How to Identify Short-finned Eel

To identify Short-finned Eel (Anguilla australis), look at these key features.

Physical Characteristics

Body shape

eel-like

Coloration

Dorsal surface typically dark olive-green to brown, fading to a lighter, yellowish-white on the ventral side. Coloration can vary depending on habitat and age, with mature 'silver eels' becoming more silvery-grey prior to their spawning migration.

Scale type

cycloid

Mouth position

terminal

Distinctive features

Small, deeply embedded scales, giving the skin a smooth appearance., Continuous dorsal, caudal, and anal fins., Lower jaw slightly protruding beyond the upper jaw., Relatively short dorsal fin, originating well behind the pectoral fins and closer to the anus than to the gill opening., Pectoral fins are well-developed.

Dorsal fin

Originates well behind the pectoral fins, closer to the anus than to the gill opening. Continuous with the caudal and anal fins.

Tail fin

Rounded, continuous with dorsal and anal fins.

Pectoral fin

Well-developed and fan-shaped.

Distinctive fins

Absence of pelvic fins. The dorsal and anal fins are confluent with the caudal fin, forming a continuous fringe around the posterior part of the body.

Identification Tips

1. 1

   Dorsal Fin Origin

   The most reliable distinguishing feature from the Long-finned Eel (Anguilla reinhardtii). In A. australis, the dorsal fin originates well behind the pectoral fins, closer to the anus than to the gill opening. In A. reinhardtii, it originates much closer to the gill opening.

2. 2

   Jaw Protrusion

   The lower jaw typically protrudes slightly beyond the upper jaw.

3. 3

   Coloration

   Generally dark olive-green to brown dorsally, with a lighter belly. Silvering occurs during maturation for spawning migration.

4. 4

   Pectoral Fins

   Relatively broad and fan-shaped.

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