Genidens

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: 63-65

publication ID

z01416p001

publication LSID

lsid:zoobank.org:pub:FFC65592-D8DB-41BE-AEAC-A41EAB6C6185

persistent identifier

http://treatment.plazi.org/id/C435DDA3-B23C-AA72-12F9-8C29B004C22D

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Thomas

scientific name

Genidens
status

 

Genidens  ZBK  Castelnau, 1855

(fig. 54)

Genidens  ZBK  Castelnau, 1855: 33. Type species: Bagrus genidens  Valenciennes, 1840 (= Pimelodus genidens  ZBK  Cuvier, 1829). Type by absolute tautonymy. Gender: masculine.

Guiritinga  ZBK  Bleeker, 1858: 62 and 67. Type species: Pimelodus commersonii  ZBK  Lacépède, 1803. Type by monotypy. Gender: feminine.

Diagnosis. The combination of two unique (1 and 2) and eight shared (3 to 10) characters distinguishes the species of Genidens  ZBK  from all other genera of the Ariidae  : (1) tooth plates associated with vomer movably attached to bone by ligamentous tissue (with exception of G. genidens  ); (2) lateral margins of orbitosphenoid converging anteroposteriorly; (3) posterior cranial fontanel reduced to a small opening [shared with Bagre  , Brustiarius  ZBK  , Cathorops  (with exception of C. dasycephalus  ), Galeichthys  ZBK  , Netuma  and Plicofollis  ZBK  (with exception of P. platystomus  )]; (4) temporal fossa very reduced or partially closed (shared with Bagre panamensis  , B. pinnimaculatus  , Brustiarius  ZBK  , Cathorops  , Cephalocassis borneensis  , Cryptarius  ZBK  , Galeichthys  ZBK  and Netuma bilineatus  , Sciades  ); (5) proximal 2/3 of maxillary lateral margins parallel, distal 1/3 of bone narrower and posterior part truncate (shared with Carlarius heudelotii  , Netuma thalassinus  , Plicofollis  ZBK  and Sciades platypogon  ); (6) dentary teeth restricted to mesial 2/3 of bone (shared with Cephalocassis  ZBK  and Cryptarius  ZBK  ); (7) posteroventral portion of opercle little pronounced posteriorly [shared with Bagre panamensis  , Carlarius  (with exception of C. heudelotii  ), Galeichthys  ZBK  , Ketengus  ZBK  , Plicofollis  ZBK  (with exception of P. platystomus  ) and Sciades  (with exception of S. couma  and S. felis  )]; (8) lateral processes of urohyal short (fig. 55) [shared with Batrachocephalus  ZBK  , Cathorops  , Cephalocassis borneensis  , Cinetodus  ZBK  , Galeichthys  ZBK  , Ketengus  ZBK  , Osteogeneiosus  ZBK  , Pachyula  ZBK  and Plicofollis  ZBK  (with exception of P. platystomus  )]; (9) urohyal lateral processes half as long as medial process (shared with Arius  ZBK  , Aspistor  ZBK  , Batrachocephalus  ZBK  , Cathorops  , Cephalocassis borneensis  , Cinetodus  ZBK  , Ketengus  ZBK  , Osteogeneiosus  ZBK  , Nedystoma  ZBK  , Nemapteryx  ZBK  , Netuma thalassinus  and Pachyula  ZBK  ); (10) posterior portion of second basibranchial short (fig. 56) (shared with Arius gagora  , A. maculatus  ZBK  , Aspistor  ZBK  and Netuma  ).

Supplementary morphological characters. Cephalic shield granulated visible under the skin; lateral ethmoid and frontal limiting a small fenestra scarcely visible under the skin; medial groove of neurocranium very distinct, limited by frontals and/or on supraoccipital; posterior cranial fontanel very reduced closing completely 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, narrower at posterior end; anterior and median nuchal plates fused and indistinct, forming a structure of semi-lunar aspect; tooth plates associated with vomer round or absent; accessory tooth plates with shape highly variable, 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 base of caudal-fin upper lobe; cleithrum wide, with second dorsal process on its upper portion; posterior cleithral process of moderate size, distinct from second dorsal process of cleithrum.

Remarks. The nominal genus Guiritinga  ZBK  is a junior synonym of Genidens  ZBK  based on the examination and analysis of its type-species Pimelodus commersonii  ZBK  Lacépède, 1803 (= Pimelodus barbus  ZBK  Lacépède, 1803). G. planifrons  (Higuchi et al., 1982) was included on the basis of presence diagnostic external morphological features observed in specimens preserved in alcohol.

Distribution and habitat. Southeast of South America, marine and brackish waters.

Kingdom

Animalia

Phylum

Chordata

Class

Actinopterygii

Order

Siluriformes

Family

Ariidae

Loc

Genidens

Alexandre P. Marceniuk & Naércio A. Menezes 2007

2007
Loc

Guiritinga

Bleeker 1858

1858