Differs from all other species of Cathorops by having the following features: fleshy papillae intercalated with gill rakers on first two gill arches; posterior margin of pectoral-fin spine with long and conspicuous serrations (except in Cathorops kailolae, Cathorops melanopus, Cathorops multiradiatus, and Cathorops tuyra); gill rakers on first arch 14-16; and snout length 9.3-11.6% SL. Can be further separated from Cathorops belizensis by its longer supraoccipital process 11.5-16.3% SL (vs. 8.8-10.5% SL), larger orbital diameter 4.6-6.9 % SL (vs. 3.6-4.4% SL), and shorter interorbital distance 9.9-12.3 (vs. 12.9-15.1% SL); from Cathorops higuchii by its gill rakers on second arch 13-16 (vs. 17-21), and larger orbital diameter 4.6-6.9 (vs. 3.3-4.4% SL); from Cathorops kailolae by its longer distance from tip of snout to dorsal-fin origin 39.0-40.7 (vs. 33.1- 38.0% SL); from Cathorops mapale species group by its gill rakers on second arch 13-16 (vs. 17-21); from Cathorops melanopus by its longer distance from tip of snout to dorsal-fin origin 39.0-40.7 (vs. 30.0-32.6% SL), and longer distance from tip of snout to posterior margin of dorsomedian groove of neurocranium 22.9-26.4 (vs. 17.9-19.1% SL) (Ref. 75004).