Cook Islands Biodiversity Database

Species Page

Back to: «« Search Page | « Results Page

Add to My List

Geograpsus grayi

Karai‘i

Purple-backed Shore-Crab

Multimedia & Additional Resources

Type	Description	Download
Image:	Adult male	21KB

General Information

COMMON NAMES: Purple-backed Shore-Crab

TRADITIONAL NAMES: Karai‘i (MG), Karaī (AT), Kara‘ī (MK MT), Karai‘i / Pāpaka Karai‘i (AK)

GLOBAL DISTRIBUTION: NATIVE e.Africa - Wake Island - Cooks - Tuamotu

COOK ISLANDS STATUS: Native; Land, coastal, breed in the sea

KEY FEATURES: Carapace 35mm, toe-toe 140mm. Hops rather than scuttles. Carapace brown with purple-brown blotching. Carapace flat with transverse lines; front less than half maximum width; widest in posterior half; lateral margin keeled in front half but not in posterolateral section. Palm and moveable finger slightly granular; fingers pointed and not spooned. Outer segments of walking legs with long bristles.

SIMILAR SPECIES: Differs from other Geograpsus in having the keel absent in the posterolateral area and in having a distinct irregular patch of fine hairs on the sternite of the chelipeds.

Cook Islands Distribution

View Distribution Map

Southern Group: Present Makatea:
RR	MG	AT	MK	MT	AK	PL	TK	MN
+++	++++	^P			^++++

Northern Group:
TN	MH	RK	PK	NS	SW
			+++

Key to Symbols

blank	no data
-	absent	L	localised
X	extinct 'naturally'	W	widespread
XQi	quarantine intercepted	R	recent
XQe	eradicated	?	query preceding category
P	present	T?	taxonomic query
S	seasonal	nn	present, said to have no name
O	occasional	?1	present, name not investigated
++++	very common	?2	presence not verified, no name recorded
+++	common	N/A	absent, name not expected
++	uncommon
+	rare
Cook Islands islands: RR =Rarotonga, MG = Mangaia, AT =‘Ātiu, MK=Ma‘uke, MT=Miti‘āro, AK=Aitutaki, PL=Palmerston, PN=Penrhyn, MN=Manuae, TK=Takūtea, TN=Tongareva (TS=Tongaleva Spoken, TW=Tongareva Written, they say "el" but write "r"), MH=Manihiki, RK=Rakahanga, PK=Pukapuka, NS=Nassau, SW=Suwarrow. After a Polynesian name: ^=orthography query. Countries and other: FIJ=Fiji, WT=Wallis & Futuna, SAM=Samoa, TON=Tonga, NIU=Niue, CK=Cook Islands, CKM=Cook Islands Māori, FP=French Polynesia, AUS=Australs, SOC=Societies, TAH=Tahiti, TUA=Tuamotus, MQS=Marquesas, MNG=Mangareva, PIT=Pitcain group, EAS=Easter Island, HAW=Hawai‘i, NZ=New Zealand, NZM=New Zealand Māori

Scientific Taxonomy

Geograpsus grayi (H. Milne Edwards, 1853)
SYNONYMS: Grapsus grayi

TAXONOMY: ANIMALIA; ARTHROPODA; CRUSTACEA; MALACOSTRACA; EUMALACOSTRACA; Eucarida; Decapoda; Reptantia; Brachyura; Brachygnatha; Brachyrhyncha; GRAPSIDAE

Vouchers & References

Vouchers:
Atiu: field-specimen, College collection, 10/2000, ID GMcC. Pukapuka: fieldspecimen+photo, 2/2004, G.McCormack with ID as Geograpsus grayi.

References:
Special Reference: Yaldwyn & Wodzicki 1979;

Data Update History (information):
zTXmx, zB02, zM02, zD02

Web Resources

Citation Information

McCormack, Gerald (2007) Cook Islands Biodiversity Database, Version 2007.2. Cook Islands Natural Heritage Trust, Rarotonga. Online at http://cookislands.bishopmuseum.org.
Please refer to our use policy.

Biodiversity Database: More Options | Help

My List: View List | Edit List | Clear List