All creatures, large and small – octopuses
“OCTOPUS” as a word is as recent as the 18th century. It was first used by the English biologist William Elford Leach in 1818 and derived from the Greek “oktopous”, octa meaning eight and buggers. Octopoda consists of around 300 identified species ranging from the giant Pacific octopus to the much smaller Mimic octopus. The largest Pacific giant (Enteroctopus dolfleini) weighs up to 15 kg with an arm span of 4.3 meters. Some were caught weighing 71 kg!
Today, octopus is a popular delicacy in Southeast Asian seafood, as well as on children’s buckets by the seaside, in children’s stories, and even in the title of a movie. by James Bond “ Octopussy ”. In years past, the octopus has appeared as a monster of the depths or “Kraken” in Norwegian folk tales and “Akkorokami” in the mythology of the Japanese Ainu people. In Bahasa Malaysia, it is called sukong kurita.
The fact that octopuses are found in temperate and tropical waters shows how well these species have adapted over the past 500 million years to their environmental conditions.
Shape and form
An octopus has inner and outer parts with its bulbous, hollow mantle attached to the back of its head which contains two gills on either side. It is connected to the external zone by a siphon. Its mouth is located under its arms, presenting a very short and pointed chitinous beak. The arms, as flexible appendages, are connected by a canvas structure to its main body. Two of the arms, called “feet”, are used to walk along the seabed. Most of his skin and, in fact, his whole body is made up of soft tissue, which allows him to lie down, contract and twist to the left or right or just stay rigid. The inside of the arms are armed with adhesive circular suction cups allowing an octopus to manipulate objects or simply to anchor itself on rocks. The muscular contractions of the suction cups allow it to attack or detach itself from objects. Her big eyes are on the top of her head.
Each of its tentacles has the ability to sense light on its own because when illuminated, it usually reacts by sliding in a dark area. Her skin is covered with thousands of specialized cells called chromatophores, which contain pigments of different colors. By contracting and expanding these cells, an octopus can mimic the colors and patterns of its habitat. Each tentacle functions independently until food is located. Two-thirds of an octopus’ neurons appear to be located in its tentacles, the other third in its brain.
Octopuses have three hearts; one systemic heart circulates blood around its body and two brachial hearts that pump blood through each of its two gills. As an escape mechanism, an octopus has an ink bag with an attached gland that produces the ink to be stored in the bag. This bag sits along a funnel that forcibly expels the ink with a jet of water. The main pigment of ink is melanin, which gives it its black or sepia color.
Offspring and lifespan
After mating, the female octopus attaches chains of fertilized eggs between 10,000 and 70,000 minutes to crevices and overhangs in the rock and keeps them for nearly five months (depending on water temperature) before that they do not hatch. The female works hard to aerate and clean the eggs, without feeding and dies soon after the eggs hatch. The male, exhausted by the mating process, dies a few weeks after mating. The short lifespan of octopuses is believed to prevent overpopulation in a limited environment, but the giant Pacific octopus has been recoded to live up to five years. The hatchlings resemble paralarves and feed on zooplankton and drift with tidal currents before sinking to the seabed to begin their adult life.
Movement and feeding
Most movements are limited to slow ramps along the seabed. Jet propulsion is the fastest form of motion in which a jet of water is forced out of the body through a siphon. They propel themselves backward with the head pointed and the tentacles backward. This method is only used to escape danger.
Ground octopus feed on worms, crustaceans, clams, and whelks, while deep-sea species feed primarily on shrimp, fish, spider crabs, and crabs. They pounce on their prey and pull it towards their beak, injecting their prey with poisonous and paralyzing saliva before returning it to their dens in the rock crevices for consumption.
Intelligence and threats
Very intelligent creatures, their behavior is innate and instinctive as they did not learn lessons from their deceased parents at the time of their hatching. Often times they have been seen escaping from aquariums and even boarded fishing boats and opened their holds in search of fish! One species collects discarded coconut shells and uses them to build dens.
All octopus species are poisonous, but only the blue-ringed octopus produces venom, which is fatal to humans, leading to respiratory failure if accidentally trampled or provoked. Bites are reported annually from Australian waters east of the Indo-Pacific Ocean. The main threats to octopuses are sharks and humans who accidentally catch them in fishing nets.
Mimic octopus (Thaumoctopus mimicus)
Found in Malaysian and Indonesian waters, this species also uses its chromatophores to blend in with its surroundings. It is mainly found in areas of cloudy sand and turbid river estuarine waters at depths below 15 meters, blending into its seabed environment with brownish beige colors. It was first identified just 23 years ago off Sulawesi, Indonesia. Living in these shallow, muddy waters, its diet consists of small fish and crustaceans, feeding on these creatures using its very slender, slender tentacles to catch its prey.
It is one of the smallest species of octopus reaching a total body length of almost two feet, with very narrow tentacles – roughly those of a pencil at their widest points. It can quickly change its coloring to a striped white and brown to scare away predators by mimicking vicious and toxic threats to invaders. Close observation has seen this species mimic lionfish by holding its arms radially to mimic the thorns, sea snakes and eels of the fish by hiding six of its tentacles and dragging the other two behind it and, in fact, flat fish. In a more aggressive crab-seeking mood, it can mimic crab movements by stealthily crawling up to a crab before devouring it. Its name “Thauma” is derived from the Greek meaning “wonder” and it bears the most appropriate name because it is truly a seabed wonder.
I’m not a big fan of octopus or squid as a food, but I enjoyed octopus mixed with other fish in paella dishes in the south of France and squid in Sicily. May octopus and squid continue to be a delicacy and a very tasty dish in Sarawak and Sabah.