Posts tagged with cephalopoda...
(Photo by Richard Ling)
The Southern calamari squid (Sepioteuthis australis) presents color patterns that vary from orange-brown, to white with black bands, to almost transparent. They have diamond-shaped fins that extend the whole length of the body. They reach mantle lengths of up to 50cm. S. australis are reported to be voracious feeders that often approach divers at night to feed on the fish and crustaceans attracted to the lights. They are predominantly active at night, but can also be seen active during the day. They are very fast at jet propulsion, and excellent at catching fast fish and shrimp. They are found in Southern Australian coastal waters; from the southern end of the Great Barrier Reef around to Ningaloo Reef in Western Australia, and also in coastal waters of the North Island of New Zealand. They are common over reefs, sand and seagrass beds in shallow, inshore waters.
Humboldt squid (see this post)
Humboldt squid (see this previous post)
The following is an excerpt from an article, view the source to read the full version.
The monstrous squid remains motionless just ten feet away. Emotions gave way to cognitive thought and I trained my camcorder on him and begin to record. Almost on cue, he begins his approach. Then, with blinding acceleration, he lurches onto me with a powerful “thud crackle”. He slams into my chest. The impact was incredibly powerful, knocking the wind out of me. His huge arms envelope my complete upper body and camera and I can feel my chest plate move as his beak grinds against it. The crackle and scratching of thousands of chitenous ring teeth against my fiberglass/kevlar chest plate is unmistakable.
(Source of photo here)
Jumbo squids or Humboldt squids (Dosidicus gigas)are members of the flying squid family, Ommastrephidae, and are known to actually eject themselves out of the sea to avoid predators. Humboldt squid are carnivorous marine invertebrates that move in shoals of up to 1,200 individuals. Jumbo squid are large impressive squids that can reach up to 2m in length. They have a large, tough, thick-walled mantle and long arms with 100-200 powerful hooked suckers on each, and lightning-fast tentacles. These elusive and mysterious creatures are aggressive predators, which has earned them the nickname “red devils” or “diablos rojos” (from Mexican shrimpers who fish for jumbo squid during the shrimping off-season). This name comes from their red hue when hooked, which is used as camouflage from predators in deep waters where most animals cannot see the color red. Like other cephalopods, they are equipped with chromatophores and are able to change color and flash light to communicate. They also have the ability to squirt ink as a defense mechanism. Jumbo squid can swim at speeds up to 24 kph rivaling some of the fastest swimmers in the ocean.They can be found at depths between 200-700 meters in the waters of the eastern Pacific from Tierra del Fuego north to California. Although Humboldt squid have a reputation of being aggressive, there is some disagreement on this subject. Recent research suggests they are only aggressive while feeding; at other times, they are quite passive. Their behavior while feeding often extends to cannibalism and they have been seen to readily attack injured or vulnerable squid of their own shoal. This behavior may account for a large proportion of their rapid growth. Some scientists claim the only reports of aggression towards humans have occurred when reflective diving gear or flashing lights have been present as a provocation.
(Photo found here)
Nautilus belauensis, also known as the Palau Nautilus, is a species of nautilus native to the waters around the Pacific island nation of Palau. Nautilus is the common name of marine creatures of cephalopod family Nautilidae (see this previous post), the sole extant family of the superfamily Nautilaceae and of its smaller but near equal suborder, Nautilina. It comprises six living species in two genera. The nautilus is similar in general form to other cephalopods, with a prominent head and tentacles. Nautiluses typically have more tentacles than other cephalopods, up to ninety. These tentacles are arranged into two circles and, unlike the tentacles of other cephalopods, they have no suckers, are undifferentiated and retractable. The radula (structure used for feeding) is wide and distinctively has nine teeth. There are two pairs of gills. Nautiluses are the sole living cephalopods whose bony body structure is externalized as a shell. The animal can withdraw completely into its shell and close the opening with a leathery hood formed from two specially folded tentacles.