Scientific Name and Authority

Chthamalus fragilis   Darwin, 1854


Chthamalus fragilis is a small barnacle (up to 9 mm in size). Its orifice is large, toothed, and sub-hexagonal. The surface is brownish-colored, with distinct sutures, and the plates never fused together. The side plates overlap over the end plates. The scutum is long with a somewhat sinuous tergal margin. The adductor muscle insertion is comparatively shallow, fairly narrow, and 'open' at the rostral end. The tergum is wide with a noticeable spur. The lateral margin is usually deeply indented, and the scutal margin is only slightly sinuous (Darwin 1854; Gosner 1978; Dando and Southward 1980).

Taxonomic Classification:

Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Crustacea
Class: Maxillopoda
Subclass: Thecostraca
Infraclass: Cirripedia
Superorder: Thoracica
Order: Sessilia
Suborder: Balanomorpha
Superfamily: Chthamaloidea
Family: Chthamalidae
Genus: Chthamalus
Species: fragilis


Chthamalus stellatus var. fragilis (Darwin, 1854)

Potentially Misidentified Species:

Chthamalus angustitergum

Florida and Caribbean (Dando and Southward 1983)

Chthamalus bisinuatus

Brazil (Dando and Southward 1983)

Chthamalus proteus

Florida and Caribbean, Brazil (Dando and Southward 1983)