Species Diversity and Morphological Characteristics of Class Asteroidea and Class Ophiuroidea in the Intertidal Zone of Banyu Meneng Beach and Ngentup Beach, South Malang Keanekaragaman Spesies dan Karakter Morfologi Kelas Asteroidea dan Kelas Ophiuroidea di Zona Intertidal Pantai Banyu Meneng dan Pantai Ngentup, Malang Selata

Abstract

This study assessed the species diversity and morphological characteristics of Asteroidea and Ophiuroidea inhabiting the intertidal zones of Banyu Meneng and Ngentup Beaches, South Malang, Indonesia, during the rainy season survey conducted on November 7, 2025. A descriptive qualitative approach was employed using a systematic transect-quadrat design consisting of three transects with five quadrats (1 m × 1 m) per transect at each site, resulting in a total of 30 quadrats. Species identification and morphological observations were performed based on external characteristics, while environmental parameters were measured in situ. A total of nine species belonging to two echinoderm classes were recorded, including two Asteroidea species (Pentaceraster affinis and Archaster typicus) and seven Ophiuroidea species. Species abundance was unevenly distributed across sampling plots, with Ophiocoma scolopendrina representing the most abundant species, followed by Clarkcoma canaliculata. The Shannon-Wiener diversity index (H′ ≈ 1.74) indicated a moderate level of species diversity, whereas Pielou’s evenness index (J′ ≈ 0.79) suggested a relatively balanced distribution among non-dominant species. Measured environmental parameters included pH (6.2–8.9), temperature (24–26°C), salinity (20–40 ppt), total dissolved solids (727–10,220 mg/L), and dissolved oxygen (0.2–11.1 mg/L). Morphological traits, including arm length, body shape, coloration, and surface texture, exhibited substantial variation among species, reflecting ecological adaptations to different substrate types and physicochemical conditions. One-way ANOVA revealed no statistically significant relationship between individual abiotic parameters and species occurrence (p > 0.05). These findings provide baseline information on echinoderm diversity in southern Malang coastal ecosystems and contribute valuable resources for marine biodiversity research, conservation planning, and biology education.