Designer clown fish: peculiar results of a breeding experiment at the Aquarium
Biologists at the Primorsky Aquarium are conducting an experimental breeding program for marine tropical fish and some invertebrates: corals and sea anemones. The aquarists have found notable success in propagating anemone fishes: of the nine clown fish species residing at the Aquarium, four reproduced in the course of the last six months. Apart from normal looking offspring, there are some individuals with bizarre, “non-natural” patterns.
“A pair of common clown fish (Amphiprion ocellaris) has produced a brood with eccentric coloration, not found in nature: their prevailing body colour is white instead of orange”, said Evgeniya Morozova, Lead Specialist at the Tropical Marine Organisms Department. “Common clown fish are typically bright orange with vertical white bands thinly edged in black. In our fish, the white colour of bands is spread over the entire body, forming complicated patterns. We also have almost white clowns whose colour is set off with black on the fins and orange on the head. Among ourselves we call these unusually coloured specimens “designer fish”.”
White clown fish with red snouts and black fins – the so-called “snowflakes” – are the rarest: such coloration occurs in one out of a thousand fry. This and other non-standard colour patterns are related to the fish’s diet and depend on a mix of fatty acids in their food.
Designer clown fish develop and mature just like their ordinary conspecifics, and are kept in the same manner. These outliers are not yet singled out in any way by the shoal. All juvenile clowns are raised in separate small nurseries containing seaweeds. Clown fish need, if not anemones with whom they usually live in symbiosis, at least seaweeds, rocks or corals nearby to feel safe.
Intraspecific aggression is an intrinsic trait of clowns that is why when growing them it is very important to pay attention to the size structure of a shoal. Fish of the same size start fighting with each other but if a larger individual is introduced into the shoal, a hierarchy is established, and there comes peace and quiet.