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An Adult Female Blanket Octopus

“Blanket octopus” sounds like an endearing nursery game, but the blanket octopuses are actually pelagic hunters which have adapted to living in the ultra-competitive environment of the open ocean.  There are four species of blanket octopuses (Tremoctopus) which can be found ranging from the surface to medium depths of open tropical and subtropical seas worldwide.  Because they often live far from any land, some of the methods which other octopuses use to escape predators do not work very well for them.  Fortunately Blanket octopuses have adapted in their own unique bag of tricks.

An Adult Female Blanket Octopus

Blanket octopuses are named after the distinctive appearance of adult female octopuses which grow long transparent/translucent webs between their dorsal and dorsolateral arms.  Blanket octopuses use these webs as nets for hunting fish, but they can also unfurl and darken their nets in order to appear much larger than they actually are.  Since blanket octopuses do not produce ink and can not camouflage themselves as rocks, coral, or sand, they rely heavily on their blankets.  As a last resort they can jettison the blankets as a decoy and jet away while the confused predator attacks the highly visible membranes.

Blanket octopuses exhibit extreme sexual dimorphism.  Whereas the female octopus can grow up to 2 meters (6 feet) in length, the male octopus is puny and does not grown longer than a few centimeters (1 to 2 inches).  Males store their sperm in a modified quasi-sentient third right arm, known as a hectocotylus.  During mating this arm detaches itself and crawls into the female’s reproductive vent.  As soon as the hectocotylus is detached the male becomes unnecessary and dies.

Male Blanket Octopus

Tiny males and immature females do not have blankets, but they utilize another trick to protect themselves.  Because they hunt jellyfish and other hydrozoans, the little octopuses are immune to the potent venom of the Portuguese man o’war.  The octopuses tear off stinging tentacles from the man o’war and wield them in their tentacles like little whips to ward off predators.

An amazing illustration of a blanket octopus sheltering in a Portuguese man o’war’s tentacles

A female velvet ant (mutillidae wasp)

Velvet ants (Mutillidae) are not actually ants at all—the insects are classified as wasps even though female velvet ants do not have wings and appear to be tiny furry colorful ants. The Mutillidae family of wasps—which is made up of more than 3000 species– illustrates how closely wasps, bees, and ants are actually related.   Male velvet ants look nothing like the females but are much larger winged creatures resembling other wasps.  So great is the sexual dimorphism between the genders that it took entomologists a tremendously long time to pair the females with the males, and in many species the connection has still not been made by science.  The genders do however both share a ridged structure called a stridulitrum, which can be rubbed or struck to produce chirps and squeaks for communication.

Male velvet ant (mutillidae wasp)

Female velvet ants are notable not just for their colorful fur but for their tremendously powerful sting which is so painful that they are nicknamed “cow killers.”  Male velvet ants look like wasps but do not sting.  The exoskeletons of velvet ants are tremendously hard to such an extent that some entomologists have reportedly found it difficult to drive pins through specimens.  The dense hard coating helps the females invade the underground burrows of larger bees and wasps which the velvet ants sting and lay eggs on.  When the velvet ant larvae hatch they feed on the paralyzed victims before metamorphosing into adult form and venturing into the world.

Blue velvet ant (female)

Velvet ants are found in warmer parts of the world particularly deserts.  The majority of species are red and black but a variety of other colors are known including blue, gold, orange, and white.  Unlike the social ants and termites, velvet ants are generally solitary, coming together only to reproduce with their strangely alien mates.

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