Similan Islands
Why dive in Similan Islands?
BEST SEASON
Featured Animals 10
- Unlikely
- Likely
- Very likely
Frequent sightingsGiant Oceanic Manta Ray
Mobula birostris
The Giant Oceanic Manta Ray is the world's largest ray, with a disc width that can reach up to 9 meters. It is a circumglobal species found in tropical to temperate pelagic waters, often near coastlines, reefs, and in the open ocean, diving to depths of 1,000 meters. These filter feeders primarily consume zooplankton, including mesopelagic sources, and can also eat small fish. While generally solitary, they aggregate at feeding grounds and cleaning stations. The species is currently listed as Endangered due to overfishing and low reproductive rates.
Frequent sightingsGiant Trevally
Caranx ignobilis
The giant trevally (Caranx ignobilis) is a large, powerful predatory fish found throughout the tropical Indo-Pacific region. Known for its steep head profile and robust body, it can reach up to 170 cm in length and 80 kg in weight. This apex predator feeds primarily on fish, but also consumes crustaceans and cephalopods, often hunting in solitary or small groups, though juveniles form schools.
Frequent sightingsGrey Reef Shark
Carcharhinus amblyrhynchos
The Grey Reef Shark (Carcharhinus amblyrhynchos) is a medium to large-sized requiem shark, common in Indo-Pacific coral reefs and adjacent waters. Characterized by its grey body and a distinctive broad black band on the trailing edge of its caudal fin, it is a fast and agile predator. These sharks are known for their social daytime aggregations, which disperse at night for individual hunting.
Frequent sightingsHumphead Wrasse
Cheilinus undulatus
The Humphead Wrasse is one of the largest reef fish, identifiable by a prominent hump on its forehead and thick fleshy lips. It is a protogynous hermaphrodite, meaning individuals are born female and some transition to males later in life. This carnivorous species plays a crucial role in coral reef ecosystems by preying on hard-shelled invertebrates and toxic animals like the crown-of-thorns starfish.
Frequent sightingsOcellated Eagle Ray
Aetobatus ocellatus
The Ocellated Eagle Ray, also known as the Whitespotted Eagle Ray, is a large ray characterized by a dark greenish-grey to black dorsal surface covered with numerous white spots, and a white underside. It possesses a flattened, diamond-shaped body, a prominent snout, and a long, whip-like tail armed with venomous spines. This species primarily feeds on hard-shelled invertebrates, such as mollusks and crustaceans, which it crushes with its specialized dental plates.
Frequent sightingsPickhandle Barracuda
Sphyraena jello
The Pickhandle Barracuda is characterized by its elongated body, prominent jaw, and distinctive dark bars on its back. It inhabits warm coastal waters and is known to be a top predator, primarily feeding on smaller fish.
Frequent sightingsReef Manta Ray
Mobula alfredi
The Reef Manta Ray (Mobula alfredi) is a large filter-feeding ray found in tropical and subtropical waters, primarily around coral reefs and coastal areas. Known for its pelagic lifestyle, it feeds on zooplankton and exhibits complex social behaviors, often forming aggregations at feeding or cleaning stations. This species is listed as Vulnerable due to threats from overfishing and its slow reproductive rate.
Frequent sightingsTitan Triggerfish
Balistoides viridescens
The Titan Triggerfish (Balistoides viridescens) is the largest species of triggerfish, reaching up to 75 cm in length, with a distinctive greyish-green body and a "moustache" pattern around its mouth. It is known for its powerful jaws and teeth, which it uses to crush the shells of sea urchins, crabs, molluscs, and coral. This diurnal fish is highly territorial, especially when guarding its nest, and can exhibit aggressive behavior towards intruders, including divers.
Frequent sightingsWhale Shark
Rhincodon typus
The whale shark is the largest fish in the world and a gentle filter feeder.
Frequent sightingsWhitetip Reef Shark
Triaenodon obesus
The Whitetip Reef Shark is a slender, medium-sized shark easily identified by the distinctive white tips on its dorsal and upper caudal fins. Primarily nocturnal, it spends its days resting in caves and under ledges on coral reefs and hunts at night for bony fishes, crustaceans, and cephalopods. These sharks are generally social, often found in groups during the day, but can hunt individually or cooperatively.
More marine life 58
Where is Similan Islands
Andaman Sea · Thailand