Common name: Clownfish
HABITAT AND GEOGRAPHICAL DISTRIBUTION
The clown fish, scientific name Amphiprion percula of the Pomacentridae family, it is a fish that is found only in the coral reefs of the tropical waters of the Indian Ocean and the Pacific Ocean. In consideration of this, it is normally found within 6 m of depth with a water temperature around 25-28 ° C, although it is not uncommon to find it at greater depths but within 12 m.
Of clownfish there are different genera and species and all belonging to the Pomacentridae family and the particularity that unites them is that they all live in symbiosis with one of the nine existing species of sea anemone (actinias). Amphiprion percula particularly prefers species Stichodactyla gigantea and the Heteractis magnifica
It is a fish whose main feature is the very lively color in fact its body is orange with three white bands delimited by more or less evident black stripes: this livery is an extraordinary phenomenon of mimicry that allows it to blend in with the corals to escape its many predators.
Its body is covered with scales coated with a thick layer of mucus that allows it to live without problems among the tentacles of the sea anemone.
It is not a fish that reaches large dimensions in fact it does not exceed 110 mm in length and has sexual dimorphism as the female is always larger than the male. It is provided with a dorsal fin formed by 10 sharp spines which form the rigid part and by 14-17 flexible rays which represent the soft part. On the hips and on the head there are a series of small sensors that are used to perceive vibrations.
CHARACTER, BEHAVIOR AND SOCIAL LIFE
The clown fish has a lifestyle in close relationship with the sea anemone that hosts it. It is a fish that has numerous enemies therefore it never moves away from the anemone as there are very few predators that dare to venture among its deadly tentacles. In fact, when the sea anemone touches a prey with its tentacles, it pierces poisoned darts that stun or kill it but in any case the conclusion is always the same: the anemone eventually ingests the prey.
CLOWN FISH AMONG SEA ANEMONE
The clownfish is not born with this thick layer of mucus but begins to secrete it only after the first contact with the anemone. In this regard, there are several theories: there are those who argue that it is a behavioral process on the part of the clown fish which means that once it has identified the anemone that will have to host it for the rest of its life, it develops this immunity towards it. secreting a mucous layer; others argue that it is instead a simple biochemical process due to the first bites that the anemone makes to the clown fish as a result of which it begins to secrete mucus.
They are animals that form stable pairs for life, they are fish that can change sex depending on their needs, in fact many clownfish are born male and then become female.
In the life of clown fish there is a strict hierarchy where the larger fish relegate the smaller ones in niches, also significantly reducing the space allowed to them to feed.
In consideration of the fact that it is an animal that does not move away from the anemone that hosts it, the clownfish does not go in search of food but captures the zooplankton that passes near its den. It also feeds on algae growing near the anemone or even leftover anemone residues. Coral fish when it finds large chunks of food takes them inside the anemone, presumably to preserve them but these are obviously eaten by the anemone.
REPRODUCTION AND GROWTH OF THE SMALL
The clown fish is an oviparous animal: when the moment of reproduction arrives, the female begins to swim slowly over the place chosen for the oviposition which is usually a broken rock or a shell near the base of the anemone that hosts it and lays it. 200 to 400 eggs of orange color and oval shape which attaches to the support with a filament. The male then passes over them and fertilizes them with his sperm.
DEPOSITION AND FERTILIZATION OF CLOWN FISH EGGS
Both parents do not abandon the eggs but check them continuously, shaking the water to oxygenate them and every now and then put them in their mouth to clean them.After about 7-10 days the eggs hatch and the larvae move to the surface and remain there for about 7-10 days living as floating zooplankton. As soon as they reach the size of about 1 cm they return to the coral reef and look for an actinia in which to take refuge to begin their adult life and spend the rest of their lives there.
The close relationship that exists between the sea anemone and the clownfish greatly discourages predators who do not venture into its vicinity. Only the young, during the early stages of their life when living as zooplankton are exposed to predators.
STATE OF THE POPULATION
Amphiprion percula is not a species classified on the IUNC Red list therefore it is not considered endangered.
ROLE IN THE ECOSYSTEM
Scholars speak of a real symbiosis between the two animals: the clown fish oxygenates the internal parts of the anemone with its movement and cleans it of food waste and impurities and at the same time, being a very territorial species, prevents the predatory species of the anemone to approach; vice versa, the actinia offers a safe refuge and protection to this small fish.