Agonostomus monticola

Common Name

Mountain Mullet

Year Described

Bancroft, 1834


Dorsal Fin: IV, 9
Anal Fin: II,10
Pectoral Fin: I, 14-15
Lateral Line Scales: 38-45
Transverse Scales: 11-13
Circumpeduncular Scales: 20-22
Gill Rakers: 16-23 (lower limb of first arch)

Body elongate; cylindrical anteriorly and becoming compressed posteriorly. Snout pointed. Top of head with convex cross-section. Eye about equal to snout length. Terminal mouth barely reaches anterior margin of orbit. Adipose eyelid absent. Spiny dorsal fin situated anterior of mid-point of body. Anal fin inserted forward of second dorsal fin. Dorsal and anal fins mostly scaleless with a few scales on anterior base. Pectoral fin fairly high on side and may reach dorsal fin origin. Tail forked. Body scales ctenoid.


Body brassy yellow to brownish, with a darkened back and white belly. Scale margins dark. There is often a pale lateral stripe in fresh individuals and young. An horizontal eyestripe can be present. Black blotches present at the base of the pectoral and caudal fins. Fins with yellow to brassy blotches. Tail brassy.


Maximum size to 36cm SL


Adults are most commonly found in freshwater and can ascend far up rivers and streams. Juveniles and young found in marine and brackish water.


S. Florida to Venezuela, including the continental coast and most of the Caribbean islands. Strays up to the U.S. Atlantic coast and also north to the Mississippi River. Another population is restricted to the rivers of the Gulf coast of Mexico.


Harrison, I.J. 2002. Mugilidae (pp 1071-1085). In: Carpenter. 2002. The living marine resources of the Western Central Atlantic. Vol. 2: Bony fishes part 1 (Acipenseridae-Grammatidae). FAO Species Identification Guides for Fisheries Purposes. American Society of Ichthyologists and Herpetologists Special Publication No. 5.

McMahan, C.D., M.P. Davis, O. Domínguez-Domínguez, F.J. García-de-León, I. Doadrio, K.R. Piller. 2013. From the mountains to the sea: phylogeography and cryptic diversity within the mountain mullet, Agonostomus monticola (Teleostei: Mugilidae). J. Biogeogr. 40 (2013) 894-904.

Other Notes

McMahan et al. (2013) resolved four lineages of Agonostomus in the New World, with Caribbean populations being sister to an East Pacific lineage, and this clade being sister to the Gulf of Mexico population. A deeply divergent second East Pacific clade was sister to the three other populations. The four clades representing the four populations were resolved by mitochondrial data but not resolved by nuclear data. It is possible that two species of Agonostomus exist in the Western Atlantic and the genus awaits additional morphological study.