Comprehensive DescriptionRead full entry
Diagnosis. The species of Brustiarius ZBK can be distinguished from the remaining ariid genera by the combination of the following exclusive (1 to 3) and shared (4 to 8) characters: (1) tooth plates associated with vomer butterfly shaped; (2) accessory tooth plates round and lateral to vomer; (3) premaxillary conspicuously longer at its lateral than at its mesial part; (4) orbitosphenoid laterally expanded [shared with Arius ZBK , Carlarius , Cinetodus ZBK , Genidens ZBK , Netuma , Notarius planiceps , Plicofollis ZBK (with exception of P. platystomus ), Potamosilurus (with exception of P. latirostris ) and Sciades (with exception of S. couma , S. emphysetus ZBK , S. passany , S. proops , S. seemanni and S. sagor )]; (5) contact face between first epibranchial and first pharyngobranchial very pronounced [shared with Arius arius , A. gagora , A. madagascariensis ZBK , Nedystoma ZBK , Osteogeneiosus ZBK and Plicofollis ZBK (with the exception of P. platystomus ) and Potamosilurus ]; (6) lateral margin of third pharyngobranchial very conspicuous and pointed (shared with Arius ZBK , Nedystoma ZBK , Neoarius ZBK , Netuma , Plicofollis ZBK and Potamosilurus ); (7) 14 or fewer ribs (shared with Amphiarius , Arius ZBK , Aspistor ZBK , Batrachocephalus ZBK , Cathorops , Cephalocassis ZBK , Cinetodus ZBK , Cryptarius ZBK , Doiichthys ZBK , Galeichthys ZBK , Hemiarius ZBK , Ketengus ZBK , Nedystoma ZBK , Nemapteryx ZBK , Osteogeneiosus ZBK , Pachyula ZBK , Plicofollis platystomus , Potamarius ZBK and Potamosilurus ); (8) base of adipose fin very short, less than one-half as long as anal-fin base [shared with Bagre , Cathorops , Cryptarius ZBK , Netuma and Plicofollis ZBK (with exception of P. platystomus )].
Supplementary morphological characters. Cephalic shield granulated visible under the skin; fenestra limited by frontal and lateral ethmoid bones of moderate size visible under the skin; medial groove of neurocranium very distinct, limited by frontal bones and/or on supraoccipital; posterior cranial fontanel very reduced, in many cases closing entirely with growth; fenestra limited by supraoccipital, pterotic and sphenotic absent; fossa limited by pterotic, supracleithrum and extrascapular very reduced; 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; vomerine tooth plates forming a butterfly shaped structure; accessory tooth plates present, round and lateral to plates related with vomer 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 not bifurcated at caudal region, reaching base of caudal-fin upper lobe; cleithrum wide, with second dorsal process on its upper portion; posterior cleithral process of moderate size and distinct from second dorsal process of cleithrum.
Remarks. The inclusion of Arius proximus ZBK Ogilby, 1898 was based on examination of external morphological characters in preserved specimens and diagnostic characters found in the literature. B. proximus is the type-species of Pararius ZBK and its condition as subjective synonym of Brustiarius ZBK needs confirmation.
Distribution and habitat. Northern New Guinea, freshwater.