Background:

The southern zone of the estuary of the Jamapa River, Veracruz, is a place of transition between the river and the marine environment to which sediments, compounds, and species of crustaceans are transported to the neritic zone where is the Parque Nacional Sistema Arrecifal Veracruzano.

Objective:

The responses of exposure of Potimirim mexicana postlarvae to diuron, glyphosate, and paraquat, as well as the relative abundance, diversity of the association of crustaceans, and values of temperature, salinity, oxygen, pH, and dissolved solids in the estuary were evaluated.

Methods:

Sampling was carried out with white light traps in November and March. Living Potimirim mexicana postlarvae were obtained from the samples to carry out the bioassays; the remaining individuals of the association were fixed in 70% alcohol for identification and quantification. The environmental factors were measured using a multiparameter Hanna HI 9828.

Results:

Dissolved oxygen was of 6-7 mgL-1, pH of 8-9, temperature of 26-27° C, total dissolved solids of 700-1,500 ppm and salinity of 0.70-16 ups. Environmental conditions permit the presence of Potimirim mexicana postlarvae. Six taxa were found: postlarvae of Macrobrachium acanthurus, M. olfersii and Potimirim mexicana, megalopae of Callinectes sapidus and Armases ricordi, and zoeae of Brachyura. Diversity ranged from 1.55 to 1.77 bits*individual-1, indicating an intermediate stability of the estuary. A total of 12,827 postlarvae of P. mexicana were obtained. The LC50 values of diuron, paraquat, and glyphosate were 5.94, 1.51, and 221.05 mgL-1, respectively.

Conclusions:

The values found here are consistent with those obtained by other authors for different species of crustaceans. Due to the important ecological in the food web of P. mexicana, its postlarvae can be used as sensitive test organisms in ecotoxicological studies.