BLANKET OCTOPUS PREDATORS DRIVER

However, understanding of anti-predator evolution is biased toward vertebrate taxa.

BLANKET OCTOPUS PREDATORS DRIVER

Predation is a major evolutionary driver of animal adaptation. 5Animal Physiology and Biochemistry, Zoological Institute and Museum, University of Greifswald, Greifswald, Germany.4Department of Zoology, Stockholm University, Stockholm, Sweden.3Department of Biology, Centre for Animal Movement Research (CAnMove), Lund University, Lund, Sweden.2Baltic Sea Centre, Stockholm University, Stockholm, Sweden.1Centre for Ecology and Conservation, University of Exeter Penryn Campus, Penryn, United Kingdom.The views expressed are those of the author(s) and are not necessarily those of Scientific American.Rahul Jaitly 1, Eva Ehrnsten 2, Johanna Hedlund 1,3, Michael Cant 1, Philipp Lehmann 4,5 and Alexander Hayward 1* These octopuses have been known to collect stinging tentacles from the jellyfish-like creatures and wield them like weapons to fend off predators. These octopuses are apparently immune to the sting of Portuguese man-o-wars ( Physalia physalis). violaceus), the common blanket octopus or the violet blanket octopus, also has the ability to drop portions of her web to serve as a distraction to potential predators.īut both males and small females have a more menacing option for defense. And the most well studied species of this group ( T. This web can also be rolled up when not in use. The large web of the blanket octopus helps her appear much bigger to potential predators-a tried and true defensive strategy in the oceans and on land. The male is assumed to die soon after he has made his contribution, and the female carries the eggs in a long strand until they hatch. To mate with the large ladies-who are carrying some 100,000 eggs-the males secrete their spermatophores into a pouch on their specialized third right arm (the hectocotylus) and then leave it behind in or on the body of the female, where it will then fertilize her eggs when she is ready to lay them. The tiny fellow swam up toward a dive light on a night research dive off the northern Great Barrier Reef in Australia. It wasn't until just a decade ago that scientists finally found their first identifiable live male blanket octopus. These measured no longer than 2.4 centimeters. And then it was only from the dead ones that occasionally appeared in plankton nets.

So, bigger females, more eggs equals better odds at continuing the genetic line.īut the blanket octopus has taken this to such an extreme that it took years to even identify males of the genus. And when it comes time to mate, the females are carrying an entire clutch of eggs-the more of which the better-and the males are contributing the sperm-which comes in small packets called spermatophores. The females of many octopus species outgrow their male counterparts, a strategy that seems to work for their non-social system. Some hundred times shorter-and tens of thousand times lighter-making the blanket octopus one of the most extreme cases of sexual dimorphism in the animal kingdom. These guys are many orders of magnitude smaller. We're not talking Napoleon complex shorter. The males, on the other hand, are, well, quite a bit smaller. Why? Although they live in the vast open ocean, they are big (up to two meters long) and have fleshy, capelike webs that extend down their longest arms. Today we meet the blanket octopus ( Tremoctopus), a genus with four species that, until recently, had only been described based on female specimens. We continue our exploration of the many mysterious octopuses that live far from shore-and the eyes of humans.

Blanket octopus predators