Analisis Aspek Reproduksi Kepiting Bakau (Scylla sp.) Di Perairan Kendal, Jawa Tengah

Abstract

Kepiting bakau Scylla sp. merupakan salah satu biota laut yang mempunyai nilai ekonomis penting. Penyebarannya hampir di seluruh kawasan pesisir Indonesia, yang memiliki ekosistem mangrove termasuk di perairan Kendal. Banyaknya penangkapan kepiting bakau tanpa memperhatikan ukuran yang layak tangkap. Oleh karena itu penelitian ini dilakukan untuk memperoleh beberapa aspek reproduksi kepiting bakau Scylla sp. di perairan Kendal, Jawa Tengah. Pengambilan sampel dilakukan pada bulan Februari–Maret 2017, dua minggu sekali selama dua bulan di perairan Kendal, Jawa Tengah. Metode yang digunakan dalam penelitian ini adalah metode deskriptif eksploratif dengan parameter pendukung seperti suhu, salinitas, pH, dan DO. Materi yang digunakan adalah kepiting bakau Scylla sp. Analisis yang digunakan untuk menghitung perbandingan jumlah kepiting bakau jantan dan betina adalah uji chi square. Hasil penelitian menunjukkan bahwa komposisi ukuran kepiting bakau mempunyai lebar karapas 81-130 mm, berat 100-350 gram dengan ukuran rata-rata yang tertangkap 99,62 mm, perbandingan jantan dan betinanya 1:2,09. Hubungan lebar karapas dengan berat menunjukkan sifat allometrik positif. Faktor kondisi yang didapatkan adalah 1,0185. Tingkat kematangan gonad kepiting bakau di dominasi oleh TKG II, nilai indeks kematangan gonad pada kepiting bakau betina berkisar antara 6,84% - 18,49%. Tingkat kematangan gonad yang di dominasi oleh TKG II dikarenakan di lokasi penelitian tidak sedang masa pemijahan.   Mangrove crab (Scylla sp.) is one of the marine biota that it has value economically important. It spreads in almost all over coastal areas of Indonesia, which has the mangrove ecosystem. Mangrove crab has a high nutritional value. Thus, encouraging people in Kendal to consume a large amount of mangrove crab and reach the local market demand.This led to the occurrence of a lot of mangrove crab catching regardless of the size of the catch.Therefore, this study was conducted to obtain some of reproduction aspects of Scylla sp. in the Kendal waters, Central Java. Sampling was conducted in February-March 2017,every two weeks in two months in Kendal waters, Central Java. The method used in this research was descriptive explorative method with supporting parameters such as temperature, salinity, pH, and DO. The used material was mangrove crab (Scylla sp.). Chi square test was used to analyze and calculate the ratio of male and female mangrove crabs. The results showed that the size composition of mangrove crab had a carbide width of 71-130 mm, weight of 100-350 grams, with average size captured was 99.62 mm, male and female ratio of 1: 2.09. The Relations between width and weight of caparace indicated negative allometric properties. The obtained condition factor was 1.0184767. Maturity level of mangrove crab gonad was dominated by TKG II, gonad index maturity value on female mangrove crab ranged between 6.84% - 18.49%. The maturity level of gonad was dominated by TKG IIbecause the research location was not in the spawning period.