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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. 

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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.

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This 1,091-pound colossal squid was frozen in a New Zealand lab after a fishing crew accidentally caught it near Antarctica in February 2007. Colossal squids (Mesonychoteuthis hamiltoni) Also known as Antarctic cranch squids, are one of the largest, most elusive, and mysterious of the cephalopods (see this post for more on cephalopods). These massive squids are reported to measure up to 14m in total length with mantle lengths of about 2-4m (keep in mind these are only reported lengths). These amazing creatures were first identified in 1925 when two colossal squid arms were recovered from a sperm whale’s stomach. Since then, few specimens have been recovered and there is still very little known about this species. Colossal squids have eyes that measure about 25cm in diameter which are thought to be the largest eyes in the entire animal kingdom. They also have the largest beaks of any squid, which makes them a fearsome predator, along with the 25 rotating hooks found in two rows on the ends of their tentacles. Colossal squids,are a deep-water species, probably living deeper than 1000m which makes it very difficult for scientists to gather data on them (though juveniles have been found above 1000m to the surface). So far they have had to depend mostly on juvenile specimens caught by deep sea trawlers. Colossal squids have been found in waters surrounding the Antarctic, primarily south of 40°S. The sperm whale is a known predator of colossal squid in the Southern Ocean.

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This is a bobtail squid (Euprymna berryi). These squid have a spherical body, two large rounded fins at the posterior end, and large eyes. A layer of iridescent cells give them their typical blue-green color. Bobtail squid have a symbiotic relationship with bioluminescent bacteria (Vibrio fischeri), which inhabit a special light organ in the squid’s mantle. The bacteria are fed a sugar and amino acid solution by the squid and in return hide the squid’s silhouette when viewed from below by matching the amount of light hitting the top of the mantle. The organ contains filters which may alter the wavelength of luminescence closer to that of downwelling moonlight and starlight. They are found predominantly in the Pacific Ocean. Squid belong to the phylum mollusca (see this previous post) and the class cephalopoda (see this previous post).

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caribbean reef squid (see this previous post)