Abstract

PARASITIC HELMINTHS IN WILD POPULATIONS OF FARFANTEPENAEUS AZTECUS IN ESTERO LA MATA, VERACRUZ, MEXICO

Arturo Valdez Murillo, Rosa Idalia Hernández Herrera and Eduardo Alfredo Zarza Meza*

ABSTRACT

A total of 270 wild juvenile specimens of the brown shrimp (Farfantepenaeus aztecus) were reviewed. These were collected in the Estero La Mata, at three sampling points covering from the low part of Puente Tampamachoco to the entrance to the lagoon of Tampamachoco, in three climatic seasons of the year 2009: cold nortes, dry and rainy. The sampling points of these organisms were selected to represent areas where the shrimp fishery is active. Captures were made at night, since these organisms are of nocturnal habits. The highest water temperature (28.9 °C) was presented during the drySeason, while the lowest temperature (23.6 °C) was presented in the cold and rainy seasons. The mean water temperature recorded was 25.7 °C. Salinity was generally higher in the dry season (37 ups) than in the cold and rainy seasons (28 ups), at the sampling points that covered from the entrance to Estero La Mata, as well as its Communication with the lagoon of Tampamachoco, and mean water salinity was 33.6 ups. In terms of brown shrimp sizes per sampling season, a significant difference total length was recorded among the three seasons of sampling, and the sizes ranged from 6.5 to 8 cm, with mean total size 7.47 cm. Significant differences were presented in the recorded values of weight of the brown shrimp among the three sampling seasons; the weights ranged from 1.9 to 3.6 g, with a mean value of 2.8 g. In terms of the proportion of sexes of the brown shrimp per sampling season, a slightly higher proportion of females to males was observed, at approximately 2:1. The parasites identified belonged exclusively to the species Prochristianella penaei (cestoda) and these were detected with a high frequency and abundance in both the nortes and dry seasons, while they were not detected in the rainy season. Likewise, no histological damage was recorded, even in the hepatopancreas. It is likely that the risk presented by the environmental variables detected in the present study exerts less of an influence on the parasite than on its intermediate hosts.

Keywords: Helminths, prevalence of Farfantepenaeus aztecus, environmental factors, Estero La Mata.