The broadclub cuttlefish is a predatory cephalopod (squid, octopus, or cuttlefish) that lives and hunts on coral reefs in the Indo-Pacific Ocean. This species is the second largest cuttlefish, reaching weights of at least 22 pounds (10 kg). Cuttlefishes are masters of camouflage and can change both their color and the texture of their skin to match their surroundings. The broadclub cuttlefish gets its common name from the wide pads on the ends of its feeding tentacles that it uses to capture prey.
Broadclub cuttlefish are active predators and feed on a variety of fish and invertebrate prey. In addition to their ability to use camouflage to sneak up on prey, they flash several colors and waves of light toward their prey, apparently to hypnotize it. They then strike with their feeding tentacles and pull the prey toward their beaked mouths. When threatened by predators, broadclub cuttlefish produce ink that confuses the potential predators and allows the cuttlefish to escape. Any individuals that do not immediately escape can perfectly mimic the color and texture of the ink, in an attempt to hide in plain sight.
During courtship, male broadclub cuttlefish defend territories near the reef surface, and females may visit and mate with several males. This species reproduces via internal fertilization, and females can store sperm from multiple mates, only later “deciding” which sperm to use to fertilize their eggs. The eggs are then attached to the reef surface or other hard surfaces, where they stay until they hatch.
The broadclub cuttlefish is purposely targeted by fishers throughout its range and is accidentally captured in fisheries targeting other species in some places. At this time, population trends are not well understood, and the conservation status of this species is unknown. The combination of climate change and ocean acidification (a phenomenon where the ocean becomes more acidified after absorbing carbon dioxide from the atmosphere) is thought to be a potential threat to this species. Continued monitoring of broadclub cuttlefish populations is necessary to determine the direction of any population trends and to assess the conservation status of this interesting reef predator.
Oceana joined forces with Sailors for the Sea, an ocean conservation organization dedicated to educating and engaging the world’s boating community. Sailors for the Sea developed the KELP (Kids Environmental Lesson Plans) program to create the next generation of ocean stewards. Click here or below to download hands-on marine science activities for kids.