Shellfish are generally thought of as fairly innocuous creatures. Mentioning their name doesn’t conjure images of grinning maws, malevolent stares, or devastating predatory instincts. This is because shellfish are, generally speaking, inoffensive to the point of being dull. This cannot be said of the Parasitic Limpet, whose name fairly comprehensively sums up its most notable feature. Fastening itself indelibly to the hides of marine animals, it feeds on their flesh and blood, slowly boring into them in search of fresh meat. The habits of such a creature are distinctly unappealing, and the author advises the reader not to continue if they are squeamish.

Appearance. The shape is fairly unremarkable; conical, with a very white and hard shell, unusually smooth, and therefore offering no handholds to anything trying to remove one from its body. The shell is roughly circular, but older specimens will shape themselves to fit the surface they are attached to. They rarely grow larger than three nailsbreadths in diameter. Inside is a muscular, fleshy body of a very bright crimson, centered on a vicious looking mouth.

The mouthparts are unique in structure, looking more like a carpenter’s drill piece than anything naturally occurring. Four curved claws surround a pair of saw-like blades made of bone. The blades are narrow and very sharply pointed, with backward pointing barbs along their length. This means that when one blade is pushed into the flesh of an animal, it becomes lodged there, acting as an anchor-point to allow the other to be pushed further in. the blades are inched into the flesh of the Limpet’s prey in this way, allowing it to get a secure hold with the minimum of effort.

Larvae are much more abundant, but harder to see, as they are so small as to be almost invisible, and translucent. They look like tiny colourless worms with a strange claw-like apparatus at what is presumably the head.

Special Abilities. Most notable and unappealing of the parasitic Limpet’s traits is its lifestyle which, funnily enough, is entirely parasitic and nauseatingly carnivorous. A full account of its life cycle and method of feeding is enclosed later in this entry, but a brief description of the process can be found in the writings of the eminent researcher Friddriv Alav, an extract of which is enclosed here:

The Limpet can secrete a powerful anesthetic to numb the pain caused by its initial boring into victim’s flesh. After a while this stops working, unfortunately, but by this time the Limpet is usually sufficiently embedded in its host to prevent itself from being dislodged, except by the occasional resourceful selkie or merperson, who might enlist the aid of a companion to help pry the Limpet loose.

They also seem to make some substance which causes blood to clot and limits decay around the feeding site. This helps keep the victim alive, therefore maintaining a fresh, clean and manageable supply of blood and flesh for the Limpet to feed on.

Territory. Parasitic Limpets are found throughout the oceans of Caelereth, especially in areas frequented by large mammals. Unlike most marine mollusks, they rarely thrive near the shore, as their favourite prey is not often found there. Although they don’t appear to be particularly common, it is hard to get a realistic idea of the numbers, as they are scattered across the sea with their often wide-ranging and elusive hosts.

As adults, by making sure they have a constant food supply, rich in nutrients and often conveniently heated, they are not affected by the coldest waters. The larvae are less resilient, but generally survive well enough to sustain numbers provided they can find a host.

Habitat/Behaviour. Parasitic limpets, as their name suggests, make their living almost entirely from clinging to the hides of marine animals such as dolpholk, feeding on their flesh and blood. As such they don’t really have to move throughout their adult lives, and die when the host dies, if they are not forcibly removed or killed by other means before then. They tend to grow in small, sparse clusters, the size of which is limited by the capacity of their host to cope with their parasitic attacks.

Once anchored to the flesh of their host, they cannot move, but as larvae they can travel hundreds of strals, drifting on ocean currents to find a suitable host. The larval stage lasts several months, and what they feed on during that time is unknown, though they seem to be fairly opportunistic. The mollusk researcher Friddriv Alav once kept some limpet larvae in a tank of sea water, and recorded his observations on their slow metamorphosis. Enclosed here is an extract from his notes thereon:

Diet. Parasitic limpets feed solely on the flesh and blood of larger animals, most often attaching to kraken, dolpholk, pinnips, selkies, whales, and any large fish, including sharks. They will latch onto anything they come into contact with, and though smaller prey such as merfolk or small fish rarely offer a secure enough anchorage, or sufficient food, for them to survive for long, they can nonetheless cause significant injury before dying or being removed, as they to latch blindly onto the first living body they come into contact with.

Occasionally, especially if there is a shortage of large hosts in an area, hundreds of Limpets will attach to relatively small fish, smothering and quickly killing them. When a limpet larvae is ready to attach to a chosen host, its body becomes shorter and grows a chalky carapace – the beginnings of its adult shell. The larvae then fastens to the hide of its chosen host, using the sickle shaped claws and fretsaw boring apparatus to quickly insinuate their way into the flesh of their prey. Whilst doing this they exude a numbing substance which prevents the animal from noticing their presence and trying to dislodge them. Once attached, they begin to feed, growing their conical shell to cover their bodies, like a cocoon that they need never shed. Limpets that have been attached for some time dig themselves a deep well in the host’s flesh, allowing them better access to fresh blood and meat, and giving better protection against external attack.

Mating. Adult Limpets’ breeding habits are relatively unknown, as they are hard to observe whilst alive in their natural habitat. Friddriv Alav suggested that they might release something into the bloodstream of their host which other individuals also feeding on it would then pick up, but it’s equally likely that, like many mollusks, they simply release their seeds into the open water; as they tend to grow in small clusters, this would likely allow cross-fertilization to occur.

Usages. There have been various attempts, with mixed success, to harvest the secretions of parasitic limpets. It is not disputed that the Limpets are able to produce substances which have both anesthetic and anticoagulant properties, as well as possibly helping to prevent infection in the affected tissue. Obviously this kind of product could have enormous medical benefits, but unfortunately it is very hard to obtain reliably. For those few who are able to get hold of any, it can fetch extremely high prices. It is purported that one enterprising sailor, apparently down on his luck, once tried to grow a limpet on his foot (the Limpet must be firmly attached before the best secretions are produced) and died from blood poisoning after the Limpet died, unable to survive in the open air, and the wound became infected. Less suicidal methods of harvesting the secretions usually stem from cutting limpets from large fish or other sea animals taken by fishing boats, and can provide a key supplement to a fisherman’s income.

Researchers. Friddriv Alav, an Avennorian human of relatively noble birth, spurned the riches of his family and rejected his inheritance to pursue his consuming fascination with shellfish of all kinds. His many writings and illustrations depict a meticulous approach to his researches, as well as a reckless disregard for his own health and welfare. It appears that the entirety of his existence was consumed by his love of aquatic gastropods. Sadly, his interest in the world did not extend to creatures possessed of more than one foot, and so his brine-spattered journals and an extensive collection of seashells are all that is known of Alav.

5th Rising Sun 1669 a.S. Information provided by Seth Ghibta