Pareiorhaphis

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 : 75

Genus Pareiorhaphis Miranda Ribeiro, 1918

Psilichthys Steindachner, 1907: 82 . Type species: Psilichthys cameroni Steindachner, 1907 . Type by monotypy. Preoccupied by Psilichthys Hall, 1899 (in fossil fishes).

Pareiorhaphis Miranda Ribeiro, 1918: 106. Type species: Hemipsilichthys calmoni [= Psilichthys cameroni Steindachner, 1907 ] . Type by subsequent designation by Regan (1920: 14). Type designation made with the unjustified emended name of Hemipsilichthys calmoni and, erroneously, with Miranda Ribeiro as author. Subsequent designation by Gosline (1947: 102) of Hemipsilichthys duseni as type is invalid (see Derijst, 1996: 63).

Included species. Pareiorhaphis azygolechis ( Pereira & Reis, 2002) ; P. bahianus ( Gosline, 1947) ; P. cameroni (Steindachner, 1907) ; P. cerosus (Miranda Ribeiro, 1951); P. eurycephalus ( Pereira & Reis, 2002) ; P. garapia Pereira, Lehmann, Schvambach & Reis, 2015 ; P. garbei (Ihering, 1911) ; P. hypselurus ( Pereira & Reis, 2002) ; P. hystrix ( Pereira & Reis, 2002) ; P. lophia Pereira & Zanata, 2014 ; P. mutuca (Oliveira & Oyakawa, 1999) ; P. nasuta Pereira, Vieira & Reis, 2007 ; P. nudulus (Reis & Pereira, 1999) ; P. parmula Pereira, 2005 ; P. proskynita Pereira & Britto, 2012 ; P. regani (Giltay, 1936) ; P. ruschii Pereira, Lehmann & Reis, 2012 ; P. scutula Pereira, Vieira & Reis, 2010 ; P. splendens (Bizerril, 1995) ; P. steindachneri ( Miranda Ribeiro, 1918); P. stephanus (Oliveira & Oyakawa, 1999) ; P. stomias ( Pereira & Reis, 2002) ; P. vestigipinnis (Pereira & Reis, 1992) ; Pareiorhaphis vetula Pereira, Lehmann & Reis, 2016 ; Pareiorhaphis C; Pareiorhaphis Z; Pareiorhaphis Co ; Pareiorhaphis Ca ; and Pareiorhaphis T.

Diagnosis. Pareiorhaphis is diagnosed by a single exclusive synapomorphy: Canal plate firmly articulated to preopercle (Char. 107.2). Non-exclusive synapomorphies include: Ventral process of sphenotic always longer than half its width (Char. 12.1), hyoid arch contacting ventral margin of hyomandibula anteriorly, close to hyosymplectic cartilage (Char. 20.1), lateral tip of hypobranchial 1 not expanded, approximately equal to mesial tip (Char. 31.1), accessory flange of epibranchial 1 long (Char. 41.2), levator arcus palatini crest with strong curvature towards dorsal margin of hyomandibula (Char. 79.1), levator arcus palatini crest with small accessory process directed towards dorsal margin of hyomandibula, giving bifurcate shape to crest (Char. 80.1), distinct rugosity on ventrolateral margin of preopercle as consequence of implantation of hypertrophied odontodes in adult males (Char. 99.1), anterior margin of preopercle long, extending close to articular condyle of quadrate (Char. 101.0), canal plate located laterally on margin of head (Char. 108.0), 9–11 pairs of pleural ribs (Char. 132.0), pectoral-fin spine of adult males highly intumesced, making spine thicker than those of females or immature males (Char. 165.1), pectoral-fin spine of adult males bearing many hypertrophied odontodes (Char. 166.1), lateral margin of head of adult males covered by small fleshy lobe that hides base of hypertrophied odontodes (Char. 224.1), and lateral margin of head of adult males covered by plates supporting long, hypertrophied odontodes (Char. 247.2).

Comparisons. The species of Pareiorhaphis can be readily distinguished from all other neoplecostomines by various characters, particularly those related to secondary sexual dimorphism. Adult males of Pareiorhaphis possess the lateral portions of the head ornamented with hypertrophied odontodes (though hypertrophied odontodes are also present in some Isbrueckerichthys ). Hypertrophied odontodes on the opercle and the exposed posterior process of the cleithrum in adult males, however, distinguish Pareiorhaphis from all remaining genera. Most Pareiorhaphis also possess a thickened pectoral-fin spine covered with hypertrophied odontodes in mature males (vs. pectoral-fin spine not thickened and without hypertrophied odontodes). Pareiorhaphis is further distinguished from Isbrueckerichthys by possessing infraorbital plates forming the lateral margin of the nasal opening, and the presence of a dorsal-fin spinelet (vs. infraorbital plate series displaced from the lateral margin of the nasal opening and dorsal-fin spinelet absent). Pareiorhaphis is also distinguished from Neoplecostomus by its naked or nearly naked abdomen (vs. abdomen covered by large and firmly united plates). From Pareiorhina , it is further distinguished by possessing an adipose fin (vs. adipose fin absent in Pareiorhina , but also absent in Pareiorhaphis nudulus , P. eurycephalus , and P. proskynita ). Pareiorhaphis is additionally distinguished from Kronichthys by having the tooth series of dentary straight or slightly curved, and the odontodes on the pelvic-fin spine aligned with the spine main axis (vs. tooth series on dentary strongly curved, U -shaped, and the odontodes on the pelvic-fin spine turned mesially). Pareiorhaphis species are distinguished from Hirtella by lacking elongate, hairy odontodes on the head and body plates of adult males, and by lacking a long middorsal ridge between the dorsal and the caudal fins. Pareiorhaphis is also distinguished from Euryochus by possessing a caudal peduncle of approximately ovoid shape in cross-section (vs. caudal peduncle conspicuously flat ventrally).

Geographic distribution. Pareiorhaphis is the most widely distributed genus of the neoplecostomines, its species being found both in coastal rivers and in the rivers draining inland throughout Brazil, such as the upper São Francisco, upper Paraná, upper Iguaçu, and upper Uruguay . In the coastal drainages, Pareiorhaphis species are present from the Maquiné River in the south, to the Paraguaçu River in the north. Noteworthy is the absence of Pareiorhaphis species in the Ribeira de Iguape and Paraíba do Sul Rivers, where it is replaced by Isbrueckerichthys and Hemipsilichthys (Delturinae) , respectively. The records of Pareiorhaphis regani from the Curicuriari and Jaú Rivers, both tributaries to the Negro in the Amazon Basin ( Pereira & Reis, 2002), are most likely erroneous, as no species of Pareiorhaphis are known to occur in that basin.