Half Nots: 8 Amazing Gynandromorph Animals

Gynandromorphs are creatures split down the middle into male and female halves. Though most commonly found in insects and arachnids (spiders), the curious condition has been noted in higher animals including crustaceans, crabs, cardinals and chickens.

Gynandromorph Butterfly

(images via: Natural History Museum and Stray and Snap)

Butterflies are among the most frequently noticed gynandromorphs, owing to the creatures’ oft-exaggerated sexual dimorphism – that is, male and female butterflies of the same species can differ greatly in both size and coloration.

(image via: [¯Ô¯] StephsShots)

Since butterflies display their brightest colors on their wings, marked asymmetry in the color and patterning of the wing scales is easily noticed from a distance by both human observers and hungry predators. One wonders what other butterflies think… do gynandromorph butterflies attract males and females, repel either gender, or a little of both?

Gynandromorph Moth

(images via: Amateur Entomologists’ Society, Africa Unlocked and eBay/Themothman35)

Moths can be afflicted by gynandromorphism to the same degree as butterflies but being primarily night-active insects, coloration plays a lesser role in display and identification. That leaves size, which isn’t good news if you’re a gynandromorphic moth. These bizarre creatures can also be identified by their antennae: those of males are feathery, those of females are slender.

(images via: Nature.com News Blog and Scielo Brasil)

It’s doubtful gynandromorphic moths of species that normally express a wide variance of sexual dimorphism can fly at all, so we must assume that most if not all of the recorded, documented and photographed examples emerged from their cocoons in captivity.

Gynandromorph Phasmid

(image via: Wikipedia)

Phasmids, like the gynandromorphic Malayan Jungle Nymph (Heteropteryx dilatata) above, are insects known variously as Walking Sticks or Leaf Insects after the inanimate objects they unconsciously imitate. The phasmid pictured is quite a piece of work since female Malayan Jungle Nymphs are much larger than males (and these insects are HUGE to begin with!), are colored bright lime green as opposed to mottled brown, and are flightless whereas males can fly.

Gynandromorph Spider

(image via: Spider Silk Stockings)

Aren’t spiders creepy enough without adding gynandromorphism to the mix? Actually, arachnids aren’t creepy at all – it’s all in your head, or ON your head if you don’t watch where you’re going! Spiders don’t exhibit as much sexual dimorphism as some insects (and spiders aren’t insects, trivia buffs) but gynandromorphs are still quite obvious even without an up-close-and-personal inspection.

(images via: KRYP and The Science Forum)

The pair of cleverly manipulated photographs above were created by “mirroring” each half of a gynandromorphic Fringed Ornamental tarantula (Poecilotheria ornata). This eight-legged, tree-dwelling, living Battle of the Sexes is native to the forests of Sri Lanka and it’s reputed to be an aggressive biter… something to consider, considering its legspan can reaches up to 10 inches (25 cm) across.