Theraps Günther 1862

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 : 221

Genus Theraps Günther 1862

( Fig. 8 )

Inclusive species. T. irregularis (type species), T. godmanni , T. intermedius , T. microphthalmus , T. nourissati .

Diagnosis. Species of the genus Theraps are all elongate ( T. irregularis ) to moderately elongate (other species) cichlids occurring in lotic riverine systems. All species possess bodies that are longer than deep, versus deepbodied as in Vieja and Maskaheros . The mouth is small and subterminal, with the upper jaw extending over the lower jaw (more so in T. irregularis than in congeners). Spots are present on the dorsal, anal, and caudal fins. This genus is most similar to Paraneetroplus and Rheoheros gen. nov. Species of Paraneetroplus possess lower jaw teeth oriented anteriorly, versus dorsally in Theraps . Species of Rheoheros gen. nov. possess a freckled appearance across the body, versus the absence of this characteristic in Theraps .

Distribution. Atlantic slope rivers of Mexico, Belize, and Guatemala, to lowland tributaries of the Río Motagua drainage in Honduras (only T. microphthalmus ).

Comments. Theraps has always included riverine, elongate to moderately elongate cichlids ( Allgayer 1989; Günther 1862). Phylogenetic relationships recovered in the present study, as well as the corroboration of Matamoros et al. (2015), support this traditional habitat association, but with some restrictions on the inclusion of other riverine species in this genus (e.g., species of Rheoheros ). Thus, this riverine ecology and elongate body shape have evolved more than once within the herichthyin cichlids. The Honduran endemic ‘ C.’ wesseli was described as a member of Theraps but is not recovered as part of this clade or genus in any phylogenetic study to date. We continue to recognize the species as a member of ‘ Cichlasoma’ (incertae sedis) pending a systematic and taxonomic treatment of this species.

Material examined. T. godmanni , BMNH 1864.1.26.49-50 [n=2 (Syntypes), Guatemala: Río Cahabon], UMMZ 146113 [n=22, Guatemala: Río Cahabon]; T. intermedium , UMMZ 143744 [n=12, Guatemala: Río La Pasion], UMMZ 161764 [n=24, Mexico: Río Usumacinta]; T. microphthalmus , UMMZ 179910 [n=5, Guatemala: Río Motagua], UMMZ 190569 [n=15, Guatemala: Río Motagua], LSUMZ 15614 [n=8, Honduras: Río Motagua]; T. nourissati , MNHN 1989-0583 [n=1 (Holotype), Mexico: Chiapas], MNHN 1989-0583 [n=2 (Paratypes), Mexico: Chiapas].

Figures

FIGURE 8. Theraps irregularis, LSUMZ 16437, 102 mm SL.