''Aiteng ater'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea slug Sea slug is a common name for some Marine biology, marine invertebrates with varying levels of resemblance to terrestrial Slug, slugs. Most creatures known as sea slugs are gastropods, i.e. they are Sea snail, sea snails (marine gastropod moll ...

, a 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 ...

mollusc Mollusca is a phylum of protostome, protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant taxon, extant species of molluscs are recognized, making it the second-largest animal phylum ...

in the family

Aitengidae ''Aiteng'' is a genus comprising three species of sea slug, ''A. ater'' and ''A. mysticus'' being found in intertidal zones while ''A. marefugitus'' is fully terrestrial. ''Aiteng'' is the only genus in the family Aitengidae. The name of a biolog ...

. The

specific name Specific name may refer to: * in Database management systems, a system-assigned name that is unique within a particular database In taxonomy, either of these two meanings, each with its own set of rules: * Specific name (botany), the two-part (bino ...

''ater'' is from the

Latin language Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

and means black, in reference to the appearance of the slug on the mud. ''Aiteng ater'' was chosen by the

International Institute for Species Exploration The International Institute for Species Exploration (IISE) was a research institute located in Syracuse, New York. Its mission was to improve Taxonomy (biology), taxonomical exploration and the cataloging of new species of flora and fauna. Betw ...

Arizona State University Arizona State University (Arizona State or ASU) is a public university, public research university in Tempe, Arizona, United States. Founded in 1885 as Territorial Normal School by the 13th Arizona Territorial Legislature, the university is o ...

to be one of the "Top 10 New Species described in 2009"."Top 10 New Species – 2010"

"Top 10 – 2010 Bug-eating Slug"
. accessed 29 November 2010.

Distribution

The distribution of ''Aiteng ater'' includes Thailand. The type locality is 8°29'18" N, 100°10'55" E, Amphoe Pak Phanang, Pak Phanang Bay, in the

Gulf of Thailand The Gulf of Thailand (), historically known as the Gulf of Siam (), is a shallow inlet adjacent to the southwestern South China Sea, bounded between the southwestern shores of the Indochinese Peninsula and the northern half of the Malay Peninsula. ...

Description

The size of the body is 8–12 mm. The shape of the body is elongate, but broad. The color of the slug is from grey to black. The eyes are the only externally clearly visible feature on its head. ''Aiteng ater'' has an unusual combination of morphological characters: * Reduction of mantle cavity * Prepharyngeal (circumpharyngeal) nerve ring * The presence of

ascus An ascus (; : asci) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some gen ...

However, re-examination of the supposed "ascus" in ''Aiteng ater'' is necessary, because an examination of an undescribed species Aitengidae sp. from Japan showed no true (i.e. sacoglossan-like) ascus containing old teeth, just a radula slightly bent at the end. * Uniseriate radula (radula with a descending and ascending limb) * The radula has a strong rhachidian tooth * The large, internal lateral eyes closely associated with the cerebral ganglia * The presence of a foot groove * A branched

digestive gland The hepatopancreas, digestive gland or midgut gland is an organ of the digestive tract of arthropods and molluscs. It provides the functions which in mammals are provided separately by the liver and pancreas, including the production of digestive ...

. This species lacks several acochlidian characteristics: * It has no

shell Shell may refer to: Architecture and design * Shell (structure), a thin structure ** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses Science Biology * Seashell, a hard outer layer of a marine ani ...

* No

tentacle In zoology, a tentacle is a flexible, mobile, and elongated organ present in some species of animals, most of them invertebrates. In animal anatomy, tentacles usually occur in one or more pairs. Anatomically, the tentacles of animals work main ...

s * No

gill A gill () is a respiration organ, respiratory organ that many aquatic ecosystem, aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow r ...

s * No

cerata :''The tortrix moth genus ''Cerata'' is considered a junior synonym of ''Cydia (genus), Cydia. Cerata, singular ceras, are anatomical structures found externally in nudibranch sea slugs, especially in aeolid nudibranchs, marine animal, marine opi ...

* It lacks the division of the body into head-foot complex and visceral hump * It lacks presence of 1–2 head appendages (with characteristic innervation of the rhinophores) * Tt lacks the ability to retract the head-foot complex into the visceral hump. ''Aiteng ater'' has a

notum The notum (plural nota) is the dorsal portion of an insect's thoracic segment, or the dorsal surface of the body of nudibranch gastropods. The word "notum" is always applied to dorsal structures; in other words structures that are part of the back ...

with a free margin. However, in the absence of a separated visceral hump, ''Aiteng ater'' is able to retract its head under the frontal part of the notum.

Ecology

''Aiteng ater'' is an amphibious species which lives in

mangrove forest Mangrove forests, also called mangrove swamps, mangrove thickets or mangals, are productive wetlands that occur in coastal intertidal zones. Mangrove forests grow mainly at tropical and subtropical latitudes because mangrove trees cannot withsta ...

s in the

intertidal zone The intertidal zone or foreshore is the area above water level at low tide and underwater at high tide; in other words, it is the part of the littoral zone within the tidal range. This area can include several types of habitats with various ...

, on the mud. It lives "amphibiously", and tolerates marine to brackish waters, but there are no observations of these animals truly leaving the water. ''Aiteng ater'' feeds on

insect Insects (from Latin ') are Hexapoda, hexapod invertebrates of the class (biology), class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (Insect morphology#Head, head, ...

s, (is

insectivorous A robber fly eating a hoverfly An insectivore is a carnivorous animal or plant which eats insects. An alternative term is entomophage, which can also refer to the human practice of eating insects. The first vertebrate insectivores we ...

). In the laboratory it has been observed to eat

pupae A pupa (; : pupae) is the life stage of some insects undergoing transformation between immature and mature stages. Insects that go through a pupal stage are holometabolous: they go through four distinct stages in their life cycle, the stages th ...

of beetles (

Coleoptera Beetles are insects that form the Taxonomic rank, order Coleoptera (), in the superorder Holometabola. Their front pair of wings are hardened into wing-cases, elytra, distinguishing them from most other insects. The Coleoptera, with about 40 ...

), pupae of

Lepidoptera Lepidoptera ( ) or lepidopterans is an order (biology), order of winged insects which includes butterflies and moths. About 180,000 species of the Lepidoptera have been described, representing 10% of the total described species of living organ ...

, imagos of

mosquitos Mosquitoes, the Culicidae, are a family of small flies consisting of 3,600 species. The word ''mosquito'' (formed by '' mosca'' and diminutive ''-ito'') is Spanish and Portuguese for ''little fly''. Mosquitoes have a slender segmented body, ...

and larvae of

ant Ants are Eusociality, eusocial insects of the Family (biology), family Formicidae and, along with the related wasps and bees, belong to the Taxonomy (biology), order Hymenoptera. Ants evolved from Vespoidea, vespoid wasp ancestors in the Cre ...

s. Inside the bodies of individuals of ''Aiteng ater'', there were found to be white elongated

endoparasite 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 ...

s; these are as yet unstudied. However the "parasites" described for ''Aiteng ater'' might represent spicules instead, because the presence of spicules is confirmed for the undescribed species Aitengidae sp. from Japan.

References

This article incorporates CC-BY-2.0 text from Jörger et al. 2010.Jörger K. M., Stöger I., Kano Y., Fukuda H., Knebelsberger T. & Schrödl M. (2010). "On the origin of Acochlidia and other enigmatic euthyneuran gastropods, with implications for the systematics of Heterobranchia". ''

BMC Evolutionary Biology ''BMC Ecology and Evolution'' (since January 2021), previously ''BMC Evolutionary Biology'' (2001–2020), is a peer-reviewed open access scientific journal covering all fields of evolutionary biology, including phylogenetics and palaeontology ...

'' 10: 323. . {{Taxonbar, from=Q4699301 Aitengidae Gastropods described in 2009