Trap-Crabs
Basic Information
Anatomy
Trap-crabs are specialized for the highly-exposed lifestyle the Elkreld Islands provide. The lack of cover in all but a few places has given them a tough carapace. This carapace has a frilled skirt around the edge which allows the crab to push themselves into the sandy soils and discourage attack by birds.
Despite what their name would imply, trap-crabs are not generally hunters, but instead farmers, with special protrusions on their claws capable of scraping shallow grooves into rocks, as well as the gross motor control to grasp and hit rocks to break them to expose a flat surface to scrape.
Genetics and Reproduction
Trap-crabs have an annual breeding season in early spring. At this time, the crabs scuttle into the water to mate, with a sperm sac being transferred from the males to the females. The females then find a relatively calm spot to lay their eggs, excreting a sticky paste to secure the eggs to the surface of choice. They will then break the sperm sac over the eggs to fertilize them.
Trap-crabs go for a reproductive strategy of quantity brood size over quality care, leaving their clutch of sixty to eighty thousand eggs and returning to their daily life. After a prolonged gestation period of roughly two months (hatching generally occurs in late spring), any eggs that have survived hatch (usually around ten percent), sending the newly-hatched crabs into the waters surrounding the Elkreld Islands in their still-soft first shell.
Growth Rate & Stages
As newly-hatched crabs make their way to beaches, trap-crabs exhibit a behavior called "swarming", where adult crabs will herd the younglings together and surround them with scratched stones that have been given time to grow algae already. This early meal enables quick growth, and the first hardening and molt will occur while in the swarm with ample food and protection.
After this first molt, the crabs are considered independent, growing and molting quickly until they hit the size of a human fist, after which they molt seasonally.
Conservation Status
While trap-crabs are plentiful on the Elkreld Islands, they are virtually unheard of outside the region. The settlements of the islands keep careful watch on population numbers of the native species and discourage hunting for the crabs during their breeding times.
Thankfully, given the generally inhospitable nature of the islands, it is generally only members of the settlements in the region to hunt them in the first place.
Geographic Distribution
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