Otocinclus mimulus Axenrot & Kullander, 2003

Otocinclus mimulus Axenrot & Kullander, 2003 View in CoL Fig. 4

Otocinclus mimulus Axenrot & Kullander, 2003: 251 . Type locality: Paraguay: Departamento Caaguazú: río Paraná drainage, small stream (arroyo) at Estancia María Belén, 8 km from Colonel Patricio Colman   GoogleMaps ; 25°40’13”S 55°5’52”W. Holotype: MNHNP uncatalogued (ex NRM 43480), 34.1 mm SL [ Holotype originally cited as MNHNP uncat.].

Diagnosis. Otocinclus mimulus is distinguished from all other Otocinclus species except O. arnoldi , by having five branched rays in the pectoral-fin ( vs. six branched pectoral-fin rays), and except from O. arnoldi and O. xakriaba by having the prootic involved in the contact with the hyomandibular articular condyle ( vs. only compound pterotic contacting the hyomandibular articular condyle). It is distinguished from O. arnoldi by having an elevated patch of enlarged odontodes on the postero-dorsal parieto-supraoccipital tip and typically having 16-17 caudal vertebrae (see Table 2; vs. having a not elevated patch of enlarged odontodes on the parietosupraoccipital and having 15 caudal vertebrae). It is further distinguished (except for O. affinis , O. hasemani , O. xakriaba , O. arnoldi , and O. flexilis ) by possessing an iris operculum, and (except for O. affinis and O. xakriaba ) by having an elevated patch of enlarged odontodes on the postero-dorsal parietosupraoccipital tip. It is also distinguished from all remaining Otocinclus species (except for O. xakriaba , O. arnoldi , and O. flexilis ) by having a lateral trunk coloration composed of either a row of 3-6 distinct dark blotches or a distinct dark stripe extending from the compound pterotic to the base of the caudal fin, or a diffuse mixture of those two color patterns ( Fig. 4).

Distribution. Otocinclus mimulus is only known from the río Mondai in Paraguay, a left-bank tributary of the lower rio Paraná ( Fig. 5).