Deep-sea squid finds way to maximize mating success
Talk about wonders of the deep.
Scientists have found a male squid that mates just as frequently with members of its own sex as with members of the opposite sex.
The squid in question is the Octopoteuthis deletron, a deep-sea species found in the eastern Pacific. Little is known about the animals because they're generally difficult to find -- they're solitary creatures living in a world of little light.
However, according to the cheekily titled paper, "A shot in the dark: Same-sex sexual behavior in a deep-sea squid" recently published in the Royal Society's Biology Letters, scientists have determined that in this particular species, males have tried to impregnate other males at the same rate that they have tried to impregnate females.
Males of the genus Octopoteuthis use a long terminal organ -- the report says it's often referred to as a squid penis -- to transfer a complex packet containing millions of sperm directly onto its mate's body. If the packet makes it onto a female, it will discharge sperm-containing sacs into the female's tissue, but the empty packet stays attached to her body, providing evidence of recent mating.
But looking at footage of 108 of these animals collected by remotely operated vehicles, scientists found equal numbers of the sperm packs on male O. deletron as on female O. deletron.
The only logical conclusion? Male O. deletron are mating willy nilly with whatever squid they come upon, regardless of whether it's male or female.
The question, of course, is why would an animal presumably in pursuit of reproductive goals waste good sperm on a male by accident? The report offers this hypothesis:
"In the deep, dark habitat where O. deletron lives, potential mates are few and far between. We suggest that same sex mating behavior by O. deletron is part of a reproductive strategy that success by inducing males to indiscriminately and swiftly inseminate every conspecific that they encounter."
In other words, it's a survival strategy based on "close your eyes and shoot."
-- Deborah Netburn
Photo: A female Octopoteuthis deletron observed by the Monterey Bay Aquarium Research Institute's remotely operated vehicle Ventana on Dec. 6, 2007. Credit: MBARI