Morphology Data of Leucoraja longirostris
Identification keys
Abnormalities
Main Ref. Weigmann, S., M.F.W. Stehmann, B. Séret and H. Ishihara, 2024
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors
Remarks

Descriptive characteristics of juvenile and adult

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

The species is distinguished from all its congeners by its remarkably long and acutely angled

snout, with horizontal preorbital length 17.2-–22.6% TL (vs. 8.5-11.9% TL) and 4.2-6.1 (vs. 1.7-3.5) times orbit length, snout angle 65-85? (vs. 90-150?); with plain dorsal coloration; with an external clasper component dike; with four dorsal terminal (dt) cartilages (Ref. 131089).

Description: This medium-sized species with disc rhombic to (in adult male) evenly inverse heart-shaped, with broadly rounded outer corners and with body length to mid-vent about equal to tail length from mid-vent; preorbital snout length 17.2-22.3% TL. distance between first gill slits 11.6-12.9% of TL; orbits are moderately large, horizontal diameter 1.0-1.2 times interorbital width; dorsal disc is largely devoid of denticles, ventrally spinules at least on snout tip; thorn pattern is pronounced with 5-20 rostral thorns, a half ring of 3-5 thorns on each orbital rim, 1 supraspiracular and 1 interspiracular thorn per side, 3-5 median nuchal thorns, 0-3 lateral nuchal thorns per side, 1-2 suprascapular thorns, 0-2 lateral scapular thorns, 2-3 scapular thorns per side, a median row of 34-41 thorns from behind the shoulder girdle to just before the origin of the first dorsal fin, no interdorsal thorns, and 2-4 parallel rows of thorns on tail; bases of nearly equal-sized and long but low dorsal fins confluent or with short interspace of maximally 0.8% TL; postdorsal tail section short, 2.5-3.8% TL, with low epichordal caudal lobe, which is confluent with the second dorsal fin; brownish lateral tail folds along posterior 58.1-72.0% of tail; upper jaw tooth rows 41-49, pectoral-fin radials 69-73, pelvic-fin radials 3 + 15–3 + 18; clasper lacking external pseudosiphon; inner dorsal lobe with components roll, promontory, slit, and two clefts; inner ventral lobe with components shield, rhipidion, pent, sentinel, spike, and dike; terminal clasper skeleton with four dorsalterminal cartilages, a ventral terminal, and two accessory terminal cartilages, plus a tiny separate spindle-shaped fibrocartilage between distal tips of dorsal terminal 1 and ventral terminal; anterior cranial fontanelle with clear-cut contour all around and extending only about one fifth into rostral shaft length; scapulocoracoid subquadratic, rear corner poorly developed, large oval anterior fenestra without anterior bridge, one moderately large, oval postdorsal and postventral fenestra, respectively; pelvic girdle with massive ischiopubicbar with nearly straight anterior and deeply concave posterior contour; prepelvic processes short, solid, conical, and somewhat inclined outwards, their length 1.7–2.9 times median thickness of ischiopubic bar; differs from all congeners in the remarkably long and acutely angled snout, horizontal preorbital length 17.2-22.6% TL (vs. 8.5-11.9% TL) and 4.2-6.1 (vs. 1.7–3.5) times orbit length, snout angle 65-85? (vs. 90-150?); with external clasper component dike and with four dorsal terminal cartilages; the shape of the accessory terminal 1 cartilage with four tips is also unique within the genus. Colouration: when fresh, dorsal surface plain medium-brown, with grayish mucus coverage; ventral side plain grayish on disc and pelvic fins, snout dusky grayish, sensory pores not marked dark (Ref. 131089).

Ease of Identification

Meristic characteristics of Leucoraja longirostris

Lateral Lines Interrupted: No
Scales on lateral line
Pored lateral line scales
Scales in lateral series
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
on upper limb
total
Vertebrae
preanal
total

Fins

Dorsal fin(s)

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

Caudal fin

Attributes

Anal fin(s)

Fins number
Spines total
Soft-rays total

Paired fins

Pectoral Attributes  
Spines     
Soft-rays   
Pelvics Attributes  
Position    
Spines     
Soft-rays   
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