We know it as “strawberry squid” ( Histioteuthis heteropsis ). This ocean creature is a species of mollusk that has a very curious morphological characteristic: its eyes are disturbingly different in size and structure. One of its eyes is a very large, bulging eye that is meant to monitor its surroundings, and then it has another tiny eye below.
a great asymmetry
Sightings of these strawberry squid or cross-eyed squid are rare and they apparently enjoy spending more time in the deeper parts of their habitat.
Now, scientists at the Monterey Bay Aquarium Research Institute (MBARI) have caught a glimpse of a clueless strawberry squid as it sailed through the dark ocean. The sighting, hundreds of meters under water last month, a moment they took advantage of to record this unusual unusual creature. The specimen was bright red with one small black eye and the other large, bulbous and yellow.
Researchers in control of a remotely operated vehicle (ROV) known as Doc Ricketts spotted the squid in the Monterey Canyon off the coast of California, USA. The strawberry squid’s mantle (the body, not including the eyes and appendages) can reach up to 13 centimeters in length.
It is a really curious creature, because it is not born with eyes in this way. In hatchlings, the two eyes are the same size, but as they become juveniles, the left eye increases in size, and by adulthood, the left eye can be more than twice the size of the right eye, he explains. MBARI.
Observations of this animal suggest that the squid uses its large eye to look up, searching for the shadow of other sea creatures, while the small eye is adapted to look down, scanning darker waters.
Strawberry squid live in a region of the ocean known as the mesopelagic or ‘twilight’ zone, 200 to 1,000 meters below the surface and feed on shrimp, fish and other squid.
Is their nickname because they are the color of strawberries?
Not only for that. Another reason for being called strawberry squid is that this cephalopod has dark spots on its body that look like small seeds of this fruit . The dots on its body are actually photophores or organs that produce light through a chemical reaction or through symbiotic bacteria that glow brightly. It is one of his tools to adapt to the surrounding light as a form of camouflage. Nothing is enough to keep predators away.
Reference: Kate N. Thomas, Bruce H. Robison and Sönke Johnsen et al. Two eyes for two purposes: in situ evidence for asymmetric vision in the cockeyed squids Histioteuthis heteropsis and Stigmatoteuthis dofleini Published: 05 April 2017 Phylosophical Transactions of the Royal society B https://doi.org/10.1098/rstb.2016.0069
Monterey Bay Aquarium Research Institute (MBARI)
