KERAGAAN REMATURASI GONAD INDUK TERIPANG PASIR, Holothuria scabra DENGAN PEMBERIAN JENIS PAKAN BERBEDA

Abstract

Rematurasi gonad induk teripang pasir Holothuria scabra yang sudah memijah masih banyak masalah, padahal rematurasi diperlukan untuk keberlanjutan pemijahan dan penyediaan benih. Tujuan penelitian adalah memperoleh jenis pakan yang dapat mempercepat proses rematurasi gonad terhadap induk alam yang sudah dipijahkan sehingga dapat memenuhi kebutuhan untuk pembenihan teripang di hatcheri, serta mengetahui performa benih yang dihasilkan secara fenotipe dan genotipe. Penelitian rematurasi gonad dengan pemberian pakan berbeda telah dilakukan di Balai Besar Penelitian dan Pengembangan Budidaya Laut, Gondol. Penelitian dilakukan dengan metode eksperimental secara rancangan acak lengkap dengan perlakuan perbedaan jenis pakan, yaitu: A) Ulva sp. dan bentos; B) Gracilaria sp. dan bentos, dan C) bentos saja. Dosis pemberian pakan sebanyak 4% dari bobot badan dengan frekuensi pemberian 1 kali/hari. Setiap perlakuan terdiri atas tiga ulangan. Jumlah induk setiap ulangan sebanyak tiga ekor dengan ukuran panjang dan bobot 13,08 ± 2,04 cm dan 182,75 ± 47,74 g. Benih yang dihasilkan sebelum induk dirematurasi dan setelah rematurasi diamati performa fenotipe dan genotipenya. Analisis genotipe menggunakan metode mikrosatellit dengan empat lokus (Hsc-11; Hsc-28; Hsc-49; dan Hsc-59). Parameter yang diamati meliputi frekuensi pemijahan induk teripang, tingkat kematangan gonad, indeks gonadosomatik, fekunditas, diameter telur, pertumbuhan benih F-1 sebelum dan sesudah rematurasi, serta performa genotipe benih tersebut. Data indeks gonad somatik dan diameter telur dianalisis dengan ANOVA, sedangkan data pertumbuhan, pemijahan, dan fekunditas disajikan dalam bentuk tabel dan grafik. Hasil penelitian menunjukkan bahwa semua perlakuan dapat mempercepat rematurasi gonad dan induk teripang memijah setelah dua bulan pemeliharaan. Jenis pakan bentos menghasilkan indeks gonadosomatik dan diameter telur lebih baik dibandingkan dengan perlakuan pakan lainnya (P<0,05). Keragaman genetik benih dari induk sebelum rematurasi (0,719) berbeda nyata (P<0,05) dengan sesudah rematurasi (0,634); sedangkan secara fenotipe, pertumbuhan panjang, dan bobot benih hingga umur 150 hari tidak berbeda (P>0,05).

Successful rate of gonad re-maturation of sea cucumber, H. scabra broodstock after spawning still faces some problems presumably due to lack of essential nutrients to support the process. However, re-maturation is vitally important to speed up the fingerling production. The aim of the research was to determine the best feed composition able to induce gonad re-maturation of sea cucumber natural broodstock which had been previously spawned. In addition, this research was also aimed to study the fingerling genetic performance, both phenotypically and genetically. The research on gonad re-maturation was carried out using different feeds at the Institute for Mariculture Research and Development, Gondol. The research was designed in a completely randomized design with three different feed compositions as treatments: A) Ulva sp. and benthos; B) Gracilaria sp. and benthos, and C) only benthos. The amount of given feed was 4% of the total biomass and once daily. Each treatment has three replicates. The number of broodstock in each replicate was three individuals with the averages of total length and body weight were 13.08 ± 2.04 cm and 182.75 ± 47.74 g, respectively. Fingerlings produced from natural maturation and re-maturation broodstock were phenotypically and genetically analyzed. Microsatellite method was used for the genetic analysis of four loci (Hsc-11; Hsc-28; Hsc-49; and Hsc-59). The parameters measured were gonad maturity level, gonadosomatic index, spawning frequency, fecundity, eggs diameter, phenotypic, and genetic performance of F-1 fingerlings produced from both natural maturation and re-maturation broodstock and compared to each other. Data on gonadosomatic index and eggs diameter were statistically analyzed using Anova-test, while growth rate, spawning, and fecundity were descriptively compared using tables and figures. The results showed that all feed treatments were able to induce gonad re-maturation and all sea cucumber broodstock re-spawned after two months. Benthos feed had a significant effect in increasing gonad somatic index and eggs diameter compared to the other feed treatments (P<0.05). Genetic variance of F-1fingerlings produced from the natural maturation broodstock (0.719) was significantly different (P<0.05) compared to the fingerlings produced from the re-maturated broodstock (0.634). However, phenotypically, the growth of length and weight after 150 days old fingerling was not significantly different (P>0.05) between the two fingerling generations.