10 facts about reef squids
- They are members of the 10 arm cephalopods (decabrachia) with torpedo-shaped bodies. All 10 appendages of the squid are "fixed to its head", and are arranged in a circle around the mouth.
- Reef squids are often encountered in small schools (4-30) and are usually unafraid of divers, if not curious about them.
- The habitat of reef squid changes according to the squid's stage of life and size. New hatchlings tend to reside close to the shore in areas from 0.2-1 m below the surface on or under vegetation. Young small squid typically congregate in shallow turtle grass near islands and remain several centimeters to two meters from the surface to avoid bird predators. Adult reef squid venture out into open water and can be found in depths up to 100 m. When mating, adults are found near coral reefs in depths of 1.5-8 m.
- They communicate through a variety of complex signals controlling the pigment in their skin. Messages such as readiness to mate, sexual identification, and alarm are flashed through various colorful spots, blotches, and background color. To signal slight alarm, their brow ridges turn bright gold and the central arms turn white, the entire body will pale if the squid retreats from its potential predator and in open water when faced with an extremely aggressive predator, reef squid will obstruct themselves and confuse the predator by ejecting a cloud of black ink
- Reef squid can also move using jet propulsion by pressing water from the pallial cavity (in the mantle) through their funnel to move through the water. Reef squid can also fly out of the water using jet propulsion.
- Reef squid is a voracious eater and can consume 30-60% of its body weight daily. They consume small fish, other mollusks and crustaceans.
- They use very tricky hunting tactics to catch their prey. When hunting, they often mimic weeds in the water to blend in. Most of there hunting is done at night.
- Caribbean reef squid, are semelparous; that means, they die after reproducing. Females lay their eggs then die immediately after. The males, however, can fertilize many females in a short period of time before they die
- The squid can hear a range of sound from 400Hz to 1500Hz
- They have three hearts and blue blood due to it binds oxygen using a blue, copper-containing protein called hemocyanin. Human blood is red because the oxygen-binding protein hemoglobin contains iron.
