Theodoxus altenai 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 freshwater snail

Freshwater snail

A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....

 with a 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...

 and an operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

. It is an aquatic

Aquatic animal

An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 gastropod mollusk in the family Neritidae, the nerites.

Distribution

Distribution of this species include Antalya Province

Antalya Province

Antalya Province is located on the Mediterranean coast of south-west Turkey, between the Taurus Mountains and the Mediterranean sea.Antalya Province is the centre of Turkey's tourism industry, attracting 30% of foreign tourists visiting Turkey. The province of Antalya corresponds to the lands of...

, southern Turkey.

The type locality is lake near Döşemealti, Antalya Province

Antalya Province

Antalya Province is located on the Mediterranean coast of south-west Turkey, between the Taurus Mountains and the Mediterranean sea.Antalya Province is the centre of Turkey's tourism industry, attracting 30% of foreign tourists visiting Turkey. The province of Antalya corresponds to the lands of...

, Turkey.

Description

The 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...

 is exceptionally thin, light horny yellowish, translucent and shiny. Whorls

Whorl (mollusc)

A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in of numerous gastropods, but it is also found in shelled cephalopods including Nautilus, Spirula and the large extinct subclass of cephalopods known as the...

 are flat and very rapidly increasing, with brown quadrangular color pattern. The operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

is reddish, without apophysis.

The width of the shell is 9.0-10.0 mm. The height of the shell is 6.0 - 7.0 mm.