''Chthamalus'' (χθαμαλός, "flat" or "on the ground") is a
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
barnacle
Barnacles are arthropods of the subclass (taxonomy), subclass Cirripedia in the subphylum Crustacean, Crustacea. They are related to crabs and lobsters, with similar Nauplius (larva), nauplius larvae. Barnacles are exclusively marine invertebra ...
s that is found along almost all non-boreal coasts of the
northern hemisphere
The Northern Hemisphere is the half of Earth that is north of the equator. For other planets in the Solar System, north is defined by humans as being in the same celestial sphere, celestial hemisphere relative to the invariable plane of the Solar ...
, as well as many regions in the
southern hemisphere. These small barnacles have been studied in part because of the
taxonomic
280px, Generalized scheme of taxonomy
Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme of classes (a taxonomy) and the allocation ...
confusion over a group of species that, by and large, are
morphologically and ecologically quite similar. In recent years, molecular techniques have identified a number of
cryptic species
In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
that have been subsequently confirmed by taxonomists using morphological measurements. Most recently the genus has been shown to be
paraphyletic
Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...
, with the genus ''Microeuraphia'' nested within ''Chthamalus''.
Field Identification
Identification of barnacles in the field can be challenging, and identification of particular species of ''Chthamalus'' is not considered reliable in the field other than a few species. However, a notable distinction in the arrangement of wall plates can help biologists distinguish Chthamalid barnacles from the other common barnacles in the family Balanidae. In chthamalid barnacles, the side plates overlap both the rostrum and the carina (the plates at the ends of the opercular opening), while in balanids one end plate (the rostrum) overlaps the adjoining side plates (rostrolaterals).
Species
The following species are included in the genus ''Chthamalus'':
* ''
Chthamalus angustitergum''
Pilsbry, 1916
* ''
Chthamalus anisopoma''
Pilsbry, 1916
* ''
Chthamalus antennatus''
Darwin, 1854
* ''
Chthamalus barnesi''
Achituv & Safriel, 1980
* ''
Chthamalus bisinuatus''
(Pilsbry, 1916)
* ''
Chthamalus challengeri''
Hoek, 1883
* ''
Chthamalus dalli''
Pilsbry, 1916 (little brown barnacle)
* ''
Chthamalus dentatus''
Krauss, 1848 (tooth barnacle)
* ''
Chthamalus fissus''
Darwin, 1854
* ''
Chthamalus fragilis''
Darwin, 1854 (fragile barnacle)
* ''
Chthamalus hedgecocki''
Pitombo & Burton, 2007
* ''
Chthamalus malayensis''
Pilsbry, 1916
* ''
Chthamalus montagui''
Southward, 1976 (montagu's stellate barnacle)
* ''
Chthamalus moro''
Pilsbry, 1916
* ''
Chthamalus newmani''
Chan, 2016
* ''
Chthamalus panamensis''
Pilsbry, 1916
* ''
Chthamalus proteus''
Dando & Southward, 1980 (Atlantic barnacle)
* ''
Chthamalus sinensis''
Ren, 1984
* ''
Chthamalus southwardi''
Poltarukha, 2000
* ''
Chthamalus southwardorum''
Pitombo & Burton, 2007
* ''
Chthamalus stellatus
''Chthamalus'' (χθαμαλός, "flat" or "on the ground") is a genus of barnacles that is found along almost all non-boreal coasts of the northern hemisphere, as well as many regions in the southern hemisphere. These small barnacles have bee ...
''
(Poli, 1791) (poli's stellate barnacle)
* ''
Chthamalus williamsi''
Chan & Cheang, 2015
* † ''
Chthamalus graziani''
Carriol, 2008
* † ''
Chthamalus ligusticus''
de Alessandri, 1895
* † ''
Chthamalus nasus''
Carriol, 2008
* † ''
Chthamalus robustus''
Carriol, 2008
References
Barnacles
Taxa named by Camillo Ranzani
Maxillopoda genera
{{Maxillopoda-stub