Psednos cf. dentatus Chernova and Stein 2002
publication ID |
z01019p001 |
DOI |
https://doi.org/10.5281/zenodo.6265686 |
persistent identifier |
https://treatment.plazi.org/id/142A5693-DF18-4AAC-7C54-D4207EBA94AB |
treatment provided by |
Thomas |
scientific name |
Psednos cf. dentatus Chernova and Stein 2002 |
status |
|
Psednos cf. dentatus Chernova and Stein 2002 View in CoL ZBK
Material examined. MCZ 146979, male, 65 mm SL, “Anton Bruun” cruise 1302, Sta. 55, 33° 30' S, 72° 15' W, off Valparaiso, Chile, 1680-1960 m, 2 February 1966. Badly damaged, poor condition.
Description. Counts: Vert. 48 (11+37), D 42, A 36, P 16 (8+3+5), C at least 5. Proportions: Head ca 22.5 % SL, predorsal length ca 26.9, preanal length ca 36.8, upper jaw length 10.2 (45.2). No other measurements possible.
Head a little more than a fifth of SL, body depth approximately the same. Snout short, blunt. Mouth apparently at an angle of about 50°, dentaries missing. Premaxillary teeth small, sharp, acuminate canines forming a narrow band nowhere wider than four or five teeth. Teeth arranged in very long, irregular oblique rows of up to 9 teeth each, a narrow symphyseal notch present. Nostrils single, possibly on horizontal with upper margin of eye or orbit. Eyes and gill opening unknown. Gill rakers on first branchial arch unmodified. Cephalic pores unknown.
Pectoral fin upper ray apparently on horizontal with corner of mouth, certainly below lower margin of orbit. Upper lobe rays 8, closely spaced; notch rays 3, distinctly spaced from upper and lower lobes, distance between middle, dorsal, and ventral notch rays much greater than between each of them and upper and lower lobes respectively. Lower lobe of 5 rays, approximately below middle of head. Radials unknown.
Body tapering evenly to caudal fin. First dorsal ray inserted between vertebrae X and Y; first anal fin ray between vertebrae A and B. Hypurals fused, overlap of caudal by dorsal and anal fins unknown.
Color of body skin unknown; shreds of brown skin remaining on head. Mouth and branchial cavity dusky, peritoneum dark brown, stomach completely brown.
Remarks. This specimen is similar in counts (and the few proportional measurements available) to Psednos dentatus ZBK which was collected from the same region. However, it differs in several significant characters. Whereas the teeth of P. dentatus ZBK are exceptionally long and arrow-shaped, this specimen has small simple canines; the color of the orobranchial cavity of P. dentatus ZBK is pale, in this specimen, dusky; and the stomach of P. dentatus ZBK is dorsally brown but ventrally unpigmented, whereas this specimen has an evenly brown stomach. On the other hand, this specimen is an adult, possibly ripe, male, whereas the holotype of P. dentatus ZBK is an adult female. These few differences could represent sexually dimorphic characters, but without more specimens it is impossible to verify or reject this hypothesis. Therefore, the specimen will not be named as new here.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.