En el Estado de Tabasco, México, existen diversos reportes de los efectos toxicológicos de contaminantes con orígenes de pesticidas organoclorados, hidrocarburos y metales pesados. Todos los reportes existentes en el Estado de Tabasco, México son en fauna silvestre y en la actualidad no existe reporte en la flora local. Se utilizó la técnica de citogenética vegetal convencional con células de raíces de la especie Chloris gayana, zacate común africana del sureste mexicano. Se identificaron tres cariotipos diferentes: 2n=10 cromosomas (cuatro submetacéntricos “sm”+ seis telocéntricos “t”), 2n=20 cromosomas (4sm+16t) y 2n=20 cromosomas (6sm+14t). También, en el análisis intracelular de C. gayana se identificó la presencia de siete malformaciones: células diploides, células triploides, células tetraploides, micronúcleos, puentes nucleoplásmicos, alargamiento celul...

Ten specimens of Thorichthys helleri (five females and five males) were collected in a lagoon ofthe town from Paraiso, Tabasco, Mexico. Conventional cytogenetic technique was applied toorgan tissues (pancreas and kidney) and peripheral blood. Cytogenetic study on T. helleri revealed a karyotype of 2n=48 chromosomes which is described; chromosome classification corresponded to 2 metacentric-submetacentric + 44 subtelocentric-telocentric + 2 sex chromosome (1 msm + 1 stt). The fundamental number in T. helleri was NF=51. The karyotype of T. helleri from Paraiso, Tabasco, Mexico, is different from 19 other species of the cichlid family.It contributes unpublished biological information on T. helleri with distribution in Southern of Mexico.

Kinosternon leucostomum is one of the common freshwater turtles in Tabasco State, Mexico. However, studies of this species are limited for this region. The pollution in aquatic ecosystems from Tabasco is increasing and the effects on wildlife have not been properly made. Therefore, a chromosomic study and DNA lesion and nuclear malformation was performed in K. leucostomum from Tabasco. The karyotype in the turtle K. leucostomum is 34 msm/A + 22 T/C(2n=56 chromosomes). Also, intracellular malformations were identified: Chromosomes and DNA damage (micronucleus), binucleated cells, trinucleated cells, tetranucleated cells, cells in apoptosis and nucleoplasmic bridge, in irregular proportions. The probable origin of cell disorders is due to the presence of contaminants in aquatic ecosystems from Tabasco.