The ocean is home to some of the most breathtaking creatures on Earth – and few are as stunning as these vibrant fish. Whether it’s the electric hues of the mandarinfish, the regal flutter of a Siamese fighting fish’s tail, or the deadly beauty of a lionfish, these species blend form and function in striking ways.
Most beautiful fish
Flamboyant cuttlefish
So called because of its bright, vibrant colours, the flamboyant cuttlefish is a small, 8cm-long cuttlefish that uses its fins to walk along the seafloor. Majestic and brightly coloured from the day it is born, watch this video to see how the flamboyant cuttlefish hatches and takes its first steps.
Clownfish
Easily recognised thanks to its starring role in the Pixar movie franchise, Finding Nemo, the clownfish has an arresting image – an orange body punctuated with a single white stripe, that blends into black around the lower fins. Its beautiful orange and white stripes are far from the most interesting thing about the clownfish, however – in fact, this species is oceanic hermaphroditic, and the clownfish can change sex to complement that of their partner.
Clownfish are predominantly found in coral reefs, living in the protective cover of an anemone’s tentacles.
Mandarinfish
The Mandarinfish’s scientific name is Synchiropus splendidus – and it certainly is rather splendidus, with dazzling hues of blue, orange and green. Found in the shallow waters of the western Pacific, Mandarinfish are renowned for their spectacular dusk mating ritual, in which they show off their bright colours and raised dorsal fins.
Clown triggerfish
With bold white spots and flashes of yellow across its body, the clown triggerfish is also known as the bigspotted triggerfish and is found in the Indian and west Pacific oceans. Triggerfish are territorial, creating grinding noises by moving their dorsal spines in their sockets – a sound which wards off potential intruders or predators.
Lionfish
Despite its impressive red markings and trailing fins, the lionfish is one of the deadliest animals in the sea, as its fins can deliver a dose of powerful venom that can cause extreme pain – and even sometimes temporary paralysis in their victim. Found across the entire Indo-Pacific region, the lionfish has recently been found as far as the Mediterranean Sea.
The lionfish is one of the deadliest fish in the ocean.
Seahorses
While they might look staggeringly different to the other fish in this round-up, seahorses are indeed still fish. Seahorses look like horses because they hide among blades of seagrass, with a hydrodynamic head that allows it to slip through the water without creating ripples, helping it avoid predators. Seahorses can also change their colour using small organs called chromatophores, which are embedded in their skin and contain several different pigments.
These sea creatures aren’t just unique for their horse-like appearance: seahorses also display reversed pregnancy, with the male seahorses getting pregnant and carrying the fertilised eggs (one of the craziest animal births ever).
Siamese fighting fish
Also known as the red crowntail betta fish, thanks to its majestic fanned tail, the freshwater Siamese fighting fish is native to Southeast Asia and is among the most beautiful sea creatures in the ocean.
Moorish idol
Another star of Finding Nemo (Gill), the Moorish idol is named after the fishermen of Southeast Asia, who have long held a profound respect for these fish. While the yellow, black and white stripes of the Moorish idol are impressive, it’s the stunning shape of these fish that mark them out from the rest. A compressed, disc-like shape is paired with a long dorsal fin, which resembles a whip, sweeping off the back of the body.