Accumulation and Regulation Effects from the Metal Mixture of Zn, Pb, and Cd in the Tropical Shrimp Penaeus vannamei Gabriel Núñez-Nogueira & Laura Fernández-Bringas & Alfredo Ordiano-Flores & Alejandro Gómez-Ponce & Claudia Ponce de León-Hill & Fernando González-Farías Received: 29 May 2012 / Accepted: 14 August 2012 / Published online: 5 September 2012 # Springer Science+Business Media, LLC 2012 Abstract Environmental metal pollution is one of the major problems faced by humankind. This type of pol- lution affects aquatic systems (estuaries, coastal lagoons, etc.), which are very dynamic systems, therefore making the study of the effects on the organisms that inhabit them an essential issue. In this study, the capacity of metal regulation by decapod crustacean Penaeus vanna- mei juveniles was determined. The effects of zinc, lead, and cadmium were tested individually and as a metal mixture exposure to determine possible synergism. The results showed that juvenile shrimps were capable of regulating zinc and lead, whereas cadmium was accu- mulated without any excretion, at least within the con- centrations studied. It was also proved that under the estuarine conditions tested here, P. vannamei juveniles showed capacity to act as a bioindicator for cadmium. Keywords Penaeus vannamei . Accumulation . Regulation . Toxic metals . Essential metal Introduction In Mexico, intensive and extensive cultures of peneid shrimps including the white Pacific shrimp Penaeus vannamei, which are one of the economic resources of great significance among world fisheries, are made in estuaries and along the Pacific coast [1]. However, these coastal environments contain mix- tures of metals like nickel (Ni), zinc (Zn), lead (Pb), cadmium (Cd), among others, keeping the local fauna in constant expo- sure [2, 3]. The levels of these dissolved metals might not be lethal but can induce accumulative processes in fauna. Indeed, some studies have reported toxic effects by metals in P. vannamei post-larvae [4], such as alterations to the oxygen consumption, ammonia excretion, osmoregulation, food con- sumption, and nutritional condition [5, 6]. In aquatic animals, metal intake is through respiratory (gills) and body surfaces (adsorption and/or absorption) and the digestive tract through food ingestion and water filtration [7, 8]. On the other hand, the excretory and digestive systems seem to be internal sites for temporary accumulation or storage of metals, mainly kidney, hepatopancreas, liver, antennal gland, etc., before elimination from the body. If this elimination allows to keep the internal body concentration below the threshold level, no adverse effect is developed, but if this con- centration exceeds its regulation capacity, then perturba- tions appear, with different array of effects, including death of the organism. These effects depend basically on the level of pollution in the environment, on the species, on the individual, on the pollutant type, and the environmental conditions involved [9]. The sublethal effects of toxic metals lead to changes in the morphology or histology in a variety of organisms [7] such as the thickening of the branchial epithelium and G. Núñez-Nogueira (*) : L. Fernández-Bringas : A. Gómez-Ponce Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, Estación El Carmen, Ciudad del Carmen, Campeche, Mexico 24157 e-mail: nunezng@yahoo.com.mx C. P. de León-Hill Facultad de Ciencias, Unidad de Análisis Ambiental, Universidad Nacional Autónoma de México, Circuito Interior s/n, Ciudad Universitaria, Coyoacán, México, D.F., Mexico 04510 A. Ordiano-Flores : F. González-Farías Instituto de Ciencias del Mar y Limnología, Laboratorio de Química Ambiental, Universidad Nacional Autónoma de México, Circuito Interior s/n, Ciudad Universitaria, Coyoacán, México, D.F., Mexico 04510 Biol Trace Elem Res (2012) 150:208–213 DOI 10.1007/s12011-012-9500-z