''Modiolus auriculatus'', the eared horse mussel, is a
bivalve
Bivalvia (), in previous centuries referred to as the Lamellibranchiata and Pelecypoda, is a class of marine and freshwater molluscs that have laterally compressed bodies enclosed by a shell consisting of two hinged parts. As a group, biv ...
mollusc of the
family
Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...
,
Mytilidae
Mytilidae are a family of small to large marine and brackish-water bivalve molluscs in the order Mytilida. One of the genera, '' Limnoperna'', even inhabits freshwater environments. The order has only this one family which contains some 52 ge ...
, which has a natural range in the
Indian and Pacific Oceans. It has colonised the eastern
Mediterranean Sea
The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the ...
from the
Red Sea
The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; ...
by
Lessepsian migration via the
Suez Canal.
Description
''Modiolus auriculatus'' has an equivalve shell with each valve being inequilateral with their beaks being very close to the anterior end. The shell is the typical mussel form with the ligament and dorsal margins distinctly disjunct and the dorsal and ventral margins being parallel; the dorsal margin is concave. The shell has a smooth with growth lines and the covering
periostracum
The periostracum ( ) is a thin, organic coating (or "skin") that is the outermost layer of the shell of many shelled animals, including molluscs and brachiopods. Among molluscs, it is primarily seen in snails and clams, i.e. in gastropods a ...
is pubescent. The outer surfaces of the shell is olive-brownish or orange-brown and the shell interior is browny-purple. The commonly grow to a shell size of 70mm.
Distribution
''Modiolus auriculatus'' occurs naturally in the Indian Ocean and the Pacific Ocean from the Red Sea south to
South Africa
South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring count ...
, east to eastern
Polynesia
Polynesia () "many" and νῆσος () "island"), to, Polinisia; mi, Porinihia; haw, Polenekia; fj, Polinisia; sm, Polenisia; rar, Porinetia; ty, Pōrīnetia; tvl, Polenisia; tkl, Polenihia (, ) is a subregion of Oceania, made up of ...
, north as far as
Japan and south to
Australia.
It was first recorded in Suez Canal in the 1900s
[ and in the Mediterranean in 1935][
]
Biology
''Modiolus auriculatus'' is not restricted to a single specific habitat, it is commonest in rocky habitats and least common in areas which contain rocky sand and algae. It is often associated with small holes in rocky shores, especially on the seaward edge of sea grass beds and at the landward margin of ridges vegetated with algae.
Uses
''Modiolus auriculatus'' has been suggested as a biological indicator used to monitor marine pollution
Marine pollution occurs when substances used or spread by humans, such as industrial, agricultural and residential waste, particles, noise, excess carbon dioxide or invasive organisms enter the ocean and cause harmful effects there. The major ...
in tropical waters.[
]
References
{{Taxonbar, from=Q13860137
Bivalves described in 1848
auriculatus