SCP Foundation

None of my boilerplate advice applies here. Good job!

CONCEPT:

• The core idea of this skip is rather fascinating. It's a species of bottom-feeding catfish that subsists on knowledge. I mean, as a Dungeon Master with 20+ years under his belt, this is quite reminiscent of the Aboleth from D&D. However, it's different enough that I can read your article without constantly being reminded of the Monster Manual.
• The addenda are interesting enough to carry the article forward without bogging it down with pedantic exposition, so… good job there!

SPECIFICS:

• "… measuring from 0.3 to 0.5 meters long and weighing an average of 6 kilograms." <— I would use ‘cm’ for the length and abbreviate ‘kilograms’. Try, "… measuring between 30-50cm long and weighing an average of 6kg.
• "SCP-XXXX-1 possess powerful hearing, a feature which they use to seek prey." <— For this, I'd suggest tightening up the language here. Try, "SCP-XXXX-1 instances possess advanced auditory sensory organs." The ‘… a feature …’ is rather unnecessary because, well, of course that's why a fish would have heightened senses.
• "… it consumes the memories of its prey." <— Here's the thing that bothers me here. You refer to memories as a physical thing that can be consumed, stored, and digested. Maybe you could describe the physical nature of ‘memories’ in regards to the skip.
  • Does SCP-XXXX-1 secrete an oily substance into the braincase of its victim which is what picks up the information, solidifies into a semisolid state like noodles, and gets schlorped back up by SCP-XXXX-1?
• "These corpses usually belonged to whales, sharks, or other large deep-sea fauna." <— Overly casual. Try something like, "The majority of the corpses found belonged to large-bodied deep-sea fauna."

There are a couple more instances of casual language that can be tightened up pretty easily.