Many kinds of octopus, cuttlefish, and squid are masters of disguise. They conceal themselves using chromatophores—specialized skin cells that hold pigment and reflect light. Cephalopods expand or contract these colored areas, rapidly shifting color or changing skin patterns to blend with their surroundings. A new study shows that even deep-sea dwellers use camouflage to their advantage. Two species—a squid and an octopus—are normally transparent, which makes them invisible to predators that look for silhouettes against surface light. But transparency can't protect them against ocean predators that use their own bioluminescence to illuminate transparent prey. Scientists tested the responses of the two cephalopods to light sources similar to the bioluminescence of deep-sea predators, and observed that the squid and octopus shifted quickly from transparent to opaque in response to this particular spectrum of light. These quick-change artists provide scientists with an important example of camouflage strategies in the ocean depths.
This latest Bio Bulletin from the American Museum of Natural History's Science Bulletins program is on display in the Hall of Biodiversity until August 5, 2012.
Science Bulletins is a production of the National Center for Science Literacy, Education, and Technology (NCSLET), part of the Department of Education at the American Museum of Natural History. Find out more about Science Bulletins at amnh.org/sciencebulletins/.
Mesopelagic Cephalopods Switch between Transparency and Pigmentation to Optimize Camouflage in the Deep
Duke University Biology Department: Research
Tree of Life Web Project: Onychoteuthis banksii
Integrated Taxonomic Information System: Japetella heathi
NOAA: What is bioluminescence?
Creatures of Light