Growth, reproduction, and size at first maturity of blue shrimp, Litopenaeus stylirostris (Stimpson, 1874) along the east coast of the Gulf of California, Mexico

The shrimp fishery is one of the most important fishery in the Gulf of California. Blue shrimp Litopenaeus stylirostris (Stimpson, 1874) is the target species in the catch, in bays and coastal lagoons and represents about 30% of offshore fishing along the coast of the state of Sonora. We present growth estimates, reproductive periods, and size at first maturity for this species from samples conducted during three fishing seasons: 1993-1994, 1995-1996, and 1996-1997. Daily samplings of length, weight, sex, and sexual maturity were conducted from the catch of the fishing fleet of Sonora during the three seasons, as well as from bay catches in 1996-1997. A length-based method software (FiSAT) was used to assess growth, the longevity was calculated from Pauly's equation, and the maturity-length relationship was described with a logistic curve. The growth parameters obtained were: (i) females L∞ (abdominal length in mm) 160 ≤ L∞ ≤ 163 and K (1/year) 1.8 ≤ K≤ 1.92; (ii) males 152 ≤ L∞ ≤ 153 and 2.16 ≤ K ≤ 2.28; and (iii) for both sexes 159 ≤ L∞ ≤ 160 and 1.9 ≤ K ≤ 2.04. The longevity estimated was 1.7 years. Reproduction occurred from March to September. The recruitment pattern, obtained through the ELEFAN II method, was from March to October, with a maximum from May to July. Size at first maturity was 109 mm (abdominal length). There were inter-annual variations in reproduction, as well as in the recruitment pattern.