Abstract:

The purpose of this research was to determine windows of increased sensitivity to combined oil and hypoxic exposure under varying salinity regimes during early life stage development of sheepshead minnows. The early life development was divided into three stages: embryonic (< 15 hpf), post-hatch (<10 hph), and post larval (96 hph). Immediately after each transition period sheepshead minnow larvae were exposed to four concentrations of HEWAF (6.25%, 12.5%, 50% and 100% of 1g/L stock solution) under different oxic (2.5 mg/L and >5.0 mg/L) and salinity (10 and 30 ppt) regimes, while temperature was maintained at 30°C. After the 48 h exposure period, larvae were transferred to normoxic clean water to monitor growth and mortality for up to 10 days. The experiments were static experiments with water renewals every 48 hours. Water quality and organism performance were monitored and recorded daily. A sample of 3.5 mL of exposure water was collected from each test chamber during water quality monitoring at 0 h, 24 h, 48 h, and 72 h for fluorescence analysis to measure PAH concentrations. Whole body tissue samples were collected directly after the 48 h exposure period measure relative gene expression and investigate pathway inhibition between the aryl hydrocarbon and hypoxia inducible factor 1-α signaling pathways. Target genes included Cytochrome P450 1A1 (CYP1A1), Erythropoietin (EPO), and Aryl hydrocarbon receptor nuclear translocator (ARNT).

Suggested Citation:

Griffitt, Robert J., joe.griffitt@usm.edu. 2017. Impacts of oil exposure during early life developmental stages in Sheepshead minnows (Cyprinodon variegatus) under different environmental factors. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7639N4C

Publications:

Jones, E. R., Simning, D., Serafin, J., Sepúlveda, M. S., & Griffitt, R. J. (2020). Acute exposure to oil induces age and species-specific transcriptional responses in embryo-larval estuarine fish. Environmental Pollution, 263, 114325. doi:10.1016/j.envpol.2020.114325

Purpose:

The purpose of this research was to determine windows of increased sensitivity to combined oil and hypoxic exposure under varying salinity regimes during early life stage development of sheepshead minnows.

Data Parameters and Units:

Data are separated by environmental folder and gene expression folder; File names describe the development state (embryonic, post-hatch, or post-larval), oxygen regime (hypoxic or normoxic), and salinity regime (low or high) Normoxic = 5.0 mg/L Hypoxic = 2.0 mg/L Low salinity = 10 ppt High Salinity = 30 ppt Temperature = 30°C oil loading rate (g/L) temperature (deg C) salinity (ppt) treatment (control, 6.25%, 12.5%, 50%, 100%, NCNT) date (mm/dd/yyyy) time (HHHH) period (hr) number at start of test number alive number hatched number of non-treatment mortality number of treatment mortality notes recorded by number of viable embryos mean heartbeat (/10 sec) mean heartbeat (/min) # of heartbeats in 10 sec for individual embryos pH dissolved oxygen (mg/L) ammonia measured in parts per million (ppm or mg/L) ppb = parts per billion HEWAF = high-energy water accommodated fraction PAH = polycyclic aromatic hydrocarbons (ng/mL) dpf = days post fertilization dph = days post hatch SHM = sheepshead minnows CYP1A1 = cytochrome P450 1A1 EPO = Erythropoietin ARNT = Aryl hydrocarbon receptor nuclear translocator 18S = control HK = housekeeping gene Ct = threshold cycle (no units) RQ = relative quantitation values (no units) RQ min = minimum relative quantitation values (no units) RQ max = maximum relative quantitation values (no units) Tm = melting temperature of the primers (degrees C) NOAMP = no amplification EXPFAIL = exponential algorithm failed HIGHSD = High standard deviation in replicate group MTP = Multiple Tm peaks

Methods:

RNA extraction, cDNA synthesis, PCR

Individual Files: