Histological and relative gene expression data obtained from the gills of juvenile turbot (Psetta maxima) after the exposure to varying degrees of severe environmental hypercapnia for 8 weeks

The experiment was conducted in the so called respirometer, a recirculating aquaculture respirometer system (RARS) which allowed the persistent, stable manipulation of carbon dioxide concentrations. Juvenile turbot (Psetta maxima) where subjected to different levels of environmental hypercapnia (low: ~3000 μatm, medium: ~15000 μatm, high: ~25000 μatm).

After eight weeks, fish where sacrificed and gill samples were taken for further histological and transcriptional analysis. For histological investigation of the gills, samples where fixed in 4% phosphate-buffered formalin and examined via a microscope equipped with a digital camera. In order to investigate changes in the transcriptome, a fraction of the gill samples was stored in RNAlater.