Morphology Summary - Phenacogaster nukak
Morphology Data of Phenacogaster nukak
Identification keys
Abnormalities
Main Ref. Romero-Figueroa, A. and T.P. Carvalho, 2024
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors
Remarks Males with small bony hooks on anal fin, from first to eleventh branched ray, ranging from 2-6 hooks per ray on its posterior margin, 2 hooks per segment, on pectoral fins from first to third or fourth branched ray, ranging from 4-6 hooks per ray arranged on its posterior margin of distal branching, no hooks on pelvic fins (Ref. 132565).

Descriptive characteristics of juvenile and adult

Striking features
Body shape lateral  (shape guide)
Cross section compressed
Dorsal head profile
Type of eyes
Type of mouth/snout
Position of mouth
Type of scales
Diagnosis

This species is distinguished from its congeners by the following characters: an incomplete lateral line; position of the humeral spot near the anterior origin of the base of the dorsal fin between the fifth and eighth ribs counted from the posterior limit of the pseudotympanum; differs from P. tegatus by a longer caudal peduncle 7.1-11.0% SL, 9.1% on average (vs. 4.7-7.8% SL, 6.0% on average), shorter maxillary length 19.0-33.6% HL, 29.6% on average (vs. 33.8-43.2% HL, 38.1% on average), and larger orbit diameter 32.2-43.8% HL, 38.3% on average (vs. 22.9-26.5% HL, 24.5% on average); differs from P. yari by the higher number of perforated scales in the lateral line 8-11 (vs. 6-7), circumpeduncular scales 11-12 (vs. 10), anal-fin rays 32-34 (vs. 29-32), pectoral-fin rays 12-14 (vs. 10-11); no bony hooks on the pelvic-fin rays on males; presence of hooks on pectoral-fin rays of males; caudal vertebrae 22 (Ref. 132565).

Ease of Identification

Meristic characteristics of Phenacogaster nukak

Lateral Lines Interrupted: No
Scales on lateral line
Pored lateral line scales 11 - 11
Scales in lateral series
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle 11 - 12
Barbels
Gill clefts (sharks/rays only)
Gill rakers
on lower limb 7 - 7
on upper limb 4 - 4
total
Vertebrae
preanal 14 - 14
total 36 - 36

Fins

Dorsal fin(s)

Attributes
Fins number
Finlets No. Dorsal   
Ventral  
Spines total
Soft-rays total 8 - 9
Adipose fin

Caudal fin  (shape guide)

Attributes

Anal fin(s)

Fins number
Spines total
Soft-rays total 32 - 34

Paired fins

Pectoral Attributes  
Spines     
Soft-rays   12 - 14
Pelvics Attributes  
Position    
Spines     
Soft-rays   7 - 7
(e.g. 9948)
(e.g. oophagy)
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cfm script by eagbayani, 17.10.00, php script by rolavides, 13/03/08 ,  last modified by sortiz, 06.27.17