sampling.id Factor with 671 levels for one of 692 trout individuals (in qPCR files this is called 'Sample.Name') River Factor with two levels for either River Altja or River Mustoja Area Factor with 8 levels of combinations of four areas (I to IV) in each of the two rivers (abbreviated 'Alt' for Altja or 'Mus' for Mustoja) fork.length Continuous variable for the individual trout fork length in mm (snout to fin fork) mass Continuous variable for the individual trout body wet mass in g Tot_blood_I Continuous variable for the length measuremnt in mm of the total blood in the capillary RBC_I Continuous variable for the length measuremnt in mm of the red-blood-blood cell part in the capillary haematocrit Continuous variable for RBC_I / Tot_blood_I total Continuous variable for the length measurement in pixels of the distance between the lower kidney boundary and root of the dorsal fin muscle Continuous variable for the length measurement in pixels of the distance between the upper kidney boundary and root of the dorsal fin kidney Continuous variable for the length measurement in pixels of the distance between the lower and upper kidney boundary ruler Continuous variable for the length measurement in pixels of a 30 mm distance on scale paper muscle.std Continuous variable for muscle / ruler * 30, corresponds to the distance between the upper kidney boundary and root of the dorsal fin in mm kidney.std Continuous variable for kidney / ruler * 30, corresponds to the distance between the lower and upper kidney boundary in mm Sire Factor with 88 levels for the first parent inferred by parental recunstruction based on 14 short tandem repeats, not the sire - sex is unknow Dam Factor with 100 levels for the second parent inferred by parental recunstruction based on 14 short tandem repeats, not the dam - sex is unknow Family Factor with 234 levels for the interaction of Sire by Dam