Cynodonichthys Meek, 1904: type species: Cynodonichthys tenuis Meek, 1904;

Cynodonichthys was a sub-genus erected by Meek in 1904 in the genus Rivulus. Costa (2011) upgraded this subgenus to the genus status and assigned a number of taxa to this genus, all from the more northern part of Colombia, the Central American region and some of the caribbean islands not far from the coast of the continent of South America. Costa also nested the subgenus Vomerivulus (Fowler 1944) in this genus. These moves are discussed and not followed in this site.

Vomerivulus Fowler, 1944: 244 (first proposed as a subgenus; type species: Rivulus leucurus Fowler, 1944;

Cynodonichthys and Vomerivulus form 2 related subgenera of Rivulus, that have invaded central America from Colombia.

Costa included then 26 species which were: Cynodonichthys birkhahni (Ber- kenkamp & Etzel, 1992), C. boehlkei (Huber & Fels, 1985), C. brunneus (Meek & Hildebrand, 1913), C. chucunaque (Breder, 1925), C. elegans (Steindachner, 1880), C. frommi (Berkenkamp & Etzel, 1993), C. fuscolineatus (Bussing, 1980), C. glaucus (Bussing, 1980), C. godmani (Regan, 1907), C. hendrichsi (Alvarez & Carranza, 1952), C. hildebrandi (Myers, 1927), C. isthmensis (Garman, 1895), C. kuelpmanni (Berkenkamp & Etzel, 1993), C. leucurus (Fowler, 1944), C. magdalenae (Eigenmann & Henn, 1916), C. monikae (Berkenkamp & Etzel, 1995), C. montium (Hildebrand, 1938), C. myersi (Hubbs, 1936), C. pacificus (Huber, 1992), C. rubripunctatus (Bussing, 1980), C. siegfriedi (Bussing, 1980), C. sucubti (Breder, 1925), C. tenuis Meek, 1904, C. uroflammeus (Bussing, 1980), C. villwocki (Berkenkamp & Etzel, 1997), C. wassmanni (Berken- kamp & Etzel, 1999), C. weberi (Huber, 1992).

After Costa's work a new paper was released by Huber (2012) in which Huber stated that paper from Costa was not well supported by evidence and in which he reversed the genus names, erected by Costa 2011, back into Rivulus based on 144 external characters that produced evidence that Rivulus was still a monophyletic assemblage.

Several new discoveries were described after 2012 and you can find now a total of 30 valid taxa (+ 3 discussed taxa) in the list under this introduction page.

In this site we follow the latest evidence produced by Huber (2012) and recon the genus Rivulus as a monophyletic group.

Literature:

Meek, S.E. 1904. The Freshwater Fishes of Mexico North of the Isthmus of Tehuantepec. Field Columbian Mus. Zool. Ser. (Chicago Nat. Hist. Mus. Fieldiana Zool.) Publication, 5: 101. 

Fowler, H.W. 1944. Freshwater Fishes from Northwestern Colombia. Proc. Acad. Nat. Sci. Philad., 96: 244.

Costa, W.J.E.M., 2011. Phylogenetic position and taxonomic status of Anablepsoides, Atlantirivulus, Cynodonichthys, Laimosemion and Melanorivulus (Cyprinodontiformes: Rivulidae). *Ichthyological Exploration of Freshwaters* 22 (3): 233-249.

Huber, J.H. 2012b. Reappraisal of the Phylogeny of Rivulus and its Allied focused on External Characters. Killi-Data Series 2012, 9-25, 3 figs., 2 tabs.