crab

Diagnostic anatomy evidence

Record evidence for the carapace, stalked eyes, folded abdomen and chelae, including features that could not be observed.

1. Which visible characters support identifying this animal as a crab rather than another decapod? definition
2. Could immaturity, missing limbs or an obscured underside explain an apparent mismatch with the registry definition? boundary

Supported taxonomic assignment

Retain the accepted name at the supported rank, authority, identification evidence and verified external identifiers without inventing a crab-wide binomial.

1. Which consulted authority supports the identification, authorship and any GBIF or NCBI identifier? provenance
2. Does this assertion concern a named taxon, a local population or one crab, and does its common-name usage include animals outside Brachyura? boundary

Repeatable size and form

Record carapace landmarks, spine treatment and left-right chela differences rather than reducing size to an undefined overall length.

1. What are the carapace width and length, and exactly which landmarks and spines were included? measurement
2. Is chela asymmetry supported as normal for this taxon and sex, or could damage and regeneration explain it? boundary

Moult-aware condition assessment

Preserve uncertainty when interpreting a soft shell, inactivity, detached limbs or an apparently empty body.

1. What observations distinguish a living crab, a shed exoskeleton and a dead animal? boundary
2. What shell and appendage evidence supports the assigned moult state or an injury assessment? measurement
3. Does suspected moulting require deferring handling or changing the immediate holding conditions? action

Stage-specific identification

Use appropriate larval, juvenile or adult characters and leave the developmental pathway unresolved until supported.

1. Which developmental stage is supported, and what characters distinguish it from adjacent stages? definition
2. What source establishes this taxon's developmental sequence and any changes between larval and adult habitats? provenance

Reproductive evidence

Document abdominal or appendage characters used for sex determination and record visible eggs without treating body size alone as proof of maturity.

1. Which taxon-appropriate characters support sex and maturity, and how certain is each determination? measurement
2. Are eggs visibly carried beneath the abdomen, and what disturbance or collection constraints follow in this locality? action

Environmental fit

Record water regime, substrate and environmental measurements alongside sourced requirements for the taxon and stage.

1. What salinity, temperature, water access, substrate and shelter conditions were actually observed? measurement
2. Which evidence establishes whether this locality is within the taxon's native, introduced or unresolved range? provenance

Observed ecological behaviour

Record feeding, burrowing, refuge use, competition and predation evidence with observation context.

1. What feeding or shelter-use behaviour was directly observed, and what remains inferred from species accounts? provenance
2. What evidence of aggression, predation or shelter competition affects a proposed shared enclosure or habitat intervention? action

Condition-guided interaction

Consider movement, visible injury, moult state and environmental exposure when choosing observation, handling or specialist assessment.

1. What changes in movement, posture, limb use or visible tissue condition have been observed, and over what interval? measurement
2. What taxon-appropriate handling method and environmental conditions are supported for the proposed interaction? action

Sourced action constraints

Resolve relevant assessments and rules before collection, movement or release, retaining unassessed status where no assessment is found.

1. What conservation assessment applies to the identified taxon or population, and what are its assessment year and geographic scope? provenance
2. Which current local rules and ecological considerations govern collecting, transporting or releasing this crab? action

Check these first

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these check these first hold for the sense of crab this model covers, and on what evidence? provenance

Kinds and varieties

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these kinds and varieties hold for the sense of crab this model covers, and on what evidence? provenance

Identifiers and schemes

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these identifiers and schemes hold for the sense of crab this model covers, and on what evidence? provenance

Standards and regulation

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these standards and regulation hold for the sense of crab this model covers, and on what evidence? provenance

Real-world use

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these real-world use hold for the sense of crab this model covers, and on what evidence? provenance

Failure modes and hazards

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these failure modes and hazards hold for the sense of crab this model covers, and on what evidence? provenance

Regional variation

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these regional variation hold for the sense of crab this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Recalled without web access and unsourced; every item is a lead to verify.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of crab this model covers, and on what evidence? provenance