Life Stage, chorion, and hatchery origin differences in the toxicity of 6PPDQ to coho salmon

Several salmonid species die from acute exposure to 2-((4-methylpentan-2-yl)amino)-5-(phenylamino)cyclohexa-2,5-diene-1,4-dione (6PPDQ) – a ubiquitous pollutant that enters waterways via roadway runoff. Coho salmon (Oncorhynchus kisutch) is the most sensitive species. Toxicity has been characterized for some coho life stages, but differences in study design and source populations between studies diminish comparability of life stage sensitivity. Coho were exposed to 6PPDQ at five distinct life stages (embryos, alevins, fry, parr, and adults) and as alevins from two different hatcheries; results were characterized by measures of sublethal morphological and behavioral effects, survival analysis, and concentration response analysis. Exposures during embryo development significantly altered morphology and caused post-hatch mortality and differences in phototaxis. Dechorionated embryos were vulnerable to 6PPDQ, with increased mortality relative to intact embryos. Embryos did not die in acute ..., Six replicate aquaria containing ~100 coho salmon embryos each were episodically exposed to 6PPDQ on 13, 24-hour intervals over the first 55 days of development, alongside six replicate control aquaria. Mortality rates were recorded daily for all replicates, and on two occasions five individuals from each replicate were subsampled and their yolk sizes, eye sizes, and lengths were measured. After hatching, 20 individuals from each replicate were placed in light/dark decision aquaria and the number of fish observed in the lighted half of each aquarium was recorded each minute in two, 10-minute tests.
In another experiment, the survival of three replicates containing 10, 27-day-post-fertilization coho salmon embryos of each of four treatments was monitored for 17 days. The dechorionated exposure treatment exposed embryos that had been removed from their chorion to 6PPDQ for 24 hours followed by 16 days of clean water. The intact exposure treatment exposed embryos with intact chorions to th..., # Life Stage, chorion, and hatchery origin differences in the toxicity of 6PPDQ to coho salmon

Dataset DOI: [10.5061/dryad.j6q573nsk](10.5061/dryad.j6q573nsk)

## Description of the data and file structure

### Files and variables

#### File: Acute_Exposure.csv

**Description:** rows describe the conditions and outcomes of each acute exposure aquarium. 

##### Variables

* Measured_6PPDQ_ng_L: the concentration of 6PPDQ, measured by LC-MS/MS, in nanograms per liter from 200 milliliter water samples taken from the replicate at the beginning of the experiment. 
* Number_Dead: the number of individual coho salmon in the replicate that were determined to be dead after 24 hours of exposure.
* Number_Total: the total number of individual coho salmon included in the replicate.
* MortalityRate: Number_Dead/Number_Total
* Group: the life stage or creek of origin of the individuals in the replicates. 
* Days_Post_Fertilization: the age in days since fertilization of the individuals in the replic...,