Isbrueckerichthys Derijst 1996

Pereira, Edson H. L. & Reis, Roberto E., 2017, Morphology-based phylogeny of the suckermouth armored catfishes, with emphasis on the Neoplecostominae (Teleostei: Siluriformes: Loricariidae), Zootaxa 4264 (1), pp. 1-104 : 72-73

Genus Isbrueckerichthys Derijst 1996

Isbrueckerichthys Derijst, 1996: 64 . Type species: Hemipsilichthys duseni Miranda Ribeiro, 1907 . Type by original designation. New name for Pareiorhaphis sensu Gosline (1947: 102) .

Included species. Isbrueckerichthys alipionis ( Gosline, 1947) ; I. calvus Jerep, Shibatta, Pereira & Oyakawa, 2006 ; I. duseni (Miranda Ribeiro, 1907); I. epakmos Pereira & Oyakawa, 2003 ; and I. saxicola Jerep, Shibatta, Pereira & Oyakawa, 2006 .

Diagnosis. Isbrueckerichthys is diagnosed by one exclusive synapomorphy: Levator arcus palatini crest slightly sinuous ending with dorsal orientation (Char. 77.1). Non-exclusive synapomorphies include: Infraorbital 2 separated from lateral rim of nasal opening (Char. 15.0), anterior end of basibranchial 2 not expanded and similar in size to its posterior end (Char. 71.0), anterodorsal margin of hyomandibula slightly expanded, projecting above posterior margin of metapterygoid (Char. 84.1), dorsal margin of metapterygoid articulated to lateral ethmoid through interdigitated suture (Char. 105.2), lateral wall of metapterygoid incomplete, not extending along entire dorsal margin of metapterygoid canal (Char. 108.0), anterior margin of preopercle long, extending close to articular condyle of quadrate (Char. 101.0), VPCC long and appearing to surround articulation of sixth centrum and its rib when viewed ventrally (Char. 114.2), possession of 31–33 centra after complex centrum (Char. 119.0), bifid neural spines not articulated to dorsal series of plates (Char. 125.0), all ribs posterior to sixth centrum connected to respective centra by means of ligament (Char. 135.2), dorsal-fin spinelet absent (Char. 146.2), segmented portion of pectoral-fin spine shorter than ossified portion (Char. 168.1), pectoral fin reaching distinctly beyond middle of pelvic-fin unbranched ray (Char. 172.2), second radial of pectoral fin not bearing any expansion or process on its dorsal margin (Char. 175.0), pelvic fin not reaching to anal-fin origin (Char. 202.0), posterior region of caudal peduncle with six or more series of plates (Char. 239.3), papillae of lower lip tightly united, leaving no free lip surface between them (Char. 254.1), and posterior margin of lower lip smooth and without fringes (Char. 256.0).

Comparisons. lsbrueckerichthys can be readily distinguished from all other neoplecostomines, except Pareiorhaphis nasuta and P. scutula , by possessing an abdomen covered by many tiny platelets embedded in the skin between the pectoral girdle and pelvic-fin insertions (vs. abdomen naked in most other genera, or with large, heavy plates in Neoplecostomus ). Isbrueckerichthys is further distinguished from other neoplecostomines, except Neoplecostomus ribeirensis and N. franciscoensis , by having the infraorbital series displaced from the lateral margin of the nasal opening (vs. infraorbital series forming the lateral margin of the nasal opening). Isbrueckerichthys can also be distinguished from other neoplecostomines, except Pareiorhaphis cameroni and P.

vestigipinnis , by possessing six or more longitudinal rows of lateral plates on the caudal peduncle (vs. five rows or less), and by lacking a dorsal-fin spinelet (vs. spinelet mostly present, but absent in Neoplecostomus ribeirensis , Pareiorhaphis cameroni , P. hypselurus , P. mutuca , P. nudulus , P. stomias , and P. vestigipinnis ).

Geographic distribution. The five species of Isbrueckerichthys are known to occur in the Ribeira de Iguape River Basin, a coastal basin in southern São Paulo State, as well as in the Tibagi River , a tributary to the Paranapanema River , Paraná Basin, in northern Paraná State .