''Ixa monodi'', the Red Sea pebble crab is a species of pebble crab from the family

Leucosiidae Leucosiidae is a family of crabs containing three subfamilies and a number of genera ''incertae sedis'': ;Cryptocneminae Stimpson, 1907 * '' Cryptocnemus'' Stimpson, 1858 * '' Leucisca'' MacLeay, 1838 * '' Lissomorpha'' Ward, 1933 * '' Onych ...

which prefers to burrow in sandy, shallow coastal waters. It was first described from the eastern Mediterranean where it is an

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

having colonised the coasts of the

Levantine Sea The Levantine Sea (Arabic: بحر الشام, tr, Levanten Denizi, el, Θάλασσα του Λεβάντε) is the easternmost part of the Mediterranean Sea. Geography The Levantine Sea is bordered by Turkey in the north and north-east co ...

from the Red Sea by Lessepsian migration from the Red Sea via the

Suez Canal The Suez Canal ( arz, قَنَاةُ ٱلسُّوَيْسِ, ') is an artificial sea-level waterway in Egypt, connecting the Mediterranean Sea to the Red Sea through the Isthmus of Suez and dividing Africa and Asia. The long canal is a popular ...

Description

''Ixa monodi'' has a transversely ovoid

carapace A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tor ...

which is laterally stretched to form a process on each side which is cylindrical and covered in tubercles. The forehead is forked and the orbits are deep and completely overhang the eyes with three indentations in their outer margins. The posterior margin bears two granulose tubercles. The dorsal surface of the carapace has two longitudinal grooves which fork before the long. thin chelipeds. The carapace is pale reddish-orange in colour with more intensely coloured granules, the lateral processes are paler towards their tips, the chelipeds are orange and the pereopods are paler orange. The largest individual recorded had a carapace length of 59.2 mm.

Distribution

''Ixa monodi'' is native to the Red Sea and was probably originally identified as ''

Ixa cylindrus ''Ixa'' is a genus of Indo-Pacific pebble crabs from the family Leucosiidae. The genus was erected by William Elford Leach in 1816. One species, the Red Sea pebble crab ('' Ixa monodi''), is a Lessepsian migrant and the species was first describ ...

'' by Dr. Theodore Monod in 1938 from the Gulf of Suez but it was definitely described in 1956 from specimens collected by

Holthuis Lipke Bijdeley Holthuis (21 April 1921 – 7 March 2008) was a Dutch carcinologist, considered one of the "undisputed greats" of carcinology, and "the greatest carcinologist of our time". Holthuis was born in Probolinggo, East Java and obtained ...

& Gottlieb off the coast of south-eastern Turkey at Mersin Bay in 1955. It has since been recorded from Israel,

Syria Syria ( ar, سُورِيَا or سُورِيَة, translit=Sūriyā), officially the Syrian Arab Republic ( ar, الجمهورية العربية السورية, al-Jumhūrīyah al-ʻArabīyah as-Sūrīyah), is a Western Asian country loc ...

, Rhodes and Egypt.

Habitat

''Ixa monodi'' occurs on sandy or muddy substrates in shallow waters between 14m and 60m in depth.

Naming

''Ixa monodi'' is named in honour of Dr. Theodore Monod, who was director of the Institut Francais d'Afrique Noire at Dakar, as he was the first scientist to publish an illustration of this species. The specimen collected by Holthuis and Gottlieb in Mersin Bay in 1955 is the holotype of ''Ixa monodi'' and has been preserved in the collection of the Rijksmuseum van Natuurlijke Historie in Leiden.

References

{{Taxonbar, from=Q13372520 Crabs Crustaceans described in 1956