Euraphia withersi   (Pilsbry),  1916 (Barnacle)
Organism information awaits expert curation
Class: Maxillopoda

Image copyrights: Ocean Science and Technology Cell, CUSAT, Kochi

Size: Shell diameter from 7mm-13m, height from 4-5 mm.

Color: Externally plates light grey; light ash gray towards apical area, brown towards basal margin.

Shell: Small, depressed, conical, carino-rostral diameter. Externally plates smooth but ranging from slight to strong vertical riblets near the basal rim. Sutures between compartments distinct. Orifice ovate or rhomboid, opercular valves in some individuals protruding above the level (Rosell, 1972), observed protruding of the operculum only when the individuals are crowded, while in the present observation, even solitary individuals showed protruding opercular valves. Apex of rostro laterals narrow and tooth-like and in some specimens produced as truncated spur. As observed by Rosell (1972), lateral compartments with distinct oval pits, deep or sometimes quite shallow, situated below sheath.
Scutum: Triangular, occludent margin slightly longer than tergal margin; externally with a broad shallow depression near basi-tergal angle, this side of valve tends to bend outwardly; pit for adductor distinct; adductor ridge obsolete. Articular ridge short; articular furrow very shallow; crest for depressor muscles indistinct.
Tergum: Apical part broader, basi-scutal angle elongated. Crests for depressor muscles not constant (varying between 0 to 4 ridges).
Mouth Parts: Labrum with wide shallow groove armed with blunt or sharp denticles either in groups closely packed together or situated far apart numbering up to 34. Palpous, spatulate, apex truncated, their edges rounded bearing large pinnate setae, inner margin carries short smaller setae. Mandible with 3 teeth, some with only 1 or 2 minute denticles on upper margin of 3rd tooth; margin inferior to 3rd tooth, pectinate, not comb like. There are 2-6 pectinations; 2-4 spines found at inferior angle plus one or two minute below this.
Inner maxilla cutting edge notched. First notch below the single large spine. Rosell (1972) observed 2 large spines above the notch, on this notch are 2 or 3 minute setae; margin between first and second notches bears five to six moderate-sized spines. Second notch shallow and broad with or without minute setae on its margin; below second notch margin including its protuberant with several straight spines. Outer maxilla apical part blunt and narrow, frontal margin with a distinct notch devoid of setae; margin below this bears few minute straight setae; posterior margin highly setose, larger setae finely pinnate.

Synonym (s)
Chthamalus withersi Pilsbry 1916
Chthamalus withersi Nilsson-Cantell 1921
Chthamalus withersi Nilsson-Cantell 1930
Chthamalus withersi Zevina and Tarazov 1963
Chthamalus withersi Southward 1964
Chthamalus malayensis Pope 1965
Chthamalus withersi Karande and Palekar 1966
Chthamalus malayensis Utinomi 1968
Chthamalus withersi Wagh and Bal 1974
Chthamalus withersi Rosell 1972
Chthamalus withersi Rosell 1973
Euraphia withersi Newman and Ross 1976

Common Name (s)
Economic Importance and Threats

Habitat:  Coastal


• Maharashtra, Madh Island INDIA (Record: 2001)
• Maharashtra, Bandra INDIA (Record: 2001)
• Maharashtra, Thane INDIA (Record: 2006)
• MADAGASCAR (Record: 2006)
• Maharashtra, Mumbai INDIA (Record: 2006)
• West Bengal, Hugli Matla Estuary INDIA (Record: 2006)

Literature Source(s)
  • Fernando, SA (2006) Monograph on Indian Barnacles Ocean science and technology Cell, Kochi 9-199 Available at - NIO, Goa
  • Society for the Management of European Biodiversity Data (2009) World Register of Marine Species (WoRMS) Available at -

Page last updated on:2012-05-21

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