''Paraconcavus pacificus'', the red-striped acorn barnacle,
is a species of
balanid barnacle
A barnacle is a type of arthropod constituting the subclass Cirripedia in the subphylum Crustacea, and is hence related to crabs and lobsters. Barnacles are exclusively marine, and tend to live in shallow and tidal waters, typically in eros ...
known from
subtidal
The neritic zone (or sublittoral zone) is the relatively shallow part of the ocean above the drop-off of the continental shelf, approximately in depth.
From the point of view of marine biology it forms a relatively stable and well-illuminated ...
sandy habitats of the outer northeastern Pacific coast, from
Baja California
Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...
north to
Monterey Bay
Monterey Bay is a bay of the Pacific Ocean located on the coast of the U.S. state of California, south of the San Francisco Bay Area and its major city at the south of the bay, San Jose. San Francisco itself is further north along the coast, by a ...
.
It grows to 35 mm in diameter, with pink longitudinal stripes over white plates, and can be distinguished from other large, pink-striped barnacles in its range (e.g. ''
Amphibalanus amphitrite'') by the longitudinal striations across the growth rings of its plates.
While it will attach to many different kinds of hard substrate, it shows a preference for attaching to the shells of other organisms, particularly
sand dollars
Sand dollars (also known as a sea cookie or snapper biscuit in New Zealand, or pansy shell in South Africa) are species of flat, burrowing sea urchins belonging to the Order (biology), order Clypeasteroida. Some species within the order, not qui ...
.
References
Barnacles
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