Every layer below draws on the sources above — open one to explore it, or use ← → to move between tabs.
NarrativeWikipediaarticle
Traits & measurements1 literature sources5 traits
Occurrence & distributionGBIF · OBIS476 records
DNA & barcodingBOLD8 specimens
01Narrative
Plagusia squamosa is a marine crab of the family Plagusiidae, formerly considered a subspecies of Plagusia depressa (as P. d. tuberculata). It is found in tropical Indo-Pacific oceans. P. squamosa's carapace is bumpy and quite coarse, seemingly scaly, leading to its common name: The Scaly Rock Crab. They are also commonly referred to as "rafting crabs" due to their propensity to live on pelagic marine animals such as sea turtles-- most notably olive ridleys (Lepidochelys olivacea).1 2 3 Frick, Michael G.; Kopitsky, Kerry; Bolten, Alan B.; Bjorndal, Karen A.; Martins, Helen R. (2011-04-09). "Sympatry in grapsoid crabs (genera Planes and Plagusia) from olive ridley sea turtles (Lepidochelys olivacea), with descriptions of crab diets and masticatory structures". Marine Biology. 158 (8): 1699–1708. doi:10.1007/s00227-011-1684-9. ISSN 0025-3162. They characteristically cling and float on organisms or objects. It is still not fully understood of the relationship shared between the crabs and the sea turtles, though it can be hypothesized that the relationship is either mutualistic or commensalistic.
No narrative description available for this taxon yet.
A DNA barcode is a short, standardised stretch of genes that works like a fingerprint — enough to tell one species from another. Below is the molecular trace Plagusia squamosa has left across the world's sequence archives.
At a glance
DNA specimens8
BINs1
Marker genes1
Countries2
The DNA barcodethe species' typical barcode, built from every sequenced specimen
COI-5P658 bp consensus7 specimens
ACGT
▸ drag or hover over the strip to read any position — letter and how much it varies
Violet ticks below the strip = positions where individuals differ; flat = the species' unchanging signature. 98% of positions are identical in every specimen.
Where individuals differ — all 11 variable positions, in barcode order
Each circle is a barcode variant; bigger = more specimens, colour = region. Lines join the most similar variants and the tick marks count the mutations between them — a tight cluster is one “dialect”, a long line a more divergent lineage. Click a circle to list its actual specimens.
Diversity (π)0.55%
Haplotypes4
BIN1
Most divergent pair1.4%
OtherN.America
Closest relatives by DNA barcode
The species whose COI barcode is most similar to this one — a quick “who is this most like”. The percentage is how much the barcode differs; it approximates, but is not, the full evolutionary tree.
★ the standard DNA barcode for this group — the short region actually read to tell this species apart. The rest are extra genes sequenced along the way.
★COI-5P
animal barcode
Organelle genome
Besides the big genome in the nucleus, cells carry a small, circular loop of DNA inside the cell's energy factories — the mitochondria. It is inherited almost only from the mother and is a leftover from ancient bacteria that moved into the cell. The mitochondrial markers above (ND*, COX, CYTB…) are read from exactly this loop. Outer ring = one strand, inner ring = the other.
▸ Tap any coloured segment — or a gene chip — to see what it is
◖ violet arc = the COI-5P barcode — the ~650 bp read used to ID this species
Pick a coloured segment on the ring — or a gene chip — to read what that gene does.
protein-codingrRNAtRNA
07Deep time~89.4 Ma lineage
How far back this lineage goes — and how we know. Everything here is measured in Ma, short for “mega-annum”: millions of years ago. The chart reads left to right like a calendar of the Earth, from the deep past on the left to today at the right edgetop to bottom like a core drilled through the Earth, from the deep past at the top down to today at the bottom.
At a glance
DNA clock origin89.4 Ma TimeTree
When this lineage existed
How to read this: the coloured strip along the bottomdown the left is the geological calendar — the standard periods (Jurassic, Cretaceous…) every museum uses, shown so you can see which chapter of Earth's history this lineage lived in. The dashed rules marked ✦ are the five great mass extinctions. The orange marker is the DNA clock: DNA accumulates mutations at a roughly steady rate, so comparing this species' DNA with its relatives estimates when the lineage split off — independently of any fossil.
DNA clock originmass extinction
08Occurrence & distribution
Record type476 records
Wild obs. + sensor289
Museum / vouchered187
Range
Area of Occupancy AOO1 140 km²
Depth
0–200 m sunlit4
200–1000 m twilight0
1–4 km midnight0
>4 km abyssal0
median 2.2 m · max 3 m · 4 records with depth
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
Coordinate accuracy86% within 1 km
≤100 m 130≤1 km 48≤10 km 13>10 km 16
207 georeferenced · 82 without coordinates
Open the mapobservation + sensor289
Museum / Voucheredphysical evidence
Backed by a physical specimen — a herbarium sheet, sample or voucher held in a collection. “Vouchered” means supported by material evidence, not just an observation.
Coordinate accuracy34% within 1 km
≤100 m 6≤1 km 7≤10 km 18>10 km 7
38 georeferenced · 149 without coordinates
Open the institutions mapphysical evidence187
Wildobservation + sensor
Human sightings and records, or camera-trap / sensor detections — someone (or a device) saw or captured the species in the wild.
10Collections & institutions
Holding institutions8 of 15 geolocated
Institutions and collections holding physical, vouchered specimens of this species — click a row to fly to it on the map.
Institution
Specimens
Sydney, AU
30
Florida Museum of Natural History- Zoology, Paleontology & Paleobotanylocation not on record
25
Washington, US
20
Frankfurt am Main
12
Western Australian Museumlocation not on record
9
Paris, FR
4
Museum für Naturkunde Berlin (Zoological Collections)location not on record
4
Honolulu, US
3
Helsinki, FI
2
Los Angeles, US
2
National Marine Biodiversity Institute of Korealocation not on record
2
Earth Sciences New Zealandlocation not on record
1
Oceanographic Research Institutelocation not on record
1
CASlocation not on record
1
Auckland, NZ
1
15 institutions · 117 of 187 vouchered records shown · 1 without an institution code
WikipediaWikimedia Foundation5 languages↗
BioWikiNetmultilingual Wikipediamultilingual↗
GBIFGlobal Biodiversity Information Facility379 records↗
OBISOcean Biodiversity Information System97 records↗
BOLD SystemsCentre for Biodiversity Genomics8 specimens↗
Open Tree of LifeOpenTreephylogeny backbone↗
Catalogue of LifeCOLtaxonomy↗