Morphology Data of Nannothrissa parva
Identification keys
Abnormalities
Main Ref. Whitehead, P.J.P., 1985
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs no special organs
Different appearance males alike females
Different colors males alike females
Remarks

Descriptive characteristics of juvenile and adult

Striking features none
Body shape lateral fusiform / normal
Cross section compressed
Dorsal head profile more or less straight
Type of eyes more or less normal
Type of mouth/snout more or less normal
Position of mouth terminal
Type of scales cycloid scales
Diagnosis

Diagnosis: Body slender, depth about 20% of standard length; scutes beginning at isthmus, or just behind, very strongly keeled, 12-15 pre-pelvic and 6-8 post-pelvic scutes; lower jaw projecting, toothless; no teeth on premaxillae or maxillae; posterior supra-maxilla as deep as maxilla blade and with long slender anterior shaft; lower gill rakers 24-31; pelvic fin with 1 unbranched and 6-7 branched rays, its insertion just before dorsal fin origin; anal fin rays 20-23; scales in lateral series 35-40 (Ref. 188, 2263). It differs from Nannothrissa stewarti in having more gillrakers, 24-31 vs. 20-23, more anal fin rays, 20-23 vs. 17-19, and more scales in lateral series, 35-40 vs. 34-35 (Ref. 188, 2263, 94752).

Description: Depth of body 4 to 5 times in its length; caudal peduncle longer than deep (Ref. 2263). Snout a little shorter than diameter of eye, which is rather more than 1/3 the length of head; lower jaw a little projecting, toothless; no teeth on pre-maxillary and maxillary; maxillary extending to vertical from anterior edge of eye; posterior supra-maxilla half as long as maxilla (Ref. 188, 2263, 93833). Lower gillrakers 24-31 (Ref. 188, 93833). Dorsal fin with 12-15 rays; anal fin with 20-23 rays; pectoral fin with 11-12 rays; pelvic fin with 1 unbranched and 6-7 branched rays, its insertion about half eye diameter before dorsal fin origin; caudal fin with 18-19 rays (Ref. 188, 2263, 93833, 94751). Scales: 35-42 in a longitudinal series (Ref. 188, 2263, 93833, 94751). Scutes very strongly keeled, beginning at isthmus or just behind; 12-15 pre-pelvic and 6-8 post-pelvic scutes (Ref. 188, 2263). Number of vertebrae 39-40 (Ref. 94751).

Colouration: More or less transparent, entirely silvery with pearly blue-green and pink reflections; dorsal region slightly darker; top of head, tip of snout and chin black; eye black; ventral scutes and base of impaired fins blackish; ventral and anal fins transparent, pectoral and dorsal fins slightly darkened, lobes of caudal fin blackish; a weak black band on the caudal peduncle, widening towards the base of the latter, and clearly visible in preserved specimens (Ref. 41580).

Ease of Identification

Meristic characteristics of Nannothrissa parva

Lateral Lines Interrupted: No
Scales on lateral line
Pored lateral line scales
Scales in lateral series 35 - 42
Scale rows above lateral line
Scale rows below lateral line
Scales around caudal peduncle
Barbels
Gill clefts (sharks/rays only)
Gill rakers
on lower limb 24 - 31
on upper limb
total
Vertebrae
preanal
total 39 - 40

Fins

Dorsal fin(s)

Attributes no striking attributes
Fins number 1
Finlets No. Dorsal   
Ventral  
Spines total 0 - 0
Soft-rays total 12 - 15
Adipose fin absent

Caudal fin

Attributes forked; more or less normal

Anal fin(s)

Fins number 1
Spines total 0 - 0
Soft-rays total 20 - 23

Paired fins

Pectoral Attributes  more or less normal
Spines     0
Soft-rays   11 - 12
Pelvics Attributes  more or less normal
Position    abdominal  before origin of D1
Spines     0
Soft-rays   7 - 8
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
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