Length-weight relationships of the Emerald Shiner (Notropis atherinoides - Rafinesque, 1818) in the Western Basin of Lake Erie

Abstract

Total length and standard length (mm) were compared to weight (mg) in the Emerald Shiner (Notropis atherinoides - Rafinesque, 1818) in the western basin of Lake Erie. Length and weight relationship (n = 400), length-frequency distribution, and sex ratios were evaluated for  coastal and tributary habitats and compared to open water habitats. A strong positive correlation was observed between length and weight for both males and females. For males (n = 195) there was a significant positive relationship between standard length (SL) and weight (F = 935.64, d.f = 195; R2 = 0.989) and between total length (TL) and weight (F = 918.75, d.f. = 195; R2 = 0.991). In females (n = 205), there was also a strong positive correlation between SL and weight (F = 1108.18, d.f. = 204; R2 = 0.976) and between TL and weight (F = 1208.86, d.f. = 204; R2 = 0.983). This same positive relationship between SL and weight (F = 1909.58, d.f. = 399; R2 = 0.984,) and between TL and weight (F = 1960.07, d.f. = 399; R2 = 0.988) that was found for  the individual sexes was present in the combined data for the two sexes. Length-weight relationship patterns in Emerald Shiner were significantly influenced by sex (ANCOVA, F= 313.03, p < 0.01) and habitat (ANCOVA, F = 6.693, p = 0.013).  Three separate age classes were distinguished in the data. Age 0 males ranged from 15-33 mm TL, while age 0 females ranged from 18-30 mm TL. Age I males ranged from 39-78 mm TL and Age I females ranged from 42-78 mm TL. Age II+ males ranged from 78-111 mm TL and Age II+ females ranged from 81-108 mm TL. Emerald Shiner exhibit indeterminate growth and sex influenced growth patterns based on the von Bertalanffy growth model.