Cephalopods 2

Cephalopods fall into two groups. Tetrabranchs have 4 gills, up to 90 tentacles without suckers and are quite primitive. e.g. Nautilus are living fossils that inhabit deep water in the circum tropical zone. Octopusses, Cuttles and Squid are far more advanced having two well developed gills each with its own heart that vastly increases the oxygen carrying capacity of these powerful hunters. This is especially true for Squid.Squid have highly developed suckers on their tentacles for holding prey.

 

 
Nautilus Nautilus

This Nautilus was caught in a trap whilst on Undersea Explorer. Research scientist, Doc Holiday (Dean) set baited traps to 200 m depth overnight. We raised the trap at dawn. People could sponsor an animal and get a number.

Nautilus are living fossils. 99.9% of their relatives are extinct. However, they are common in deep water across the Pacific. Unfortunately, they are fished for tourist trade. Nautilus have 80 to 90 tentacles with no suckers, a tough leathery oral hood that they hide behind when it closes over the shell. You can see it clearly in the photo. More detailed information is included in my Marine Biology course.

 

Two Blue ring octopus Dying female octopus
At Cronulla Fisheries in 1979, we had two Blue Ring Octopus in a tank. The one on the right attacked the other one and appeared to bite it very hard. The one on the left wriggled and writhed in pain but it did not die. There was a territorial dispute and a fight. I wonder if they are partially immune to their own toxin. I am night diving at Oak Park, Sydney in the 1980's. A very large female octopus has had three arms ripped of by Leatherjackets who were attacking it and biting chunks of flesh off of her. She had just spent 90 days caring for her several thousand eggs without eating. This is the ultimate act of motherly sacrifice. Now she waits to die in the most cruel manner. Death by a thousand bites. Note the unique colour pattern!