Diversity and distribution of crustaceans in the mangrove forest of Nusa Lembongan, Bali, Indonesia

Abstract

Abstract. Ginantra IK, Muksin IK, Joni M, Wijaya IMS. 2023. Diversity and distribution of crustaceans in the mangrove forest of Nusa Lembongan, Bali, Indonesia. Biodiversitas 24: 4533-4541. Research on the diversity and distribution of crustaceans in the mangrove forest of Nusa Lembongan, Bali, Indonesia was conducted from March to June 2022. Sampling was carried out using the quadratic method at seven mangrove forest sites. The identification of crustacean species is based on morphological characteristics, namely carapace color, claw shape, legs, and body size. Crustacean density was determined based on the number of individuals per unit area of mangrove forest, diversity was determined by the Shanon-Wiener Index, and crustacean distribution was determined based on the frequency of species presence in each square at the seven study sites. Environmental factors were also measured: Mangrove vegetation, substrate type, temperature, pH, and salinity. The results showed that 12 species of crustaceans were found, consisting of 10 species of crabs and two species of hermit crabs. Several species of crabs are quite dominant in the mangroves of Nusa Lembongan namely Sesarma pictum (De Haan, 1835), with a density of 7 individuals/5 m2, Uca tetragonon (Herbst, 1790) of 3.7 individuals/5 m2, Uca rosea (Tweedie, 1837) with a density of 2.5 individuals/ 5 m2, and Uca triangularis (A. Milne-Edwards, 1873) with a density of 2 individuals/5 m2. Environmental factors support the life of Nusa Lembongan crustaceans, namely the type of substrate, mostly muddy and sandy, diverse species of mangrove plants, both true and associated mangroves, water temperature 27.70-29.00°C, pH 6.88-7.15 and water salinity ranging from 27.83-31.53‰. Crustacean diversity is included in the moderate category with their diversity index. There are three crab species with moderate to frequent (absolute) frequency of presence, namely U. rosea (Fi: 57.15%), S. pictum (Fi: 71.43%), and U. tetragonon (Fi: 85.71%). These species are present in four to six mangrove forest sites.

The relationship between crustacean diversity and population dynamics of Blood Cockle Tegillarca granosa in the coastal area of West Langsa, Aceh Province, Indonesia

“…The size of the "kepiting biola" is relatively smaller compared to other crab families found in the research location. The underutilization of this crab family by the community as a food source and for various other purposes has resulted in the dominance of this crab number of specimens compared to other crab species from the Portunidae family (Ginantra et al 2023). Unlike the Portunidae and Penaeidae families, which belong to the crab and shrimp group and have high demand in the national and international markets, the natural populations of these animals in their habitats are decreasing due to regular exploitation by the community and fishermen (Muhammadar et al 2021).…”

“…Sampling took place during daylight hours at low tide, using a hand shovel to excavate crustacean burrows and blood cockles at depths of 10-20 cm in each research plot (Setyadi et al 2021). All samples collected at the research locations were placed in sample bottles and fixed with 4% formalin, then transported to the University Samudra Biology Laboratory for identification, based on morphological similarities among crustacean species, including color, body size, legs and claws shapes, and various other morphological features (Ginantra et al 2023;WoRMS 2024). The water parameters measured include water salinity, water pH and water temperature.…”

“…Crustaceans and bivalves are highly dominant groups of macroinvertebrates found in coastal areas, play the role in maintaining the balance of mangrove ecosystem (Mahilac et al 2023). In mangrove habitats, crustaceans are decomposers and detritus feeders, exerting a significant impact on carbon productivity (Ginantra et al 2023;Swasta et al 2023). Tegillarca granosa (Linnaeus, 1758) (Arcidae, Bivalvia) primarily inhabits in coastal areas with stable water circulation (Kim et al 2022).…”