Background:

Knowledge of growth is relevant because it provides information on the local dynamics of the population.

Goals:

This study evaluated the growth, size structure, morphometry, and sex ratio of C. bellicosus crab caught in the El Colorado lagoon, Ahome, Sinaloa, Mexico.

Methods:

Through size distributions and by the modal-progression method using the FISAT II program. Similarly, the growth parameters of the von Bertalanffy stationalized equation and the growth performance or Munro index (Ø) were determined from March 2012 to March 2013.

Results:

3,242 organisms of C. bellicosus were captured of which 1,770 were males and 1,472 were females. The population of C. bellicosus in the lagoon ranged in size from 40 mm to 190 mm (CW), showing two similar modes for males and females (100 mm and 110 mm, respectively). The relationships between CL-CW for both sexes were adjusted to a linear type model (males, CL = 0.5265CW-0.0539, R2 = 0.8058, p <0.05, females, CL = 0.581CW-0.6335, R2 = 0.7643, p <0.05). The CW-TW relationship was of potential type (males, TW = 0.561AC3.0751, R2 = 0.7968, p <0.05; females, TW = 0.0834C2.9077, R2 = 0.7589, p <0.05). In females, K = 0.90 years-1 and L∞ = 169 mm, K = 1.20 years-1 and L∞ = 178.5 mm.

Conclusions:

The growth curves suggest that C. bellicosus reaches its maximum length at 2.5 to 3 years. The sex ratio of 0.81 F : 1 M was significant (X2 (0.05, 11) = 19.675, X2 observada = 58.481, p < 0.05).