“Grapsus planifrons.
Nudus. Frons fere horizontalis, sat latus. Margo carapaces lateralis bene arcuatus, antero-lateralis bi-emarginatus. Epistoma brevissimum. Articulus maxillipedis externi 3tius vix longior quam latus. Pedes antici sat crassi, manu supra pustulatâ, extus infraque lævi; brachio apicem anticum 5-6 denticulato. Pedes 8 postici valde compressi, articulo 3tio pedis postici ad apicem inferiorem integro, articulo penultimo supra scabro.
Naked. Front nearly horizontal, rather broad; lateral margin of carapax arcuate, antero-lateral bi-emarginate. Epistome very short. Third joint of outer maxillipeds as long as broad. Anterior feet rather stout; hand above small postulate, externally and below smooth; arm with five or six teeth at anterior apex. Eight posterior feet much compressed, third joint of posterior pair entire at inferior apex; penult joint scabrous above.
Plate 21, fig.3a, animal, natural size; b, abdomen and sternum of male; c, outer maxillipeds, natural size; d, hand, natural size; e, spine of tarsus.
Valparaiso, Chili; Callao, Peru.
Length of carapax, seventeen and one-third lines; breadth, nineteen lines; length of front, six and three-fourths lines; breadth of front to front of præmedial areolets (which but slightly project), two and one-fourth lines. Colour, finely lined and spotted irregularly with brown-ish black or black, with intervening spaces a little yellowish.
Sides of carapax much arcuate. The species is near G. variegates; but according to Edwards’s description of that species, and the figure in Guerin’s “Iconographie.” It has the third joint of the outer maxillipeds much oblong, while in this species, the joint is not longer than broad.
The figure in the Voy. De l’Uranie, under Freycinet, pl. 76, f. 2, may be this species.”
(Dana, 1852)
Leptograpsus variegatus, known as the purple rock crab, is a marine large-eyed crab of the family Grapsidae, found in southern subtropical Indo-Pacific Oceans.[1] It grows to around 50 millimetres (2.0 in) shell width.[1] It is the only species in the genus Leptograpsus.[2]
Leptograpsus variegatus was first described in 1793 as Cancer. variegatus.[3] In 1803, C. variegatus was moved to the Grapsus genus and became Grapsus variegatus.[4] In 1818, 1842 and 1852, L. variegatus was described again as Grapsus personatus, Grapsus strigilatus and Grapsus planifrons.[5][6][7] In 1853, Henri Milne-Edwards erected the Leptograpsus genus and used G. variegatus as the type taxon.[8] In his publication, Milne-Edwards recognized G. personatus, G. strigilatus and G. planifrons to be synonyms of L. variegatus.[8] Milne-Edwards also described Leptograpsus ansoni, Leptograpsus gayi and Leptograpsus verreauxi, however these would later also be recognized as synonyms of L. variegatus.[9]
Individuals are large and may have a carapace that reaches up to 50mm in width.[10] The crab has an overall purple colouration with a variable amount of white patterning when mature. Juveniles are a bluish grey colour with black patterning. The carapace is shaped somewhat like a square and eyes are relatively short. The body is smooth overall with no hairs.[11]
When immature, the eggs are about 0.36mm in diameter and have a very dark brown colour. When the eggs are about to hatch, they are roughly 0.44x0.42mm and the eggs are light brown.[12]
The first zoea of the crab are about 1.31mm in length.
Leptograpsus variegatus is known to occur in Australia (from western Australia to southern Australia), South America (from Peru to Chile), New Zealand and numerous islands in the Pacific Ocean.[10] The crab lives in upper intertidal rocky zones and is often spotted running along exposed rock, hiding in cracks or under boulders.[11]
Adult females are known to carry eggs only in December. The females will incubate the eggs for roughly six weeks.[12]
Leptograpsus variegatus is an omnivore and will eat a broad range of plant and animal life. While the crab may eat algae growing on rocks (such as Corallina and Ulva lactuca), they have also been observed feeding on barnacles and limpets. The crab captures limpets by quickly placing their chelae under the limpets shell when it begins to move and then flips it over.[13] Notably, there is also a single observation of this species preying upon a Raukawa gecko, which is native to New Zealand.[14]
{{cite web}}: CS1 maint: url-status (link) Leptograpsus variegatus, known as the purple rock crab, is a marine large-eyed crab of the family Grapsidae, found in southern subtropical Indo-Pacific Oceans. It grows to around 50 millimetres (2.0 in) shell width. It is the only species in the genus Leptograpsus.
