BIOLOGI REPRODUKSI IKAN KEPEK Barbonymus collingwoodii) DI SUNGAI OPAK KABUPATEN BANTUL

ILMA FATIMAH YUSUF, Dr. Ir. Djumanto, M. Sc.

2013 | Skripsi | MANAJ. SUMBER DAYA PERIKANAN

Ikan Kepek (Barbonymus collingwoodii) memiliki bentuk badan agak panjang dan pipih dengan punggung meninggi, kepala kecil, moncong meruncing, mulut kecil terletak pada ujung hidung. Penelitian ini bertujuan untuk mengetahui biologi reproduksi ikan kepek meliputi rasio kelamin, tingkat kematangan gonad, indeks kematangan gonad, fekunditas, hubungan panjang total dengan fekunditas, dan distribusi ukuran diameter telur. Pengambilan sampel ikan dilakukan setiap 2 minggu sekali dalam waktu 3 bulan (Februari-April 2013) di Sungai Opak Kabupaten Bantul menggunakan alat electrofishing. Ikan hasil tangkapan dibawa ke laboratorium Manajemen Sumberdaya Perikanan untuk diamati dan dianalisis. Ikan kepek diukur panjang dan berat serta diamati jenis kelaminnya melalui pembedahan. Data rasio kelamin dianalisis dengan uji “chi-square” untuk mengetahui keseimbangan populasi jantan dan betina. Jumlah telur ikan dihitung berdasarkan metode gravimetrik. Populasi diameter telur dianalisis menggunakan metode Battacharya untuk mengetahui ukuran telur siap pijah. Sampel ikan kepek yang didapatkan dari hasil penangkapan sebanyak 209 ekor. Hasil penelitian menunjukkan panjang total kepek berkisar antara 4,1–17,6 cm dan berat berkisar antara 0,73–40,24 gram. Nisbah kelamin kepek selama penelitian 1,4:1. Perbandingan presentase antara TKG jantan dan betina pada TKG I, II, III, IV secara berturut-turut adalah: (40,2:39,1); (27:41,4); (25,4:8); dan (7,4:11,5). Nilai IKG kepek jantan berkisar antara 0–10,91% dengan reratanya 0,81%, sedangkan nilai IKG kepek betina berkisar antara 0–10,52% dengan reratanya 1,32%. Ukuran diameter siap dikeluarkan berkisar antara 0,42-0,89 mm yang memiliki proporsi sebesar 49,65% dari total telur. Fekunditas kepek berkisar antara995-4.862 butir dengan rata-rata sebesar 2.861 butir. Hubungan fekunditas dengan panjang total tubuh kepek (B. coolingwoodii) mengikuti persamaan F=39,397^1,631 (R2 = 0,0747). Ikan kepek yang tertangkap didominasi ikan kepek muda, sehingga perlu dilakukan pengaturan pada penangkapan ikan di Sungai Opak supaya populasi ikan kepek dapat seimbang.

The species of Barbonymus collingwoodii with local name of Kepek is riverine fish that has a thin body shape elongated with the back elevated, small head, pointed snout, small mouth located at the tip of the nose. The purpose of this research was to know reproductive biology of “Kepek” fish namely sex ratio, gonads maturity level, gonad maturity index, fecundity, relationship between total length with fecundity, egg diameter and size distribution. Fish sampling was done be weekly for three months from February to April 2013 in Opak river of Bantul regency using electrofishing. All fish samples was collected than transferred to the laboratory of Aquatic Resource Management for lengt hand weight measurement, and gonad investigation. Sex ratio data were analyzed with the \\"chi - square\\" test to know the population balance of male and female. The number of eggs fish calculated based on gravimetric method. Eggs diameter were analyzed using the Battacharya method to know population size and ripening of eggs that ready to spawn. The total fish was 209 individual. The results showed total length ranged from 4.1 to 17.6 cm and weigh from 0.73 to 40.24 grams. The sex ratio was1.4:1. Comparison percentage the gonade maturity level (GML) of I, II , III , IV between male and female were : (40,2:39,1); (27:41,4); (25,4:8), and (7,4:11,5), respectively. The gonade somatic index (GSI) for male was from 0 to 10.912% with average 0.817%, while the gonade somatic index (GSI) for females was from 0 to 10.52% with average 1,32%. Egg diameter that ready to release was from 0.42 to 0.89 mm which has a proportion of 49.65% from the total eggs. The fecundity was varied from 995 to 4.862 eggs with average 2.861 eggs. Relationship between fecundity with total body length was F = 39.397 L1.631 (R2 = 0.0747). The dominance catches was young group, hence regulation of fishing was necessary to manage the populations of Kepek fish in order sustain.

Kata Kunci : Barbonymus, Reproduksi, Fekunditas, Opak