Miguel Hernández-Pedraza¹, Jesús Alvarado-Flores^2,, Marcelo Silva-Briano³, Araceli Adabache-Ortiz³, Roberto Rico-Martínez^1,

The elemental composition of biological structures in ostracods cultured under standard conditions is a biological reference material and a baseline to study bioaccumulation due to exposure to inorganic compounds in laboratory experiments or samples collected from the environment in ostracods. Ostracods are used as paleoclimatic, and paleo-evolutionary study models, and are sentinels of climatic change and anthropogenic pollution. The main goal was to collect ostracods from the Yucatan peninsula and culture them in the laboratory under standard conditions to establish the elemental composition. Seven strains of ostracods of three species Cypridopsis cf. vidua (OF Müller), Diaphanocypris meridiana (Furtos), Heterocypris cf. incongruens (Ramdohr), were collected using a Wisconsin-type plankton net of 54 µm of mesh opening. We use EPA medium (NaHCO3, CaSO4•H2O, MgSO4•7H2O, and KCl) pH 7.5, and a hardness range of 80-100 CaCO3 mg L-1 to culture the ostracods, which were kept in a bioclimatic chamber with 25 + 2 oC and a photoperiod of 16:8 h light: darkness. Ostracods were fed commercial lettuce Lactuca sativa. A two-month acclimation period was enforced after which ostracod specimens were identified to genera and fixed with 5% formaldehyde. These samples were processed and photographed with the Scanning Electron Microscope with which the elemental analysis using X-ray diffraction was performed in valves and appendages. Our results indicate that most of the elemental Ca are in the valves (41% of total dry weight) when compared to appendages (4%). A total of twelve elements were found in valves and appendages: Al, Br, Ca, Cd, Cl, Cr, Cu, Mg, Na, O, and Si. Ostracods are excellent bioindicators of inorganic elements for the study of environmental contamination.

Bioaccumulation, Environmental Toxicology, Exploratory Strategies, Metal Toxicity, Zooplankton