Wish I could remember where (maybe Chris Kresser's?), but I recall reading that skate liver oil was similar to cod liver oil except it was lower in vitamin A. And Green Pastures says that skate liver oil contains:
unique nutrients ... such as
chondroitin, squalene, and
Any reasons to go with one over the other? Since I eat liver regularly, I was leaning towards going with the skate.
I just did a bunch of averaging on GPP's FCLO figures to get some ballpark nutritional figures for Vitamin A & D content. They don't have as much data on SLO (skate liver oil) but you can average their IU/mL figures to compare its vitamin content. I'm taking FCLO for D but if there's comparable D levels in SLO and their A is lower I'd definitely consider it.
Although I am limiting my PUFA to less than 4g a day, sometimes 2g (thanks Peat and Danny!), I will say when I took 1 tablespoons of skate liver oil per day for a week awhile ago, my skin looked AMAZING. I did not stick with it because it wasn;'t cheap. But god damn it looked good. Cod Liver did not have the same effect.