Cathorops

Key to the species of Cathorops from the Pacific Coast of Central and South America

1. 37-40 gill rakers on first and second arches; distance between anterior nostrils 6.92-7.14% SL; distance between posterior nostrils 8.19-8.51% SL.......................................................... Cathorops hypophthalmus

- 13-22 gill rakers on first and second arches; distance between anterior nostrils 3.60-5.98% SL; distance between posterior nostrils 4.23-7.26% SL..................................................................................................2

2. Medial groove of neurocranium very narrow and shallow, with irregular margins all its length........................................................................................................................................................... Cathorops fuerthii

- Medial groove of neurocranium deep and large, with lateral margins regular and progressively narrower posteriorly.................................................................................................................................................. 3

3. 19-23 anal fin rays.......................................................................................................................................4

- 24-27 anal fin rays.......................................................................................................................................6

4. Vomerine tooth plates present; osseous bridge formed by lateral ethmoid and frontal granulated in all its length.................................................................................................................... Cathorops dasycephalus

- Vomerine tooth plates absent; osseous bridge formed by lateral ethmoid and frontal without granulation......................................................................................................................................................................5

5. 19-20 anal fin rays; accessory tooth plates with very large molariform teeth; dentary with a well pronounced posterior projection and very large and numerous molariform teeth on posterior portion.......................................................................................................................................................... Cathorops tuyra

- 22-23 anal fin rays; accessory tooth plates with molariform teeth of moderate size; dentary with moderately pronounced posterior projection and small and few molariform teeth on posterior portion................................................................................................................................................ Cathorops steindachneri

6. Maxillary barbel 22.9-27.7% SL; 16-19 gill rakers on first arch; pectoral fin spine 16.9-18.7% SL; dorsal fin spine longer than pectoral fin spine................................................................... Cathorops multiradiatus

- Maxillary barbel 28.4-38.2% SL; 13-16 gill rakers on first arch; pectoral fin spine 18.5-22.5% SL; dorsal fin spine shorter than pectoral fin spine.................................................................. Cathorops manglarensis