''Actogidiella'' is a

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

amphipod Amphipoda is an order of malacostracan crustaceans with no carapace and generally with laterally compressed bodies. Amphipods range in size from and are mostly detritivores or scavengers. There are more than 9,900 amphipod species so far descr ...

crustaceans Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

. It contains only the species ''Actogidiella cultrifera''. The genus' name derives from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word for seacoast and the suffix ''-gidiella'' which refers to its habitat.

Description

The genus has small

coxal In vertebrate anatomy, hip (or "coxa"Latin ''coxa'' was used by Celsus in the sense "hip", but by Pliny the Elder in the sense "hip bone" (Diab, p 77) in medical terminology) refers to either an anatomical region or a joint. The hip region is ...

plates which are wider than they are long. Towards the rear, these plates do not overlap. There are three pairs of coxal gills. The

mandibles In anatomy, the mandible, lower jaw or jawbone is the largest, strongest and lowest bone in the human facial skeleton. It forms the lower jaw and holds the lower tooth, teeth in place. The mandible sits beneath the maxilla. It is the only movabl ...

are reduced in chewing capabilities, having a slightly transformed

palp Pedipalps (commonly shortened to palps or palpi) are the second pair of appendages of chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to the chelicerae ("jaws") ...

with swollen second segments. The first

maxilla The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The t ...

has a palp with 2 segments and a bristled inner lose. The second maxilla is similar, but is slightly less bristly. The

maxilliped An appendage (or outgrowth) is an external body part, or natural prolongation, that protrudes from an organism's body. In arthropods, an appendage refers to any of the homologous body parts that may extend from a body segment, including anten ...

has short inner and outer lobed which have short spines pointed outwards. This maxilliped is not sexually dimorphous, but is the same in both male and female members of the genus. The pleopodal lungs are not transformed, but one spine on the second segment of the second pleopod is transformed in male specimens. The first

uropod Uropods are posterior appendages found on a wide variety of crustaceans. They typically have functions in locomotion. Definition Uropods are often defined as the appendages of the last body segment of a crustacean. An alternative definition sugge ...

is transformed in both males and females. The endopodites are curved and dagger-like; the exopodite is shorter than the endopodite; in females they are rod-like with transformed spines. The second uropod is not transformed, and the third uropod is monomerous with a very shallow outward notch.

Taxonomy

Specimens

The

type specimen In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to a ...

of ''Actogidiella cultrifera'' is a female collected in the Virgin Islands by

Jan Hendrik Stock Jan, JaN or JAN may refer to: Acronyms * Jackson, Mississippi (Amtrak station), US, Amtrak station code JAN * Jackson-Evers International Airport, Mississippi, US, IATA code * Jabhat al-Nusra (JaN), a Syrian militant group * Japanese Article Numb ...

west of the Well Bay airfield on

Beef Island Beef Island is an island in the British Virgin Islands. It is located to the east of Tortola, and the two islands are connected by the Queen Elizabeth Bridge. Beef Island is the site of the Terrance B. Lettsome International Airport (IATA cod ...

, in the species' type locality. Today, the specimen is kept at the

Zoological Museum of Amsterdam The Zoological Museum Amsterdam (ZMA) was a natural history museum located close to Oosterpark in Amsterdam, Netherlands. It was part of the Faculty of Science, Mathematics and Computer Science (Science) of the University of Amsterdam. It was o ...

along with several

paratype In zoology and botany, a paratype is a specimen of an organism that helps define what the scientific name of a species and other taxon actually represents, but it is not the holotype (and in botany is also neither an isotype nor a syntype). Of ...

and allotype specimens.

Species

In its original description in 1981, ''Actogidiella'' was stated to be a monotypic genus containing only the species ''Actogidiella cultrifera''. However, it is possible that related species could be placed into the genus, and one as yet unnamed species in

Curaçao Curaçao ( ; ; pap, Kòrsou, ), officially the Country of Curaçao ( nl, Land Curaçao; pap, Pais Kòrsou), is a Lesser Antilles island country in the southern Caribbean Sea and the Dutch Caribbean region, about north of the Venezuela coast ...

is likely to be another member.

Distribution and habitat

The genus has been recorded in Tortolla in the West Indies. Its habitat can be intertidal, interstitial, or marine beaches.

References

{{Taxonbar, from=Q104856129 Amphipoda Monotypic crustacean genera