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Bagre Cloquet, 1816
Bagre Cloquet, 1816: 52. Type species: Silurus bagre ZBK Linnaeus, 1766. Type by absolute tautonymy. Gender: masculine.
Bagre Oken, 1817: 1183. Type species: Silurus bagre ZBK Linnaeus, 1766. Type by absolute tautonymy. Gender: masculine.
Ailurichthys ZBK Baird & Girard, 1854: 26. Type species: Silurus marinus Mitchill, 1815. Type by subsequent designation by Jordan & Evermann (1896). Gender: masculine.
Diagnosis . The following exclusive (1 to 13) and shared (14 to 26) characters distinguishes Bagre from the remaining ariid genera: (1) about half of anterior cranial fontanel limited by posterior branches of mesethmoid (fig. 15); (2) anterior infraorbital shaped like number seven (fig. 16); (3) posterior infraorbital conspicuously curved medially (fig. 16); (4) lower end of subvertebral process rounded; (5) maxillary long and thin (fig. 17); (6) maxillary condyles well developed (fig. 17); (7) palatine claviform, anteriorly very broad (fig. 18); (8) lower part of palatine with a bony crest (fig. 18); (9) anterior process of metapterygoid very large (fig. 19); (10) third basibranchial hourglass shaped its posterior portion shorter and wider than anterior; (11) second dorsal process of cleithrum on inferior part of lateral face of this bone (fig. 20); (12) maxillary barbel compressed, tape-like; (13) one pair of mental barbells; (14) lachrymal with two anterior and one mesial branches (fig. 21) (shared with Batrachocephalus ZBK ); (15) occipital process ventral crest developed through the entire length of the process (shared with Amphiarius , Aspistor ZBK , Cathorops , Cephalocassis ZBK , Cinetodus ZBK , Hemiarius ZBK , Nedystoma ZBK , Nemapteryx ZBK , Pachyula ZBK and Sciades platypogon ); (16) contact face between transcapular process and basioccipital wide and depressed (shared with Amphiarius , Arius gagora , A. maculatus ZBK , A. manillensis ZBK , Aspistor ZBK , Cathorops , Cryptarius ZBK , Doiichthys ZBK , Nedystoma ZBK , Nemapteryx ZBK , Notarius ZBK , Plicofollis platystomus and Potamosilurus latirostris ); (17) parasphenoid wing process very long and thin [shared with Amphiarius , Aspistor ZBK , Cathorops (with exception of C. dasycephalus ), Cochlefelis ZBK , Hemiarius ZBK , Notarius ZBK (with exception of N. planiceps ), Pachyula ZBK , Plicofollis platystomus , Potamarius ZBK , Potamosilurus (with exception of P. velutinus ), Sciades emphysetus ZBK , S. passany and S. proops ]; (18) face for articulation between palatine and lateral ethmoid slightly displaced to the anterior portion of former bone (fig. 18) (shared with Doiichthys ZBK ); (19) tip of urohyal medial process bifid (fig. 22) (shared with Doiichthys ZBK ); (20) urohyal lateral processes as long as or longer than medial process (fig. 22) (shared with Potamarius ZBK ); (21) transversal crest associated with neural spine of fourth vertebra very high (shared with Amphiarius , Batrachocephalus ZBK , Cathorops , Cinetodus ZBK , Cryptarius ZBK , Ketengus ZBK , Hemiarius ZBK , Nemapteryx ZBK , Nedystoma ZBK , Notarius planiceps , Osteogeneiosus ZBK , Pachyula ZBK and Sciades platypogon ); (22) median crest associated with neural spine of third vertebra very high (shared with Amphiarius , Aspistor ZBK , Cathorops , Cephalocassis ZBK , Cinetodus ZBK , Hemiarius ZBK , Nedystoma ZBK , Nemapteryx ZBK , Pachyula ZBK and Sciades platypogon ); (23) more than 39 caudal vertebrae (shared with Cochlefelis ZBK ); (24) base of adipose fin very short, less than one-half as long as anal-fin base [shared with Brustiarius ZBK , Cathorops , Cryptarius ZBK , Netuma and Plicofollis ZBK (with exception of P. platystomus )]; (25) pectoral-fin spine prolonged as a tape-like filament (shared with Arius madagascariensis ZBK ); (26) lateral line bifurcated at caudal region (shared with Arius ZBK , Batrachocephalus ZBK , Ketengus ZBK , Netuma , Osteogeneiosus ZBK , Plicofollis ZBK and Sciades couma ).
Supplementary morphological characters. Cephalic shield smooth, covered by muscle and scarcely visible under the skin; a well developed fenestra limited by frontal and lateral ethmoid bones visible under the skin, but sometimes obliterated by superficial ossifications; medial groove of neurocranium not very distinct, limited by frontal bones and/or on supraoccipital; posterior cranial fontanel very reduced in small specimens, sometimes completely closed in large adult specimens; fenestra limited by supraoccipital, pterotic and sphenotic absent; fossa limited by pterotic, supracleithrum and extrascapular varying in size; epioccipital not invading dorsal portion of cephalic shield; occipital process short, progressively narrower toward its posterior part; anterior and median nuchal plates fused, indistinct (except in B. bagre ) forming a structure of semi-lunar aspect; vomerine tooth plates present and transversely elongate; accessory tooth plates narrow and transversely elongate, bearing conical teeth; maxillary barbel basally bony, fleshy for remaining part of its length and compressed in form of tape; a single pair of mental barbels; base of adipose fin very short, less than onehalf length of anal-fin base; lateral line bifurcated at caudal region, reaching base of caudal-fin upper and lower lobes; cleithrum wide with second dorsal process on its lower portion; posterior cleithral process moderately long and distinct from second dorsal process of cleithrum.
Remarks. The genera Bagre Cloquet, 1816, Bagre Oken, 1817, Glanis ZBK , Stearopterus ZBK , Breviceps ZBK non Merrem, 1820, Felichthys ZBK , Mystus ZBK non Scopoli, 1777 were established based on the same type-species, Silurus bagre ZBK Linnaeus, 1766 and are therefore objective synonyms (Code of Zoological Nomenclature, article 61b).
Ailurichthys ZBK and Anemanotus ZBK , represented respectively by the type-species, Silurus marinus Mitchill, 1815 and Aelurichthys panamensis ZBK Gill, 1863, are subjective synonyms. The nominal genus Breviceps ZBK Swainson, 1838 and Mystus ZBK Gray, 1854 are invalid since the names are pre-occupied. Breviceps ZBK was replaced by Felichthys ZBK Swainson, 1839.
Distribution and habitat. Eastern and western America, predominantly marine waters, but also in brackish waters.