Paragenidens, Marceniuk & Ingenito & Lima & Gasparini & Oliveira, 2019

Marceniuk, Alexandre Pires, Ingenito, Leonardo Ferreira Da Silva, Lima, Flávio César Thadeo, Gasparini, João Luiz Rosetti & Oliveira, Claudio, 2019, Systematics, biogeography and conservation of Paragenidens grandoculis n. gen. and n. comb. (Siluriformes; Ariidae), a critically endangered species from southeastern Brazil, Zootaxa 4586 (3), pp. 425-444 : 427-430

Paragenidens , new genus Marceniuk & Oliveira

Type species. Arius grandoculis Steindachner 1877

Diagnosis. The new genus Paragenidens is supported by combined evidence from both morphological and molecular data ( Figure 1 ), with Parsimony Analysis ( Figure 1a ) used to recognize the derived characters supporting the new genus. Morphological synapomorphies are represented by 24 derived conditions acquired independently in other ariid genera (1–22) and synapomorphies with ambiguous optimization (23–24): (1) Mesethmoid median portion very narrow Marceniuk et al. (2012: 2), convergent in Amphiarius Marceniuk & Menezes 2007 , Arius Valenciennes 1840 , Amissidens Kailola 2004 , Aspistor Jordan & Evermann 1898, Cathorops Jordan & Gilbert 1883, Cephalocassis Bleeker 1857 , Cinetodus Ogilby 1898 , Ketengus Bleeker 1846 , Notarius armbrusteri Betancur-R. & Acero 2006, N. planiceps Steindachner 1876 , Osteogeneiosus Bleeker 1846 , Pachyula Ogilby 1898 , Potamarius izabalensis and P. nelsoni ; (2) Lateral horn of lateral ethmoid very long and posteriorly oriented, Marceniuk et al. (2012: 12), convergent in Doiichthys Weber 1913 , Plicofollis dussumieri (Valenciennes 1840) , P. nella (Valenciennes 1840) , P. polystaphylodon (Bleeker 1846) , Potamarius izabalensis and P. nelsoni ; (3) Bony bridge formed by lateral ethmoid and frontal cylindrical and thin, Marceniuk et al. (2012: 16), convergent in Amphiarius , Arius arius (Hamilton 1822) , A. gagora (Hamilton 1822) , A. maculatus (Thunberg 1792) , A. madagascariensis Vaillant 1894 , Aspistor , Cathorops , Cephalocassis , Cinetodus , Chinchaysuyoa , Cryptarius Kailola 2004 , Doiichthys , Hemiarius Bleeker 1862 , Nedystoma Ogilby 1898 , Nemapteryx Ogilby 1908 , Pachyula , Potamarius usumacintae , and Potamosilurus Marceniuk & Menezes 2007 ; (4) Frontal mesial laminar projection absent, Marceniuk et al. (2012: 23), convergent in Amissidens , Amphiarius , Arius Valenciennes 1840 [except A. leptonotacanthus Bleeker 1849 and A. nenga (Hamilton 1822) ], Aspistor , Cathorops , Cephalocassis , Doiichthys , Galeichthys , Hemiarius , Nedystoma , Nemapteryx , Notarius biffi Betancur-R. & Acero 2004, N. cookei Acero & Betancur-R. 2002, N. kessleri (Steindachner 1876) , N. neogranatensis Acero & Betancur-R. 2002, Osteogeneiosus , Potamarius izabalensis , P. nelsoni and Potamosilurus latirostris (Macleay 1883) ; (5) Vomer anterior margin very pronounced and acute, Marceniuk et al. (2012: 48), convergent in Amissidens , Amphiarius , Arius , Aspistor , Cephalocassis , Cinetodus , Chinchaysuyoa , Notarius Gill 1863 (except N. cookie and N. planiceps ), Osteogeneiosus , Pachyula , Plicofollis Kailola 2004 , Potamarius izabalensis , P. nelsoni and Potamosilurus ; (6) Lateral expansions of orbitosphenoid and pterosphenoid absent, Marceniuk et al. (2012: 62), convergent in Batrachocephalus Bleeker 1846 , Cephalocassis , Cryptarius , Doiichthys , Ketengus , Nedystoma , Nemapteryx , Osteogeneiosus , Potamarius izabelensis , P. nelsoni (present in all other representatives); (7) Optic foramen very large, Marceniuk et al. (2012: 65), convergent in Potamarius ; (8) Distance between optic foramen and trigeminofacialis foramen small, equal to width of trigemino-facialis foramen, Marceniuk et al. (2012: 66), convergent in Potamarius ; (9) Articulation face of transcapular process with the basioccipital, large and depressed, Marceniuk et al. (2012: 78), convergent in Amphiarius , Arius gagora , A. leptonotacanthus , A. madagascariensis , Aspistor , Bagre Cloquet 1816 , Cathorops , Cryptarius , Doiichthys , Nedystoma , Nemapteryx , Notarius , Plicofollis platystomus Day 1877 , Potamarius , Potamosilurus , Sciades utarus (Kailola 1990) (small and columnar in all other representatives); (10) Transcapular process short and thick, Marceniuk et al. (2012: 80), Ariopsis felis (Linnaeus 1766) , A. guatemalensis (Günther 1864) , Arius leptonotacanthus , A. nenga , Galeichthys Valenciennes 1840 , Nemapteryx , Notarius lentiginosus (Eigenmann & Eigenmann 1888) , N. planiceps and Potamarius ; (11) Maxilla lateral and mesial margins considerably closer to each other proximally, distally narrow and pointed, Marceniuk et al. (2012: 95), convergent in Brustiarius Herre 1935 , Cochlefelis Whitley 1941 , Neoarius Castelnau, 1878 and Potamarius ; (12) Premaxilla very wide and short, as long as wide, Marceniuk et al. (2012: 113), convergent in Cinetodus froggatti (Ogilby 1898) , Doiichthys , Pachyula , Potamarius izabalensis and P. nelsoni ; (13) Opercle posterior portion well developed posterodorsally, Marceniuk et al. (2012: 122), convergent in Amissidens , Amphiarius , Arius , Aspistor , Bagre [except B. panamensis (Gill 1863) ], Batrachocephalus , Brustiarius , Carlarius heudelotii (Valenciennes 1840) , Cathorops , Cephalocassis , Cinetodus , Cochlefelis , Cryptarius , Doiichthys , Hemiarius , Netuma , Notarius , Osteogeneiosus , Nedystoma , Nemapteryx , Neoarius , Pachyula , Plicofollis argyropleuron (Valenciennes 1840) , P. platystomus , Potamarius , Potamosilurus , Sciades leptaspis (Bleeker 1862) , S. mastersi (Ogilby 1898) , S. sona (Hamilton 1822) and S. utarus ; (14) Interopercle rectangular, Marceniuk et al. (2012: 127), convergent in Potamarius ; (15) Metapterygoid one and a half times longer than deep, Marceniuk et al. (2012: 128), convergent in Cephalocassis , Cinetodus , Cryptarius , Chinchaysuyoa , Pachyula , Plicofollis and Potamarius izabalensis ; (16) Metapterygoid anterior process truncate, Marceniuk et al. (2012: 131), convergent in Cinetodus , Cochlefelis , Netuma , Pachyula , Plicofollis , Potamarius izabalensis , Potamosilurus and Sciades sona ; (17) Bony blade connecting posterolateral processes of urohyal absent, Marceniuk et al. (2012: 152), convergent in Arius leptonotacanthus , Cinetodus , Potamarius izabalensis and Sciades utarus ; (20) First pharyngobranchial on mesial end of first epibranchial, Kailola (2004: 13), Marceniuk et al. (2012: 184), convergent in Doiichthys and Ketengus ; (21) Ventral surfaces of parapophyses of fifth and sixth vertebrae straight, Marceniuk et al. (2012: 202), convergent in Amissidens , Amphiarius , Arius , Aspistor , Batrachocephalus , Brustiarius , Cathorops , Cephalocassis , Cinetodus , Cryptarius , Doiichthys , Galeichthys , Hemiarius , Ketengus , Osteogeneiosus , Nedystoma , Nemapteryx , Notarius lentiginosus , Pachyula , Plicofollis platystomus , Potamarius izabalensis and Potamosilurus ; (22) Tooth plates associated with vomer absent, Marceniuk et al. (2012: 53), convergent in Amissidens , Amphiarius , Arius , Batrachocephalus , Carlarius Marceniuk & Menezes 2007 , Cathorops [except C. dasycephalus (Günther 1864) ], Cephalocassis , Cinetodus froggatti , Cryptarius , Doiichthys , Genidens genidens (Cuvier 1829) , Ketengus , Osteogeneiosus , Nedystoma , Pachyula , Plicofollis platystomus , Potamarius izabalensis , P. nelsoni and Potamosilurus velutinus (Weber 1907) ; (23) Posterior cranial fontanel relatively narrow and long, Marceniuk et al. (2012: 27), convergent in Arius (except A. leptonotacanthus and A. nenga ), Carlarius , Cathorops dasycephalus , Cinetodus , Cochlefelis , Cryptarius , Ketengus , Neoarius , Notarius (except N. biffi ), Osteogeneiosus , Pachyula , Plicofollis platystomus , Potamarius , Potamosilurus (except P. latirostris ) and Sciades sona ; (24) Mesial margin of pterotic, articulated with parieto-supraoccipital, longer than anterior margin, articulated with sphenotic, Betancur- R. et al. (2007: 7), convergent in Amissidens , Amphiarius , Arius (except A. nenga ), Aspistor , Bagre bagre , Batrachocephalus , Carlarius , Cathorops , Cinetodus , Chinchaysuyoa , Cochlefelis spatula (Ramsay & Ogilby 1886) , Cryptarius , Doiichthys , Galeichthys ater Castelnau 1861 , G. feliceps Valenciennes 1840 , Ketengus , Notarius armbrusteri , Nemapteryx , Neoarius , Occidentarius Betancur-R. & Acero 2007, Osteogeneiosus , Pachyula , Plicofollis , Potamarius izabalensis , Potamosilurus and Sciades proops (Valenciennes 1840) .

Etymology. The first part of the generic name “para (Latin form for παρά) is a Greek preposition meaning close to, and Genidens is from Latin, a generic name applied to ariid fishes, the sister group of the new genus, alluding to the relationships of the two genera.

Figures

FIGURE 1. Phylogenetic tree inferred from combined evidence from molecular and morphological data based on Parsimony Analysis (A), Bayesian inference (B) and Maximum Likelihood (C), with bootstrap values greater than 50%. In red, neotropical freshwater species, included in Potamarius sensu Marceniuk & Menezes (2007).