Siurblius

Siurblius is a fictional genus of deep-sea cephalopods created for speculative biology and science fiction. It appears in in-universe field guides, narrative fiction, and game lore to illustrate deep-sea adaptation and evolutionary experimentation.

In the fictional taxonomy, Siurblius is placed in the family Siurbliidae within the class Cephalopoda, with the type species Siurblius abyssus, though some authors expand to multiple species. Morphology includes a gelatinous mantle, up to 0.6 meters in length, eight arms plus two elongated feeding tentacles; a dorsal row of photophores, a semi-fluid body texture, and a stout beak.

Habitat and ecology place it in dark abyssal zones of the fictional Oceanus Basin, typically between 2,000 and 7,000 meters. It is primarily nocturnal, uses bioluminescence for communication and luring prey, and displays limited predation on small fish and zooplankton. Reproduction and life history are variably portrayed across works.

In culture, Siurblius serves as an example of convergent evolution and extreme environmental adaptation; it appears in novels, role-playing game supplements, and educational materials. Note that it is not a real taxon.