Squid/Cuttlefish/Octopus

Squid Fishing, also known as Eging is popular among local anglers especially those who are interested in artifical lures. There are several ways to catch squid and cuttlefish; all of which can be pretty interesting. The three main types of squid fishing found locally are: Netting with lighting aid, baiting and use of artificial lures.

Live squids are excellent baits for surfcasting and deep offshore fishing during night time. Being able to catch the squids live for fishing gives angler a marginally high advantage over using other types of baits. Therefore it makes it worthwhile for many anglers to bring the necessary bulky equipments for catching squids on their fishing trips.

Conventionally, the most productive way in Singapore to get fresh squid is to use a pressure lamp to illuminate the water surface, and to use a live squid, dead Tamban or Indian Anchovy to act as a lure for other squids. When squid is sighted, a long-handled net is used to scoop up the squid. Most of the equipment used, besides the pressure lamp, are self-fabricated by the anglers themselves to suit the location. Places where squid can be scooped in Singapore include Bedok Jetty and Labrador Park Jetty.

Squid become invisible by turning red, a colour that is virtually invisible underwater, as sunlight does not travel to the seabed.

Although squids have eight arms that grow back if cut, their two tentacles do not. Their tentacles are the appendages that contain suckers along the edge, which can grip things. These allow them to either capture prey or climb up vertical surfaces when out of the water. For males, the lower half of their left tentacle lacks suckers because that end acts as their penis.

All squid species have beaks, which are sharp and pointed. These are very hard, and are used to kill and tear their prey apart. Unlike the teeth and jaws of most other animals, these beaks contain no minerals whatsoever, and can even survive digestive juices. This is why squid beaks are often found inside whale stomachs when they’re opened up. Squid beaks are extremely hard to scratch or break, making them tougher and more resilient that virtually all metals and polymers.

One of the little-known squid facts is that they have three hearts. This is because their bodies are very complex. Their two smaller hearts serve their gills, while the larger one pumps blood to the rest of their bodies, and all three are faintly greenish in color

Another of our squid facts is that some of these animals can make people very happy indeed. This is because some squid species can produce an ink which contains very high levels of dopamine. This is a neurochemical that targets our brains and creates feelings of euphoria. Dopamine also exists in illegal drugs and is what makes people high. It’s believed the ink also makes some fish high, making them easier to catch. Whether it also makes the squid happy is not yet known.

Squid blood is blue, not red as in humans. This is because squid blood contains a copper-containing compound called haemocyanin. In humans the blood is red and contains the iron compound haemoglobin.

Cuttlefish are referred to as the “chameleons of the sea” due to their color-changing abilities. They can do this even though they are completely color blind. They can even successfully change color to match their surroundings in complete darkness.

Within their bodies, cuttlefish have a long, oval bone called a cuttlebone. This bone is used to regulate buoyancy using chambers that may be filled with gas and/or water depending on where the cuttlefish is in the water column. Cuttlebones from dead cuttlefish may wash up on shore and are sold in pet stores as a calcium/mineral supplement for domestic birds.

When threatened, cuttlefish may release an ink called sepia in a cloud that confuses predators and allows the cuttlefish to get away. This ink historically was used for writing and drawing, can be used to treat medical conditions and is also used as a food coloring.

Cuttlefish can’t see color, but they can see polarized light, an adaptation which may aid in their ability to sense contrast and determine what colors and patterns to use when blending into their surroundings. The pupils of cuttlefish are W-shaped and help control the intensity of light entering the eye. To focus on an object, a cuttlefish changes the shape of its eye, rather than the shape of its eye’s lens, as we do.

A female cuttlefish likes to have options when it comes to selecting desirable genes for the next generation. During mating season, she'll play the field, taking on multiple sperm packets and storing them in her mouth cavity until she's comfortable enough to lay her eggs. Male cuttlefish know about this strategy, however, and they've developed a tactic of their own to counteract it: They'll initiate mating by shooting a jet stream of water into the female's mouth cavity to clear out sperm from previous males who have already laid claim.

Although they typically use their color-changing abilities to blend in to avoid getting eaten, when cuttlefish go on the offensive, they turn their bodies into pulsating light and color shows in an attempt to hypnotize potential prey.

Octopuses are widely considered to be the most intelligent of all invertebrates.

Scientists say octopuses are capable of learning from experience and maintaining short- and long-term memory. They’ve also been observed using tools in an intelligent manner — such as coconuts for personal fortresses.

Octopuses have three hearts. And blue blood.

Two hearts serve to move blood past the gills, while the third pumps blood through the rest of the body.

They aren’t called “tentacles,” they’re called ‘’arms.”

Which, again, is way less fun. Tentacles are reserved for squid, cuttlefish and nautiluses. Octopuses have eight arms, zero tentacles.

Octopus arms have a mind of their own. Two-thirds of an octopus’ neurons reside in its arms, not its head. As a result, the arms can problem solve how to open a shellfish while their owners are busy doing something else, like checking out a cave for more edible goodies. The arms can even react after they’ve been completely severed. In one experiment, severed arms jerked away in pain when researchers pinched them.

Partly because they can “see” with their skin.

Scientists recently found that octopus skin contains the same light-sensitive proteins present in octopus eyes, meaning an octopus’s skin can sense and respond to light without information from the eyes or brain.

An octopuses can change the color of its entire body in just three-tenths of a second. But the creature doesn't simply take on the general pattern of its surroundings. Instead, it often mimics specific undersea objects, like plants or rocks, to disappear into the underwater scenery.

Octopus ink doesn’t just hide the animal. The ink also physically harms enemies. It contains a compound called tyrosinase, which, in humans, helps to control the production of the natural pigment melanin. But when sprayed in a predator’s eyes, tyrosinase causes a blinding irritation. It also garbles creatures’ sense of smell and taste. The defensive concoction is so potent, in fact, that octopuses that do not escape their own ink cloud can die.

After mating, it’s game over for octopuses. Mating and parenthood are brief affairs for octopuses, who die shortly after. The species practices external fertilization. Multiple males either insert their spermatophores directly into a tubular funnel that the female uses to breathe, or else literally hand her the sperm, which she always accepts with one of her right arm (researchers do not know why). Afterwards, males wander off to die. As for the females, they can lay up to 400,000 eggs, which they obsessively guard and tend to. Prioritizing their motherly duties, females stop eating. But she doesn’t starve to death–rather, when the eggs hatch, the female’s body turns on her. Her body undertakes a cascade of cellular suicide, starting from the optic glands and rippling outward through her tissues and organs until she dies.