Hyporhamphus mexicanus

Common Name

Mexican Halfbeak

Year Described

Álvarez, 1959


Dorsal Fin: 15
Anal Fin: 13-15
Pectoral Fin: 10-11
Pelvic Fin: 6
Gill Rakers: 19-20 (17-19 on lower limb of first arch)

Body relatively slender. Preorbital ridge present and snout covered in scales. Lower jaw elongate. Dorsal and anal fins without scales, or scales restricted to anterior part of fin. Pectoral fin relatively short: does not extend past nasal opening when depressed forward*. Caudal fin moderately forked, with lower lobe enlarged.


Body pale to silvery with a silver lateral stripe widening posteriorly. Lower jaw with red tip. Caudal fin with dark posterior border.


Maximum size to 16cm SL.


A freshwater species that can be found near the mouth of the Rio Usumacinta.


Endemic to the Usumacinta and Papaloapan river systems of eastern Mexico.


Contreras-Balderas, S., M.L. Lozano-Vilano, and M.E. Garcia Ramirez. 1997. Distributional and ecological notes on the halfbeaks of eastern Gulf of Mexico, with a provisional key for their identification. Gulf Research Reports. January 94: 327-331.

Miller, R. R. 2006. Freshwater fishes of México. Chicago. University of Chicago Press. xxvi + 1-490.

Other Notes

Included as it is closely allied to the other marine species in the genus.