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Thalassoma purpureum, commonly known as the Green Wrasse or Surge Wrasse, is a vibrant and active species of wrasse found in tropical and subtropical Indo-Pacific waters. It is characterized by its striking coloration, which can vary significantly between initial and terminal phases, and its elongated, streamlined body. These fish are typically found in shallow, turbulent reef environments, often in surge zones, where they actively forage for small invertebrates.
Physical Characteristics
- Body shape
- elongated
- Coloration
- Initial phase individuals are typically greenish-brown to reddish-brown with lighter ventral surfaces, often displaying irregular dark blotches or stripes. Terminal phase males are much more vibrant, exhibiting brilliant green to blue-green bodies, often with a distinct purplish-red band running from the snout through the eye to the caudal fin base. The head may have intricate pink or red markings. The caudal fin is typically lunate with elongated lobes in terminal males.
- Scale type
- cycloid
- Mouth position
- terminal
- Distinctive features
- Elongated, streamlined body, Vibrant coloration, especially in terminal phase males, Lunate caudal fin with elongated lobes in terminal males, Small, protractile mouth with prominent canine teeth
- Dorsal fin
- Single dorsal fin with 8 spines and 13 soft rays, continuous and relatively low.
- Tail fin
- Lunate (crescent-shaped) with elongated upper and lower lobes, particularly pronounced in terminal phase males.
- Pectoral fin
- Large and fan-like, used for propulsion and maneuvering.
- Distinctive fins
- Pelvic fins are small and located thoracically.
Identification Tips
Coloration (Terminal Phase)
Look for the brilliant green to blue-green body with a prominent purplish-red band extending from the snout through the eye to the caudal fin base. This is a key identifier for mature males.
Caudal Fin Shape
The lunate (crescent-shaped) caudal fin with elongated upper and lower lobes is characteristic, especially in larger individuals.
Habitat Preference
Often observed in high-energy, turbulent reef environments, such as surge zones, which helps distinguish it from some other wrasse species that prefer calmer waters.
Body Shape
Its elongated and streamlined body is typical of the genus Thalassoma.
Habitat
- Water type
- saltwater
- Depth
- 0-30 meters (0-100 feet), typically in shallow, turbulent areas.
- Environment
- Coral reefs, rocky shorelines, surge zones, and outer reef slopes. Prefers areas with strong water movement and abundant invertebrate prey.
- Geographic range
- Indo-Pacific region, from the Red Sea and East Africa across to the Hawaiian Islands, French Polynesia, and south to Australia and New Zealand. Also found in the eastern Pacific from Baja California to the Galapagos Islands.
Aquarium Information
- Care level: intermediate
- Temperament: semi-aggressive
- Diet: carnivore
- Minimum tank size: 120 gallons
- Temperature: 72-78°F (22-26°C)
- pH level: 8.1-8.4
- Hardness: 8-12 dKH
- Compatibility: Can be kept with other robust, semi-aggressive fish. Not suitable for reef tanks with small invertebrates or peaceful, slow-moving fish. May be aggressive towards conspecifics unless introduced simultaneously in a very large tank.
- Special requirements: Requires a well-established aquarium with plenty of live rock for hiding and foraging. A tight-fitting lid is essential as they are known jumpers. Needs a sand bed for burying at night or when stressed. A varied diet of meaty foods is crucial.
Wild Information
- Conservation status: least concern
- Seasonality: No specific seasonal patterns for availability; present year-round in its natural habitat.
- Market price: Varies, generally moderate for the aquarium trade.
- Commercial importance: low
- Taste: Mild, white flesh
- Texture: Flaky, firm
- Cooking methods: Grilled, Baked, Fried
- Nutritional value: Good source of protein and omega-3 fatty acids.
Key Facts
Protogynous Hermaphroditebehavior
Thalassoma purpureum is a protogynous hermaphrodite, meaning individuals are born female and can later change sex to male. This is common among many wrasse species.
Surge Zone Specialistinteresting
This species is particularly adapted to living in high-energy surge zones, where strong currents and wave action are prevalent. Their streamlined bodies and powerful swimming allow them to thrive in these challenging environments.
Diurnal Foragerbehavior
Green Wrasses are active diurnal foragers, spending their daylight hours actively searching for small invertebrates, crustaceans, and mollusks among rocks and corals.
Color Transformationamazing
The dramatic color change from the initial phase (often drabber females and juveniles) to the terminal phase (vibrant males) is one of its most striking features and serves an important role in reproductive signaling.
Safety Information
Safe- Safety level: safe
- Venomous: No
- Edibility: edible
- Handling notes: No specific handling precautions beyond standard fish handling. They are active and can be slippery, so handle with care to avoid injury to the fish. They do not possess venomous spines.
Similar Species
Six-bar Wrasse
Thalassoma hardwicke
T. hardwicke has distinct dark vertical bars on its body and lacks the prominent purplish-red band on the head and body seen in terminal phase T. purpureum. Its caudal fin is also less deeply lunate.
Moon Wrasse
Thalassoma lunare
T. lunare typically has a more yellowish-green body with a distinct crescent-shaped yellow caudal fin. While it shares the lunate tail, its overall body coloration and markings differ significantly from T. purpureum.
Christmas Wrasse
Thalassoma trilobatum
T. trilobatum has a more mottled green and red pattern, often with three distinct dark blotches along the lateral line, which are absent in T. purpureum. Its caudal fin is also less elongated.
Scientific Classification
- Kingdom
- Animalia
- Phylum
- Chordata
- Class
- Actinopterygii
- Order
- Perciformes
- Family
- Labridae
- Genus
- Thalassoma
- Species
- purpureum
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