Evidence
Where all of this came from.
39 reference records rest on 224 published pages, and 109 of those come from state and provincial natural-resources departments. That suits a set of records about what lives in the water those departments survey. The rest is federal survey work, university and extension guides, and interagency reports. The counts are below. Every reviewed line sits behind a record or a search, with the sources standing behind its record.
How to read this
A line is cited as precisely as someone checked it.
Where a reviewer traced a line to the pages that carry it, the line names those pages and, when the evidence is narrower than the record, where it comes from — one coast, one lake, one region. 605 of 1049 of the lines below are traced that way. The rest show the sources standing behind their whole record, marked “record’s sources”, because nobody has yet checked which page carried which line, and printing a single citation there would be a mapping nobody made.
National
52
A federal or national government body — USGS, NOAA, EPA, the Fish and Wildlife Service, the Park Service, Fisheries and Oceans Canada.
State
109
A state, provincial or commonwealth natural-resources department. Most of this carrier rests here, which suits it: these are the bodies that survey the water the records describe.
Interagency
12
A commission or joint survey run across several agencies, such as the Great Lakes Fishery Commission's forage task groups.
University
45
A university research programme, cooperative extension service or Sea Grant office. Published work, but not the agency that manages the water.
Journal
6
A peer-reviewed paper, or a curated scientific register such as the World Register of Marine Species. Added with the 2026-09-25 evidence review, which went to the primary study where no agency page said what a claim needed.
Probe leftovers
What the weekly check could not treat as ordinary.
These addresses are still the citations. The check named what it saw. None of them is a gone page in the MISIN sense, so the records were not rewritten to hide a redirect, a timeout, or a bot wall.
Iowa DNR — BluegillMoved
The cited address answers through a permanent redirect. GET on the page that lands still names Bluegill.
A same-site move that still names the animal is not the MISIN case. The citation stays until a reviewer reads the new address into the record.
CASG — market squidUnreachable from this network
The California Sea Grant market-squid page times out from the probe network.
NOAA still covers the same animal on this record. The CASG address stays; a timeout is not a reason to drop a citation.
Mass.gov — menhaden and longfin squidRefused the probe
Both creature-feature pages answered 403 from the probe network.
A bot wall is not evidence the page is gone. The citations stay; the weekly check does not fail the build on unverifiable.
Michigan DNR — crayfish identification PDFRefused the probe
The cited PDF answered 403 from the probe network.
A refused PDF is not a 404. The citation stays on the crayfish record until a reviewer can open it.
Smithsonian Tropical Research Institute — silversidesRefused the probe
The Menidia page answered 500 from the probe network.
A 500 is not a 404, and it is not a 403. The citation stays.
Claims
Every reviewed line in the app.
Crayfish →29 lines
- What you can seeOne pair of pincers, much larger than the walking legsUMW-AQUATIC-INVERTS, VT-EXT-CRAYFISH
- What you can seeA domed carapace over the fused head and thorax, with a triangular rostrum between the eyesMDC-CRAYFISH, MIDNR-CRAYFISH-GUIDE
- What you can seeAn obviously segmented abdomen ending in a flat, fan-like tailMDC-CRAYFISH, VT-EXT-CRAYFISH
- What you can seeLong outer antennae and a shorter inner pairVT-EXT-CRAYFISH
- What you can seeThe abdomen is flattened top to bottom, not side to sideUMW-AQUATIC-INVERTS, EPA-MACROINVERT-FIELD-GUIDE, VT-EXT-CRAYFISH
- What argues against itA body flattened side to side, with no enlarged pincers, points to a scud or amphipodUMW-AQUATIC-INVERTS
- What argues against itFreshwater shrimp have a cylindrical abdomen with only slight side-to-side flattening and no greatly enlarged first clawsUMW-AQUATIC-INVERTSEvidence from: Upper Midwest (University of Minnesota guide)
- What argues against itA soft newly moulted crayfish is the same animal, not a different one — the shell stays soft for two to four daysVT-EXT-CRAYFISH
- Declared limitSources disagree on basic counts: whether crayfish have four pairs of walking legs plus chelipeds or five pairs with the first enlarged, and whether the abdomen has six or seven segments. Neither count is offered as a field character.MDC-CRAYFISH, VT-EXT-CRAYFISH, UMW-AQUATIC-INVERTS, EPA-MACROINVERT-FIELD-GUIDE
- Declared limitSize varies with moult stage. Young crayfish moult six to fourteen times in the first year and older crayfish one to three times a year.VT-EXT-CRAYFISH
- Declared limitNo source consulted stated that crayfish enter the invertebrate drift, so this reference makes no claim that they do.MDC-CRAYFISH, VT-EXT-CRAYFISH, MIDNR-CRAYFISH-GUIDE, UMW-AQUATIC-INVERTS, EPA-MACROINVERT-FIELD-GUIDE
- Declared limitNo source consulted gives a size for first-year crayfish; newly hatched young are about 8 mm (a third of an inch).VT-EXT-CRAYFISH
- Size bandadult: 25-150 mmVT-EXT-CRAYFISH, MDC-CRAYFISH, UMW-AQUATIC-INVERTS
- Water typestreamrecord’s sources
- Water typeriverrecord’s sources
- Water typelake-marginrecord’s sources
- Water typereservoirrecord’s sources
- Water typespringrecord’s sources
- Life stageyoung-of-yearrecord’s sources
- Life stageadultrecord’s sources
- Where it sitson and in the bottomrecord’s sources
- Where it sitsunder rocks and logs by dayVT-EXT-CRAYFISH, UMW-AQUATIC-INVERTS
- Where it sitsburrowed into the substrateUMW-AQUATIC-INVERTS, MIDNR-CRAYFISH-GUIDE
- Where it sitsrarely far from the bottomVT-EXT-CRAYFISH
- How it moveswalking slowly forward on the legsVT-EXT-CRAYFISH
- How it movesflicking rapidly backwards when threatened by curling the tail fan under the bodyVT-EXT-CRAYFISH
- How it movesactive largely at nightVT-EXT-CRAYFISH
- Sources disagreeLeg counts are worded two ways. Missouri and Virginia Tech give four pairs of walking legs plus one pair of pincers; the Upper Midwest guide and EPA's Pacific Northwest guide give five pairs of walking legs with the first enlarged.record’s sources
- Sources disagreeAbdominal segments differ by source: six in the Upper Midwest guide, seven in Virginia Tech's.record’s sources
- Missouri Department of ConservationMDC-CRAYFISH · State · read 2026-09-02
- Virginia Cooperative Extension, Virginia TechVT-EXT-CRAYFISH · University · read 2026-09-02
- Michigan Department of Natural ResourcesMIDNR-CRAYFISH-GUIDE · State · read 2026-09-02
- Water Resources Center, University of MinnesotaUMW-AQUATIC-INVERTS · University · read 2026-09-25
- U.S. Environmental Protection Agency, Region 10 (prepared by the Xerces Society)EPA-MACROINVERT-FIELD-GUIDE · National · read 2026-09-25
- U.S. Geological Survey Nonindigenous Aquatic SpeciesUSGS-NAS-SIGNAL-CRAYFISH · National · read 2026-09-25
The pages themselves
All 224, and what each one is holding up.
- Michigan Department of Natural Resources
MIDNR-CRAYFISH-GUIDE
- Missouri Department of Conservation
MDC-CRAYFISH
- U.S. Environmental Protection Agency, Region 10 (prepared by the Xerces Society)
EPA-MACROINVERT-FIELD-GUIDE
- U.S. Geological Survey Nonindigenous Aquatic Species
USGS-NAS-SIGNAL-CRAYFISH
- Virginia Cooperative Extension, Virginia Tech
VT-EXT-CRAYFISH
- Water Resources Center, University of Minnesota
UMW-AQUATIC-INVERTS
Next