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dogtoling · 6 days ago

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Biology of Inkfish - Defenses

Cephalings have multiple defenses that are shared across species. All Cephalings have a strong, chitinous beak, and several powerful and flexible limbs. Many species additionally have venom, specialized ink or strong claws. They also have several deimatic displays, many which differ between species.

Deimatic Displays

Cephalings have a handful of threat displays in their arsenal. Although fleeing is typically the first course of action against predators, this is not always an option. A cephaling in distress will typically show a deimatic display in the form of showing the beak, facing the attacker and making itself look larger to look as menacing and unappealing to fight as possible. As a sign of aggression, the pupils of cephalings expand to take up almost the whole volume of the iris, which is a universal sign of aggression within cephalopods. Darker tentacle shades also signal aggression, and are highly prevalent in threat displays. The tentacles are usually turned dark and raised up in order to signal readiness to lunge and look larger. In species with papillae, spiking out the papillae is used for a similar reason.

Against a lot of predators, the bright and saturated colors inkfish naturally present their tentacles in are sometimes enough to discourage predators that understand them to signal toxicity.

[The deimatic display of a cuttling, portraying neutral display (A) and threat display (B). Many species of cuttling incorporate varying degrees of stripes in their deimatic display, but dark colors are still present. Inkfish in particular are often able to flare their masks to make their eyes stand out and appear more menacing.]

Some inkfish have ocelli, or false eye-spots, on their bodies. These ocelli are usually located on the back tentacles. Ocelli can come in many forms - as opposed to the mostly dark ocelli of their ancestors, the ocelli of inkfish mimic colorful eyes and can be vibrant, with often dark rims. This is because the function of the ocelli, when at their most visible, is to make potential predators that approach from behind think that the inkfish is facing them, even if it is facing the other way, as they are then less likely to attack. Many ocelli have vibrant rings consisting of iridophores tucked in the patterns.

Some cephalings have unique deimatic displays that deviate from standard threat displays. The most famous examples are the blue-ringed octolings, which may present a bright yellow, orange, or white with dark patches with iridescent blue rings inside to advertise their toxicity. Other honorable mentions include Humboldt squid, which rapidly flash between light and dark, and striped pyjama squid which display striking black-and-white stripes.

Camouflage

While cephalopod ancestors had very advanced ways of camouflage, from changing their shape to look like corals or seaweed to digging into the rubble or looking like venomous animals, all inkfish have relatively simple and similar camouflage abilities. Modern inkfish do not camouflage onto clean ground; they actually prefer flat ground that they have inked prior. With their more streamlined bodies and solid, bright colors, they are able to blend into a thin layer of ink nearly anywhere with the added bonus of being able to move quickly within the ink. This is a flexible type of camouflage that comes with an additional defense of being covered by ink, something many predators avoid stepping into.

Due to an inkfish’s main form of camouflage being lying flat in their own ink, their former complex color- and pattern-changing abilities are largely reduced to just larger-scale, blank vibrant colors with relatively little patterning. Species with prominent patterns are able to deactivate these patterns or mask them almost perfectly with ink.

Beaks and Claws

[An image showing the simplified structure of the beak and its position in the mouth. The inner buccal mass is brightly colored to serve as an additional threat display. Beaks often have black and white gradients, which imply hardness.]

All cephalings have chitinous beaks in their mouth. The exact bite strength depends on the species and their typical diet, with crustacean-eating cephalings typically having the strongest bites and scavengers having the weakest ones. The cephaling beak is designed to be softer around its attachment to the muscular base, and harder towards the tips where biting occurs - this design results in the beak often having a black-to-white gradient. Beaks with more black tend to have higher bite strength, with plenty of species being able to pierce straight through carapaces, but even softer white beaks can easily rip through flesh or even bone. The bite of most inkfish comes with a dose of nasty venom, which is also advertised by the brightly colored inner buccal mass in the mouth, visible when the beak is held open as a threat display and often matching the color of the ink.

All cephalings except octopodiformes have a variety of claws or hooks in their suction cups. The suckers on the limbs of squidlings are lined with small hooks or claws in the rim, giving them a nasty grip. While the denticulation on the crown tentacle suckers is very weak, species with longer hunting tentacles have club suckers designed for attack. These club suckers vary from having simple denticulated rims to having inch-long claws lining the edges all the way to having sharp, curved hooks. Other ten-limbed cephalings, such as the cuttling, also have denticulated suckers, but the denticulation is much lighter and less pronounced and thus isn’t much worse than a pinch. Ten-limbed cephalings typically use their claws both for hunting and defending themselves from predators, as well as territorial fights with other cephalings.

Limbs

Even beside all the possible armature in a cephaling’s suckers, even just the tentacles can be a hard thing to deal with for a predator. The limbs of a cephaling are incredibly flexible and strong, and even species with no claws such as octolings are able to cause some serious damage with them, typically in the form of constriction. Cephaling arms may be used like whips or to latch onto predators or prey in an attempt to strangle them, block the gills, or block air flow in the throat. The crown tentacles can be especially devastating, as the grip power of the suction cups in octolings is enough to leave behind bad bruising.

The limbs of a cephaling are useful bait in dire situations. Even if a cephaling is caught by a predator, losing a limb - especially a crown tentacle - is the ideal takeaway from the situation. From the perspective of very strong predators, cephaling limbs tear off easily, and oftentimes the cephaling itself can quickly escape the scene mostly unharmed. Limbs don’t bleed heavily and regenerate right back in less than a year, while crown tentacles typically regenerate in a month if not less. Crown tentacles are thus sometimes sacrificed intentionally to make an escape.

Venom

All cephalings have venom that is channeled into their saliva at will. This venom is primarily used in hunting and immobilizing prey, but it is also an asset at repelling predators and giving very nasty bites. The severity and strength of the venom differs largely by species, but as a rule of thumb, most inkfish don’t get severe effects from the bites of other inkfish’ venom, especially those of close relation. Bites themselves are devastating for other reasons, usually coming down to bacteria - but venom will rarely cause more than burning and pain in the general area.

The venom of cephalings includes digestive enzymes, which means that it will readily start dissolving and killing cells as it enters the bloodstream. This effect causes a near-immediate burning pain around the bite area, and the pain will typically spread across the body as the venom spreads. The venom of cephalings is built mostly to immobilize prey, and is lethal to crustaceans and smaller fish. As the venom spreads, it will cause its victim to lose feeling and control of their body. The aftermath of a cephaling bite can last for days, leaving the victim sluggish, tired and sore.

Most cephalings are either immune or have greatly reduced effects from the venom of their own exact species. Cephalings are still able to envenomate other cephalings through a bite, although serious bites are rarely present in an inkfish quarrel. Many octolings in particular have genetic cross immunity or tolerance to neurotoxins such as saxitoxin and tetrodotoxin, but many squids do not, which makes inkfish venom immunities a confusing subject.

Ink

[Function of the inkfish propulsion sac, used both for firing ink out of the siphon at high velocity and for launching during jet propulsion. It is also used for primary breathing and for storing air during short periods of flight.]

Many types of cephaling have ink sacs. In species where the ink sacs are functional, ink is used mostly defensively, although many cephalings have small and insignificant ink sacs with ink that is mildly irritating at best and which is produced in small quantities. In contrast to this is the largest group of cephalings, the ink-using cephalings, also known as inklings or inkfish, which store and produce massive quantities of specialized, colorful ink that has many purposes.

Inklings get their common name from the unique relationship with their ink. The high-capacity, high-pressure ink sac in an inkling’s body is a major organ, forming the center of the ink vein system and producing massive quantities of colorful ink. This ink has many active uses relating to locomotion, hunting and defense as well as various passive uses that have to do with the inkling’s everyday activities. Ink is produced en masse in the ink sac and usually fired out of the siphon at high pressure, likely aimed to hit the eyes of an attacking predator.

Inkfish ink is antimicrobial and slightly acidic, protecting the body and skin from infections quite efficiently. It is thus effective both as a defense against predators as it is against disease. The acidity and chemical composition of inkfish ink make it an efficient method of tagging prey as well as repelling an attacker. Ink spray towards a target is often followed by a bite. In addition to being acidic, inkfish ink is sticky and causes a strong irritant reaction in contact to numerous animals’ skin, being especially devastating in contact with eyes or other sensory organs. Inkfish ink also oxidizes rapidly in contact with air, which makes it spread into a smokescreen when fired at certain consistencies, lending the inkfish time to escape. Additionally, this effect triggers ink to expand rapidly when released from the ink sac, which makes inkfish a surprisingly risky prey item as puncturing the ink sac will trigger a brief explosion of highly irritating material out of the body. Between this and the sticky ink flow coating the exterior of inkfish, they have long been difficult prey items for predators that do not hold resistance to either the ink or venom.

Inkfish ink grants the creatures great escape capabilities. Aside from ink spray to cloud the senses of a predator and sticky ink to slow them down, inkfish also move extremely fast in their ink. When faced by predators with poor eyesight, their camouflage abilities within the ink also allow them to slip by undetected or hide in plain sight, potentially leaving the predator to search empty traces of ink on the ground. Their ink and suction cups also allow them to scale vertical surfaces to high altitudes that many predators cannot follow them to. As an ultimate plan of escape, inkfish can use the propulsion organ in their mantle to shoot ink and even air or water in a pinch to launch themselves into the air and reorient hundreds of meters away from a dangerous situation.

Kraken

[Comparison between a regular inkling (left) and the same inkling after a Kraken response was triggered (right). The exponential increase in size is part of the greatly increased ink production associated with the state, with a lot of the ink concentrating in the muscles and under the skin to create the appearance of a much larger and more imposing creature.]

The “Kraken” is a last ditch-effort deimatic display present in most inkfish species. While some people refer to it as if it’s a form of some sort, it’s more of a state of mind and body. The activation of the Kraken is referred to as the Kraken response, for which the threshold lies at different levels of fear, anger or stress based on the individual. As a rule of thumb, though, the Kraken response is typically only reached in life-threatening or equally dire situations. This is often referred to as “krakening”.

The purpose of the Kraken response is to prepare a cornered inkfish that is out of options to flee a potentially lethal situation for a battle with the best chances to win. As a result, it is an all-or-nothing state that exists not for longevity, but for desperation and momentary survival. It is then unsurprising that the cocktail of chemicals present in the brain during transformations evens out to cause a mix of blind aggression, confusion, general disorientation and easily weaponized fear and alertness. The Kraken response triggers every intimidation tactic from showing one’s beak and claws to puffing out ink to the ink veins, which makes the inkfish look significantly larger and less approachable. Ink production and ink flow are greatly increased during Krakening, causing the inkfish to have a very thick ink coat near-constantly. A Kraken is quite easily distinguished through the apparent increase in size, prominent ink bleed, and a bold, dark color palette often with brightly contrasting stripes or miscellaneous patterns to create a foolproof threat display.

Typically, Kraken transformations are short-lived and largely depend on how quickly the affected inkfish’s mental state stabilizes. The peak of a Kraken transformation is in the beginning when its overwhelming psychological effects are at its strongest, but they quickly begin to subside when the situation calms and hormonal balance begins to even out largely through the amount of excess stress hormones that get removed through the ink flow. Full Kraken transformations that occur naturally are not regularly sustainable, nor are they usually expected - most people will only Kraken one to three times in their lives. The intense emotional load during Krakening as well as the metabolic cost of producing so much ink make the state an extremely exhausting one to recover from.

The Kraken is commonly used in ink battles as a special weapon by people who enjoy pure power or showmanship. In ink battles, it is triggered by a substance that artificially lowers the threshold for physical short-term effects of the transformation at a much lower level of agitation for a set amount of time, triggering the physical effects and bypassing most of the psychological ones. This makes it a relatively safe way of Krakening, although frequent use of the substance in the past has caused routine users’ natural Kraken response to become easier to trigger over time. As a result, legality has been widely questioned in ink battling circles for several years, but recently a new version of the substance has come out on the market.

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