Scientists are studying cephalopods' large brains, elaborate sense organs, and complex behavior in order to understand more about learning and behavior patterns in all species. Sepioteuthis sepioidea is among the species being studied. (Hanlon and Messenger 1996, New 1995)
US Federal List: no special status
CITES: no special status
Sepioteuthis sepioidea does not compete with humans for food or for habitat and consequently do not affect humans negatively in any respect. (New 1995)
All types of squid, including the species S. sepioidea, are particularly important to humans as a food source. Squid have little other significant economic importance for humans. (New 1995)
The diet primarily inculdes fishes (most of which are schooling sardines) and arthropods (usually shrimp floating near the surface at night). Squid eat on fish proportional to their own size. Very few fish larger than 12 cm are ever eaten; most are only a few centimeters in length. Presumably, S. sepioidea eat many planktonic animals that have not been recorded because they cannot be seen with the human eye. No available list of their prey is all inclusive since feeding patterns are derived entirely from observations made in the field.
S. sepioidea track food entirely by sight, which limits their feeding. They use body color changes to express emotion as well as to confuse or distract potential prey. Their tentacles remain hidden except during strikes when they extend the tentacles to bend upward and produce a hooklike effect.
It is not known upon what the semiplanktonic, newly-hatched squid feed. (Moynihan and Rodaniche 1982)
Sepioteuthis sepioidea lives in the ocean waters of Flordia and Bermuda through the West Indian islands and from Venezuela to Cozumel along the Caribbean shores of Central America and the northeast of South America. It lives in waters that are relatively clear and shallow to approximately 100 meters, with average salinity. It finds success and dominance in many localized areas of its range. (Moynihan and Rodaniche 1982)
Biogeographic Regions: atlantic ocean (Native )
The habitat of S. sepiodea changes according to the squid's stage of life and size. For ease of understanding, they will be divided into four size categories to help explain habitat preferences: very small (newly hatched), small, nonbreeding large, and large (breeding adult). The new hatchlings tend to reside in a very narrow range close to or between islands. Their habitat primarily includes areas from 0.2-1.0m below the surface on or under vegetation and 1-10m from the ocean bottom. These smallest individuals are found primarily during the day.
The small squid typically congregate in shallow turtle grass near islands and remain several centimeters to two meters from the surface to avoid bird predators. They also do not dwell on the ocean floor because of possible snapper predation. At night however, they often will swim to deeper waters and hunt with older, larger squid.
Nonbreeding adult S. sepioidea avoid the turtle grass flats of their younger years because of insufficient room to maneuver in these shallow waters. Most of the waters in the San Blas are home for these, including all varieties of ocean bottoms. They venture to depths of 100m and prefer open waters at night opposed to their shoreline home of their days.
Breeding and courting adults spend their days upon coral reefs of 1.5-8m depths. These large squid avoid all or most other habitats during this period.
Habitat Regions: saltwater or marine
Aquatic Biomes: pelagic ; reef ; coastal
The youngest individuals are semiplanktonic and swim rather passively due to their small, short fins. Their dorsal mantle is typically 8-9mm in length when they emerge from their eggs.
Adults of the species Sepioteuthis sepioidea resemble their close relative, the cuttlefish. They are less elongated, streamlined, and arrow-shaped than many other squids. Their triangular fins extend nearly the entire length of the body, which is a wide flattened viseral mass. Adult females' dorsal mantles reach lengths of at least 120 mm and males' reach at least 114 mm.
Their coloring is typically finely mottled, medium brown on the dorsal side and clear, light brown, or whitish on the ventral side. A distinct white line runs longitudinally on the dorsal side. Prominent brow ridges are above their large eyes. At night, individuals appear to be completely colorless because their pigment cells do not expand. It is not certain if this change in color at night has any significant purpose. (Moynihan and Rodaniche 1982)
Other Physical Features: ectothermic ; bilateral symmetry
The mating rituals of S. sepioidea are ambiguous and complex. Large adults typically form pairs of one female and one male before they disengage from the squid school to head for the reefs to mate. Most cephalopods, including the Caribbean reef squid, are semelparous; that is, individuals die after reproducing for the first and only time. Females lay eggs in clutches and die immediately after. However, males can copulate many times in a concentrated short period of time before they die. Females lay the eggs in well protected areas, scatterering them within the reefs, but do not care for the young in any direct way. It is advantageous for the male partner to escort the egg-bearing female to the reef in order for him to protect his investment from large carnivorous fish. (Hanlon and Messenger 1996)
Key Reproductive Features: semelparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (Internal ); oviparous
The Caribbean reef squid (Sepioteuthis sepioidea), commonly called the reef squid, is a species of small, torpedo-shaped squid with undulating fins that extend nearly the entire length of the body, approximately 20 cm (8 in) in length. In 2001, marine biologist Silvia Maciá discovered that squid were able to propel themselves up out of the water about 2 m (6.6 ft) and fly approximately 10 m (33 ft) before re-entry; a discovery which led to the identification of six species of flying squid.[3]
The Caribbean reef squid is found throughout the Caribbean Sea as well as off the coast of Florida, commonly in small schools of four to thirty in the shallows associated with reefs. The habitat of the 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 to 1 metre (1 to 3 ft) 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. Adults venture out into open water and can be found in depths up to 150 m. When mating, adults are found near coral reefs in depths of 1.5 to 8 metres (5 to 26 ft). The Caribbean reef squid is the only squid species commonly sighted by divers over inshore reefs in the Florida, Bahamas and Caribbean regions.
Reef squid, Bonaire
A school in Dry Tortugas National Park, Florida
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Caribbean reef squid hovering just above seafloor
Close-up of a Caribbean reef squid
This species, like most squids, is a voracious eater and typically consumes 30–60% of its body weight daily. Prey is caught 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.
Caribbean reef squid have been shown to communicate using a variety of color, shape, and texture changes. Squid are capable of rapid changes in skin color and pattern through nervous control of chromatophores.[4] In addition to camouflage and appearing larger in the face of a threat, squids use color, patterns, and flashing to communicate with one another in various courtship rituals. Caribbean reef squid can send one message via color patterns to a squid on their right, while they send another message to a squid on their left.[5][6]
Like other cephalopods, the Caribbean reef squid, is semelparous, dying 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. Females lay the eggs in well-protected areas scattered around the reefs. After competing with 2-5 other males, the largest male approaches the female and gently strokes 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. As he reaches out with the sperm packet, he displays a pulsating pattern. The female places the packet in her seminal receptacle, finds appropriate places to lay her eggs in small clusters, and then dies.
The Caribbean reef squid (Sepioteuthis sepioidea), commonly called the reef squid, is a species of small, torpedo-shaped squid with undulating fins that extend nearly the entire length of the body, approximately 20 cm (8 in) in length. In 2001, marine biologist Silvia Maciá discovered that squid were able to propel themselves up out of the water about 2 m (6.6 ft) and fly approximately 10 m (33 ft) before re-entry; a discovery which led to the identification of six species of flying squid.
