April 4, 2010
April 4 - Synodontis multipunctatus
Well, we've had cuckoo birds on this blog before, which most people would at least have heard of, but what about the cuckoo catfish? The cuckoo catfish, Synodontis multipunctatus, a popular ornamental fish that is somewhat well-known amongst aquarium enthusiasts. It is originally from Lake Tanganyika in Africa which is hotspot of cichlid fish biodiversity. The cuckoo catfish has a rather unusual breeding habit, it is a brood parasite of mouthbrooding cichlids found in Lake Tanganyika. Just like their bird namesake, the cuckoo catfish displaces the legitimate offspring of its host, forcing the cichlid to rear its young, and they have a rather clever way of accomplishing this. The catfish is attracted by the scent of the brooding cichlids, and as soon as they detect any such brooding cichlid in the vicinity, they race to the scene of the coupling. The catfish mob the pair of spawning cichlids and as soon as their eggs are fertilised, a mating pair of cuckoo catfish dash in, the female laying her own eggs amidst the brood, with the male following closely behind to fertilise them. When the brooding cichlid scoop up the clutch of eggs to brood them in its mouth, it's a mixed-bag of cichlid and catfish eggs. The catfish fry hatch a few days earlier than the cichlid fry and proceed to feed on the host's eggs with which they are sharing the brood chamber. So the cichlid is unknowingly and unwittingly carry a brood composed of juvenile catfish - imagine seeing a mouthbrooding cichlid open its mouth and out swim a swarm of splotchy little catfish!
The paper that originally described this fishy brood parasite is:
Sato, T. 1986. A brood parasitic catfish of mouthbrooding cichlid fishes in Lake Tanganyika. Nature 323:58-59
Contributed by Tommy Leung.