Sei Carang waters are baronang fish habitat (Siganus guttatus). The research was to determine the length-weight correlationship and condition factors of baronang fish (S. guttatus) in Sei  Carang. Sampling of baronang fish (S. guttatus) in two months (September-Oktober 2019) is taken once a week based on fishing activities and water conditions. Length-weight correlationship of female and male baronang fish (S. guttatus) were W = 2,0895E-05L^2,9575 and W = 1,30073E-05L^3,0424 respectively, based on this value show that female and male baronang fish (S. guttatus) in Sei Carang have isometric growth patterns (b = 3). Condition factors of female and male baronang fish (S. guttatus) were 1,735 and 1,633 respectively.

Sei Pulai Reservoir is one of the sources of raw water for the people of Bintan Island, Riau Islands, to be precise in Tanjungpinang and its surroundings. Sei Pulai Reservoir is also a habitat for belida fish (Notopterus notopterus). The purpose of this study was to determine the relationship between length and weight of belida fish (N. notopterus) in Sei Pulai Reservoir, Bintan Regency. Sampling was carried out once a week from April to May 2021 based on fishermen's catch areas and fish habitats. The relationship between length and weight of male fish is W = 0,00000006L^3,4839 which indicates a positive allometric growth pattern and for female fish is W = 0,000002L^2,761which indicates a negative allometric growth pattern.

Sei Gesek Reservoir is one of the reservoirs in Bintan Regency. This reservoir was dammed in 2011 which is intended to meet the water needs of Tanjungpinang City. One of the types of fish found in Sei Gesek Reservoir is belida fish (Notopterus notopterus). The purpose of this study was to determine the relationship between length and weight of bronze featherback (N. notopterus) in Sei Gesek Reservoir, Bintan Regency. Sampling was carried out from April to June 2021 based on fishermen's catch areas and fish habitats. The relationship between length and weight of male fish W = 0.0000005L^3.5115 and female W = 0.000001L^2.9067. The b value obtained for male fish shows positive allometric and female fish shows negative allometric.