Electronic Theses and Dissertation

ABSTRAK


Chiton merupakan moluska laut dari kelas Polyplacophora yang memiliki tubuh oval dan pipih secara dorsoventral serta dilindungi oleh delapan lempeng cangkang yang tersusun berderet. Penelitian ini bertujuan mendeskripsikan karakter morfologi dan morfometrik serta menghitung kepadatan dan pola sebaran Acanthopleura gemmata di Pantai Leungah, Kecamatan Seulimeum, Aceh Besar. Penelitian dilaksanakan pada Februari-Maret 2026. Lokasi ditentukan secara purposive berdasarkan keberadaan habitat intertidal berbatu. Sebanyak 20 kuadrat berukuran 1 × 1 m ditempatkan secara sistematis dengan interval 5 m di sepanjang transek 100 m. Sebanyak 39 individu A. gemmata ditemukan selama penelitian. Spesies ini memiliki tubuh oval, delapan lempeng cangkang, warna dorsal cokelat kekuningan hingga kehijauan, dan girdle yang dipenuhi duri-duri pendek. Panjang total tubuh rata-rata sebesar 35,83 ± 8,22 mm, lebar tubuh 25,88 ± 5,05 mm, tinggi tubuh 12,18 ± 3,04 mm, dan berat tubuh 8,37
± 4,82 g. Kepadatan keseluruhan A. gemmata sebesar 1,95 ind/m². Nilai Indeks Morisita sebesar 0,918 menunjukkan bahwa pola sebarannya cenderung seragam. Suhu selama pengukuran sebesar 31°C, pH 7, salinitas 32–33 ppt, dilakukan secara in situ dan DO 5,1–6,8 mg/L dilakukan secara ex situ. Penelitian ini menyediakan data dasar mengenai karakter morfologi, morfometrik, kepadatan, dan pola sebaran A. gemmata pada habitat intertidal berbatu di Pantai Leungah.

Kata kunci: Acanthopleura gemmata, morfometrik, kepadatan, Polyplacophora, zona intertidal.

ABSTRACT Chitons are marine mollusks of the class Polyplacophora, characterized by an oval, dorsoventrally flattened body protected by eight serially arranged shell plates. This study aimed to describe the morphological and morphometric characteristics and to determine the density and distribution pattern of Acanthopleura gemmata at Leungah Beach, Seulimeum District, Aceh Besar. The study was conducted from February to March 2026. The study site was selected purposively based on the presence of rocky intertidal habitat. Twenty 1 × 1 m quadrats were placed systematically at 5-meter intervals along a 100-meter transect. A total of 39 A. gemmata individuals were found during the study. The species exhibits an oval body, eight shell plates, a dorsal color ranging from yellowish brown to greenish, and a girdle covered with short spines. The mean total body length was 35.83 ± 8.22 mm, body width 25.88 ± 5.05 mm, body height 12.18 ± 3.04 mm, and body weight 8.37 ± 4.82 g. The overall density of A. gemmata was 1.95 ind/m². A Morisita Index value of 0.918 indicated a tendency toward a uniform distribution pattern. Environmental parameters recorded during the study were. The temperature during the measurements was 31°C, pH 7, salinity 32–33 ppt, carried out in situ and DO 5.1–6.8 mg/L was carried out ex situ. This study provides baseline data on the morphological characteristics, morphometrics, density, and distribution patterns of A. gemmata in the rocky intertidal habitat at Leungah Beach. Keywords: Acanthopleura gemmata, morphometrics, density, Polyplacophora, intertidal zone.