User:Milessilber/Sepiidae

Sepiidae

The cuttlebone, the distinguishing feature of a member of the Sepiidae

The Sepiidae family is characterized by the presence of the cuttlebone, a structure that provides buoyancy to the cuttlefish. This excludes some of the bobtail squids and other animals in the larger order Sepiida. The cuttlebone is comprised of aragonite and calcium. It consists of a complex arrangement of calcified pillars and membranes, and it is not clear how the bone is formed. Sepiidae are the only cephalopod genus to have this chambered shell, and it has been found that species that live in greater depths have a thicker septa and less space between pillars in their cuttlebones. This observation led to the inference that these specialized bones are used as a tool to protect against implosion from hydrostatic pressure. The animals in this family are widely distributed in seas around the world and display higher levels of intelligence like other cephalopods.

Classification

Kingdom- Animalia

Phylum-Mollusca

Class-Cephalopoda

Order-Sepiida

Family-Sepiidae

Habitat

Sepiids are mostly a benthic taxon that inhabit coastlines and continental shelf zones. Benthic means that these creatures inhabit the seafloor and arent swimming/occupying open water as often as they are on the reefs or floor. They are mainly found in the 0-100 meter region of the water column but can be found as deep as 200 meters. A young Sepiid will hatch in shallower water and then after a few months will descend down to deeper waters. They will return to shallow waters only during mating seasons, which in many of the species is determined by water temperature. They have been found in tropical waters off the coast of Asia, Australia, Europe, and Africa.

Reproduction

A mating pair of a species of Sepiid

One aspect of this taxa that is well studied is their reproductive behavior. These behaviors vary from species to species but one specific behavior that the males in multiple species often display is sperm displacement where they will scrape away sperm masses from the female using their tentacles. It has been observed in captivity that a male will even scrape away its own masses of sperm. When a pair of Sepiids mate, they position themselves in a "face to face" arrangment as you can see in the photo.

Diet

Sepiids grow extremely quickly in their short lifespans so their bodies have a high energy demand. Their diet changes throughout their lifespan and vary in different habitats but generally they will eat crustaceans, fish, bivalves, and other cephalopods. Smaller Sepiids will have a mainly crustacean-based diet whereas the larger older Sepiids will mainly hunt and eat fish. They are opportunistic predators, meaning they will prey on any smaller animal they are capable of eating. It has also been observed that species of Sepiidae can be cannibalistic and will even bite one another when caught in a fishing net.