''Agatha'' is a small
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 minute
sea snail
Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...
s or
marine gastropod
Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, freshwater, and fro ...
mollusk
Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...
s within the subfamily
Syrnolinae, which is a part of the family
Pyramidellidae
Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs. The great majority of species of pyrams are micromol ...
.
[Rosenberg, G. (2012). Agatha A. Adams, 1860. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=599126 on 2012-08-27]
They have
bilateral symmetry
Symmetry in biology refers to the symmetry observed in organisms, including plants, animals, fungi, and bacteria. External symmetry can be easily seen by just looking at an organism. For example, the face of a human being has a plane of symme ...
and only have
endoderm
Endoderm is the innermost of the three primary germ layers in the very early embryo. The other two layers are the ectoderm (outside layer) and mesoderm (middle layer). Cells migrating inward along the archenteron form the inner layer of the gastr ...
and
ectoderm
The ectoderm is one of the three primary germ layers formed in early embryonic development. It is the outermost layer, and is superficial to the mesoderm (the middle layer) and endoderm (the innermost layer). It emerges and originates from the o ...
tissues.
The species of this genus are
ectoparasites
Parasitism is a close relationship between species, where one organism, the parasite, lives (at least some of the time) on or inside another organism, the host, causing it some harm, and is adapted structurally to this way of life. The en ...
on other
invertebrates
Invertebrates are animals that neither develop nor retain a vertebral column (commonly known as a ''spine'' or ''backbone''), which evolved from the notochord. It is a paraphyletic grouping including all animals excluding the chordate subphylum ...
.
Distribution
* Marine
Species
* † ''
Agatha alexanderi''
(Marwick, 1929)
* ''
Agatha amabilis''
Nomura, 1936
* ''
Agatha australis''
(Angas, 1871)
* ''
Agatha brevis''
Yokoyama, 1922
* ''
Agatha filia''
(Melvill, 1893)
* ''
Agatha georgiana''
(Hutton, 1885)
* ''
Agatha laevis''
(Angas, 1867)
* ''
Agatha obesa''
Peñas & Rolán, 2016
* † ''
Agatha otaioensis''
Laws, 1940
* ''
Agatha pacei''
(Dautzenberg & Fischer, 1906)
* † ''
Agatha pittensis''
(Marwick, 1928)
* ''
Agatha placida''
Nomura, 1936
* ''
Agatha vestalis''
Melvill, 1910
* ''
Agatha virgo''
Weisbord, 1962
;Species brought into synonymy:
* ''Agatha angasi''
(Tryon, 1886): synonym of ''
Syrnola angasi''
(Tryon, 1886)
* ''Agatha infrequens''
Nomura, 1937: synonym of ''
Odostomia infrequens''
(Nomura, 1937)
* ''Agatha lepidula''
Habe, 1961: synonym of ''
Tibersyrnola lepidula''
(Habe, 1961)
* ''Agatha simplex''
(Angas, 1871): synonym of ''
Megastomia simplex''
(Angas, 1871)
References
Spencer H.G., Willan R.C., Marshall B.A. & Murray T.J. (2011) ''Checklist of the Recent Mollusca Recorded from the New Zealand Exclusive Economic Zone''
{{DEFAULTSORT:Agatha (Gastropod)
Pyramidellidae