In response, the female nibbles on the markings, seemingly as though she can’t resist the desire to hide them in her mouth. During courtship, the male flashes these markings, known as egg dummies. Meanwhile, in some of these same species, males display yellow, orange, or red markings on their back fins that look an awful lot like eggs. Biologists believe this behavior, known as mouthbrooding, evolved to protect eggs from being eaten by other fish. Mirjam Amcoff, an evolutionary biologist at Uppsala University, suspected that, at least for cichlid fishes, the oddly ornamented males may be tapping into a strong female desire that evolved before it had any connection to choosing a mate.įemales of many of the nearly 2,000 species of cichlids in the Great Lakes of East Africa scoop their eggs into their mouths after mating and don’t release them until the eggs hatch weeks later.

There’s no end to the lengths a male animal’s body can be stretched and decorated to win a female’s attention.īut where does the female preference for the elaborate and downright strange come from in the first place? And male koalas produce deep bellowing calls from highly specialized vocal tracts. Male widowbirds flaunt tails extending over twice the lengths of their bodies. Male stalk-eyed-flies dangle eyes from the ends of long antennae-like stalks.

(Photo credit: Maha Dinesh, Creative Commons) A male red zebra cichlid fish displays orange egg dummies on his back fin.

Red zebra cichlid male female