Kataman Crab

The kataman crab is a species of crab common to the beaches of Asuria, known for it's peculiar behavior of gathering materials into a ball for future use.

Anatomy

Like most crabs, the kataman crab is a shelled creature with eight legs, 2 claws, and eyes on retractable stalks. Most specimens are small enough to fit in the hand, but they grow indefinitely and periodically shed and regrow their shells, so particularly old specimens can be much larger - the largest on record had a shell that was a quarter of a metre, slightly smaller than a human's foot.
There are two major anatomical traits that set the kataman crab apart from other crabs - their claws and their saliva

• Their claws are unusually dextrous and cautious. While they are capable of giving every bit as strong a pinch as any other crab of their size, they often grip far more gently. This is most commonly seen with how they manipulate the ball they carry with them, allowing them to grasp potential additions, inspect them, and them push them into place. Additionally, the tips of their claws are quite sharp, allowing them to snip objects down to size as needed.
• While many crabs can spit water from their mouths, the kataman crab seems to produce a powerful adhesive, effectively allowing them to spray glue onto a desired object before attaching it to the ball they form and add to throughout their lives.

Kataman

The ball of material these crabs create is called a kataman, a term derived from ancient Asurian, meaning "a random collection of stuff, with no apparent purpose." Despite this name, further examination has determined that a crab's kataman has many purposes, and is crafted with as much care and attention as any bird's nest. Crabs typically maintain their kataman in a hollow, roughly spherical structure about double the size of the crab, and keep it about neutrally buoyant by adding wood and sand/pebbles to the structure as needed. Known uses of the kataman include:

• Food storage: Kataman crabs feed mainly on seaweed and dead things that wash up on shore, spending much of their time in the intertidal zone of beaches. When they find more than they can eat, they collect seaweed and meat and attach it to the interior of the kataman, where it is sheltered from the sun and can stay suitably moist for a couple of days in even the most hostile conditions.
• Shelter: Between the salt and the hot sun, the intertidal zone can be a difficult and hostile environment. Crabs often carry their kataman such that they stay in its shadow, using it as a parasol. This appears to give them far more endurance than most creatures trying to traverse the intertidal zone at low tide. Sometimes they even wait out high tide on upper portions of the beach, typically when in a section of beach particularly rich with food.
• Protection: Like most shelled creatures, kataman crabs periodically outgrow their rigid shell and have to molt, withdrawing from their suit of armour and growing a new one. While most creatures find cracks or dig burrows to hide in during this extremely vulnerable phase, the kataman crab simply climbs into its kataman while the new shell grows. Crabs tend to stock up on food before molting, ensuring they have plenty of food available to them without having to risk exposing themselves to harvest more.
• Travel: While it is debated as to how intentional this is, the neutral buoyancy of the kataman means it and the crab that own it tend to be pushed around in the water far more than a crab normally would be. This helps them cover a wider area in their search for sustenance, being shifted to a new section of beach every time they are overtaken by the tide.
• Mating: During mating season, kataman crabs seem to become artists, adorning their katamans with colourful shells and other interesting bits of debris in an artful arrangement, demonstrating their ability to find suitable materials in order to attract a mate. When successful, a pair of kataman crabs adhere their katamans together, with entrances aligned such that they can move from their sphere to their mate's. After mating is concluded, they use their claws to cut their katamans apart, as well as shedding the decorations adoring them. Female crabs lay their eggs in wet sand burrows, much like any other crab species, though they lay far fewer eggs - only a couple of hudred rather than many thousands - researchers believe this is an adaptation to prevent overpopulation, as kataman crab mortality is far lower than it is for most crab species.