Aiteng ater is a species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of sea slug

Sea slug

Sea slug is a common name used for several different groups of saltwater snails that either lack a shell or have only an internal shell, in other words this name is used for various lineages of marine gastropod mollusks that are either not conchiferous or appear not to be.The phrase "sea slug" is...

, a marine

Marine (ocean)

Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...

 gastropod mollusk in the family Aitengidae.

The specific name ater is from Latin language 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

International Institute for Species Exploration

The International Institute for Species Exploration is a research institute hosted by Arizona State University, dedicated to improving taxonomical exploration and the cataloguing of new species of flora and fauna. It is located in Tempe, Arizona, in the United States of America. The institute's...

 of Arizona State University

Arizona State University

Arizona State University is a public research university located in the Phoenix Metropolitan Area of the State of Arizona...

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

Distribution

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

Amphoe Pak Phanang

Pak Phanang is a district of Nakhon Si Thammarat Province, southern Thailand.The name of district means Sheltered Mouth, referring to the mouth of the Pak Phanang river protected from the open sea by a long peninsula.- History :...

, Pak Phanang Bay, Gulf of Thailand

Gulf of Thailand

The Gulf of Thailand , also known in to Malays as Teluk Siam literally meant Gulf of Siam, is a shallow arm of the South China Sea.-Geography:...

.

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. Eyes are the only externally clearly visible feature on its head.

Aiteng ater has unusual combination of morphological characters:

• reduction of mantle cavity
• prepharyngeal (circumpharyngeal) nerve ring
• presence of ascus
  Ascus
  An ascus is the sexual spore-bearing cell produced in ascomycete fungi. On average, asci normally contain eight ascospores, produced by a meiotic cell division followed, in most species, by a mitotic cell division. However, asci in some genera or species can number one , two, four, or multiples...
  
   However re-examination of the doubtful "ascus" in Aiteng ater is necessary, because examination of 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 with 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.

This species lacks several acochlidian characteristics:

• it has no shell
  Gastropod shell
  The gastropod shell is a shell which is part of the body of a gastropod or snail, one kind of mollusc. The gastropod shell is an external skeleton or exoskeleton, which serves not only for muscle attachment, but also for protection from predators and from mechanical damage...
  
  
• no tentacle
  Tentacle
  A tentacle or bothrium is one of usually two or more elongated flexible organs present in animals, especially invertebrates. The term may also refer to the hairs of the leaves of some insectivorous plants. Usually, tentacles are used for feeding, feeling and grasping. Anatomically, they work like...
  
  s
• no gill
  Gill
  A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
  
  s
• no cerata
  Cerata
  Cerata are anatomical structures found in nudibranch sea slugs, marine opisthobranch gastropod mollusks.They are dorsal and lateral outgrowths on the upper surfaces of the body....
  
  
• 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)
• it lacks the ability to retract the head-foot complex into the visceral hump.

Aiteng ater has a notum

Notum

The notum is the dorsal portion of an insect's thoracic segment. It is typically a single large sclerite. It can be further divided into the alinotum which bears the wings and the postnotum which bears the phragma....

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

Ecology

Aiteng ater is an amphibious species which lives in mangrove forests in the intertidal zone

Intertidal zone

The intertidal zone is the area that is above water at low tide and under water at high tide . This area can include many different types of habitats, with many types of animals like starfish, sea urchins, and some species of coral...

, 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

Insect

Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...

s, (is insectivorous). In the laboratory it has been observed to eat pupae of beetles (Coleoptera), pupae of Lepidoptera

Lepidoptera

Lepidoptera is a large order of insects that includes moths and butterflies . It is one of the most widespread and widely recognizable insect orders in the world, encompassing moths and the three superfamilies of butterflies, skipper butterflies, and moth-butterflies...

, imagos of mosquitos and larvae of ant

Ant

Ants are social insects of the family Formicidae and, along with the related wasps and bees, belong to the order Hymenoptera. Ants evolved from wasp-like ancestors in the mid-Cretaceous period between 110 and 130 million years ago and diversified after the rise of flowering plants. More than...

s.

Inside the bodies of Aiteng ater there were found to be white elongated endoparasites; these are as yet unstudied. However the "parasites" described for Aiteng ater might represent spicules instead, because the presence of spicules is confirmed for undescribed species Aitengidae sp. from Japan.