Food habits of belida fish (Notopterus notopterus, Pallas 1769) in Sei Gesek Reservoir, Bintan Regency, Riau Island, Indonesia

Abstract

Sei Gesek Reservoir is located in Bintan Regency, Riau Island Province. The reservoir is one source of water for the community in Tanjungpinang City. One of the freshwater fish that inhabit the Sei Gesek Reservoir is the belida fish (Notopterus notopterus). The objective of this study was to the Relative Length of the Gut (RLG), type and food composition of belida fish (N. notopterus), and food comparative in the digestive tract of the belida fish (N. notopterus) with food resources in the substrate Sei Gesek reservoir, Bintan Regency, Riau Island. The method used in this research was the survey method. A sampling of belida fish (N. notopterus) was carried out in three months according to the fishing grounds. The data analysis used is Relative Length of the Gut (RLG), Index of Preponderance (IP), and Index of Electivity (E). The result showed that the total fish caught was 30, there were 16 males and 14 females. The relative length of the gut female and male belida fish (N. notopterus) were 0.21 and 0.25 respectively. Based on the relative length of the gut value, belida fish (N. notopterus) was classified as a carnivore. The food types of belida fish (N. notopterus) were fish, crustaceans, microalgae, macrophytes, annelids, nematodes, and detritus. Index of preponderance showed that the main food of belida fish (N. notopterus) in Sei Gesek Reservoir was small fish based on sex, the month of capture, and body length measurement. Index of electivity showed that the food type from the microalgae is Asterionella sp. and Closterium sp. not selected by belida fish (N. notopterus) as food.