Mirelurk

Mirelurk is a commonly used term referring to a range of mutated aquatic species endemic to the Eastern Seaboard, particularly the Capital Wasteland, the Commonwealth and Appalachia.

A similar term, lakelurk, is used to refer to species in the Colorado watershed in the Mojave Wasteland.

Background
Mirelurks have the dubious distinction of being one of the first radioactive mutants to emerge into the world, as a result of widespread radioactive pollution of the environment by United States megacorporations such as Poseidon Energy and General Atomics. Environmental organizations such as Nahant Oceanological Society, dedicated to saving the oceans, attempted a variety of last-ditch efforts to raise awareness of this problem and encourage radical action to curtail environmental destruction at the hands of reckless corporations. However, their efforts were in vain. Ignored by authorities, to the point where they refused to even take their phone calls (as was the case with the Boston Port Authority), they attempted to garner attention by reporting the situation to the Galaxy News Network. The media ignored their reports as well, except for running a story about the upcoming shellfish season and how great it was going to be. Of course, it neglected to mention that the average increase in mass on the order of 14% in crabs and 12% in lobsters meant that the available food supply would run out quickly, leading to colony collapse and localized extinction.

Although the Great War put an end to corporate pollution, it was replaced by overwhelming amounts of nuclear fallout instead. In the ensuing melting pot of mutations, the modern mirelurks emerged, due to radiation hyper-mutating crustaceans like the horseshoe crab. Wasteland scholars generally assign it its own classification: Scylla serrata horrendus. The knowledge that mirelurks were much smaller before the bombs dropped and mutated them still persists among some wastelanders in the Commonwealth. Mirelurks are also known to have a pronounced sensitivity towards white noise, as seen in Vault 92 and on Spectacle Island.

Although mirelurks tend to inhabit polluted rivers, coastal waters, and sewers, their meat is considered a delicacy among wastelanders. Mirelurk hunters or herders can count on a steady demand for their meat and make a high profit selling it to wasteland traders. However, the size of the meat market means competition is stiff and suppliers can be targeted by rivals attempting to knock them out of the market (sometimes literally). They also grow remarkably fast, requiring just a few weeks for them to reach maturity. If corraled and domesticated, mirelurks can be a flexible supply of food.

Mirelurks can also be a blight on permanent settlements, as is the case with Rivet City. Mirelurks nesting below inhabited decks are a continued nuisance for denizens of the city, despite regular extermination operations by the city's security team. They lay their eggs in several small clutches. The social order of the Mirelurk is noted to be similar to that of a caste-like system. 

Crab mirelurk


 Mirelurks are heavily armored and resistant to most forms of damage, but their faces are vulnerable. Other animals tend to avoid mirelurks, perhaps instinctively realizing the danger posed by the shell. 

Mirelurk king


Mirelurk kings have distinct adaptations to their water-rich environment, with pronounced webbed extremities and numerous fins all over its body. They also have the ability to cloak themselves in order to ambush unsuspecting prey.

Behind the scenes



 * Porter Gage refers to mirelurks as "mudcrabs" when talking to him. 