Population structure capture of the oyster Crassostrea virginica, in two lagoons of Tampamachoco and Tamiahua, Veracruz, Mexico

Abstract

The objective of this research was to evaluate the size structure of the capture of Crassostrea virginica in the lagoons of Tamiahua and Tampamachoco, located in the north of the state of Veracruz, Mexico. Monthly samples were collected during the period from April 2011 to March 2012, by means of the fishing tackle of gafas; (Spanish word for clamp). The structure of sizes and distribution of stadiums of C. virginica, the relationship between length-weight and growth ratio of the species for each of the lagoons was determined. The oyster population of Tamiahua was dominated by two groups of individuals with sizes of 48-52 mm and of 52-56 mm. In Tampamachoco, organisms with sizes of 52-56 mm and 56-60 mm were predominant. The highest proportion of juvenile oysters in Tamiahua appeared in April and in June 2011, with 28%; adults were more abundant in February 2012, with 92%. For Tampamachoco, the highest percentage of juvenile oysters was observed in July and September 2011, with 16%, and adults in October 2011 with 97%. The relationship between weight and total length of C. virginica in Tamiahua was represented by the equation: (PT=3.76 * Lt 1.18; r= 0.59181), whereas for Tampamachoco, the equation was: (PT= 2.64 * Lt 1.26 r= 0.5792). The projection of the growth equation for the Lagoon of Tamiahua showed that at the relative age of 5 years, C. virginica could reach 95% of its growth, whereas for the population of Tampamachoco, this growth percentage could be reached at the age of 4 years.