Table 2. Properties of the type I AFPs from the four groups of fish.
| Species or group | Different categories | Size range (kDa) | Skin/blood isoforms different | Signal peptides | Pro-peptide | Thr spacing | Codon preference | Internal Pro/Gly | Introns |
| Cunner | 2a | 4–7 | Yes | No | No | Yes/? | GCT | No/? | 1 |
| Snailfishes | 1 | 9–10 | No | No | No | No | GCC | Yes | ? |
| Flounders | 3 | 3–33 | Yes | Yes/No | Yes/No | Yes | GCC | No | 1 |
| Sculpins | 2 | 3–8 | Yes/Nob | No | No | Yes/No | GCG | No | 0 |
a
The sequence of a larger circulating isoform is unknown but an accurate mass and rough composition were determined from an enriched sample [66].
b
Longhorn sculpin skin and circulating isoforms are highly similar, but one shorthorn sculpin cDNA from skin encodes a distinct isoform.