This week in Lembongan, during the discovery dive of Vishal, we focused a bit on the usual inhabitants of the coral reef, and particularly the damselfish which are populating the coral reel. Damselfishes are these energetic little fish that you will spot everywhere on the reefs of South-East Asia seas. They have 321 known species, usually with oval body shapes (up to around 35cm) and bright colors.
Damselfish usually eat zooplankton, small crustaceans and algeas. They are often very territorial and can defend their area vigorously. Male damselfish perform a courtship behavior called the signal jump, in which they rise in the water column and then rapidly swim back downward. The signal jump involves large amounts of rapid swimming, and females choose mates based on the vigor with which males do so. As the male damselfish swims down the water column, it creates a pulsed sound, and females determine the male courtship rates using sounds that are produced during signal jumps.
Very emblematic members of the family are sergeant fish, these black vertical striped fish which swim in schools in the first few meters of our waters – although they can have a individualistic behaviour. They are visible all around Lembongan waters, at least when the current is not too strong.
Together with the sergeant fish, common inhabitants of our reef are anemone fishes (the famous clown fish of Finding Nemo is one of them) who make the happiness of photographers. They can have a very aggressive behaviour when a diver comes too close from their anemone, and swim at an impressive distance from their shelter to ‘growl and bark’ at the intruder… watch out, they can bite you if you leave your fingers at their reach!
Another common but fascinating type of damselfish is the dascyllus, in particular the three-spot dascyllus. While the adult fish is dark gray with black edges, at juvenile stage it is black with three large white spots: one on the forehead and two on the upper flank at each side. The juveniles are quite small (max 5 cm) and will use the coral tables and some anemones to shelter from predators.
Lots of divers have already been hypnotized by these fish hiding in the corals then swimming back up before hiding again at first move…