Cameras deep in the Pacific Ocean have unexpectedly recorded caring behavior by squid moms.
The remotely operated vehicle Tiburon has encountered five Gonatus onyx squids, each dragging along thousands of developing eggs, says Brad A. Seibel of the University of Rhode Island in Kingston.
Parental care was unknown among squids. In the most-studied species, mothers often lay eggs on the ocean bottom and leave the clutch to its fate. Getting details of deep-water squid family life has been tricky.
Tiburon found the offspring-caring mother squids at depths between 1,500 and 2,500 meters in Monterey Canyon off California’s coast. Each G. onyx mother, which has a body length of about 14 centimeters, pulled 2,000 to 3,000 eggs behind her in a membrane sack almost as long as her body (To see a video, click here). The eggs are sandwiched between the sack’s inner and outer membranes, and the outer membrane attaches to hooks on the mother’s arms. The females typically flare their arms once or twice a minute, as if flushing water over the egg mass to provide oxygen, says Seibel.
The females probably have to carry the eggs for months, which would encumber their swimming and raise the risk of getting caught by a whale or seal. The researchers show off their squid pictures in the Dec. 15, 2005 Nature.