Atlantic pygmy octopus
species of mollusc
The Atlantic pygmy octopus (Octopus joubini), also known as the small-egg Caribbean pygmy octopus, is a small species of octopus in the order Octopoda. Fully grown, this cephalopod reaches a mantle length of 4.5 cm (1.8 inches) with arms up to 9 cm (3.5 inches) long. They are known for being intelligent creatures with keen senses, particularly good sight.
O. joubini often seeks shelter from predators in empty clamshells, cans or small openings, pulling the opening closed with its arms, combining sand and gravel to form a lid. It employs the two defensive mechanisms typical of all octopuses: ink sacs and camouflage. All Cephalopods have chromatophores, special pigmented and light reflecting cells on their skin which allows them to change colour and texture quickly.
They are found in the Atlantic Ocean, particularly in the tropical waters of the Caribbean and the Gulf of Mexico. The first holotype was collected in 1929 by Guy Coburn Robson and became a key factor in distinguishing between O. joubini and the closely related Octopus mercatoris (or in some cases, an unidentified species referred to as Octopus sp. X). Much of the information about O. joubini was obtained through laboratory studies of captive specimens and what little is known about their behavior in a natural environment is inferential.
Begin with the source’s own compact description: “Atlantic pygmy octopus” is species of mollusc. The dossier treats that line as a proposition to test through Atlantic, pygmy and octopus, not as a finished interpretation.
Why this record matters
The phrase “species of mollusc” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated Aug 23, 2026. The linked authority identifier is Q2626939. None of the 0 selected statements returned an explicit reference. The first chronological checks are 1929.
Scientific names, classifications and consensus can change while older terminology persists in catalogues and historical literature. 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 “Atlantic pygmy octopus”, its source revision and the description used here.
- Expand the search: follow Atlantic pygmy octopus primary sources, Atlantic pygmy octopus archive and Atlantic 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 “Atlantic pygmy octopus”?
- 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 “Atlantic pygmy octopus” 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.