Short synopsis of Theraps Günther, 1862

Type species: Theraps irregularis Günther, 1862

Distinctive characters: Theraps are rheophil cichlids with elongated, laterally compressed bodies, a long caudal peduncle and a small, slightly subterminal mouth. Stawikowski and Werner (1990) diagnosed the genus as following:

• elongated, laterally compressed body (body height 2.5 to 3times in SL) with ctenoid scales, caudal peduncle longer than high
• mouth opening small, upper jaw longer than lower jaw
• teeth bicuspid; anterior teeth of the upper jaw conically elongated
• more than five rows of small scales on cheeks
• DXV-XVIII/ 11-13; posterior basis of dorsalis with small scales (not in T. irregularis)
• A(III) IV-VI/ 7-19

Species currently included:

Theraps coeruleus	C
Theraps irregularis	C
Theraps lentiginosus	C
Theraps wesseli	C, A(Natural history)

C=CRC Catalogue, A=Article

Distribution: Atlantic versant of South México, Belize, Guatemala and Honduras from the Rio Grijalva to the Rio Papaloteca system.

Behavior/ Ecology: Theraps are open breeder except for T. lentiginosus, which breeds in crevices.

Further information: T. wesseli differs from the other Theraps in the size and position of the mouth. Stawikowski and Werner (1998) assign this species only preliminaryly to the genus.

Miller synonymized Paraneetroplus and Tomocichla with Theraps on the basis of osteological data (Heijns, 2000; Miller, 2005). Other morphological, genetic and ecological data, however, indicate that these genera represent different evolutionary lineages.

Furthermore, Miller (2005) considers T. rheopilus as a valid species and instead synonymizes T. coeruleus with T. lentiginosus.