Faunus ater
Encyclopedia
Faunus ater is a species
of brackish water
snail with an operculum
, an aquatic
gastropod mollusk in the family Pachychilidae
.
Faunus ater is the only species within the genus Faunus.
is thick, and the color of the periostracum is dark brown or black. The shell has about 20 whorls
. The apical whorls may be eroded in older snails. The aperture
is ovate and white. The shell
is unique among Cerithioidea
, because it has two deep sinuses: an anal sinus which is close to the suture and an anterior sinus more forward in the aperture. The height of the aperture is about one-fifth of the height of the shell.
The height of the shell is usually 50-60 mm, but can be up to 90 mm.
The operculum
is oval, corneous
and dark brown in color.
The snail has a broad snout
. The radula
is large and is located in a correspondingly large buccal mass.
. It has also been reported from freshwater. It is the only pachychilid species that lives in brackish water; the other species in the family are freshwater snail
s.
The population density
can reach up to 6700 snails per m².
This snail probably feeds by grazing.
It is oviparous. It probably has free-swimming larvae.
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 brackish water
Brackish water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
snail with 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...
, 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 Pachychilidae
Pachychilidae
Pachychilidae, common name pachychilids, is a taxonomic family of freshwater snails, gastropod molluscs in the clade Sorbeoconcha.- Distribution :Pachychilids are freshwater snails with a worldwide distribution in the tropics...
.
Faunus ater is the only species within the genus Faunus.
Distribution
The distribution of Faunus ater includes:- India
- Sri Lanka
- Andaman Islands
- Myanmar
- Thailand
- Singapore
- Indonesia
- Philippines
- New Guinea
- western and southern Pacific IslandsPacific IslandsThe Pacific Islands comprise 20,000 to 30,000 islands in the Pacific Ocean. The islands are also sometimes collectively called Oceania, although Oceania is sometimes defined as also including Australasia and the Malay Archipelago....
: Solomon IslandsSolomon IslandsSolomon Islands is a sovereign state in Oceania, east of Papua New Guinea, consisting of nearly one thousand islands. It covers a land mass of . The capital, Honiara, is located on the island of Guadalcanal... - northern Australia
- China
Description
The periostracumPeriostracum
The periostracum is a thin organic coating or "skin" which is the outermost layer of the shell of many shelled animals, including mollusks and brachiopods. Among mollusks it is primarily seen in snails and clams, i.e. in bivalves and gastropods, but it is also found in cephalopods such as the...
is thick, and the color of the periostracum is dark brown or black. The shell has about 20 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...
. The apical whorls may be eroded in older snails. The aperture
Aperture (mollusc)
The aperture is an opening in certain kinds of mollusc shells: it is the main opening of the shell, where part of the body of the animal emerges for locomotion, feeding, etc....
is ovate and white. 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 unique among Cerithioidea
Cerithioidea
The Cerithioidea is a superfamily of marine, brackish water and freshwater gastropod containing more than 200 genera. The Cerithoidea are included in the clade Sorbeoconcha. The original name of this superfamily was Cerithiacea, in keeping with common superfamily endings at the time.- Ecology...
, because it has two deep sinuses: an anal sinus which is close to the suture and an anterior sinus more forward in the aperture. The height of the aperture is about one-fifth of the height of the shell.
The height of the shell is usually 50-60 mm, but can be up to 90 mm.
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 oval, corneous
Corneous
Corneous is a biological and medical term meaning horny, in other words made out of a substance similar to that of horns and hooves in some mammals....
and dark brown in color.
The snail has a broad snout
Snout
The snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...
. The radula
Radula
The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...
is large and is located in a correspondingly large buccal mass.
Ecology
This snail lives in slightly brackish waterBrackish water
Brackish water is water that has more salinity than fresh water, but not as much as seawater. It may result from mixing of seawater with fresh water, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root "brak," meaning "salty"...
. It has also been reported from freshwater. It is the only pachychilid species that lives in brackish water; the other species in the family are 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....
s.
The population density
Population density
Population density is a measurement of population per unit area or unit volume. It is frequently applied to living organisms, and particularly to humans...
can reach up to 6700 snails per m².
This snail probably feeds by grazing.
It is oviparous. It probably has free-swimming larvae.
Human use
This snail is used as a food source for humans in the Philippines and in Thailand.Further reading
- Gray J. E.John Edward GrayJohn Edward Gray, FRS was a British zoologist. He was the elder brother of George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray ....
(1867). "On the species of the genera Latiaxis, Faunus and Melanatria". American Journal of Conchology 3: 330. - Houbrick R. S. (1991). "Anatomy and systematic placement of Faunus Montfort 1810 (Prosobranchia: Melanopsinae)". Malacological Review 24: 35-54.
- Yap C. K., Hisyam M. N. D., Edward F. B., Cheng W. H. & Tan S. G. (2010). "Concentrations of heavy metal in different parts of the gastropod, Faunus ater (Linnaeus), collected from intertidal areas of Peninsular Malaysia". Pertanika Journal of Tropical Agricultural Science 33(1): 45-60.