Morphology Data of Xenurobrycon varii
Identification keys
Abnormalities
Main Ref. Mendonça, M.B., L.A.W. Peixoto, G.M. Dutra and A.L. Netto-Ferreira, 2016
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance always different morphology between mature adults
Different colors
Remarks

Descriptive characteristics of juvenile and adult

Striking features
Body shape lateral
Cross section
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth terminal
Type of scales cycloid scales
Diagnosis

Xenurobrycon varii can be easily distinguished from its congeners by the dark posterior half of both caudal-fin lobes (vs. hyaline) and the lack of infraorbitals 4 and 5 (vs. absence of infraobitals 1, 4 and 5 in X. coracoralinae and presence of infraorbitals 1-5 in X. heterodon, X. macropus, X. polyancistrus and X. pteropus). It further differs from other species of Xenurobrycon , except X. coracoralinae and X. macropus, by having a set of lamellar processes on the eighth principal ray of the lower caudal-fin lobe (vs. absence in X. heterodon, X. polyancistrus and X. pteropus). It can be diagnosed from X. coracoralinae by having hooks on the last unbranched plus the first 9th-12th branched anal-fin rays of mature males (vs. hooks present only on last unbranched and first 4th-5th branched rays). In addition, it can be distinguished from X. heterodon by having only conical dentary teeth (vs. anterior dentary teeth tricuspid). It differs also from X. polyancistrus by the posterior anal-fin hooks approximately equal or reduced in size posteriorly in mature males (vs. posterior larger anal-fin hooks). It can be further differentiated from X. pteropus by the absence of adipose-fin (vs. presence) and by having 15-18 predorsal scales (vs. 13) (Ref. 109914).

Ease of Identification

Meristic characteristics of Xenurobrycon varii

Lateral Lines Interrupted: No
Scales on lateral line
Pored lateral line scales 3 - 7
Scales in lateral series 30 - 38
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle 10 - 13
Barbels
Gill clefts (sharks/rays only)
Gill rakers
on lower limb
on upper limb
total
Vertebrae
preanal 12 - 12
total

Fins

Dorsal fin(s)

Attributes no striking attributes
Fins number 1
Finlets No. Dorsal   
Ventral  
Spines total
Soft-rays total 8 - 9
Adipose fin absent

Caudal fin

Attributes forked

Anal fin(s)

Fins number
Spines total
Soft-rays total 16 - 20

Paired fins

Pectoral Attributes  more or less normal
Spines     
Soft-rays   8 - 9
Pelvics Attributes  more or less normal
Position    abdominal  before origin of D1
Spines     
Soft-rays   7 - 8
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
Comments & Corrections
Back to Search
cfm script by eagbayani, 17.10.00, php script by rolavides, 13/03/08 ,  last modified by sortiz, 06.27.17