I finally got to see some decent size reef squid on our last dive in Lauderdale by the sea. I had previously only spotted some tiny ones. These graceful creatures are super quick and hard to capture on film. To me, they are very alien like with their undulating fins and humungous eyes. They have torpedo shaped bodies that can jettison through the water. Squids are mollusks(cephalapods): they are closely related to cuttlefish and octopuses and more distantly to snails, clams, oysters, and sea slugs. These squid are often confused with cuttlefish because they have large fins that wrap around their mantles. They are also broader than many squid and these traits make them look like cuttlefish. They are characterized by having two longer tentacles used to capture prey and eight smaller arms all located near the mouth. The head is also comprised of the mantle which houses all of the stomach, reproductive and digestive organs. The Caribbean Reef Squid have fins that span the entire length of the body
Did you know they can fly out of the water?
Jet propulsion is the key for getting out of the water in the first place. A squid first expands its mantle (the cloak of soft muscular tissue that surrounds its body—which fills with water). Then the squid quickly contracts it to send the trapped water shooting through a flexible tube below its head, called the funnel or siphon. By changing the position of this funnel, a squid can propel itself in almost any direction. Underwater, squid use jet propulsion to pounce on swift prey and escape intimidating predators. But sometimes jetting through the currents is not enough to make a successful getaway—sometimes, a squid needs to get out of the water altogether. So they fly.
They are usually found in schools of 4-30 but I have never seen more than 3 in a group myself. This Caribbean reef Squid, is found off Florida coast, in Bermuda and the Caribbean. The reef squid can consume 30-605 of its body weight every day. Usually juvie squid are found close to the shoreline in amongst the turtle grass and algae. Larger reef squid roam in the open in waters up to 300 feet.
The reef squid eats his unsuspecting prey by using the club-like end of the long tentacles which are then pulled towards the mouth supported by the shorter arms. Like other cephalopods, it has a strong beak which it uses to cut the prey into parts so that the raspy tongue, or radula, can be used to further process the food. It consumes small fish, other molluscs, and crustaceans.
The caribbean reef squid communicates with his brothers and sisters by changing color, texture and size. Caribbean Reef Squid are fun to watch because they can instantly change their color and their skin pattern, both for camouflage and to communicate with each other. When communicating they can send one message via color patterns to a squid on their right, while they send another message to a squid on their left. Caribbean reef squid are believed to display nearly 40 different patterns. It also can appear larger than what it is to scare off another sea creature looking for a tasty treat. When a predator swims by the squid quickly change color, often to pale and jet away. In addition to their colorful signaling behavior, they can point their bodies upward or vertically prior to striking a fish or prey, curling upward during territorial disputes and in hostile situations, and pointing head-down when approached by a predator in open water. The main adult squid predators include the yellowfin grouper as well as other large predatory fishes.
Compared to the size of their body, squid’s eyes are strikingly large. They have the largest eye-to-body ratio in the entire animal kingdom.
Caribbean reef squid, are semelparous. That means they die die after reproducing. Females lay their eggs and then die immediately afterward. The males, however, can fertilize many females in a short period of time before they die. Females lay the eggs in well-protected areas around their reefs. After competing with 2-5 other males, the largest male has been observed to approach the female of interest and gently stroke her with his tentacles. At first she may indicate her alarm by flashing a distinct pattern, but the male soon calms her by blowing water at her and jetting gently away. He returns repeatedly until the female accepts him, however the pair may continue this dance or courting for up to an hour. The male then attaches a sticky packet of sperm to the female’s body. The female finds a rock, lays her eggs and dies.
Reef squid 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. They can also shoot a “black ink” to try to scare away predators. I have to admit this fact kept me from getting too close to them!