Ramli, AminRamses, RamsesAgustina, Fenny2021-03-122021-03-122019-11978-60251349-1-3wahyu sari yenihttps://repository.unri.ac.id/handle/123456789/9956The aim of study was to analyze the biological aspects, morphometrics, length-weight relationships, growth patterns and condition factors, mullet fish (Mugilidae) caught in Pulau Panjang waters. This research was conducted in May-June 2019. The research location is Pulau Panjang waters, Sijantung, Galang District, Kota Batam. Fish samples were obtained by using gill nets with 1.5 inc mesh size, 2.5 meters width, and 250-meter lengths. Weight length relationship analysis using the Allometric Linear Model (LAM) to calculate parameters a and b through measurement of changes in weight and length. The relative weight condition factor (Wr) and Fulton koefisen (K) are used to evaluate the condition factors of each individual fish sample. There are as many as 3 types of Belanak fish namely Liza tade (belanak bakau), Liza vaigiensis (belanak tamok), and Crenimugil crenilabis (belanak putih). The length and weight range of mullets caught during the study were L.tade with a length range of 17.20- 26.10 cm (an average of 21.9 cm), and a weight of 58.00-187.00 grams (an average of 111.32 gr). L.vaigiensis ranges in length from 13.80-28.60 cm (21.68 cm), and weighs 39.00-322.00 grams (an average of 158.00 gr). And C.crenilabis range in length from 16.50-27.50 (an average of 21.12 cm) and a weight of 51.00-234.00 (an average of 101.30 gr). The length-weight relationship of L.tade has a regression equation y = 2.882x -4.222 with a value = 0.0147 (W = 0.0147L3.649). L. vaigiensis has the equation y = 3.079x -4.568 with a value = 0.0104 (W = 0.0104L3.079). Whereas C. crenilabis has a regression equation y = 2,703x -3,675 with a value = 0.0253 (W = 0.0253L2.703). L. tade has a negative allometric growth pattern with an exponent value of 'b' <3 (2,882), and C. crenilabis also has a negative allometric growth pattern with an exponent value of 'b' <3 of 2,703. Whereas L.vaigiensis has positive allometric growth with an exponent value of 'b'> 3 (3,079). Based on the coefficient of determination (R2) all species show that weight gain is influenced by the increase in fish length. Condition factors indicate good environmental conditions and a balance between prey and predatorenBioecologyLength-Weight RelationshipMullet FishCondition FactorsArticle