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Priacanthus sagittarius, commonly known as the Red bigeye or Arrowhead bigeye, is a species of marine ray-finned fish belonging to the family Priacanthidae. These fish are characterized by their large eyes, typically reddish coloration, and a deep, compressed body. They are primarily nocturnal predators, inhabiting coral reefs and rocky bottoms in tropical and subtropical waters. Their distinctive large eyes are an adaptation for low-light conditions, aiding in their nocturnal hunting strategy.
Physical Characteristics
- Body shape
- compressed
- Coloration
- Typically reddish to pinkish-red, often with silvery or whitish blotches or stripes. Fins are usually reddish. Can exhibit rapid color changes depending on mood or environment.
- Scale type
- ctenoid
- Mouth position
- superior
- Distinctive features
- Very large eyes, characteristic of the family Priacanthidae, adapted for nocturnal vision., Deep, compressed body., Oblique mouth with a protruding lower jaw., Caudal fin is truncate to slightly emarginate., Lateral line complete and arched.
- Dorsal fin
- Single dorsal fin with 10 spines and 12-14 soft rays. The spiny portion is continuous with the soft-rayed portion.
- Tail fin
- Truncate to slightly emarginate.
- Pectoral fin
- Relatively small, with 17-19 rays.
- Distinctive fins
- Pelvic fins are large and inserted anterior to the pectoral fin base, often with a dark membrane between the rays.
Identification Tips
Eyes
The most prominent feature is the exceptionally large, often red, eye, which is disproportionately large compared to the head.
Body Color
Predominantly red or reddish-pink, which can vary in intensity. Some individuals may display silvery or mottled patterns.
Body Shape
Deep and laterally compressed body, giving it a somewhat disc-like appearance when viewed from the front.
Mouth
An oblique mouth with a distinctly protruding lower jaw.
Habitat
- Water type
- saltwater
- Depth
- Typically found at depths of 10 to 100 meters, but can range from 5 to 200 meters.
- Environment
- Associated with coral reefs, rocky bottoms, and sometimes sandy or silty areas adjacent to reefs. Often found in caves or under ledges during the day.
- Geographic range
- Indo-Pacific region, from East Africa to the Central Pacific, including the Red Sea, Persian Gulf, and extending north to southern Japan and south to Australia.
Aquarium Information
- Care level: intermediate
- Temperament: semi-aggressive
- Diet: carnivore
- Minimum tank size: 180 gallons
- Temperature: 24-28°C (75-82°F)
- pH level: 8.1-8.4
- Hardness: 8-12 dKH
- Compatibility: Can be kept with other large, semi-aggressive fish. Avoid keeping with very small fish or invertebrates as they may be preyed upon. Best kept singly or in very large tanks with ample hiding spots if multiple are desired.
- Special requirements: Requires a well-established aquarium with plenty of rockwork for hiding and open swimming space. A varied diet of meaty foods is essential. Good filtration is necessary due to their carnivorous diet.
Wild Information
- Conservation status: least concern
- Seasonality: No specific seasonal patterns for availability; caught year-round in its range.
- Market price: Variable, often sold as food fish
- Commercial importance: medium
- Taste: Mild, slightly sweet
- Texture: Firm, flaky white flesh
- Cooking methods: fried, baked, grilled, steamed
- Nutritional value: Good source of protein and omega-3 fatty acids.
Key Facts
Nocturnal Hunterbehavior
The Red bigeye is primarily active at night, using its large eyes to locate prey in low-light conditions.
Color Changerinteresting
Like many bigeyes, Priacanthus sagittarius can rapidly change its coloration to blend in with its surroundings or express mood.
Deep Dwelleramazing
While often found on reefs, this species can inhabit depths up to 200 meters, showcasing its adaptability to varying light and pressure conditions.
Safety Information
Safe- Safety level: safe
- Venomous: No
- Edibility: edible
- Handling notes: No specific handling precautions beyond standard fish handling. The dorsal and anal fin spines are sharp and can cause minor punctures if not handled carefully.
Similar Species
Glasseye
Priacanthus hamrur
P. hamrur typically has a more deeply forked caudal fin and often exhibits a more uniform red coloration without distinct blotches or stripes. The body depth of P. hamrur is generally less than that of P. sagittarius.
Bloch's bigeye
Priacanthus blochii
P. blochii often has a more elongated body shape compared to the deeper body of P. sagittarius, and its caudal fin is typically truncate to slightly rounded, not emarginate. Coloration can also differ, with P. blochii sometimes having more prominent dark spots or lines.
Scientific Classification
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Actinopterygii
- Order
- Perciformes
- Family
- Priacanthidae
- Genus
- Priacanthus
- Species
- Priacanthus sagittarius
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