''Omalonyx convexus'' is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of air-breathing
land snail
A land snail is any of the numerous species of snail that live on land, as opposed to the sea snails and freshwater snails. ''Land snail'' is the common name for terrestrial gastropod mollusks that have shells (those without shells are known as ...
, a
terrestrial
Terrestrial refers to things related to land or the planet Earth.
Terrestrial may also refer to:
* Terrestrial animal, an animal that lives on land opposed to living in water, or sometimes an animal that lives on or near the ground, as opposed to ...
pulmonate
Pulmonata or pulmonates, is an informal group (previously an order, and before that a subclass) of snails and slugs characterized by the ability to breathe air, by virtue of having a pallial lung instead of a gill, or gills. The group includ ...
gastropod
The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda ().
This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...
mollusc
Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is esti ...
in the
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Succineidae
Succineidae are a family of small to medium-sized, air-breathing land snails (and slugs), terrestrial pulmonate gastropod molluscs in the superfamily Succineoidea.MolluscaBase eds. (2021). MolluscaBase. Succineidae Beck, 1837. Accessed thr ...
, the amber snails. This species of snail is found on emergent vegetation in
lentic
A lake ecosystem or lacustrine ecosystem includes biotic component, biotic (living) plants, animals and micro-organisms, as well as abiotic component, abiotic (non-living) physical and chemical interactions. Lake ecosystems are a prime example ...
environments, and also submerged among
macrophytes
Aquatic plants are plants that have adapted to living in aquatic environments (saltwater or freshwater). They are also referred to as hydrophytes or macrophytes to distinguish them from algae and other microphytes. A macrophyte is a plant that g ...
.
Distribution
The distribution of ''Omalonyx convexus'' includes
Brazil
Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...
.
Description
''Omalonyx convexus'' can be up to 4 cm in total length.
Tegument and
mantle
A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that.
Mantle may refer to:
*Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear
**Mantle (vesture), an Eastern Orthodox ve ...
coloring varies between milky-white, orange and beige.
The tegument and mantle have irregularly sized and distributed blackish spots, which, depending on their quantity, can sometimes give the animal a dark gray appearance.
Beige was the most commonly observed coloring (Arruda & Thomé).
Because of their translucence, milky-white individuals sometimes display the same coloring as the
substrate.
Because of its wide variability in color, ''Omalonyx convexus'' can be confused with other ''
Omalonyx
''Omalonyx'' is a genus of air-breathing land snails, terrestrial pulmonate gastropod molluscs in the family Succineidae, the amber snails. These snails are amphibious, living very close to water and moving around both on emergent plants and also ...
'' species: ''
Omalonyx matheroni'', ''
Omalonyx pattersonae
''Omalonyx'' is a genus of air-breathing land snails, Terrestrial animal, terrestrial pulmonate gastropod molluscs in the family (biology), family Succineidae, the amber snails. These snails are amphibious, living very close to water and moving a ...
'' and ''
Omalonyx unguis
''Omalonyx unguis'' is a species of air-breathing land snail, a terrestrial pulmonate gastropod mollusc in the family Succineidae, the amber snails.
Distribution
The distribution of ''Omalonyx unguis'' includes:
* Argentina
*Brazil
*Paraguay
...
''.
The
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
** Thin-shell structure
Science Biology
* Seashell, a hard ou ...
is translucent with a slightly amber tint, and it can be covered by the mantle to various extents. The shell was not completely covered by the mantle in any of the specimens observed by Arruda and Thomé.
Ecology
Habitat
Arruda and Thomé found this species in both clean and polluted freshwater environments (polluted by household
sewage
Sewage (or domestic sewage, domestic wastewater, municipal wastewater) is a type of wastewater that is produced by a community of people. It is typically transported through a sewer system. Sewage consists of wastewater discharged from residenc ...
), as well as on both natural and artificial substrates.
The habitat of ''Omalonyx convexus'' includes vegetation bordering ditches used for rice paddy irrigation, drainage ditches,
floodplain
A floodplain or flood plain or bottomlands is an area of land adjacent to a river which stretches from the banks of its channel to the base of the enclosing valley walls, and which experiences flooding during periods of high discharge.Goudi ...
s, lakes, rivers and streams. The species was also found on the dry portion of a semi-submerged tree in a temporarily flooded location.
These snails are mainly seen on the macrophytes ''
Eicchornia azurea'', ''
Salvinia auriculata'', ''
Pistia stratiotis'' and ''
Eryngium
''Eryngium'' is a genus of flowering plants in the family Apiaceae. There are about 250 species.Wang, P., et al. (2012)Phytochemical constituents and pharmacological activities of ''Eryngium'' L. (Apiaceae). ''Pharmaceutical Crops'' 3 99-120. The ...
'' species, but they were also found on artificial substrates such as canvas, cardboard, plastic bottles, tetra-pak boxes and
styrofoam
Styrofoam is a trademarked brand of closed-cell extruded polystyrene foam (XPS), commonly called "Blue Board", manufactured as foam continuous building insulation board used in walls, roofs, and foundations as thermal insulation and water barrie ...
.
Arruda & Thomé reported that the snails are found on different substrate areas during the course of the day, a behavioral adaptation to guard against
desiccation
Desiccation () is the state of extreme dryness, or the process of extreme drying. A desiccant is a hygroscopic (attracts and holds water) substance that induces or sustains such a state in its local vicinity in a moderately sealed container.
...
, since apparently the temperature change influences their choice of habitat substrates. In the early morning (between 7 a.m. and 10 a.m.) and at the end of the afternoon (between 4 p.m. and 6 p.m.) during sunny days, the animals were observed on the stem and on the