Morphology Data of Tylosurus crocodilus
Identification keys
Main Ref. Myers, R.F., 1991
Appearance refers to
Bones in OsteoBase

Sex attributes

Specialized organs
Different appearance
Different colors
Remarks

Descriptive characteristics of juvenile and adult

Striking features striking type of mouth
Body shape lateral elongated
Cross section circular
Dorsal head profile more or less straight
Type of eyes more or less normal
Type of mouth/snout other (see Diagnosis)
Position of mouth terminal
Diagnosis

Diagnosis: body elongate; upper and lower jaws extremely long, forming a stout beak armed with very sharp teeth; gill rakers absent (Ref. 57228, 90102). Nostrils in depression before eyes (nasal pit); pelvic fins abdominal; 21-23 dorsal-fin rays; anal fin long, 5.5-8.0 times in body length; small, black lateral keel on either sides of caudal peduncle; caudal fin deeply forked (Ref. 57228).

Description: relatively stout, cylindrical body and a shorter head as compared to other needle fishes. Jaw teeth point anteriorly in juveniles (to 40 cm BL) but are straight at all sizes in other species of Tylosurus (Ref. 9682). Anterior rays of dorsal and anal fins forming relatively high lobes that are comprised from 5.4-10.6 and from 5.5-8.0 times, respectively, in body length (Ref. 57228, 90102). Dorsal fin origin about equal with or slightly anterior to origin of anal fin (Ref. 90102). Lower lobe of caudal fin longer than upper (Ref. 57228). 240-290 (Ref. 57228) or 270-340 (Ref. 90102) predorsal scales. Both left and right gonads present, but right one longer than left (Ref. 57228).

Coloration: back-bluish green, belly silvery; dark blue band along sides; scales and bones green (Ref. 57228). In young individuals (to 20 cm BL), dorsal fin has elevated black posterior lobe which disappears in adults (Ref. 9682, 57228).

Ease of Identification

Meristic characteristics of Tylosurus crocodilus

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 0
Gill clefts (sharks/rays only)
Gill rakers
on lower limb 0 - 0
on upper limb 0 - 0
total 0 - 0
Vertebrae
preanal
total 80 - 86

Fins

Dorsal fin(s)

Attributes no striking attributes
Fins number 1
Finlets No. Dorsal   0 - 0
Ventral  0 - 0
Spines total 0 - 0
Soft-rays total 21 - 23
Adipose fin absent

Caudal fin

Attributes forked; asymmetric

Anal fin(s)

Fins number 1
Spines total 0 - 0
Soft-rays total 18 - 22

Paired fins

Pectoral Attributes  more or less normal
Spines     0
Soft-rays   13 - 15
Pelvics Attributes  more or less normal
Position    abdominal  before origin of D1
Spines     0
Soft-rays   6 - 6
Main Ref. (e.g. 9948)
Glossary ( e.g. cephalopods )
Entered by Garilao, Cristina V.
Modified by Geelhand, Dimitri
Checked by Collette, Bruce B.
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