Systematics of the family Ariidae (Ostariophysi, Siluriformes), with a redefinition of the genera. Author Alexandre P. Marceniuk Author Naércio A. Menezes text Zootaxa 2007 1416 1 126 http://www.zoobank.org/urn:lsid:zoobank.org:pub:FFC65592-D8DB-41BE-AEAC-A41EAB6C6185 journal article z01416p001 FFC65592-D8DB-41BE-AEAC-A41EAB6C6185 Animalia Insecta Coleoptera Cerambycidae Sciades genus Sciades Müller & Troschel, 1849 (fig. 89) Animalia Insecta Coleoptera Cerambycidae Sciades genus Sciades Müller & Troschel, 1849: 6. Type species: Animalia Actinopterygii Siluriformes Bagridae Bagrus Sciades emphysetus species Bagrus (Sciades) emphysetus Müller & Troschel, 1849. Type by subsequent designation. Type apparently designated first by Bleeker 1862: 8 (subgenus of Animalia Actinopterygii Siluriformes Bagridae Bagrus genus Bagrus ). Gender: masculine. Animalia Actinopterygii Siluriformes Ariidae Hexanematichthys genus Hexanematichthys Bleeker, 1858: 61, 126. Type species: Animalia Actinopterygii Siluriformes Bagridae Bagrus sondaicus species Bagrus sondaicus Valenciennes, 1840. Type by monotypy. Gender: masculine. Animalia Siluriformes Ariidae Sciadeichthys genus Sciadeichthys Bleeker, 1858: 62, 66. Type species: Animalia Actinopterygii Siluriformes Bagridae Bagrus Sciades emphysetus species Bagrus (Sciades) emphysetus Müller & Troschel, 1849. Type by monotypy. Gender: masculine. Animalia Siluriformes Ariidae Selenaspis genus Selenaspis Bleeker, 1858: 62. Type species: Animalia Actinopterygii Siluriformes Siluridae Silurus herzbergii species Silurus herzbergii Bloch, 1794. Type by subsequent designation by Jordan & Evermann (1896: 119). Gender: feminine. Animalia Actinopterygii Siluriformes Ariidae Ariopsis genus Ariopsis Gill, 1861: 56. Type species: Animalia Actinopterygii Siluriformes Ariidae Arius milberti species Arius milberti Valenciennes, 1840. Type by monotypy. Gender: feminine. Animalia Siluriformes Ariidae Leptarius genus Leptarius Gill, 1863: 170. Type species: Animalia Siluriformes Ariidae Leptarius dowii species Leptarius dowii Gill, 1863. Type by monotypy. Gender: masculine. FIGURE 89. Animalia Insecta Coleoptera Cerambycidae Sciades emphysetus species Sciades emphysetus , USNM 215204, 193 mm TL. Lateral view. Diagnosis. The species of Animalia Insecta Coleoptera Cerambycidae Sciades genus Sciades can be differentiated from all other genera of the Animalia Actinopterygii Siluriformes Ariidae family Ariidae by the combination of the following exclusive (1 to 5) and shared (6 to 8) characters: (1) medial groove of neurocranium delimited mostly or exclusively by frontal bones (fig. 90); (2) temporal fossa very reduced or entirely closed during ontogenetic development (fig. 90) (with exception of Animalia Insecta Coleoptera Cerambycidae Sciades leptaspis species Sciades leptaspis ); (3) otic capsules little developed; (4) space between transcapular process and otic capsule very wide; (5) subvertebral process indistinct or little differentiated; (6) posterior cranial fontanel absent (fig. 90) (with exception of Animalia Insecta Coleoptera Cerambycidae Sciades platypogon species Sciades platypogon and shared with Animalia Actinopterygii Siluriformes Ariidae Batrachocephalus genus Batrachocephalus ); (7) epiphyseal bar indistinct (with exception of Animalia Insecta Coleoptera Cerambycidae Sciades platypogon species Sciades platypogon and shared with Animalia Actinopterygii Siluriformes Ariidae Batrachocephalus genus Batrachocephalus ); (8) exoccipital posterior process sutured to Muller’s ramus (with exception of Animalia Insecta Coleoptera Cerambycidae Sciades platypogon species Sciades platypogon and shared with Animalia Actinopterygii Siluriformes Ariidae Potamarius izabalensis species Potamarius izabalensis ). Supplementary morphological characters. Cephalic shield conspicuously granulated visible under the skin; lateral ethmoid and frontal limiting a small fenestra not visible under the skin; medial groove of neurocranium limited by frontal bones and/or on supraoccipital distinct or not very distinct; posterior cranial fontanel always closed (except in Animalia Insecta Coleoptera Cerambycidae Sciades platypogon species S. platypogon ); fenestra limited by supraoccipital, pterotic and sphenotic absent; fossa limited by pterotic, supracleithrum and extrascapular absent (except in Animalia Insecta Coleoptera Cerambycidae Sciades leptaspis species S. leptaspis ); epioccipital not invading dorsal portion of cephalic shield; occipital process triangular, its length and width variable, progressively narrower toward its posterior part; anterior and median nuchal plates fused and indistinct, forming a structure of semi-lunar aspect or broad in form of shield; tooth plates associated with vomer round; accessory tooth plates large, oval shaped or subtriangular, bearing conical teeth; maxillary barbel fleshy and cylindrical; two pairs of mental barbels; base of adipose fin moderately long, about half as long as anal-fin base; lateral line not bifurcated at caudal region, reaching caudal-fin upper lobe (with exception of Animalia Insecta Coleoptera Cerambycidae Sciades couma species S. couma ); cleithrum wide, with second process on its upper portion; posterior cleithral process moderately long and distinct from dorsal process of cleithrum. Remarks. Animalia Insecta Coleoptera Cerambycidae Sciades genus Sciades contains the largest number of ariid species from the eastern and western Americas, south and southeast Asia, southern New Guinea and northern Australia. The nominal genera Animalia Actinopterygii Siluriformes Ariidae Hexanematichthys genus Hexanematichthys , Animalia Siluriformes Ariidae Selenaspis genus Selenaspis and Animalia Actinopterygii Siluriformes Ariidae Ariopsis genus Ariopsis represented by the respective type-species Animalia Actinopterygii Siluriformes Pimelodidae Pimelodus sagor species Pimelodus sagor Hamilton, 1822, Animalia Actinopterygii Siluriformes Siluridae Silurus herzbergii species Silurus herzbergii Bloch, 1794 and Animalia Actinopterygii Siluriformes Ariidae Arius milberti species Arius milberti Valenciennes, 1840 (= Animalia Actinopterygii Siluriformes Siluridae Silurus felis species Silurus felis Linnaeus, 1766), are considered junior synonyms of Animalia Insecta Coleoptera Cerambycidae Sciades genus Sciades . The genus Animalia Insecta Coleoptera Cerambycidae Sciades genus Sciades and Animalia Siluriformes Ariidae Sciadeichthys genus Sciadeichthys are based on the same type-species, Animalia Actinopterygii Siluriformes Bagridae Bagrus Sciades emphysetus species Bagrus (Sciades) emphysetus Müller & Troschel, 1849 and the latter is considered an objective synonym of the former. The osteology of Animalia Siluriformes Ariidae Leptarius dowii species Leptarius dowii Gill, 1863, the type-species of Animalia Siluriformes Ariidae Leptarius genus Leptarius , was not examined but morphological information from preserved specimens indicates that this genus is junior synonym of Animalia Insecta Coleoptera Cerambycidae Sciades genus Sciades . In addition to Animalia Insecta Coleoptera Cerambycidae Sciades mastersi species S. mastersi (Ogilby, 1898), Animalia Insecta Coleoptera Cerambycidae Sciades paucus species S. paucus (Kailola, 2000) and Animalia Insecta Coleoptera Cerambycidae Sciades utarus species S. utarus (Kailola, 1990) were considered to belong in the genus based on the presence of external diagnostic morphological characters available in the literature. The inclusion of Animalia Insecta Coleoptera Cerambycidae Sciades sona species S. sona (Hamilton, 1822) is only tentative. The species Animalia Insecta Coleoptera Cerambycidae Sciades couma species Sciades couma (Valenciennes, 1840), Animalia Insecta Coleoptera Cerambycidae Sciades emphysetus species S. emphysetus , Animalia Actinopterygii Siluriformes Siluridae Silurus herzbergii species S. herzbergii , Animalia Insecta Coleoptera Cerambycidae Sciades passany species S. passany (Valenciennes, 1840) and Animalia Insecta Coleoptera Cerambycidae Sciades proops species S. proops (Valenciennes, 1840), form a subgroup well supported by the following exclusive characters, indicating that they might be considered a separate genus in future studies: lateral margin of premaxillary with a conspicuous concavity; mesopterygoid irregularly shaped (fig. 91); ectopterygoid very elongated (fig. 91); posterior nostrils connected by a groove (with exception of Animalia Insecta Coleoptera Cerambycidae Sciades emphysetus species S. emphysetus and Animalia Insecta Coleoptera Cerambycidae Sciades proops species S. proops ). Distribution and habitat. Eastern and western America, south and southeast Asia, southern New Guinea and northern Australia.