Pajama Squid
Sepioloidea lineolata
These adorable small creatures, pajama squid, are commonly mistaken to be a type of squid, but they are actually a species of cuttlefish. Pajama squid are masters of disguise appearing white and black in the sand and purple-brown next to coral. They will commit most of their day to flipping sand over their body and burying themselves underground except for their yellow eyes that peek out the top. Don’t underestimate them for their cute appearance; they have a deadly slime at the ready for any potential predators!
Credit: Aquarium of the Pacific / Robin Riggs
SPECIES IN DETAIL
Pajama Squid
Sepioloidea lineolata
CONSERVATION STATUS: Data deficient
CLIMATE CHANGE:
Geographic Distribution
Their range is the Indo-Pacific oceans of Australia.
Habitat
Pajama squid are found on the seafloor of coastal waters. They can be located buried in mudflats, sand, and seagrass beds about 20 meters (60 feet) deep in the water.
Physical Characteristics
A full grown pajama squid can reach up to 7 centimeters (2.76 inches) in length and has very distinct black stripes that warn potential predators of its venom. Its stripes are also used as a means of camouflage for the pajama squid when it is buried in the sand and shells, but the cuttlefish can change its color to a dark purple-brown when it is next to coral or rocks. It has two long fins on the side of its body above its eight arms and two tentacles; the tentacles are used for feeding and have small suckers and horny rims. The pajama squid’s yellow eyes have a similar structure to those of vertebrates and are thought to have polarization sensitivity unlike those of the pajama squid’s color-blind relatives.
Size
The are about 7 centimeters (2.76 inches) in length.
Diet
They use their front two tentacles that have small suckers and horny rims to gather food. They eat small fish and crustaceans such as shrimp.
Reproduction
When mating, the male positions itself with the female so that they are head to head and places its sperm pocket close to her mouth. The male has a specialized scoop on his lower arm in the event that he discovers another male’s sperm in the female’s mouth. He will try to remove it. The female stores the sperm close to her mouth and uses it when she lays her round white eggs in clumps on the ocean floor. The young pajama squid already have visible black stripes when they hatch.
Behavior
The pajama squid is usually buried in the sand or hiding in seagrass with only its eyes exposed and looking around upwards. However, when it is threatened, it secretes a slime from the small glands in the underside of its body. It is a quick defense mechanism that scares off potential predators.
Adaptation
They have a couple major differences from other cephalopods because of their horizontal slit pupil and high-density photoreceptors. The unusual dorsal position of the pupil is most likely due to its behavior of hunting with most of its body underground; the photoreceptors that increase the sharpness of their field of vision adapted most likely for the same reason. They rely heavily on their eyes, so the photoreceptors help them to be able to see clearer and with more color.
Longevity
The pajama squid can live between eight to twenty-four months (two years). This length can vary depending on water temperature and amount of available food.
Conservation
Though their habitat in shallow coastal waters may be vulnerable to human interaction, they are not a target of commercial fishing. At the moment, there is not enough data to determine the conservation status of the pajama squid.
Special Notes
The pajama squid has an internal shell. The shape of the pajama squid inspired people to call it “the striped dumpling squid”. They are nocturnal, so they come out at night to feed. It is one of the few venomous cuttlefish.
SPECIES IN DETAIL | Print full entry
Pajama Squid
Sepioloidea lineolata
CONSERVATION STATUS: Data deficient
CLIMATE CHANGE:
Their range is the Indo-Pacific oceans of Australia.
Pajama squid are found on the seafloor of coastal waters. They can be located buried in mudflats, sand, and seagrass beds about 20 meters (60 feet) deep in the water.
A full grown pajama squid can reach up to 7 centimeters (2.76 inches) in length and has very distinct black stripes that warn potential predators of its venom. Its stripes are also used as a means of camouflage for the pajama squid when it is buried in the sand and shells, but the cuttlefish can change its color to a dark purple-brown when it is next to coral or rocks. It has two long fins on the side of its body above its eight arms and two tentacles; the tentacles are used for feeding and have small suckers and horny rims. The pajama squid’s yellow eyes have a similar structure to those of vertebrates and are thought to have polarization sensitivity unlike those of the pajama squid’s color-blind relatives.
The are about 7 centimeters (2.76 inches) in length.
They use their front two tentacles that have small suckers and horny rims to gather food. They eat small fish and crustaceans such as shrimp.
When mating, the male positions itself with the female so that they are head to head and places its sperm pocket close to her mouth. The male has a specialized scoop on his lower arm in the event that he discovers another male’s sperm in the female’s mouth. He will try to remove it. The female stores the sperm close to her mouth and uses it when she lays her round white eggs in clumps on the ocean floor. The young pajama squid already have visible black stripes when they hatch.
The pajama squid is usually buried in the sand or hiding in seagrass with only its eyes exposed and looking around upwards. However, when it is threatened, it secretes a slime from the small glands in the underside of its body. It is a quick defense mechanism that scares off potential predators.
They have a couple major differences from other cephalopods because of their horizontal slit pupil and high-density photoreceptors. The unusual dorsal position of the pupil is most likely due to its behavior of hunting with most of its body underground; the photoreceptors that increase the sharpness of their field of vision adapted most likely for the same reason. They rely heavily on their eyes, so the photoreceptors help them to be able to see clearer and with more color.
The pajama squid can live between eight to twenty-four months (two years). This length can vary depending on water temperature and amount of available food.
Though their habitat in shallow coastal waters may be vulnerable to human interaction, they are not a target of commercial fishing. At the moment, there is not enough data to determine the conservation status of the pajama squid.
The pajama squid has an internal shell. The shape of the pajama squid inspired people to call it “the striped dumpling squid”. They are nocturnal, so they come out at night to feed. It is one of the few venomous cuttlefish.