dia.

Paling tidak, ia mengatakan bahwa dapat berbagi informasi tentang keadaan kelautan dan perikanan Indonesia di dunia. Sehingga diharapkan lambat-laun portal yang sekaligus merupakan program kampanye ini dapat menjaring masukan dari seluruh dunia untuk memerangi pencurian ikan.

Dalam portal www.stopiuufishing.com memberikan fasilitas forum diskusi untuk menjaring pendapat dan masukan dalam memerangi praktik pencurian ikan.

"Topik utama kita memang `IUU Fishing` walaupun pada awalnya akan bersifat luas pada kelautan dan perikanan," tambah Rizka.

Organisasi Pangan dan Pertanian Dunia (FAO) mengasumsikan bahwa 25 persen hasil perikanan dunia berasal dari praktik penangkapan ikan secara ilegal. Kondisi tersebut terus meningkat dalam hal jumlah dan area, sehingga menjadi masalah utama ekonomi, baik internasional maupun di kawasan Asia Tenggara.

Dikutip dari ANTARA
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MEGABASS XPOD

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Kali ini Mancing Gembira akan membahas sedikit mengenai lure top-water yang cukup unik yang diproduksi oleh Megabass, produsen alat pancing dari Jepang. Lure ini diberi nama Megabass Xpod oleh Yuki Ito, designernya. Keunikan lure ini berada pada rahang bawahnya yang dapat diatur posisinya sehingga berfungsi seperti lip ketika diklik ke bawah.

Disain Xpod
Dengan berbagai posisi berbeda, lure ini menghasilkan action yang berbeda pula sehingga cocok bagi pemancing untuk memancing pada berbagai kondisi dan situasi. Bayangkan saja mempunya 1 lure dengan 6 action + 1 secret action untuk berbagai kondisi. Berikut ini action yang bisa dihasilkan oleh lure ini:
  1. Posisi 1: Pencil Bait (roll walker mode)
  2. Posisi 2: Pencil Popper
  3. Posisi 3: Active Popper
  4. Posisi 4: Diving Popper / Splash Mode
  5. Posisi 5: Sama dengan posisi #4 tapi dive lebih dalam dan lebih banyak cipratan
  6. Posisi 6: Darting Swimbait Mode
  7. Secret Position: More Active Swimbait Mode & Pivot/Turn walking action
Megabass Xpod - Wagin Ayu
Selain inovasi pada rahang atau lip, lure buatan Megabass ini didisain sangat mirip ikan. Dilihat dari corak sisik, pewarnaan dan detailnya, lure ini bisa dikatakan didisain dengan sentuhan seni dan teknologi yang tinggi. Seperti pada lure top water lainnya, rongga dalam tubuh lure ini diisi beberapa bola besi kecil yang tujuannya menghasilkan bunyi ketika bergerak yang akan menggoda rasa penasaran ikan-ikan predator. Dua terble hook yang digunakan juga merupakan treble hook dengan kualitas dan ketajaman tinggi. Pada mata Xpod terdapat tulisan kanji yang sangat kecil namun masih bisa terbaca.

Pilihan Warna, Ukuran, & Harga Xpod
Saat ini dipasaran ada 11 pilihan warna bagi pemancing yang ingin mencoba atau mengkoleksi lure Megabass X-pod ini, antara lain: GW Dorado, GW Fire, GW Stardust Shad OB, HT Hakone Wakasagi, Matte Tiger, PM bass, Wagin Ayu, Wagin Hasu, Wagin Higai, Wagin Oikawa, serta Wagin Ugui. Sayangnya produsennya hanya memproduksi lure ini satu ukuran saja, yaitu 4.55" dengan berat 3/4 oz. Harga retail sekitar $29.99 di Amerika.

Kesimpulan
Lure ini merupakan inovasi teknologi dan seni yang mampu menghasilkan bentuk yang nyaris sama dengan ikan hidup dan mampu menghasilkan 6 action berbeda + 1 secret ation untuk berbagai situasi mancing. Harga yang lumayan tinggi pada dasarnya jika dilihat dari action yang kita dapat masih tergolong murah dibanding membeli 6 atau 7 lure untuk tiap action.
Sayangnya ukuran yang ditawarkan hanya satu saja. Untuk mendapatkan lure ini didalam negeri terbilang cukup sulit. Penulis kebetulan berkesempatan membeli lure ini dari seorang teman yang mengimport langsung dari Jepang dan dijual terbatas.
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FLY FISHING

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Fly fishing merupakan teknik mancing yang cukup kuno, umumnya dikenal sebagai teknik mancing ikan trout dan salmon, tetapi saat ini digunakan untuk memancing berbagai jenis ikan seperti hampala, toman, bass, pacu, dan lain-lain.

Dalam fly fishing, ikan pancing dengan menggunakan fly atau umpan buatan yang menyerupai serangga atau ikan kecil yang dicast (dilempar) dengan menggunakan fly rod dan fly line. Fly line cukup berat untuk membuat fly atau serangga buatan melayang dan jatuh di dekat ikan target. Inilah yang membedakannya dengan teknik cast yang lain, karena pemberatnya ada pada line bukan pada umpan atau timah pemberat.

Fly atau serangga buatan yang digunakan dalam fly fishing sangan bervariasi dalam bentuk, ukuran, berat, warna, dll. Fly atau serangga buatan, dibuat dengan cara tying atau mengikat bulu, rambut hewan, serta bahan lainnya baik sintetis maupun alami pada hook atau kail dengan benang. Awalnya pembuatan fly menggunakan bahan-bahan alami, tetapi seiring dengan perkembangan teknologi dan kesulitan memperoleh bahan-bahan alami, bahan-bahan sintetis mulai populer. Fly biasanya dibuat berdasarkan ukuran, warna, corak yang sesuai dengan kondisi setempat dan serangga air, ikan umpan atau mangsa yang menarik bagi species ikan yang menjadi target.
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FLY LINE

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Dalam fly fishing, fly line adalah komponen yang sangat penting dalam melontarkan fly kearah ikan. Fly line juga merupakan penentu apakah ikan memakan fly atau tidak, apakah ikan berhasil diangkat atau tidak. Dari line yang digunakan, kita bisa menentukan apakah seseorang mancing menggunakan teknik fly fishing atau teknik lain. Dalam fly fishing, line yang digunakan menghasilkan berat pada rod yang menghasilkan energi kinetis untuk melontarkan fly ke target.
Fly line terdiri dari beberapa ukuran, jenis (float atau sinking), dan tapper. Tiap fly line terdiri dari core (inti) dan coating (pelapis). Modifikasi keduanya memungkinkan fly line didisain secara khusus untuk performance karakteristik - castability, shootability, dan durability - yang dibutuhkan untuk berbagai situasi.

CORE
Core atau bagian inti dari fly line menentukan rentang kekuatan (strength), tingkat kelenturan (stretches), dan tingkat kekakuan (stiff).
Strength - inti pada line dibuat lebih kuat dari pada tippet yang biasa digunakan sebagai leader pada fly line.
Stretch - sangat penting bagi sebuah fly line memiliki stretch yang cukup. Jika kurang stretch line akan memiliki masalah memori, sementara jika terlalu stretch fly line akan lembek dan sulit dikendalikan.
Stiffness - fly line yang didisain untuk mancing didaerah tropis harus tahan panas yang extrim dan mampu mempertahankan tingkat kekakuan yang cukup, sementara line yang didisain untuk iklim dingin harus mampu mempertahankan kekakuan yang cukup sehingga tidak mengalami masalah memori jika terlalu kaku.

COATING
Hal yang paling mendasar dan penting dari coating pada line ialah merupakan pemberat dan memberi daya bagi rod. Kepadatan dari coating menentukan apakah fly line tersebut sinking atau floating. Pada floating line terdapat gelembung udara mikro yang dicampurkan pada coating pada kepadatan tertentu yang membuat line mengapung. Sementara sinking line terdiri dari material coating dengan kepadatan tinggi sehingga bisa tenggelam dengan kecepatan dan kedalaman yang diinginkan.
Selain itu coating pada fly line mengandung pigmen atau pewarna yang bisa dilihat pemancing dan ikan.

TAPER
Bentuk fly line atau taper menentukan bagaimana energi disalurkan pada saat casting. Dengan memvariasikan diameter dan panjang dari bagian-bagian line, performa tertentu yang diinginkan dapat dihasilkan. Bagian-bagian dari taper:
  1. Tip - ujung tali paling depan (panjangnya 6 - 12 inci) tempat mengikat leader. Bagian ini tugasnya melindungi taper karena biasanya para pemancing sering berganti-ganti leader dengan cara memotongnya.
  2. Front Taper - bagian ini menentukan seberapa kuat fly dilontarkan. Biasanya front taper panjangnya 4 ft hingga 8 ft, dari bagian belly hingga tip, terlihat diameternya mengecil.
  3. Belly - bagian ini merupakan bagian dengan diameter terlebar dan panjangnya paling panjang, dimana casting energi terletak.
  4. Rear Taper - bagian ini bentuknya, kebalikan dari front taper, gunanya untuk memperlancar casting.
  5. Head - istilah ini untuk menjelaskan kombinasi front taper, belly dan rear taper.
  6. Running Line - bagian ini untuk mempermudah jarak lempar.

JENIS-JENIS TAPER
Level (L) - didisain tanpa taper sama sekali, line ini bisa digunakan dalam berbagai situasi tetapi memiliki kinerja yang rendah. Energi ditransfer tidak secara konsisten dan sangat sulit mengendalikannya saat casting.
Weight Forward (WF) - didisain untuk memungkinkan pemancing untuk melakukan casting jarak dekat maupun jarak jauh (20 - 80 ft) dengan ukuran fly yang normal.
Double Taper (DT) - sebuah line yang memiliki bentuk ujung yang sama dan keduanya berfungsi sama sehingga pemancing bisa menggunakannya bergantian.
Shooting Taper - biasanya disebut shooting head yaitu fly line yang terdiri dari 2 line terpisah yang digabungkan dengan sebuah loop.
Triangle Taper - dirancang oleh Lee Wulff. Banyak pemancing percaya bahwa disain ini memberikan transfer energi casting yang paling effisien dalam berbagai jarak.
Teeny Taper - sebuah line tipe weight forward yang radikal yang diperkenalkan oleh Jim Teeny. bentuknya hampir sama dengan shooting head tetapi tanpa front taper diharapkan bisa meluncur dan tenggelam dengan cepat pada bagian headnya.
STANDAR UKURAN FLY LINE
AFTMA (the former American Fishing Tackle Manufacturers Association- now the ASA- American Sportfishing Association) menetapkan standar untuk ukuran fly line sebagai berikut:

Selain ukuran, fly line juga dibedakan jenisnya:
  1. Floating Line - mengambang karena kepadatannya lebih kecil dari pada air dan mengandung gelembung udara kecil. Tiga tipe dasar dari line jenis ini adalah: level, double taper, dan weight forward.
  2. Sinking Line - line ini memiliki bagian belly yang tenggelam lebih cepat dari pada bagian yang lebih tipis. Sinking line jenisnya ada yang weight forward dan shooting head.
  3. Sinking Tip - jenis line ini terdiri dari floating line dengan tip (ujung) yang bisa tenggelam. Biasanya panjang tip ini 5 - 30 ft.
Source: http://www.flyfishusa.com; Fly Fishing - The Lifetime Sport (David & Cheryl Young); dan sumber lain
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FLY TACKLE - ROD & REEL

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Mancing Gembira kali ini membahas mengenai tackle yang digunakan untuk mancing dengan teknik fly fishing. Dalam fly fishing, tackle utama yang digunakan terdiri dari fly rod, reel khusus fly fishing, line khusus fly fishing serta mata kail yang sudah di tying biasanya disebut fly.
FLY ROD
Fly rod didisain untuk memancing dengan melontarkan fly dengan cara memanfaatkan momentum dari fly line dan mengendalikan arah dan jarak. Suatu fly rod yang baik akan cocok dengan line tertentu. Menurut www.fly-fishing-colorado.com, faktor2 yang perlu diperhatikan dalam memilih fly rod antara lain:
  1. Budget - sesuaikan fly rod dengan budget anda (walaupun banyak orang bilang harga tidak pernah berbohong). Bagi pemula sebaiknya membeli rod combo untuk mengurangi biaya.
  2. Garansi - biasanya beberapa manufaktur fly rod memberikan lifetime garansi.
  3. Fish Species - Jenis ikan apa yang akan anda pancing? Dimana anda akan gunakan (di laut, sungai berarus, atau danau)?
  4. Fishing Distance - Berapa jarak pancing normal anda? Umumnya ikan biasanya bisa dipancing dalam jarak 20ft dari tempat kita berdiri. Pilihlah rod yang bisa melakukan overhead cast secara nyaman hingga 45ft. Ini akan memenuhi kebutuhan memancing secara umum.
  5. Gender - pemilihan fly rod bagi pria berbeda dengan wanita. Karena pria memiliki bagian tubuh atas lebih kuat dari pada wanita, maka fly rod bagi pria lebih panjang dari wanita. Panjang rod untuk pria biasanya 9ft sedangkan untuk wanita biasanya 8ft hingga 8.5ft.
  6. Casting Ability - dalam hal ini dibedakan antara seorang pemancing pemula, intermediate dan advanced. Kemampuan ini yang akan menentukan pemilihan flexibilitas rod atau action. Rod dengan medium action biasanya cocok untuk pemancing pemula, intermediate hingga advanced. Sementara fast action cocok untuk pemancing tingkat advanced.
  7. Fly Lines - pemilihan fly rod juga harus disesuaian dengan ukuran dan jenis fly line yang kita pakai.


FLY REEL
Dalam teknik mancing fly fishing reel yang digunakan melekat pada ujung bawah fly rod yang digunakan. Fly reel digunakan untuk memuat backing line serta fly line dan kadang digunakan untuk mengendalikan ikan. Jika kita sering memancing dengan teknik lain, melihat fly reel sepertinya terlalu sederhana. reel fly terlihat banyak lobang disisinya, ini gunanya untuk mengurangi berat dan juga untuk mengeringkan air yang menempel pada fly line. Fly reel biasanya digunakan untuk freshwater tapi ada juga yang dibuat untuk saltwater, hal ini dibedakan dari material yang digunakan. Drag sistem yang digunakan dari yang sederhana (click and pawl system) hingga yang bisa diatur dragnya. Fly reel juga dibuat dalam beberapa ukuran yang disesuaikan dengan ukuran fly line dan rod.
Saran dalam memilih fly reel, sebaiknya sebelum membeli dicoba dahulu. Sedapat mungkin membeli fly reel bersamaan dengan membeli fly rod agar kita bisa tahu balanced rig nya. Jangan sampai reel yang kita beli terlalu besar dan terlalu berat bagi rod kita sehingga kehilangan keseimbangan yang menyebabkan mengurangi kenyamanan.
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GOLD'N CRANK LURE JENIS MAS KOKI

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Mancing Gembira: Gold n CrankSalam Strike... Ikan Mas Koki merupakan santapan yang lezat bagi ikan predator air tawar. Mancing Gembira tertarik pada Gold'n Crank 40, lure buatan River2Sea yang bentuknya dan actionnya mirip sekali dengan ikan Mas Koki. Pada beberapa sungai di Amerika penggunaan umpan Mas Koki hidup untuk mancing dianggap ilegal, padahal ikan Mas Koki merupakan umpan yang paling digemari ikan-ikan predator didanau tersebut. Hal ini yang mengilhami River2Sea untuk menciptakan lure yang menyerupai ikan Mas Koki ini.

Design
Lure ini diberi nama Gold'n Crank oleh produsennya, diciptakan hanya dalam ukuran 1 3/4 Inci dengan berat 1/8 oz. Lure jenis slow sinking ini dilengkapi dengan Daiichi (BN) Treble #8. Lure ini memiliki Lip yang akan membuat tubuhnya bergoyang-goyang saat diretrive. Terdapat Joint diantara tubuh dan ekornya yang membuat gerakannya sangat identik dengan ikan Mas Koki yang sedang berenang jika diretrive.

Pilihan Warna dan Harga
Pilihan warna yang tersedia untuk lure ini ada 8 pilihan yaitu: Red White, Orange, Black Gold, Light Blue, Black White, Orange Black, Gold Brown dan Red Head. Harga retail untuk lure ini berkisar $8.99.
Mancing Gembira: Pilihan Warna
Kesimpulan:
Lure ini menghadirkan warna yang menggoda serta action yang sangat mirip dengan ikan Mas Koki. Harga lure ini cukup sesuai dengan harga lure sejenis dipasaran.
Mancing Gembira
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ENGLISH EDITION!!!! Giant trevally

Senin, 28 Maret 2011
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Giant trevally
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Perciformes
Suborder: Percoidei
Superfamily: Percoidea
Family: Carangidae
Genus: Caranx
Species: C. ignobilis
Binomial name
Caranx ignobilis
(Forsskål, 1775)
Approximate range of the giant trevally
Synonyms
  • Scomber ignobilis
    Forsskål, 1775
  • Caranx lessonii
    Lesson, 1831
  • Caranx ekala
    Cuvier, 1833
  • Carangus hippoides
    Jenkins, 1903
The giant trevally, Caranx ignobilis (also known as the giant kingfish, lowly trevally, barrier trevally, ulua, or GT), is a species of large marine fish classified in the jack family, Carangidae. The giant trevally is distributed throughout the tropical waters of the Indo-Pacific region, with a range stretching from South Africa in the west to Hawaii in the east, including Japan in the north and Australia in the south. The giant trevally is distinguished by its steep head profile, strong tail scutes and a variety of other more detailed anatomical features. It is normally a silvery colour with occasional dark spots, however males may be black once they mature. It is the largest fish in the genus Caranx, growing to a maximum known size of 170 cm and a weight of 80 kg. The giant trevally inhabits a wide range of marine environments, from estuaries, shallow bays and lagoons as a juvenile to deeper reefs, offshore atolls and large embayments as an adult. Juveniles of the species are known to live in waters of very low salinity such as coastal lakes and upper reaches of rivers, and tend to prefer turbid waters.
The giant trevally is a powerful apex predator in most of its habitats, and is known to hunt individually and in schools. The species predominantly takes various fish as prey, although crustaceans, cephalopods and molluscs make up a considerable part of the diet in some regions. The species has some quite novel hunting strategies including following monk seals and stealing prey that is stirred up, as well as using sharks to ambush prey. The species reproduces in the warmer months, with peaks differing by region. Spawning occurs at specific stages of the lunar cycle, when large schools of giant trevally congregate to spawn over reefs and bays, with reproductive behaviour observed in the wild. The fish grows relatively fast, reaching sexual maturity at a length of around 60 cm at 3 years of age. The giant trevally is both an important species to commercial fisheries and a recognised gamefish, with the species taken by nets and lines by professionals and by bait and lures by anglers. Catch statistics in the Asian region show hauls of 4000-10 000 tonnes, while around 10 000 lbs of the species is taken in Hawaii each year. The species is considered poor to excellent table fare by different authors, although ciguatera poisoning is common in the fish. Dwindling numbers around the main Hawaiian Islands have also led to several proposals to reduce the catch of fish in this region.

Taxonomy and phylogeny

The giant trevally is classified within the genus Caranx, one of a number of groups known as the jacks or trevallies. Caranx itself is part of the larger jack and horse mackerel family Carangidae, a group of percoid fishes in the order Perciformes.
The giant trevally was first scientifically described by the Swedish naturalist Peter Forsskål in 1775 based on specimens taken from the Red Sea off both Yemen and Saudi Arabia, with one of these designated to be the holotype. He named the species Scomber ignobilis, with the specific epithet Latin for "unknown", "obscure" or "ignoble". It was assigned to the mackerel genus Scomber, where many carangids were placed before they were classified as a separate family. This later revision in classification saw the species moved to the genus Caranx, where it has remained. Even after its initial description, the giant trevally (and the bigeye trevally) were often confused with the Atlantic crevalle jack, Caranx hippos, due to their superficial similarity, which led to some authors claiming the crevalle jack had a circumtropical distribution.After Forsskål's initial description and naming, the species was independently renamed three times as Caranx lessonii, Caranx ekala and Carangus hippoides, all of which are now considered invalid junior synonyms. The latter of these names once again highlighted the similarity with the crevalle jack, with the epithet hippoides essentially meaning 'like Carangus hippos',which was the crevalle jack's Latin name at that point in time. Despite the resemblance with the crevalle jack, the two species have never been phylogenetically compared, either morphologically or genetically, to determine their relationship.
Caranx ignobilis is most commonly referred to as the 'giant trevally' (or 'giant kingfish') due to its large maximum size, with this often abbreviated to simply 'GT' by many anglers.Other names occasionally used include 'lowly trevally', 'barrier trevally', 'yellowfin jack' (not to be confused with Hemicaranx leucurus), Forsskål's Indo-Pacific jack fish and Goyan fish. In Hawaii, the species is almost exclusively referred to as 'ulua', often in conjunction with the prefixes 'black', 'white', or 'giant'. Due to its wide distribution there are many other names for the species in different languages also.

 Description


Profile of an adult giant trevally
The giant trevally is the largest member of the genus Caranx, and the fifth largest member of the family Carangidae (exceeded by the yellowtail amberjack, greater amberjack, leerfish and rainbow runner), with a recorded maximum length of 170 cm and a weight of 80 kg. Specimens this size are very rare, with the species only occasionally seen at lengths greater than 80 cm. It appears the Hawaiian Islands contain the largest individuals, where indivduals over 100 lbs are common. Elsewhere in the world, only three individuals over 100 lbs have been reported to the IGFA.
The giant trevally is similar in shape to a number of other large jacks and trevallies, having an ovate, moderately compressed body with the dorsal profile more convex than the ventral profile, particularly anteriorly. The dorsal fin is in two parts, the first consisting of 8 spines and the second of 1 spine followed by 18 to 21 soft rays. The anal fin consists of 2 anteriorly detached spines followed by 1 spine and 15 to 17 soft rays. The pelvic fins contain 1 spine and 19 to 21 soft rays. The caudal fin is strongly forked, and the pectoral fins are falcate, being longer than the length of the head. The lateral line has a pronounced and moderately long anterior arch, with the curved section intersecting the straight section below the lobe of the second dorsal fin. The curved section of the lateral line contains 58-64 scales while the straight section contains 0 to 4 scales and 26 to 38 very strong scutes. The chest is devoid of scales with the exception of a small patch of scales in front of the pelvic fins. The upper jaw contains a series of strong outer canines with an inner band of smaller teeth, while the lower jaw contains a single row of conical teeth. The species has 20 to 24 gill rakers in total and there are 24 vertebrae present. The eye is covered by a moderately well developed adipose eyelid, and the posterior extremity of the jaw is vertically under or just past the posterior margin of the pupil. The eye of the giant trevally has a horizontal 'streak' in which ganglion and photoreceptor cell densities are markedly greater than the rest of the eye. It is believed this allows the fish to gain a panoramic view of its surroundings, removing the need to constantly move the eye. This in turn will allow easier of detection of prey or predator in that field of view.
At sizes less than 50 cm, the giant trevally is a silvery-grey fish, with the head and upper body slightly darker in both sexes. Fish greater than 50 cm show sexual dimorphism in their colouration, with males having a dusky to jet black body, while females are a much lighter coloured silvery grey. Individuals with a darker dorsal colouration often also display striking silvery striations and markings on the upper part of their body, particularly their back. Black dots of a few millimetres in diameter may also be found scattered all over the body, although the coverage of these dots varies between widespread to none at all. All the fins are generally light grey to black, although fish taken from turbid waters often have yellowish fins, with the anal fin being the brightest. The leading edge and tips of the anal and dorsal fins are generally lighter in colour than the main fin. There is no black spot on the operculum. Traces of broad cross-bands on the fish's sides are occasionally seen after death.

 Distribution


A mature male giant trevally showing the black colouration common in these older fish
The giant trevally is widely distributed throughout the tropical and subtropical waters of the Indian and Pacific Oceans, ranging along the coasts of three continents and many hundreds of smaller islands and archipelagos. In the Indian Ocean, the species easternmost range is the coast of continental Africa, being distributed from the southern tip of South Africa north along the east African coastline to the Red Sea and Persian Gulf. The giant trevally's range extends eastwards along the Asian coastline including Pakistan, India and into South East Asia, the Indonesian Archipelago and northern Australia.The southernmost record from the west coast of Australia comes from Rottnest Island,not far offshore from the capital city of Perth. Elsewhere in the Indian Ocean, the species has been recorded from hundreds of small island groups including the Maldives, Seychelles, Madagascar and the Cocos (Keeling) Islands.
The giant trevally is abundant in the central Indo-Pacific region, found throughout all the archipelagos and offshore islands including Indonesia, Philippines and Solomon Islands. Along continental Asia, the species has been recorded from Malaysia to Vietnam, but not China. Despite this, its offshore range does extend north to Hong Kong, Taiwan and southern Japan. In the south, the species reaches as far south as New South Wales in Australia and even to the northern tip of New Zealand in the southern Pacific. Its distribution continues throughout the western Pacific including Tonga, Western Samoa and Polynesia, with its westernmost limits known to be the Pitcairn and Hawaiian Islands.

Habitat


A giant trevally patrolling a reef in Hawaii
The giant trevally inhabits a very wide range of offshore and inshore marine environments, with the species also known to tolerate the low salinity waters of estuaries and rivers. It is a semi-pelagic fish known to spend time throughout the water column, but is mostly demersal in nature.The species is most common in shallow coastal waters in a number of environments including coral and rocky reefs and shorefaces, lagoons, embayments, tidal flats and channels. They commonly move between reef patches, often over large expanses of deeper sand and mud bottoms between the reefs.Older individuals tend to move to deeper seaward reefs, bomboras and drop-offs away from the protection of fringing reefs, often to depths greater than 80 m. Large individuals however do often return to these shallower waters as they patrol their range, often to hunt or reproduce. In Hawaii, the juvenile to subadult giant trevally are the most common large carangids in the protected inshore waters, with all other species apparently preferring the outer, less protected reefs. It is also easily attracted to artificial reefs, where studies have found it to be one of the predominant species around these structures in Taiwan.
Juvenile to sub-adult giant trevally are known to enter and inhabit estuaries, the upper reaches of rivers and coastal lakes in several locations including South Africa, Solomon Islands, Philippines, India,Taiwan, Thailand, northern Australia and Hawaii.In some of these locations, such as Australia, it is a common and relatively abundant inhabitant, while in others including South Africa and Hawaii, it is much rarer in estuaries. The species has a wide salinity tolerance, as evident from the ranges juvenile and subadult fish in South African estuaries have been recorded from; 0.5 to 38 ‰, with other studies also showing tolerance levels of less than 1 ‰. In these estuaries, the giant trevally is known from both highly turbid, dirty water to clean, high visibility waters, however in most cases the species prefers the turbid waters. It appears younger fish actively seek out these turbid waters, and when no estuaries are present they live in the turbid inshore waters of bays and beaches. These young fish eventually move to inshore reefs as they mature, before again moving to deeper outer reefs. In the Philippines, a population of giant trevally inhabit (and were once common in) the landlocked fresh waters of Taal lake, and are referred to as "maliputo" to distinguish them from the marine variant, (locally named "talakitok"). Along with Taal volcano and Taal lake, the land locked maliputo is prominently featured on the reverse side of the newly redesigned Philippine 50 Peso bill.

Biology and ecology

The giant trevally is a solitary fish once it reaches sexual maturity, only schooling for the purposes of reproduction and more rarely for feeding Juveniles and sub-adults commonly school, both in marine and estuarine environments. Observations from South African estuaries indicate the schools of smaller juveniles tend not to intermingle with schools of other species, however larger sub-adults are known to form mixed species schools with the brassy trevally. As well as the movement between habitats as the species grows, there has also been research conducted on the movements of larger fish around their habitats to understand how marine reserves impact on the species. Adult giant trevally are known to range back and forth up to 9 km along a home range, with some evidence of diel and seasonal shifts in habitat use. In the Hawaiian Islands it has been shown giant trevally do not normally move between atolls, but have specific core areas they spent most their time. Within these core areas, habitat shifts during different times of the day have been recorded, with the fish being most active at dawn and dusk, and usually shifting location near sunrise or sunset. Furthermore, large seasonal migrations appear to occur for the purpose of aggregating for spawning, with this also known from the Solomon Islands. Despite not moving between atolls, they do make periodic atoll-wide journeys of up to 29 km. Long term studies show that juveniles can move up to 70 km away from their protected habitats to outer reefs and atolls. The giant trevally is one of the most important apex predators in its habitats, both as adults on reefs and as juveniles in estuaries. Observations in relatively untouched waters of the Northwestern Hawaiian Islands showed the giant trevally was of high ecological importance, constituting 71% of the apex predator biomass, and was the dominant apex predator. This number is considerably less in heavily fishes Hawaiian waters. At smaller sizes, the species is prey to sharks, and large individuals have been recorded as a host of the sharksucker, Echeneis naucrates, a fish which is normally seen attached to the underside of sharks.

 Diet and feeding


Frontal view of a giant trevally illustrating the compressed form of the species
The giant trevally is a powerful predatory fish, and is an apex predator in most environments; from the estuaries it inhabits as a juvenile to the outer reefs and atolls it patrols as an adult. Hunting appears to occur at different times of the day in different areas of its range; off South Africa it is most active during the day, especially at dawn and dusk, while off Zanzibar and Hong Kong it is said to be nocturnal in its habits.The species diet has been determined in several countries and habitats, with this research finding the diet generally varies slightly between locations and age. In all but one study (which was of juveniles), the giant trevally dominantly takes other fishes, with various crustaceans, cephalopods and occasionally molluscs making the remainder of the diet. In Hawaii the species has a predominantly fish based diet consisting of Scaridae and Labridae, with crustaceans, including lobsters, and cephalopods (squid and octopus) making up the remaining portion of the diet. The large number of reef fishes suggests that it spends much of its time foraging over shallow-water reef habitats, but the presence of squid and the schooling carangid Decapterus macarellus indicates exploitation of more open-water habitats as well. Off Africa the diet is similar, consisting mostly of fish including eels, with minor squid, octopus, mantis shrimps, lobsters and other crustaceans. Younger fish inside Kaneohe Bay, Hawaii showed the only instance when crustaceans were preferred over fish; stomatopods, shrimps and crabs were the most common prey taken at 89% of stomach content by volume, with fish, mostly of the family Blennidae, making up only 7% of the stomach contents. Estuarine fish in both Hawaii and Australia have mostly fish-based diets, with crustaceans such as prawns and amphipods also of importance, and are known to take more novel prey such as spiders and insects in these habitats. There have also been reports of juvenile turtles and dolphins being found within the stomach contents of larger giant trevally. Studies of different size classes of fish have found the diet does change with age in some locations, with the changes relating to an increased volume of fish taken.
Studies in controlled environments on the giant trevally's feeding strategies have found that hunting in schools increases their capture efficiency, however is not necessary for an individual's survival. When a school is formed during feeding, one individual will take a leading position, with others trailing behind it. Several individuals will attack the prey school, striking and stunning the prey, with the leading individual generally being more successful. Some individuals act individually and opportunistically within the school if one of the prey fish becomes isolated, with the main advantage of schooling appearing to be the ability to further break up and isolate prey schools. The only time hunting in schools is a disadvantage is when only isolated prey are present, such as close to a reef; here an individual hunter has a greater probability of capturing it than if a group is present. Another hunting strategy of the giant trevally is to 'escort' Monk Seals, a behavior which has been observed in the Hawaiian Islands. The trevally swim close by the seal, and when the seal stops to forage, the trevally positions its mouth inches away from the seal. If a prey item is disturbed, the trevally will attempt to steal the prey from the seal, which routinely does occur. The seal does not appear to gain any benefit from this relationship, and it is thought juvenile seals being followed in this way may be outcompeted by the larger fish. A similar strategy has been employed by fish in the presence of large reef sharks, as they use the larger animal as a tool to ambush prey. The opportunistic nature of giant trevally has also been made evident by studies on the mortality rate of undersized or egg-bearing lobsters released from traps at the water's surface in the Hawaiian Islands. The fish are efficient predators of these crustaceans, with individuals often seizing a lobster before it could sink to the seafloor after being released, or attacking before the lobster moves into a defensive position. Some bolder large individuals are even known to eat the lobster head first when its in a defensive stance.

 Life history


A school of subadult giant trevally in a sandy bay, Hawaii
The giant trevally reaches sexual maturity at 54 to 61 cm in length and 3 to 4 years of age, although many authors narrow this down to 60 cm and 3 years of age. Sex ratio estimates from the Hawaiian Islands suggest that the population is slightly skewed toward females, with the male:female ratio being 1:1.39. Spawning occurs during the warmer months in most locations, although the exact dates differ by location. In southern Africa this occurs between July to March, with a peak between November and March; in the Philippines between December and January with a lesser peak during at June; and in Hawaii between April and November with a major peak during May to August. Lunar cycles are also known to control the spawning events, with large schools forming in certain locations at specific phases of the moon in Hawaii and the Solomon Islands. Locations for spawning include reefs, the reef channels and offshore banks. Sampling of schools prior to spawning suggests the fish segregate into schools of only one sex, although the details of this are still unclear. Observations in the natural habitat found spawning occurred during the day immediately after and just before the change of tide when there were no currents. Giant trevally gathered in schools of over 100 individuals, although ripe individuals occurred slightly deeper; around 2 to 3 m above the seabed in groups of 3 to 4, with one silver female being chased by several black males. Eventually a pair would sink down to a sandy bottom, where eggs and sperm were released. The fish then diverged and swum away. It appears that that each individual spawns more than once in each period, with only part of the gonads ripe in spawners. Fecundity is not known, although females are known to release several thousand eggs on capture during the spawning process. Eggs are described as pelagic and transparent in nature.
The giant trevally's early larval stages and their behaviour have been extensively described, with all fins having formed by at least 8 mm of age, with larvae and sub-juveniles being silver with six dark vertical bars.
Laboratory populations of fish show a significant variability in the length at a certain age, with the average range being around 6.5 mm. Growth rates in larvae between 8.0 and 16.5 mm are on average 0.36 mm per day. The speed at which larvae swim increases with age from 12 cm/s at 8 mm in length to 40 cm/s at 16.5 mm, with size rather than age a better predictor of this parameter. Size is also a better predictor of endurance in larvae than age. These observations suggest that the species becomes an effective swimmer (is able to swim against a current) at around 7–14 mm. No obvious relationships with age and either swimming depth or trajectory have been found. Larvae appear to also opportunistically feed on small zooplankton while swimming. The larvae actively avoid other large fish, and jellyfish are occasionally used as temporary cover. Larvae have no association with reefs, and appear to prefer to live pelagically. Daily growth is estimated at between 3.82 g/day and 20.87 g/day, with larger fish growing at a more rapid rate. Age at 1 year old is 18 cm, age at 2 years is 35 cm and by 3 years, the fish is around 50 to 60 cm. The use of von Bertalanffy growth curves fitted to observed otolith data shows an individual of around 1 m in length is approximately 8 years old, while a 1.7 m fish would be around 24 years old. The maximum theoretical length of the species predicted by the growth curves is 1.84 m,however the largest reported individual was 1.7 m long. As previously mentioned, as the giant trevally grows it shifts from turbid inshore waters or estuaries to reefs and lagoons in bays, moving finally to outer reefs and atolls. A hybrid of C. ignobilis and C. melampygus (bluefin trevally) has been recorded from Hawaii. The specimen was initially thought to be a bluefin trevally of world record size, however was later rejected when it was discovered to be a hybrid. Initial evidence of hybridisation was morphological characteristics intermediate to the two species, with later genetic tests confirmed that it was indeed a hybrid. It is known the two species school together, including at spawning time, which was considered to be the reason for hybridisation.

 Relationship to humans


A giant trevally taken by a soft plastic lure
The giant trevally has been utilised by humans since prehistory, with the oldest known records of the capture of this species by Hawaiians, whose culture held the fish in high regard. The ulua, as the fish is known to Hawaiians, was likened the fish to a fine man and strong warrior, which was the cause of a ban on women eating the species in antiquity. The species was often used in Hawaiian religious rites, and took place of a human sacrifice when none was available. Culturally, the fish was seen as a god, and treated as gamefish which commoners could not hunt. There are many mentions of ulua in Hawaiian proverbs, all generally relating to the strength and warrior like qualities of the fish.The Hawaiians considered the fish be of excellent quality, with white firm flesh. Despite this, intrusions of giant trevally into modern day fishponds used by Hawaiians for rearing fish is unwelcome, as being a predator it eats more than it is worth at market.
The giant trevally is of high importance to modern day fisheries throughout its range, although quantifying the amounts taken is very difficult due to the lack of fishery statistics kept in most of these countries. Hawaii has the best kept statistics, with the 1998 catch consisted of 10 194 pounds of giant trevally worth around 12 000 US dollars. Historically the species has been taken in far greater numbers, and have been important food, market and game fish since the early 1900s. However their exploitation has seen the landings of the species decrease by over 84% since the turn of the century, declining from 725 000 lb catches to the 10 000 lb catches of recent. FAO statistics of the Asian region record catches between 4000 and 10 000 tonnes between 1997 and 2007, although this excludes most fisheries which are not monitored or don't discriminate between trevally species. The giant trevally is commercially caught by a number of methods including hook and line, including handlines, gill nets and other types of artisinal traps. The species has also successfully been bred for aquaculture purposes in Taiwan. It is sold at market fresh, frozen, salted, smoked, and as fishmeal and oil.
The giant trevally is considered one of the top gamefish of the Indo-Pacific region, having outstanding strength, speed and endurance once hooked. It can be taken by many methods, including baits of cut or live fish and squid, as well as a wide array of lures. The species is commonly taken on bibbed plugs, minnows, spoons, jigs and poppers as well as soft plastic lures and saltwater flies. In recent years, the development of both jigging and surface-popping techniques have seen the giant trevally become an extremely popular candidate for catch and release fishing, with many charter operators based around this concept. The species is also popular with spearfishermen throughout its range. The species edibility has been rated from poor to excellent by different authors, although there are numerous reports of ciguatera poisoning from the species Detailed tests on a large (1m) specimen taken from Palmyra Island showed the toxicity of the fish's flesh, liver and washed intestinal tract produced no or weakly positive symptoms to laboratory mice, however the digested contents of the intestine were lethal. The authors argued that based on this test the flesh of giant trevally was safe to consume. However analysis of case studies in which ciguatera poisoning was reported after eating the fish suggested that an accumulative effect occurs with repeated consumption; and also that tests like the one outlined above are not reliable, as the toxin appears to be distributed haphazardly throughout each fish.Since 1990, giant trevally taken from the main Hawaiian islands have been blocked from sale by auction internationally due to concerns over liability from ciguatera poisoning.

 Conservation


Scuba diver interacting with a giant trevally at Guam's Gab Gab II reef
A decline in giant trevally numbers around inhabited regions has been well documented in Hawaii, with both catch data as presented above and ecological studies showing this decrease in numbers. A biomass study in the Hawaiian Islands indicates that the main Hawaiian Islands are heavily depleted in the species, which in untouched ecosystems comprises 71% of the apex predator biomass. In contrast, it comprises less than 0.03% of the apex biomass in exploited habitats, with only a single fish observed during the course of this research study. Prior to this, a 1993 report suggested the population around the main Hawaiian islands were not stressed, even though several biological indicators suggested to the contrary. This was due to the highly size-selective nature of the fishery, which theoretically should prevent a decrease in numbers.Despite this, populations have decreased, and in light of their continued falling abundance in Hawaii, several recommendations including banning the commercial take of the species, increasing minimum lengths and decreasing bag limits for anglers, as well as reassessment of protected areas for the species have been proposed by officials. The species (nor any other carangid) has not been assessed by the IUCN.
Some recreational fishing groups are also promoting a catch and release practise for the giant trevally, with this becoming an increasingly popular option for charter boat operators, who have also begun to tag giant trevally for scientific purposes.At large sizes, the species is more likely to be ciguatoxic, and therefore if the fish is kept it must be disposed of or sent to a taxidermist if it is a trophy fish. A catch and release approach has also been adopted by operators outside of Hawaii, with Australian operators who target the species by popping and jigging rarely keeping any fish.Careful fish handling techniques have also been implemented by anglers so as not to damage the fish; such techniques include supporting the fish's weight, using barbless single rather than treble hooks and restricting the time the fish spends out the water to a minimum

sumber : http://en.wikipedia.org/wiki/Giant_trevally
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