Gadidae
Enable an AI agent to recognise organisms attributable to Gadidae, assess the evidence and condition attached to those records, and determine which identification, observation or handling actions are justified.
Research draft, second pass
A second pass drafted this model: the structure a model of this thing needs, and what is known about it in the world. The line under this one says how the second half was obtained - researched against sources, or recalled without web access, in which case nothing here was read anywhere and every claim is a lead to verify. Unreviewed either way.
Researched by: Codex + Grok
Purpose and description
Enable an AI agent to recognise organisms attributable to Gadidae, assess the evidence and condition attached to those records, and determine which identification, observation or handling actions are justified.
Gadidae is the family of cold-temperate gadiform teleosts (true cods) diagnosed by three dorsal fins, two anal fins, thoracic pelvic fins and, in most genera, a mental barbel; in current catalogues it is restricted to Gadus and its immediate allies and is the source of the main northern-hemisphere whitefish catch.
It can be Screen an observed fish for Gadidae membership using an applicable diagnostic key and documented characters.; Retain a family-level identification when available evidence cannot support a genus or species.; Request targeted photographs or examination of fins, chin, jaws and pelvic-fin placement.; Route immature, damaged or morphologically ambiguous material to specialist or molecular identification.; Reassess existing records when the adopted family boundary or a specimen determination changes.; Select observation, sampling or handling steps using specimen condition and linked species-, site- and activity-specific constraints..
Distinguishing features
Require the identified species or genus to resolve to Gadidae under a named taxonomic authority; neither the common name cod nor membership of Gadiformes alone establishes membership. Gadidae is recorded at family rank by [OBIS](https://obis.org/taxon/125469).
On an intact fish at an appropriate developmental stage, test the arrangement of dorsal, anal and caudal fins. Three dorsal fins, two anal fins and a distinct caudal fin support identification in the Gadidae treatment used by the [NOAA regional guide](https://repository.library.noaa.gov/view/noaa/5354/noaa_5354_DS1.pdf); apply its geographic and taxonomic limits.
Evaluate chin-barbel condition together with jaw projection, pelvic-fin position and other key characters. A barbel is present in most species in the cited treatment, so its absence alone does not exclude Gadidae. See the [FAO family diagnosis](https://www.fao.org/4/y4161e/y4161e27.pdf).
Check the circumscription behind a key before rejecting a specimen on fin counts: the broader [Naturalis family treatment](https://fishes-fnam.linnaeus.naturalis.nl/linnaeus_ng/app/views/species/taxon.php?id=108104) permits one to three dorsal fins and one or two anal fins. Conflicting treatments require a recorded authority choice, not a silently combined diagnosis.
Scope
+ The accepted family concept, its authority and the membership interpretation used for each identification.
+ Evidence distinguishing Gadidae from other gadiform families and fish called cod in common or commercial usage.
+ Diagnostic observations on whole fish, immature stages and incomplete specimens, with explicit identification limits.
+ Location, habitat and life-stage context that supports or challenges a proposed identification.
+ Observed specimen condition and the evidence needed to select further examination or handling.
- Complete species-specific biology and diagnostic keys, owned by linked species models.
- Population abundance, recruitment, stock assessment and harvest reference points.
- Full marine habitat, food-web and ecosystem models.
- Fishing operations, gear performance, quotas and licensing rules.
- Seafood processing, commercial grading, food safety and supply-chain certification.
Characteristics
- Taxonomic circumscription
- Named authority, taxon identifier, version or access date, and included subordinate taxa Family membership and the applicability of diagnostic traits depend on the classification adopted.
- Identification resolution
- Gadiformes only; Gadidae provisional; Gadidae supported; genus supported; species supported; unresolved Prevents family-level evidence from being treated as species identification.
- Dorsal and anal fin arrangement
- Count of distinguishable dorsal and anal fins, with separation and damage notes Provides major diagnostic evidence when developmental stage and specimen integrity permit counting.
- Chin barbel
- Present; rudimentary; absent; damaged; not observable Helps discriminate candidates without confusing an obscured or lost barbel with true absence.
- Jaw and pelvic-fin configuration
- Upper jaw projects; lower jaw projects; approximately equal; pelvic position relative to pectorals; unobservable Adds independent characters to a fin-count-based identification.
- Body length
- Millimetres, explicitly total length, fork length or standard length Supports comparison with stage-appropriate descriptions and prevents incompatible measurements being combined.
- Developmental stage
- Egg; larva; juvenile; adult; unresolved, with assessment method Determines whether adult external diagnostic characters can reasonably be applied.
- Occurrence context
- Observation event with coordinates, time, depth in metres and environmental observations Helps select relevant keys and flag unusual records without making geography an absolute identity test.
- Specimen condition
- Live; dead; preserved; fragmentary; unknown, with observed injuries and preservation effects Controls which characters remain interpretable and which examination methods are appropriate.
- Identification evidence
- Linked images, voucher, key and decision path, expert determination or molecular result Makes the Gadidae attribution reviewable and allows disagreements to be resolved.
Where this came from
wikidata · CC0 1.0
Drafted structure
Bundle to layer to finding to question, as the second pass will find it: 6 bundles · 11 layers · 18 findings · 28 questions.
Family concept and membership Establishes which interpretation of Gadidae governs recognition and membership.
Different family circumscriptions can change both included taxa and usable diagnostic rules.
Taxonomic anchor
Connects the registry thing to an explicit family concept.
Authority-bound family
Record Gadidae as a family concept with an external identifier and dated authority; keep it distinct from observations of member organisms.
- Which authority, identifier and dated classification define Gadidae for this assessment? definition
- Does this record describe the family concept, an individual fish, a sample or an aggregation? boundary
Membership resolution
Handles subordinate names and disagreements between classifications.
Traceable membership
Membership must follow a documented taxonomic placement, with historical names and conflicting treatments retained as evidence rather than merged without explanation.
- What accepted genus or species, if known, connects this organism to Gadidae under the selected authority? provenance
- Would another cited classification place that taxon outside Gadidae, and how is that disagreement represented? boundary
Diagnostic anatomy Organises the external observations used to test a Gadidae identification.
Recognition requires a combination of characters interpreted through a suitable key, rather than resemblance to a familiar cod.
Fin configuration
Records fin counts and separation alongside their observability.
Interpretable fin pattern
Preserve observed dorsal and anal counts, caudal separation and pelvic placement, including uncertainty caused by folded fins, injury or incomplete views.
- How many dorsal and anal fins can actually be distinguished, and is the caudal fin visibly separate? measurement
- Which steps of the selected key does this configuration satisfy or contradict? boundary
Head and supporting characters
Adds independent evidence from the chin, jaws and other visible features.
Combined character assessment
Record barbel state and jaw projection with any key-required lateral-line, pigmentation or dentition observations; distinguish unobserved characters from absent ones.
- Is a chin barbel present, rudimentary, absent or unobservable, and which jaw projects? measurement
- What additional character would distinguish the remaining Gadidae candidate from the closest alternative in the key? action
Life stage and occurrence Places diagnostic observations in developmental and environmental context.
An adult identification key or regional expectation can mislead when applied to larvae, juveniles or records outside its coverage.
Developmental applicability
Determines whether the available characters are developed and comparable.
Stage-appropriate recognition
Attach developmental stage and a defined length measurement to the identification, and identify when a specialised early-life-stage method is needed.
- What developmental stage and length were observed, and how were they determined? measurement
- Does the identification reference cover this stage, or is a larval, egg or juvenile reference required? boundary
Occurrence plausibility
Uses capture or observation context to select references and detect records needing review.
Contextual identity check
Record the original observation location, date and depth separately from landing, market or storage location; treat ecological mismatch as a review trigger.
- Where, when and at what depth was the organism observed or collected, and how reliable is that information? provenance
- Does the candidate identification fit a cited occurrence account, or does it require additional evidence as an unusual record? boundary
Specimen state and evidence Separates biological condition from the quality of evidence supporting identification.
A damaged barbel, obscured fin or processed fragment changes what can be concluded about Gadidae membership and specimen state.
Condition and observability
Assesses which diagnostic structures and condition indicators remain interpretable.
Condition-limited assessment
Record live or dead status, injuries, missing structures and preservation effects without treating family identification as evidence of health or fitness.
- Which fins, head structures and body surfaces are intact and observable? measurement
- Which apparent abnormalities could result from capture, preservation or damage rather than the organism's prior condition? boundary
Determination support
Maintains the evidence chain behind morphological or molecular attribution.
Reviewable Gadidae attribution
Link determinations to inspectable images, vouchers, key decisions or molecular reports, preserving conflicts and the limits of reference identifications.
- Which accessible evidence supports the determination, and who or what method produced it? provenance
- If molecular evidence is used, what marker, reference identification and analytical limitations support assignment to Gadidae? provenance
Identification and handling decisions Translates identity uncertainty and specimen condition into proportionate next actions.
Family-level recognition supports triage but does not itself establish species identity, handling suitability or permission to collect.
Identification next step
Chooses the next observation or analysis needed for a useful determination.
Targeted evidence acquisition
Select additional evidence according to the unresolved distinction, such as a fin photograph, chin view, specialist examination or justified sample analysis.
- Which unresolved character or taxonomic conflict currently prevents a stronger identification? boundary
- What feasible observation or analysis would resolve it with the least disturbance or specimen loss? action
Action dependencies
Identifies the external determinations needed before consequential handling.
Context-qualified action
Connect proposed collection, retention, release, preservation or sampling to the organism's condition and applicable species, location and activity requirements.
- Is family-level identification sufficient for the proposed action, or must species or stock identity first be established? action
- Which handling protocol and applicable permissions govern that action for this specimen and location? action
Evidence and external alignment What the world already says about this thing, gathered so the model can be checked against it.
A model that cannot be lined up against existing standards, identifiers and practice cannot be adopted by anyone who already uses them.
Reported evidence
Findings from the breadth pass, kept separate from the structural claims.
Kinds and varieties
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Atlantic cod (Gadus morhua)
- Pacific cod (Gadus macrocephalus), including the Greenland form often still labelled Gadus ogac
- Alaska/walleye pollock (Gadus chalcogrammus, formerly Theragra chalcogramma)
- Haddock (Melanogrammus aeglefinus)
- Saithe/coalfish/Atlantic pollock (Pollachius virens)
- Pollack (Pollachius pollachius)
- Whiting (Merlangius merlangus)
- Arctic and shelf allies: polar cod (Boreogadus), Arctic cod (Arctogadus), tomcods (Microgadus), navaga/saffron cod (Eleginus), pouts (Trisopterus)
- Which of these kinds and varieties hold for the sense of Gadidae this model covers, and on what evidence? provenance
Identifiers and schemes
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Wikidata - Q199614 - Item for family Gadidae.
- WoRMS AphiaID - 125470 - Accepted marine taxonomic record for Gadidae Rafinesque, 1810.
- ITIS TSN - 164559 - Taxonomic Serial Number for family Gadidae.
- NCBI Taxonomy - 8045 - Family-level taxid; species sit under it (e.g. Gadus morhua 8049).
- FAO ASFIS 3-alpha - species codes, not a family code (COD, HKG/HAD, WHG, POK, POL, ALK/WAP, etc.) - Landings and trade are coded at species, not family.
- Harmonized System - 0302.51 (fresh/chilled Gadus spp.); 0303.63 (frozen Gadus spp.) - Covers true cods; pollock, haddock and whiting have neighbouring HS subheadings.
- FAO ISSCAAP - 32 - Cods, hakes, haddocks - Statistical group; it also contains Merlucciidae, so it is broader than Gadidae.
- Which of these identifiers and schemes hold for the sense of Gadidae this model covers, and on what evidence? provenance
Standards and regulation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- FAO ASFIS species list and ISSCAAP group 32 (Food and Agriculture Organization of the United Nations)
- ICES advice and stock annexes for NE Atlantic Gadus, Melanogrammus, Pollachius, Merlangius and Trisopterus (International Council for the Exploration of the Sea)
- EU Common Fisheries Policy total allowable catches and Council Regulation (EU) No 1379/2013 commercial designations for fishery products (European Union)
- NAFO conservation and enforcement measures for Atlantic cod (Northwest Atlantic Fisheries Organization)
- NPFMC/NOAA harvest specifications for Bering Sea-Aleutian Islands pollock and Pacific cod (North Pacific Fishery Management Council; NOAA Fisheries)
- US FDA Seafood List acceptable market names for cod, haddock, pollock and related gadids (U.S. Food and Drug Administration)
- Codex Code of Practice for Fish and Fishery Products, CXC 52-2003 (FAO/WHO Codex Alimentarius Commission)
- Which of these standards and regulation hold for the sense of Gadidae this model covers, and on what evidence? provenance
Real-world use
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Directed shelf trawl, longline and gillnet fisheries for Atlantic and Pacific cod, haddock, saithe and whiting
- The world's largest whitefish fishery: Alaska pollock for fillets, mince, surimi and roe (mentaiko/tarako)
- Salted-and-dried trade (bacalhau, klippfisk, saltfish) historically centred on Gadus morhua
- Fresh and frozen fillets, blocks and fish fingers in North Atlantic and North Pacific food systems
- Cod-liver oil and livers as a vitamin A/D source
- Industrial reduction of small gadids (e.g. Norway pout) to fishmeal and oil
- Recreational angling for cod, pollack and saithe in the North Atlantic
- Which of these real-world use hold for the sense of Gadidae this model covers, and on what evidence? provenance
Typical measurements
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Total length of commercial fish - family about 15-180; typical landed Atlantic cod 40-90 - cm
- Round mass of commercial fish - 0.5-10 typical; exceptional Atlantic cod historically >40 - kg
- Usual capture depth on continental shelves - 30-250 (family envelope roughly 0-600) - m
- Preferred water temperature (high-latitude species) - -1.5 to 12 - °C
- Age of commercial fish - 2-15 typical; maxima often 20-25 - years
- Muscle lipid (lean whitefish) - 0.5-1.5 - % wet mass
- Headed-and-gutted or fillet yield from round fish - fillets about 40-50 - % of round weight
- Which of these typical measurements hold for the sense of Gadidae this model covers, and on what evidence? provenance
Failure modes and hazards
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Recruitment failure and stock collapse under heavy exploitation (e.g. northern Gulf of St. Lawrence / Newfoundland-Labrador Atlantic cod)
- Anisakis and related nematodes in flesh; anisakiasis if eaten raw or undercooked
- Toughening and off-odour in frozen storage from TMAO breakdown to dimethylamine and formaldehyde
- Fillet gaping and quality loss from temperature abuse or capture of spawning fish
- Species-substitution fraud in the whitefish trade (cheaper pollock, hake or other whitefish sold as cod)
- Benthic habitat damage and bycatch from bottom trawls
- Climate-driven range shifts, borealization of Arctic shelves, and mismatch of spawning with prey
- Which of these failure modes and hazards hold for the sense of Gadidae this model covers, and on what evidence? provenance
Regional variation
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- In Australia, New Zealand and southern Africa, market 'cod' is usually a serranid, morwong or nototheniid, not Gadidae
- North American 'pollock' defaults to Alaska pollock (Gadus chalcogrammus); in the UK 'pollack' is Pollachius pollachius and 'saithe'/'coley' is P. virens
- Japanese tara is Pacific cod; suketōdara/mentai is Alaska pollock; Russian mintai is the same pollock
- Portuguese and Brazilian bacalhau historically implied salted Gadus morhua; modern supply includes other gadids and sometimes saithe
- Older European ichthyology treated lings (Molva) and rocklings as subfamilies of Gadidae; current WoRMS/Catalog of Fishes practice splits those as Lotidae (and related families)
- Greenland/ogac cod is still a trade name even where taxonomists synonymize it with Pacific cod
- Which of these regional variation hold for the sense of Gadidae this model covers, and on what evidence? provenance
Neighbouring kinds and how to tell them apart
Reported by the breadth pass; each item needs checking against its source before it becomes normative.
- Hakes (Merlucciidae) - Two dorsal fins (short first, long second) and usually no chin barbel; gadids have three discrete dorsals and typically a mental barbel.
- Lings, cusk and burbot (Lotidae) - Elongate body with one or two dorsal fins, the last dorsal and the anal very long; not the three-plus-two fin count of Gadidae.
- Morid cods (Moridae) - Usually a ventral light organ and a different otophysic (swimbladder-ear) connection; caudal fin often more clearly separate from the dorsal/anal.
- Grenadiers (Macrouridae) - Pointed, tapers-to-a-filament tail and typically no distinct caudal fin; gadids have a conventional truncated or slightly emarginate tail.
- Southern vernacular 'cods' (groupers and allies, Serranidae) - Perciform spiny dorsal fin, tropical/subtropical reefs; meristics and otoliths, and any DNA barcode, place them far from Gadiformes.
- Haddock versus Atlantic cod - Haddock has a black lateral line and a dark scapular 'thumbprint'; Atlantic cod has a pale mottled lateral line and no scapular blotch.
- Saithe versus pollack (both Pollachius) - P. virens has a nearly straight pale lateral line and a projecting lower jaw; P. pollachius has a strongly arched lateral line and a dark blotch at the pectoral base.
- Which of these neighbouring kinds and how to tell them apart hold for the sense of Gadidae this model covers, and on what evidence? provenance
Sources
- FAO Species Catalogue, Vol. 10: Gadiform fishes of the world (Order Gadiformes). FAO Fisheries Synopsis No. 125 - Family diagnosis, genera and species accounts, meristics, distribution and the fisheries identity of gadids versus hakes, morids and grenadiers.
- Fishes of the World, 5th edition - Placement of Gadidae in Gadiformes and the restricted-family concept that excludes Lotidae, Merlucciidae and Macrouridae.
- Gadidae Rafinesque, 1810 - Accepted family name, AphiaID 125470, and the current child-genera list used in marine taxonomy.
- Gadidae (Q199614) - Crosswalk among Wikidata, WoRMS, ITIS and other taxonomic identifiers for the family.
What the second pass must settle
- Which taxonomic authority and version should Vercy adopt for Gadidae, particularly where treatments differ over the placement of taxa associated with Lotidae, Phycidae or other neighbouring families?
- What minimum diagnostic character set reliably separates Gadidae under that circumscription from neighbouring families across the geographic coverage required by the registry?
- Which validated identification resources cover eggs, larvae and juveniles, and where must identification remain above family level?
- Which molecular markers and curated reference collections provide adequate coverage for ambiguous, damaged or processed material?
- Which species- and context-specific condition assessments and handling protocols should be linked before an agent recommends capture, sampling, retention or release?