Mesoheros, Mcmahan, Caleb D., Matamoros, Wilfredo A., Piller, Kyle R. & Chakrabarty, Prosanta, 2015

Mcmahan, Caleb D., Matamoros, Wilfredo A., Piller, Kyle R. & Chakrabarty, Prosanta, 2015, Taxonomy and systematics of the herichthyins (Cichlidae: Tribe Heroini), with the description of eight new Middle American Genera, Zootaxa 3999 (2), pp. 211-234 : 228-229

Genus Mesoheros gen. nov. McMahan and Chakrabarty 2015

( Fig. 17 )

Inclusive species. M. festae (type by designation), M. atromaculatus , M. ornatus

Diagnosis. The genus Mesoheros is diagnosed by an elongate body with a moderately small mouth that does not reach the anterior margin of the orbit. Seven (rarely six) dark spots (including bars in M. festae ) are present along the lateral sides of body. All other genera of herichthyin cichlids with a small mouth possess a deeper body with angular heads, and lack this number of spots and bar-type markings along the body. The caudal fin is relatively truncate to rounded, and a well-defined, round, black spot is present on the dorsal portion of the caudal peduncle sitting directly above (often resting upon) the lower lateral line. Scale rows continue onto the base of the dorsal and anal fins. Spots are present on the dorsal, caudal, and anal fins.

Distribution. Colombia, Ecuador, and Peru; Río Atrato, Río San Juan, and Río Baudó in the Atlantic, Río Patia ( Colombia) to Río Esmeraldas and Río Tumbes in the Pacific.

Etymology. Gender masculine. The generic epithet Mesoheros is based on “Meso-” which is Spanish for middle, for Middle America, given that this South American cichlid is one of the only species phylogenetically nested in a derived Middle American cichlid clade. “-heros” is in reference to the generic name formerly used for many neotropical cichlid species.

Comments. This is the only genus of South American cichlids that is part of the Middle American herichthyin clade as recovered in the present phylogeny. This relationship has been recovered consistently in molecular phylogenetic studies of neotropical cichlids ( Chakrabarty 2006; López-Fernández et al. 2010; Říčan et al. 2013; Matamoros et al. 2015) and these three species are recovered as the sister group to the northern Middle American herichthyins. Thus, we recognize these three species in their own genus, Mesoheros , based on morphological distinctiveness and phylogenetic position.

Material examined. M. festae ; FMNH 122434 [n=4, Ecuador: El Oro, Santa Rosa], FMNH 122420 [n=3, Ecuador: El Oro, Santa Rosa]; M. atromaculatus ; FMNH 58600 [n=5, Colombia: Istmina], FMNH 58606 [n=2, Colombia: Quibdo]; M. ornatus ; FMNH 58609 [n=3, Colombia: Río Telembi].

Figures

FIGURE 17. Mesoheros festae, FMNH 122420, 82.2 mm SL.