TY - JOUR
T1 - Energy resource reallocation in Daphnia schodleri (Anomopoda: Daphniidae) reproduction induced by exposure to hexavalent chromium
AU - Arzate-Cárdenas, Mario Alberto
AU - Martínez-Jerónimo, Fernando
N1 - Funding Information:
MA Arzate-Cárdenas is grateful for support from CONACYT (fellow No. 205561) as well as the Programa Institucional de Formación de Investigadores (PIFI) of the Comisión de Operación y Fomento de Actividades Académicas (COFAA). F. Martínez-Jerónimo is thankful for financial support provided by the Sistema de Estímulo al Desempeño de los Investigadores (EDI) and COFAA of the Instituto Politécnico Nacional.
PY - 2012/4
Y1 - 2012/4
N2 - Cladocerans are able to store energy in the form of macromolecules such as proteins, lipids and carbohydrates. However, their ability to do so depends to a large extent on their physiological and reproductive condition as well as their age. These macromolecules constitute the total caloric reserves of the body and may be modified as a result of environmental stress conditions by either physical or nutritional factors or by exposure to toxic compounds. Neonates of the freshwater cladoceran Daphnia schodleri were exposed to 0.0064, 0.032 and 0.064mgL-1 of hexavalent chromium - Cr(VI) - up to age 5, 7, 14, 21 or 28d. Survival and fecundity of parthenogenetic females was evaluated for 28d (maximum exposure period). Body length and maximum width were determined in specimens of all ages. Caloric content was evaluated in progeny and females within each age group. Female survival was significantly lower with exposure to 0.064mgL-1 of Cr(VI) than with other treatments, and negative effects on reproduction were observed from the lowest concentration on. Largest adult size was attained by control specimens towards the end of the observation period, but no significant differences in neonate size occurred between concentrations. Energy content decreased in adults as toxicant concentration increased, but these females allocated a larger amount of energy reserves to their progeny as a possible compensation aimed at ensuring neonate survival in an adverse environment due to toxicant presence. Sublethal concentrations of Cr(VI) modified energy content in D. schodleri, affecting to varying degrees its survival, growth and reproduction.
AB - Cladocerans are able to store energy in the form of macromolecules such as proteins, lipids and carbohydrates. However, their ability to do so depends to a large extent on their physiological and reproductive condition as well as their age. These macromolecules constitute the total caloric reserves of the body and may be modified as a result of environmental stress conditions by either physical or nutritional factors or by exposure to toxic compounds. Neonates of the freshwater cladoceran Daphnia schodleri were exposed to 0.0064, 0.032 and 0.064mgL-1 of hexavalent chromium - Cr(VI) - up to age 5, 7, 14, 21 or 28d. Survival and fecundity of parthenogenetic females was evaluated for 28d (maximum exposure period). Body length and maximum width were determined in specimens of all ages. Caloric content was evaluated in progeny and females within each age group. Female survival was significantly lower with exposure to 0.064mgL-1 of Cr(VI) than with other treatments, and negative effects on reproduction were observed from the lowest concentration on. Largest adult size was attained by control specimens towards the end of the observation period, but no significant differences in neonate size occurred between concentrations. Energy content decreased in adults as toxicant concentration increased, but these females allocated a larger amount of energy reserves to their progeny as a possible compensation aimed at ensuring neonate survival in an adverse environment due to toxicant presence. Sublethal concentrations of Cr(VI) modified energy content in D. schodleri, affecting to varying degrees its survival, growth and reproduction.
KW - Caloric content
KW - Cladocerans
KW - Environmental stress
KW - Fecundity
KW - Metals
KW - Zooplankton
UR - http://www.scopus.com/inward/record.url?scp=84857503303&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2011.12.014
DO - 10.1016/j.chemosphere.2011.12.014
M3 - Artículo
C2 - 22209250
SN - 0045-6535
VL - 87
SP - 326
EP - 332
JO - Chemosphere
JF - Chemosphere
IS - 4
ER -