Analysis of Substrate, Gastric Content and Nutrient Content of Varuna litterata

Abstract

Varuna litterata is a secondary freshwater crab found in tidal areas. This crab is caught, its eggs are taken, and it is considered a delicacy. Continuous fishing without any cultivation efforts can cause a decline in the population, leading to extinction. This study aims to determine the characteristics of the habitat substrate, stomach, and nutritional content of V. litterata. The method used in this study is descriptive exploratory. The study was conducted in the Serayu River for four months (October 2023 - January 2024). The observation location was carried out at three stations. The study showed that V. litterata prefers waters with clay sand substrates (75% sand, 25% dust, and 0% clay). This habitat is very suitable for cultivation development, as shown by the population of captured crabs. The results of observations of stomach contents show that this crab is an opportunistic omnivore. This crab has a high nutritional content with an average water content (60.72%), ash (4.57%), fat (0.52%), protein (25.66%), and carbohydrates (8.52%). Further research is essential to understand the reproductive system of V. litterata, its life cycle, and suitable habitats for spawning.Varuna litterata is a secondary freshwater crab found in the intertidal zone. This crab is a favourite food in several Asian countries, such as the Philippines, Thailand, Myanmar and Cambodia. These crabs are caught, their eggs are taken, and they are considered delicious food. Continuous fishing without any cultivation efforts can cause a decline in the population, leading to extinction. This research aims to determine the characteristics of the habitat substrate, stomach and nutritional content of Varuna litterata. The method used in this research is exploratory descriptive. The research was conducted on the Serayu River River for four months (October 2023 – January 2024). The observation locations were carried out at three stations: 1) the first station was above the Motion Serayu weir with fresh water, 2) the second station was below the dam with fresh water, and 3) the third station was below the dam with brackish water. The results showed that Varuna litterata preferred waters with a clayey sand substrate (75% sand, 25% dust and 0% clay) at the second station. This habitat is very suitable for cultivation development with the demonstrated population of crabs caught. The observations on stomach contents show that this crab is an opportunistic omnivore animal, with plants being the most dominant stomach contents, followed by miscellaneous crustaceans, fish, sand and mud. This crab has a high nutritional content compared to other brachyuran crabs, with an average content of water (60.72%), ash (4.57%), fat (0.52%), protein (25.66%), carbohydrates (8.52%). It is important to conduct further research to determine the reproductive system of Varuna litterata, its life cycle, and the habitat suitable for spawning.