Panopeus lacustris
species of crustacean
Panopeus lacustris, the knot-fingered mud crab, is a true crab belonging to the infraorder Brachyura. It can be distinguished from related species by its exceptionally broad and knobbly main chela (claw).
Description
The knot-fingered mud crab is a small crab with unequal-sized chelae. The larger one is particularly broad and has teeth in the "molar area" and an immobile finger. Often this claw is worn and coalesced. The carapace and upper side of the limbs are a dull mottled reddish colour while the undersides of the body and limbs are whitish. Individuals living in caves are paler in colour and have antennules with white spots.
Distribution and habitat
The knot-fingered mud crab is native to the subtropical western Atlantic Ocean, its range including southern Florida, Bermuda, the Caribbean Sea, the West Indies, and along the coast of South America as far south as Cabo Frio in Brazil. It was introduced into Hawaii in the 1950s and has also been present on the Pacific Coast of California since the 1980s or earlier.
Ecology
This crab is sometimes parasitised by Loxothylacus panopaei, a species of parasitic barnacle that develops inside a host crab, manipulating the behaviour of the crab so that it cares for the barnacle's eggs, carrying them around and brooding them under its abdomen as if they were its own young.
This brief starts where responsible research should: with the source description of “Panopeus lacustris” as species of crustacean. Everything that follows is an evidence route, not borrowed authority.
Why this record matters
The subject matters to the science & nature register because the source frames it as species of crustacean. Its deeper value depends on whether names, dates, institutions and citations support that framing.
Stable identifiers, scientific names and standards terminology offer the best bridge between this overview and specialist evidence. The source revision retrieved here is dated Nov 4, 2025. The linked authority identifier is Q6497447. None of the 0 selected statements returned an explicit reference.
A general summary may omit uncertainty, sample limits or methodological disagreement that is explicit in the technical record. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “Panopeus lacustris”, its source revision and the description used here.
- Expand the search: follow Panopeus lacustris primary sources, Panopeus lacustris archive and Panopeus research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Panopeus lacustris”?
- Which observation, specimen, dataset or publication supports the account?
- Is the terminology current, historical or disputed?
Search terms from this dossier
This entry incorporates text from “Panopeus lacustris” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.