Spiny-cheek Crayfish, Faxonius limosus
OTHER COMMON NAMES
None
ETYMOLOGY
Faxonius, named for Walter Faxon (1848-1920), American ornithologist and carcinologist. Former genus, Orconectes, is from Orcus, god of the underworld in Roman mythology + nectes: swimming (Greek); limosus: Latin for mud
Ecology, Habitat, & Behavior
There are plenty of things that are unique and amazing about the spiny-cheek crayfish, but all pale in comparison to their ability to reproduce parthenogenetically (source). Parthenogenesis – reproduction without fertilization – is exceptionally rare in vertebrates, and only somewhat common in invertebrates. This, however, was the first report of parthenogensis in crustaceans. For most invertebrates (nematodes, bees), parthenogenesis is obligatory, that is, they can only reproduce in this way. For others (e.g. parasitic wasps, aphids), it’s facultative, with parthenogensis occuring seasonally. Spiny-cheek crayfish are flexible and can reproduce both sexually and asexually, though it’s unclear what the underlying mechanism is that would allow a female to forgo mating.
As its species name, limosus, indicates, they’re one of the few crayfish in New England that can tolerate muddy, turbid water. They’re most frequently found in the mucky bottoms of slow moving rivers, mucky ponds, and shorelines of larger lakes where they’ll eat detritus, plant matter, and invertebrates (in that order of preference: source). As with other crayfish, however, they are not specialists and can be found in other habitats.
They burrow extensively in the soft sediment bottoms of their habitats. The burrows, called chimneys, provide protection from predators and a safeguard against desiccation during dry periods when water levels drop. Some sources suggest these burrows may destabilize river banks, though this seems to be more of a general statement about crayfish than specifically about spiny-cheek crayfish.
| Life History Event | Date/Season |
|---|---|
| Mating | Spring, a second fall breeding season in some parts of its range |
| Fertilization | Immediate (or delayed if mating in the fall) |
| Males in F1 | |
| Males in F2 | |
| Laying Eggs | April/May Hatch in 1-3 weeks |
| Young detach from female | During 3rd molt, after 1-2 weeks |
Key features for ID + similar species
- Hepatic spines (sharp projections, or tubercles, on its cheeks, otherwise its carapace is generally smooth (these spines can be tough to spot in juveniles)
ROSTRUM
The margins of the relatively long rostrum are parallel to slightly tapering, with side spines and a sharply pointed acumen.
COLOR/MARKINGS
The margins of the relatively long rostrum are parallel to slightly tapering, with side spines and a sharply pointed acumen.
CHELAE
The margins of the relatively long rostrum are parallel to slightly tapering, with side spines and a sharply pointed acumen.
AREOLA
Wide areola (the gap between the carapace plates)
General Research on Crayfish
- NOBANIS: Invasive Alien Species Fact Sheet : source
- Crayfish of the White River Watershed: source
- Crayfish curriculum for educators: source
- The Crayfishes of New England: source
- Species of Ontario Crayfish: source
- Lecture on Crayfish: video
- Some aspects of the life histories of three closely related crayfish species, Orconectes obscurus, O. sanborni, and O. propinquus: source
- Dictionary of crayfish names: source
- Biological synopsis of the rusty crayfish: source
- Observations on the life cycle of Procambarus acutus acutus in South Carolina culture ponds: source
- Natural History of the two Crayfish of Northwestern Iowa, Orconectes virilis and Orconectes immunis: source
