ASPEK REPRODUKSI IKAN WADER IJO (OSTHEOCHILUS HASSELTI) DI DANAU RAWAPENING AMBARAWA, KABUPATEN SEMARANG - Nugraha, Muhammad Rizky; Solichin, Anhar; Hendrarto, Boedi (Management of Aquatic Resources Journal (MAQUARES), 2017)
ABSTRAK Ikan Wader Ijo (O. hasselti) merupakan ikan khas di Danau Rawapening.  Populasinya saat ini diduga mengalami penurunan, akibat penangkapan ikan Wader Ijo yang sedang bertelur dan penggunaan alat tangkap dengan mesh size kecil. Penelitian ini bertujuan untuk mengetahui aspek reproduksi ikan Wader Ijo, faktor lingkungan dan mesh size gill net yang aman digunakan. Penelitian yang dilakukan bersifat deskriptif, dengan teknik pengambilan sampel acak. Penelitian dilaksanakan Juli - Agustus 2016 di Danau Rawapening. Sampel diperoleh 93 ekor menggunakan gill net mesh size 2 inchi, dengan panjang total 111 – 210 mm. Nisbah kelamin 1:6,75 dengan dominasi ikan betina. Sampel didominasi ikan matang gonad pada TKG IV. Berdasarkan analisa PCA, Ikan Wader Ijo pada TKG II, III dan IV memiliki korelasi negatif dengan pH, arus dan oksigen terlarut. Angka Indeks Kematangan Gonad tertinggi betina diperoleh 30,30%, sedangkan jantan 19,67%. Ikan Wader Ijo yang tertangkap belum mengalami recruitment overfishing karena ukuran ikan pertama kali matang gonad jantan 100,63 mm dan betina 110,90 mm lebih kecil dari ukuran rata-rata yang tertangkap153 mm. Fekunditas diperoleh 80.862 – 19.880 butir/individu. Berdasarkan analisa Regresi Power, fekunditas Wader Ijo dipengaruhi oleh panjang tubuhnya. Diameter telur yang diperoleh berkisar 0,01 – 1,01 mm. Berdasarkan analisa Chi-Square, bagian yang berbeda dalam ovarium memiliki hubungan dengan ukuran diameter telur. Mesh size gill net yang aman digunakan minimal berukuran 1,54 inchi. Kata Kunci : Wader Ijo; Aspek Reproduksi;  Rawapening ABSTRACT Bonylip Barb (O. hasselti) is a local fish in Rawapening lake which population of this species in Rawapening already decrease, because of exploitation spawning Bonylip Barb and the used of fishing gear with small mesh size. This research aimed to know reproduction aspects of Bonylip Barb, environmental factors and mesh size of gill net. The method used in this research was descriptive with random sampling method. A total of 93 specimens were collected by gill net mesh size 2 inch from July to August 2016 at Rawapening. Specimens have total lenght 111 – 210 mm. Sex ratio was 1 : 6,75 dominated by female. Gonadal stage dominated by mature fish on level IV. Based on PCA analysis, gonadal stage level II, III and IV have negative correlations with pH, current and dissolved oxygen. The highest Gonadosomatic Index on female was 30,30%, while the male one was 19,67%. Length of first maturity not only male 100,63 mm but also female 110,90 mm smaller than average length of capture 155 mm, it means that Bonylip Barb in Rawapening still safe from recruitment overfishing. Fecundity ranged from 80.862 to 19.880 granules/individual. Based on power regression, fecundity was determined by the total length. Egg diameter ranged from 0,1 to 1,01 mm. Based on Chi-Square, different path of ovary have a corelation  with  egg diameter. Mesh size gill net that used in Rawapening was not recommended under 1,54 inch. Keywords: Bonylip Barb, Reproduction Aspect, Rawapening