Netuma

Alexandre P. Marceniuk & Naércio A. Menezes, 2007, Systematics of the family Ariidae (Ostariophysi, Siluriformes), with a redefinition of the genera., Zootaxa 1416, pp. 1-126 : 78-79

Netuma Bleeker, 1858

(fig. 67)

Catastoma Kuhl & van Hasselt in Cuvier & Valenciennes, 1840b: 60. Type species: Catastoma nasutum Kuhl & van Hasselt, 1840. Type by monotypy. Gender: neuter.

Sarcogenys Bleeker, 1858: 96. Type species: Sarcogenys rostratus Kuhl & van Hasselt. Gender: feminine.

Netuma Bleeker, 1858: 62, 67, 93. Type species: Bagrus netuma Valenciennes, 1840. Type by absolute tautonymy. Gender: feminine.

Diagnosis. The combination of the following unique (1 and 2) and shared (3 to 10) characters distinguishes Netuma from all other genera of the Ariidae : (1) two pairs of accessory tooth plates; (2) orbitosphenoid with a short and acute lateral process; (3) lateral processes of vomer thin (fig. 68) [shared with Amphiarius , Brustiarius , Carlarius , Cathorops , Cephalocassis , Cochlefelis , Cryptarius , Doiichthys , Genidens , Hemiarius , Nedystoma , Neoarius , Notarius (with exception of N. planiceps ) and Potamarius ]; (4) premaxillary very wide its length more than 3 times in its width (shared with Bagre , Brustiarius , Cochlefelis and Galeichthys ); (5) posterior portion of second basibranchial short (fig. 69) (shared with Arius gagora , A. maculatus , Aspistor and Genidens ); (6) anterior process of first hypobranchial on central portion of bone (fig. 69) (shared with Neoarius ); (7) lateral face of third pharyngobranchial very conspicuous and acute (shared with Arius , Brustiarius , Nedystoma , Neoarius , Plicofollis and Potamosilurus ); (8) base of adipose fin very short, less than one-half length of anal-fin base [shared with Bagre , Brustiarius , Cathorops , Cryptarius and Plicofollis (with exception of P. platystomus )]; (9) origin of adipose fin vertically over posterior half of anal fin [shared with Bagre , Brustiarius and Plicofollis (with exception of P. platystomus )]; (10) lateral line bifurcated at caudal region (shared with Arius , Bagre , Batrachocephalus , Ketengus , Osteogeneiosus , Plicofollis and Sciades couma ).

Supplementary morphological characters. Cephalic shield granulated visible under the skin; lateral ethmoid and frontal delimiting a small fenestra indistinct under the skin; medial groove of neurocranium very distinct, limited by frontal bones and/or on supraoccipital; posterior cranial fontanel reduced or entirely closed with growth; fenestra limited by supraoccipital, pterotic and sphenotic absent; fossa limited by pterotic, supracleithrum and extrascapular present or absent; epioccipital not invading dorsal portion of cephalic shield; occipital process triangular moderately long and wide, progressively narrower toward its posterior part; anterior and median nuchal plates fused and indistinct, forming a structure of semi-lunar aspect; tooth plates associated with vomer round; accessory tooth plates present, anterior pair transversely elongate and narrow, posterior one triangular shaped, bearing conical teeth; maxillary barbel fleshy and cylindrical; two pairs of mental barbels; base of adipose fin very short, less than one-half 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 upper portion; posterior cleithral process of moderate size, distinct from second process dorsal to cleithrum.

Remarks. The nominal genera Catastoma and Sarcogenys are nomina nuda since they were published without description of the genera and of the type-species ( Catastoma nasutum Kuhl & van Hasselt, 1840 = Bagre thalassinus Rüppell, 1837 and Sarcogenys rostratus Kuhl & van Hasselt, 1858 = Bagre thalassinus Rüppell, 1837), making it impossible recognizing them (International Code of Zoological Nomenclature, articles11d and 16).

Distribution and habitat. Eastern Africa, South and southeast Asia, southern New Guinea and northern Australia, marine and brackish waters.