How to Identify Rubyfish

To identify Rubyfish (Plagiogeneion rubiginosum), look at these key features.

Physical Characteristics

Body shape

elongated

Coloration

Predominantly reddish to pinkish-red dorsally, fading to a lighter pink or silvery-white ventrally. Fins are typically reddish. Juveniles may exhibit a more vibrant red.

Scale type

ctenoid

Mouth position

terminal

Distinctive features

Large eyes, adapted for low light conditions in deeper waters., Elongated, fusiform body, slightly compressed laterally., Relatively small, ctenoid scales., A single, long dorsal fin with a distinct notch., Forked caudal fin.

Dorsal fin

Single dorsal fin, deeply notched, with X-XII spines followed by 10-12 soft rays.

Tail fin

Deeply forked caudal fin, with pointed lobes.

Pectoral fin

Moderately long pectoral fins, typically with 18-20 rays.

Distinctive fins

Pelvic fins are thoracic, located beneath the pectoral fins, with I spine and 5 soft rays. Anal fin has III spines and 9-10 soft rays.

Identification Tips

1. 1

   Coloration

   Look for the characteristic reddish-pink body color, which is quite distinct among many deep-water species.

2. 2

   Body Shape

   The elongated, torpedo-like body with a deeply forked tail is a key identifier.

3. 3

   Fin Structure

   The single, notched dorsal fin and the position of the pelvic fins (thoracic) are important diagnostic features.

4. 4

   Eye Size

   Relatively large eyes compared to body size, indicative of its deep-water habitat.

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