Basic Information
The sea urchin is, typically, a spiny, globular, bottom dwelling sea creature. Subspecies exist that are flatter (like the "sand dollar")or more elongated (like the "slate pencil urchin") but globularity is normal. Venomous spines are also possible, but rare. Generally the shape of the creature is defined by a calceacous shell called a test, this is covered in turn by a thin skin in which the spines are mounted. The rest of the creature is inside the test, connected to the outside world by two holes at top (anus) and bottom (mouth and feet). Urchins, and their related species, are notable for their five-fold radial symmetry.
Most urchins graze on algae, although some will also consume other sessile or very slow moving bottom dwellers, and so, despite their protective spines they tend to occupy a very low spot on the food chain and are an important dietary item for many other species. Urchins, and urchin roe are even found in the human diet in some cultures.
Sources
Game and Story Use
- Unlikely to be much of a threat in combat, but might serve as a terrain hazard in shallow water.
- Fantasy versions may be amphibious and/or able to fire their spines about.
- Urchin tests might make a plausible found currency (if cowrie shells can make it, so can urchin tests).
- For fans of the Cthulhu mythos, the radial symmetry of the echinoderms (including sea urchins) is clear evidence of their relation to The Elder Race.
- Presumably there is ecological room for an amphibious version - but that would still not be anything to do with a street urchin.