Octopus

 

True Wild Life | Octopus | The octopus group makes up around a third of the worlds cephalopod population, with around 300 species found in waters around the world. The octopus can be found in the all the worlds oceans, with the octopus ranging in size from a just few centimeters to number of feet depending on the species of octopus! The octopus often has a sharp beak, and an octopus will always have eight arms (unless any have been lost). Most species of octopus generally have arms with circular sucker pads on.

The lifespan of the octopus depends on the species of octopus, with many species of octopus averaging around 6 months old. Some species of octopus however, particularly the bigger octopus species, can live for a few years. The octopus is well known for being a master of disguise and is able to blend into pretty much any background using its elaborate camouflage. The octopus not only uses this to its advantage for both hiding from potential prey and predators, but it is also thought to play a role in the male octopuses mating display, in order to attract a female octopus.

The octopus is also thought to have three hearts, two of which are used for pumping blood through the gills, and another for pumping the pale blue blood of the octopus through the rest of the body.

Generally, most species of octopus have no internal or external skeleton which means that the octopus is able to squeeze itself into tight places. The octopus is known to be one of the most intelligent of all the invertebrates and the octopus uses this to its advantage mainly using elaborate disguise.

Cuttlefish

True Wild Life | Cuttlefish | Cuttlefish are found in large numbers throughout the world's ocean waters from the warm, tropical shallows to the cold depths of the deep ocean. Cuttlefish are well known for the "flashing" colours that are displayed on their bodies during fighting and mating. In the same way as squid and octopuses, the cuttlefish also has an ink sack which ejects ink in order to fool oncoming predators.

The cuttlefish is a small-medium sized mollusc that is found throughout the ocean waters of the world. In the same way as their squid and octopus relatives, cuttlefish have a large, elongated body with tentacles surrounding their mouths.

There are 120 known species of cuttlefish found across the globe which vary in size from just 15 cm to the Australian giant cuttlefish which is often half a meter in length (not including its tentacles) and weighs more than 10kg.

The cuttlefish is a carnivorous animal that primarily preys on small crustaceans such as shrimp and crabs, but the cuttlefish also eats alot of fish. The cuttlefish uses its ability to change body colour to hide itself, before catching its prey with the sucker-pads on the end of its long tentacles which bring the prey into the sharp beak of the cuttlefish.

Due to the generally relatively small size of the cuttlefish, there are numerous marine predators that hunt them. Large fish, sharks and even other cuttlefish (sometimes of the same species) are the most common predators of the cuttlefish along with humans who hunt the cuttlefish around the world.

During the mating season, male cuttlefish change their body colours in order to successfully attract a female. Some male cuttlefish have even been known to make themselves look like female cuttlefish in order to trick the dominant males and stealing their mates. The female cuttlefish lays around 200 small eggs and sadly dies soon afterwards.

Blanket Octopus

True Wild Life | Blanket Octopus | This is one weird open ocean octopus! It looks like the Batman symbol flying through the ocean. It's common name, Blanket octopus, comes from their large web which they use to glide through the ocean. Blanket octopuses are rarely observed, but when people see them they notice. One, complete with eggs, washed up in Bermuda while I was off island on vacation. It made the local news and was the talk of the island. Another was recently (Sept 2009) spotted in St. Thomas, USVI.

The blanket octopus (Tremoctopus violaceus) is a rarely encountered pelagic species that spends its entire life cycle in the open ocean (Norman et al. 2002). Until the first observation of a living male off the northern Great Barrier Reef, Australia (Norman et al. 2002), males were known only from dead individuals picked up in trawls and plankton nets. Like other pelagic octopus species, T. violaceus exhibits sexual size dimorphism. The degree of sexual size dimorphism in this species, however,  is extraordinary: Females may reach 2 m in length whereas the reproductively mature male collected by Norman et al. was just 2.4 cm long. Individual weights of males and females differ by a factor of at least 10,000 (Norman et al. 2002).

Tremoctopus violaceus lives in the open ocean often in deep water (120-750 m) in the Mediterranean and the North and South Atlantic Ocean. The offspring are likely planktonic given the small size of the eggs. These octopuses may reproduce more than once but no one really knows much about their life history.