Extract from Friddriv Alav’s “Philosophy of the Mollusk Race”: “Consider the life of a Gnacker, growing all its life in peaceful immobility, still as the pebbles it so resembles, mouth agape. Imagine that all your life were to be spent catching whatever waterborne detritus should pass your way and making use of it, somehow producing from the dregs of society the succulent meat and pearlescent shells that people across the world, with their penchant for such things, so greatly admire. How this transformation, carried out every day by creatures many people barely even view as alive, is something to fascinate the most uninterested of countenances, and in my view it is perhaps the greatest magic ever witnessed. Who but a humble Gnacker can take the effluent of a city and craft a gleaming stronghold for itself.“

Appearance. The seasoned Gnacker harvester can immediately recognise the grey-black clumps of Gnackers growing in their rocky habitat, but others may have trouble distinguishing them from smooth upright standing pebbles, growing in dense clusters out of larger rocks. They have a smooth surface and rounded, ovoid shape, with, if you look closely, a thin raised ridge running along the surface, splitting it in half. At the base, it disappears into a veritable nest of milky, tangled fibres. That’s the anchor – the strong strands of hardened mucus which secure the Gnacker indelibly to its rocky home. If you try to pluck it away from the rock it stretches slightly, you must pull hard, otherwise it won’t budge, unless a sharp blade is applied with considerable force.

Among the larger of the aquatic shellfish, Gnackers can reach three or four palmspans across, and weigh several muts.

If we gently turn the shell around, we can see that there’s a small section near the top of the outward face which is different in colour and texture – shinier, smoother, and pale pinkish beige. Not what you might call a beautiful colour, but that’s beside the point. This is the window into the Gnacker’s world – a transparent section of the shell through which the Gnacker can view the world. Look closely, and you’ll see a single tiny black eye. Have you ever been watched by a shellfish? The rest of the shell, as you will have noticed, is rather less extraordinary – a dull greyish black, ridged roughly and growing a tiny forest of algae on its surface.

However, if the shell is opened, one can examine more closely the slimy, boneless little glob of jelly which constitutes the body of this intriguing creature. There are few distinguishing features, other than the single sucker-foot with which it attaches to the shell, the beady eye, a pair of rubbery tubes protruding side by side from the body, and the hairy looking mess that is all that remains of the filter feeding tendrils, now that they are out of the water.

The inside of the shell, however, is beautifully pearlescent, coated with a tough, smooth substance known as “father of pearl”, though unlike the tryster, the Gnacker rarely produces pearls, and if it does they are tiny, gritty objects with no aesthetic or commercial value. Nonetheless, their nacreous shells have an attractive gleam notable enough for them to be named for it – the name Gnacker stems from a corruption of “nacre”. The shell itself is thick and strong, without the brittleness of other mollusks, making it useful as a tool (see Usages).

When fully submerged, Gnackers open their shells and unfurl delicate ruffs of short, frilly tendrils, with which they catch any kind of floating particle, and filter what they can’t eat (which is very little) from what they can. The tendrils appear at first to be a uniform shade of pale pink, but closer inspection reveals that each one, no longer than a nailsbreadth, is tipped in a pinpoint of crimson which pales towards the base. The tendrils are ranged in rows which arc from the top of the shell like the rays of the sun, but bathed rather than in fiery brilliance, in a pale silvery iridescence more akin to moonlight.

Special Abilities. Living on rocky shorelines which are subject to fierce currents, strong wave forces, and the changes brought about by changing tides, the Gnacker’s special abilities are immediately concerned with survival in a harsh environment. The strong “anchor” that grows from its base can hold the mollusk very tightly onto rocks, indeed, it can grip tightly enough not to be dislodged by the fiercest gales in all Santharia, as well as being a bane to those wishing to remove the versatile gastropod from its stronghold (see Usages).

Gnackers have also been credited with a method of communication by blowing jets of water at each other. By this means they are believed to alert neighbouring individuals of predators, and thus take pre-emptive defensive actions (see Habitat/Behaviour).

Territory. The most widespread of large shellfish, the Gnacker is found almost anywhere with rocky shores, saltwater estuaries, or silty seabeds. They can cope with the dirtiest waters, and indeed seem to relish the siltiest and tainted watercourses, as they provide more food for the accommodating palate of this mollusk (see Diet). In the waters surrounding Ximax, they grow in waters tainted by magical waste, in a variety of strange bright colours that really shouldn’t be eaten, due to the “unnatural effects they had on those few who have been brave or foolish enough to try.

Habitat/Behaviour. Gnackers live mostly on the shore, especially rocky ones (though they can also live on a sandy or muddy seabed and tolerate fairly fresh or even stagnant water). Most of the adult Gnacker’s time is spent clinging to a rock by its anchor, with its shell open at low tide, and its feeding tendrils are extruded. Friddriv Alav’s observations suggest that the Gnacker groups communicate by blowing jets of water at each other through the tubes by which they circulate water around their bodies, thus signalling to neighbouring Gnackers of imminent danger. This theory, though it might sound a little presumptive for a mollusk, would also explain the primitive eyes and transparent section of the shell, not apparent in other shellfish. So it seems possible that Gnackers use the “window” in their shells to look out for predators, and can then signal to their neighbours of that danger. When thus alerted, Alav described how the shellfish one by one closed their shells, and bunched together more tightly by a retraction of their anchor fibres.

As Gnackers grow continuously throughout their lives, they can reach large sizes, though in areas where they are less harvested, or able to obtain more nutrients from the water, they grow biggest. The lifespan is unknown, but the size of some shells suggests they can live for at least ten years, with the possibility of considerably more.

Diet. Gnackers had long been thought to eat rock, as they grow on it and appear to slowly wear away the surface. Whilst it is likely they do use the natural erosion of the stone for some nutrition, observation of their activity at high tide shows that they extrude delicate feeding tendrils, which they wave in the current, rapidly curling around any object, however tiny, which comes into contact with the sensitive tendrils. For this reason the Gnacker can live perfectly healthily in habitats free of large rocks, such as sandy seabeds and muddy river mouths, and even occasionally anchors itself to wooden boats and jetties.

Mating. It is the prolific breeding behaviour of Gnackers that gives them such a wide distribution, and makes them such an invaluable resource to people living by the sea. Gnackers appear to develop genders depending on their position in a cluster of individuals – those on the outside become males, and those on the inside are female. As the colony grows, males become female as they are surrounded by new individuals. When a male wants to breed, a long, thin tube is pushed out of the open “mouth” of the shell, and inserted into that of a neighbouring female, wherein he deposits his seed. This is repeated for as many females as he can physically reach. As new individuals arrive from other colonies, possibly many strals away, this can continue without a problem from interbreeding.

Clouds of eggs are released simultaneously by all female Gnackers in an area at high tide in spring and autumn. The larval stage is free floating, carried often for huge distances by currents. It looks like glitter and forms a staple food for many sea animals such as su’ufanu whales and evoor fish. On reaching a suitable anchor point, they start to develop the shell and anchor fibres of their adult form. In the short transitional point between the larval and adult stages, they appear to be able to move around a bit, creeping closer to any nearby colonies already in existence.

Usages. The Gnacker is held in near reverence by seaside peoples across the world for its versatility. To poorer people especially, it is invaluable as a source of food, tools, cutlery and glue, and artisans and craftsman will pay good money for anchor fibres or the polished shells.

Its foremost, and probably most ancient resource is one of food – to Northern Sarvonian peoples especially, Gnacker flesh provides a relatively easily obtainable, highly nutritious food source. Ice tribesmen and merfolk (including the Nybelmarians) eat them raw, straight out of their shells, but most others prefer to cook them – the Avennorians favour a thick stew or soup, and the Stratanians fry them, and eat them dipped in a variety of sauces. However, like most shellfish, Gnackers spoil very easily, and as such are not often eaten by people living far inland. They are also known to pick up any poisons in the water they live in, and so those living in particularly polluted waterways are not edible.

Fortunately, given the importance of the Gnacker as a food source to many people, plantations of yealm reeds downstream of large towns and cities mean that areas of dirty water, where the Gnackers would not be edible, are kept to a minimum, as the reeds purify the water around them and thus remove harmful substances that might taint the Gnackers.

The large, rounded and concave shaped shells of Gnackers are used as cheap, disposable bowls or spoons by those who eat them regularly, as it is easy to get more if they break. The hardness of the shells means they can also be fashioned into knives and other simple tools, which have the merit of being attractively decorated with the pearlescent nacre inlay of the shell. This father-of-pearl coating is also used by craftspeople to fashion decorative inlays on small ornaments such as handheld mirrors or hair clasps.

The transparent “window” also has its uses, as it is a weak point in the otherwise strong shell, and forms a useful place to fix handles, nails and other things to the shell. By breaking through the window, the integrity of the whole shell is not compromised, as it would be in other shells, which have a tendency to crack.

Thus large shells can have nails put through the window and serve as roofing tiles; more deeply concave ones can have handles fixed on and be used as pans; and flat, highly polished shells could in theory have been joined with some kind of staple to a strong fabric, to form scale plating like that which is believed to have formed the magical shell armour described in the Myth/Lore section. Even the tiniest shells have their uses, as polished up, with the window pierced, they make beautiful jewellery.

Finally, but perhaps most usefully, the Gnackers’ tough anchor is harvested and boiled repeatedly until it has been rendered down to make a strong, clear-drying glue, which is widely used in various crafts, such as fletching, book binding, and even surgery, as it dissolves easily on contact with strong alcohol, and is not toxic.

Due to these various usages, the job of Gnacker harvesting, or shellpicking as it is more commonly known, has become lucrative in its own right, and those living near to good Gnacker grounds are fiercely protective of their rights to the shellfish. What’s more, the practise of harvesting the Gnackers is relatively cheap and simple, as the only tool required is a sharp, strong steel knife – sharpening and cleaning the blade regularly is very important, as the tough anchor fibres blunt and clog it quickly if it is not properly cared for.

Myth/Lore. The shiny nacreous insides of the Gnacker were apparently made into scaled suits of armour by a few wealthy figures and such garments were even attributed to have magical qualities, including unnatural resilience, and the ability to summon water monsters, though none of this kind of clothing survives at present. Historically, the ground nacre coating of Gnacker shells has been eaten dissolved in vinegar as a cure for seasickness.

Researchers. Friddriv Alav, an Avennorian 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.

28th Frozen Rivers 1668 a.S. Information provided by Seth Ghibta