Kepadatan Populasi, Pola Pertumbuhan, dan Tingkat Kematangan Gonad Ikan Julung-Julung (Zenarchopterus dispar) di Sungai Belawan Sicanang, Kelurahan Belawan Sicanang, Medan Belawan

Abstract

Research on population density of julung-julung fish (Zenarchopterus dispar) in the Belawan Sicanang River, Belawan Sicanang sub-district, Medan Belawan subdistrict was carried out in August 2021. The purpose of this study was to analyze the population density of julung-julung fish and the relationship between population density of julung-julung fish (Zenarchopterus dispar). with physico-chemical factors of waters in the Belawan River, Sicanang sub-district, Medan Belawan sub-district. The method used waspurposive samplingbased on activities around the station, with determining three sampling. Samples were taken using a tangok and repeated 20 times at each station. Data analysis includes population density, length of class size, growth pattern, frequency of attendance, sex ratio, gonadal maturity index, Pearson correlation analysis. The physico-chemical parameters of the waters measured included temperature, light intensity, light penetration, salinity, pH, Dissolved Oxygen (DO), Biologycal Oxygen Demand (BOD5). The results showed that the highest population density value was at station 1, which was 0.23 ind/m2. The growth pattern of julung-julung fish was negative allometric with a b value of 2.9080 – 2.3673. The gonad maturity level (TKG) obtained varied, namely TKG I, TKG II, TKG IV, TKG V, TKG VI. Ratio highest comparison with a ratio of 1:2.9of male and female julung-julung fish was at station 17. The content of Dissolved Oxygen (DO) and Biochemical Oxygen Demand (BOD5) showed a strong correlation, salinity and pH showed a very strong correlation to population density and physico-chemical factors of waters in the Belawan River, Sicanang.

Penelitian kepadatan populasi ikan julung-julung (Zenarchopterus dispar) di Sungai Belawan Sicanang, kelurahan Belawan Sicanang, kecamatan Medan Belawan telah dilaksanakan pada bulan Juli - Agustus 2021. Tujuan penelitian ini untuk menganalisis kepadatan populasi ikan julung-julung serta hubungan kepadatan populasi ikan julung-julung (Zenarchopterus dispar) dengan faktor fisika-kimia perairan di Sungai Belawan kelurahan Sicanang kecamatan Medan Belawan. Metode yang digunakan yaitu purposive sampling, pengambilan sampel berdasarkan aktivitas di sekitar stasiun dengan menggunakan tiga stasiun. Sampel diambil dengan menggunakan tanggok dan dilakukan sebanyak 20 kali di setiap stasiun. Analisis data meliputi Kepadatan populasi, Panjang ukuran kelas, Pola pertumbuhan, Frekuensi kehadiran, Rasio kelamin, Indeks kematangan gonad, dan Analisis korelasi Pearson.Parameter fisika-kimia perairan yang diukur meliputi Suhu, pH, Dissolved oxygen (DO), Biologycal Oxygen Demand ( BOD5 ), Intensitas cahaya, Salinitas, Penetrasi cahaya. Hasi penelitian menunjukkan bahwa nilai kepadatan populasi tertinggi pada stasiun 1 yaitu sebesar 0,23 ind/m2. Pola pertumbuhan ikan julungjulung bersifat alometrik negatif dengan nilai b sebesar 2,9080 – 2,3673. Tingkat kematangan gonad (TKG) yang diperoleh bervariasi yaitu TKG I, TKG II, TKG IV, TKG V, TKG VI. Rasio perbandingan tertinggi ikan julung-julung jantan dan betina yaitu 1:2,9 yang terdapat di stasiun 1. Kandungan Dissolved Oxygen (DO) dan Biochemical Oxygen Demand (BOD5) menunjukkan korelasi kuat, Salinitas dan pH menunjukkan korelasi yang sangat kuat terhadap kepadatan populasi dan faktor fisika-kimia perairan di Sungai Belawan, Sicanang.