Clark's anemonefish

What it is

Clark's anemonefish is a small, stocky marine fish with a laterally compressed body. It typically grows to ten centimetres as a male and fifteen centimetres as a female. The fish displays vivid black, white, and yellow stripes, though patterns vary by region. Most individuals are black on the back and orange-yellow underneath, with two vertical white bands. One band sits behind the eye and the other above the anus. The tail fin is often lighter than the rest of the body.

Where it lives

This species has the widest distribution of any anemonefish. It inhabits tropical waters from the Indian Ocean to the Western Pacific, including the Red Sea. They live in sheltered reefs or shallow lagoons at depths between one and sixty metres. The fish requires host anemones for survival and protection. It is found in areas where these specific sea anemones grow, occupying reef biomes across this vast geographic range.

How it lives

These fish form mutualistic relationships with sea anemones. The anemone provides protection from predators and food scraps, while the fish defends the host from parasites and other threats. Clark's anemonefish is the least host-specific species, associating with all ten known hosting anemone types. In groups, a strict hierarchy exists where the largest individual is female. They are generally not aggressive towards humans but maintain dominance within their social group.

Breeding and life cycle

Clownfish are sequential hermaphrodites, developing as males first and potentially becoming females later. Only the dominant pair in a group reproduces through external fertilization. Studies off the Philippines show a preference for breeding in cooler months, with a peak season from November to May. Egg production tends to increase leading up to the new moon and decrease after the full moon. This seasonal pattern is similar to other temperate clownfish species.

Fish and people

The common name honours John Heaviside Clark, a Scottish engraver who illustrated fishes from Ceylon. Due to their bright colours and interesting behaviour, they are popular in the aquarium trade. Their ability to live safely among stinging anemones makes them a subject of scientific interest regarding mutualism. They are observed in various marine collections and are well-known to reef enthusiasts for their distinctive appearance and hardy nature.

Relatives and look-alikes

It can be distinguished from similar species by its forked caudal fin and specific bar patterns. Amphiprion latifasciatus lacks a white bar at the base of the tail. Amphiprion allardi and Akindynos have narrower mid-body bars and less sharp colour demarcation. Other species like A. chrysogaster have dark tail fins, whereas Clark's anemonefish usually has a lighter or whitish caudal fin.

Questions people ask about Clark's anemonefish

Good reading and sources

• Clark's anemonefish on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data