محفوظ في:
| المؤلفون الرئيسيون: | , |
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| التنسيق: | Recurso digital |
| اللغة: | |
| منشور في: |
Zenodo
2007
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| الموضوعات: | |
| الوصول للمادة أونلاين: | https://doi.org/10.5281/zenodo.6236936 |
| الوسوم: |
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جدول المحتويات:
- <p>Genidens Castelnau, 1855</p><p>(fig. 54)</p><p>Genidens Castelnau, 1855: 33. Type species: Bagrus genidens Valenciennes, 1840 (= Pimelodus genidens Cuvier, 1829). Type by absolute tautonymy. Gender: masculine.</p><p>Guiritinga Bleeker, 1858: 62 and 67. Type species: Pimelodus commersonii Lacépède, 1803. Type by monotypy. Gender: feminine.</p><p>Diagnosis. The combination of two unique (1 and 2) and eight shared (3 to 10) characters distinguishes the species of Genidens 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, Cathorops (with exception of C. dasycephalus), Galeichthys, Netuma and Plicofollis (with exception of P. platystomus)]; (4) temporal fossa very reduced or partially closed (shared with Bagre panamensis, B. pinnimaculatus, Brustiarius, Cathorops, Cephalocassis borneensis, Cryptarius, Galeichthys 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 and Sciades platypogon); (6) dentary teeth restricted to mesial 2/3 of bone (shared with Cephalocassis and Cryptarius); (7) posteroventral portion of opercle little pronounced posteriorly [shared with Bagre panamensis, Carlarius (with exception of C. heudelotii), Galeichthys, Ketengus, Plicofollis (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, Cathorops, Cephalocassis borneensis, Cinetodus, Galeichthys, Ketengus, Osteogeneiosus, Pachyula and Plicofollis (with exception of P. platystomus)]; (9) urohyal lateral processes half as long as medial process (shared with Arius, Aspistor, Batrachocephalus, Cathorops, Cephalocassis borneensis, Cinetodus, Ketengus, Osteogeneiosus, Nedystoma, Nemapteryx, Netuma thalassinus and Pachyula); (10) posterior portion of second basibranchial short (fig. 56) (shared with Arius gagora, A. maculatus, Aspistor and Netuma).</p><p>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.</p><p>Remarks. The nominal genus Guiritinga is a junior synonym of Genidens based on the examination and analysis of its type-species Pimelodus commersonii Lacépède, 1803 (= Pimelodus barbus 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.</p><p>Distribution and habitat. Southeast of South America, marine and brackish waters.</p>