Population dynamics of black brotula (Cherublemma emmelas) in deep waters of the Gulf of California
ABSTRACT: First report of the dynamic populations (structure size, growth, size at first maturity, longevity, natural mortality, and recruitment pattern) of black brotula Cherublemma emmelas in the Gulf of California. Growth parameters (L ( , k and t o ) were estimated using the von Bertalanffy model. The ELEFAN II method was used to estimate recruitment pattern and Taylor’s equation to estimate longevity. Natural mortality was determined using Pauly’s equations and Jensen’s. Size at first maturity was obtained by adjusting a logistics model. During four cruises on board the BIP-XI research ship, 2148 specimens were caught at 119-499 m depth in February and May 2005, and June and October 2007. The size structure showed a bimodal distribution with lengths from eight to 32 cm of total length and 15.9 cm average size. The biometric relationship between weight and length showing allometric growth rate (b ≠ 3) for sex. The fitted growth parameters were L∞ = 33 cm; k = 0.6 yr-1; t o = -0.26 year indicated a moderate growth, while longevity was five years of age. Size at first sexual maturity was 18.8 cm, and natural mortality was 0.77 yr-1 (by Pauly) and 0.90 (by Jensen). The recruitment pattern showed peaks in June and July.