Bioekologi Rajungan Hijau (Thalamita crenata) di Ekosistem mangrove Pulau Pramuka, Kepulauan Seribu, Jakarta

Abstract

Rajungan hijau (Thalamita crenata), merupakan sumberdaya perikanan di Pulau Pramuka yang berasosiasi dengan ekosistem mangrove dan belum banyak diteliti. Penelitian ini bertujuan untuk menganalisis bioekologi rajungan hijau di sepanjang pantai yang ditutupi mangrove di Pulau Pramuka. Pengambilan sampel rajungan hijau dilakukan di tiga stasiun dengan ulangan 10 transek dan tiga kali pengambilan sampel selama bulan November 2023 – Januari 2024. Semua sampel rajungan hijau diukur morfometriknya. Pada mangrove digunakan transek 1 x 1 m, 5 x 5 m, dan 10 x 10 m untuk mendapatkan data jenis vegetasi dan kerapatannya. Hasil analisis rajungan hijau didapatkan rasio individu jantan terhadap betina sebesar 1:0,70. Pola pertumbuhan jantan dan betina allometrik negatif dengan faktor kondisi betina lebih tinggi. Stasiun 2 mendominasi hasil tertinggi kelimpahan rajungan hijau, kerapatan mangrove terutama Rhizopora stylosa. Hubungan kelimpahan rajungan hijau dengan kerapatan mangrove linier positif dengan tingkat hubungan sangat kuat. Parameter kualitas perairan tiap stasiun masih dalam tingkat optimal, baik untuk pertumbuhan rajungan hijau maupun ekosistem mangrove.

Swimming crab (Thalamita crenata), is a fishery resource in Pramuka Island that is associated with mangrove ecosystems and has not been widely studied. This study aims to analyze the bioecology of swimming crab along the mangrove-covered coast of Pramuka Island. Swimming crab sampling was conducted at three stations with 10 transects and three sampling times during November 2023 - January 2024. All swimming crab samples were measured morphometrically. In mangroves, transects of 1 x 1 m, 5 x 5 m, and 10 x 10 m were used to obtain data on vegetation types and density. The results of the analysis of swimmig crab obtained a ratio of male to female individuals of 1: 0,70. The growth pattern of males and females is allometrically negative with a higher female condition factor. Station 2 dominated the highest results of swimming crab abundance, mangrove density and Rhizopora stylosa mangrove type. The relationship between swimming crab abundance and mangrove density is positive linear with a very strong relationship level. The water quality parameters of each station are still at an optimal level, both for the growth of swimming crabs and mangrove ecosystems.