If you have watched Finding Nemo, you are probably more interested in clownfish. How do these colorful enchanting little creatures survive amid more powerful fishes? I put in a lot of time and research to prove that these fish are in no way clowns when it comes to protecting themselves.
Clownfish protect themselves by hiding in the poisonous tentacles of an anemone. The sea anemone’s poisonous cells- nematocytes- do not have any effect whatsoever on a clownfish but will have lethal effects on any other fish. The clownfish has a mucus blanket that shields it from the toxic tentacles of the sea anemone.
Clownfish form a unique kind of relationship with the sea anemone that is truly amazing and extraordinary. This is a symbiotic relationship that provides the clownfish with protection and other side benefits as well.
How the Clownfish Protects Itself from Predators?
Clownfish are fishes that have about 30 known species. Twenty-nine of these species belong to the genus Amphiprion while the last one belongs to the genus Premnas. Clownfish, also known as anemonefish, have yellowish, reddish, blackish, or orange colors with a little presence of white. The color of the fish is dependent on the species.
Clownfish in tanks do not necessarily need any sort of protection. However, clownfish living in the wild do need protection from predatory fishes. They form a symbiotic relationship with sea anemones that is beneficial to both parties.
Sea anemones are magnificent plant-like aquatic animals that are well known for their poisonous tentacles that kill fishes except for clownfish. The tentacles contain toxic cells known as nematocytes that render their victim helpless. Any fish that gets trapped in their tentacles is injected with cytolytic toxins which kill the fish.
Clownfish secrete mucus that covers their bodies before entering into the tentacles of sea anemones. The mucus serves as a sort of protection that shields the clownfish from the toxins in the tentacles of the sea anemone.
The clownfish is then cleverly able to live within the tentacles of the anemone safely. Due to the anemone’s toxicity, any predator that poses a threat to the clownfish is killed off immediately after it attacks. The unknowing predator is attacked by the nematocytes in the tentacles of the anemone and consequently dies.
The protecting mucus of the clownfish increases in thickness, with continued residence in the anemone; hence intensifying its protective barrier. Clownfish do not only receive protection from sea anemones. They also benefit in terms of nutrition. Clownfish feed on the food remnants of anemones and at other times on dead tentacles of the anemones.
Why Don’t Anemones Sting Clownfish?
Clownfish are protected from the tentacles of sea anemones through two major immune mechanisms.
- Innate immune mechanism
Some species of clownfish are innately shielded from the anemone’s toxins without any previous encounter with an anemone. This is possible when the consistency of the mucus secreted by the clownfish is thick enough to sufficiently protect it from an anemone’s tentacles; hence the clownfish is not affected in any way when it comes in contact with an anemone.
- Acquired immune mechanism
Other species of clownfish do not possess innate immunity against the anemone’s nematocytes; hence they have to acquire it. The clownfish does this by rubbing itself on the tentacles of the anemones. Initially, the clownfish might get stung but over time it can successfully acclimate itself with the anemone. Therefore, the anemone poses no further attack as it gradually starts to perceive the clownfish as part of itself.
In this mechanism, the clownfish makes use of the anemone’s mucus as a reinforcement to enhance its mucus covering.
Few species of clownfish fall under the bridge between innate and acquired immune mechanisms. These clownfish previously possess innate immunity against the anemone’s attack but acquire more immunity by acclimating with the anemone. Upon acclimation with the anemone, it gains antigens that serve as the perfect chemical camouflage. At this point, the anemone can no longer differentiate itself from the clownfish.
Why Do Clownfish and Sea Anemones Pair Up? What Is This Relationship Called?
Clownfish and sea anemones are a perfect fit as they both reside in saltwater habitats and can survive together without harming each other. It is quite interesting that the 30 known species of clownfish can only form symbiotic relationships with just about 10 species of sea anemones. Sea anemones are known to have over a thousand known species.
This unique symbiotic relationship only gets more interesting as not all clownfish species are compatible with the 10 species of anemones. This is because the pairing is quite specific.
Specific species of clownfish are capable of living safely in certain species of anemones without the need to acclimate but strangely require acclimation with other species of anemones. A fitting example is Amphiprion Clarkii which requires no acclimation before living in Stichodactyla Haddoni but requires acclimation living in Entacmea Quadricolor.
Compatible pairs of clownfish and anemones can serve each other efficiently. The bright colors of the clownfish naturally attract predators. Once the predators close in on the clownfish, the tentacles of the anemone trap the intruding fish and paralyze it with its toxins.
The clownfish is protected from invading predators whilst the anemone feeds off on the trapped intruders.
Surprisingly, the clownfish also protects its protector. The colorful little fish can pull off aggressive behavior that wards off predators of the anemone such as the butterflyfish.
End Note
The clownfish mucus shield is much thicker than that of any other fish. However, the mucus shield can be a mix of its mucus and that of its anemone host. This is quite possible because as the clownfish continues to live within the anemone, it combines the anemone’s mucus with its own to form a stronger shield.
The clownfish is an intriguing creature. Its anatomical structure enables it to protect itself from potential predators in a suitable host. It does this while remarkably protecting itself in the host’s body despite the toxic danger the anemone poses.
