''Plato'' is a genus of
ray spider
The ray spiders (Theridiosomatidae) are a family of spiders first described by Eugène Simon in 1881. They are most recognizable for their construction of cone-shaped webs.
The family contains several genera which actively hunt for prey by using ...
(family Theridiosomatidae). The American biologist
Jonathan A. Coddington
Jonathan A. Coddington is an American museum scientist and biologist. From 2009 to 2014 he was the Associate Director for Science at the Smithsonian National Museum of Natural History (NMNH), located in Washington, D.C., United States. , he is th ...
named and
circumscribed
In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius.
Not every polyg ...
the genus in 1986. It is a
Neotropical genus and it is limited to South America. , nine species are recognized. They are found in caves and have a distinctive cubic
egg sac. The
generic name comes from the ancient Greek philosopher
Plato
Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...
.
Description
![Plato eye group](https://upload.wikimedia.org/wikipedia/commons/7/74/Plato_eye_group.svg)
The head region of the carapace is tan, and not especially elevated. The sternum is also tan, sometimes darker, as wide as long, convex, and rounds towards the rear. The abdomen is light grey or tan, with no clear markings, and bears sparse setae. The legs are long and slender, pale tan in colour without annulations. Although the genus is
troglobitic, they have no specific modifications for living in caves or other dark places.
The
clypeal height is 3x the diameter of the AME. All of the eyes are roughly the same size, although the lateral eyes may be slightly smaller. The AME are separated by half their diameter, and the PME are separated by at least their diameter.
Diagnostic features include: the base of the
epigynum in female ''Plato'' species having a median projection; the
cymbium having distal or mesal groves; and the underside of the male
conductor having a curved
apophysis.
Habitat and distribution
''Plato'' is found in the
Neotropical realm
The Neotropical realm is one of the eight biogeographic realms constituting Earth's land surface. Physically, it includes the tropical terrestrial ecoregions of the Americas and the entire South American temperate zone.
Definition
In bioge ...
. Its range is limited to South America (including the island of
Trinidad
Trinidad is the larger and more populous of the two major islands of Trinidad and Tobago. The island lies off the northeastern coast of Venezuela and sits on the continental shelf of South America. It is often referred to as the southernmos ...
), within the countries Brazil, Ecuador, Trinidad & Tobago, and Venezuela, as well as in the French overseas region
French Guiana
French Guiana ( or ; french: link=no, Guyane ; gcr, label=French Guianese Creole, Lagwiyann ) is an overseas departments and regions of France, overseas department/region and single territorial collectivity of France on the northern Atlantic ...
.
Their
orb web
A spider web, spiderweb, spider's web, or cobweb (from the archaic word '' coppe'', meaning "spider") is a structure created by a spider out of proteinaceous spider silk extruded from its spinnerets, generally meant to catch its prey.
Spid ...
s hang from the ceilings and walls near the entrance of caves. They are typically found in humid environments, near streams or other bodies of water.
Behaviour
As with other ray spiders, ''Plato'' constructs an orb web, although their webs lack a tension line.
Their
egg sacs are cubical, and are suspended
in long threads from their vertices.
Each egg sac can contain between eight and seventeen eggs.
The diet of ''Plato'' species consists of small flying insects such as
chironomids
The Chironomidae (informally known as chironomids, nonbiting midges, or lake flies) comprise a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae. Many species s ...
and other flies,
tineid moth
Tineidae is a family of moths in the order Lepidoptera described by Pierre André Latreille in 1810. Collectively, they are known as fungus moths or tineid moths. The family contains considerably more than 3,000 species in more than 300 genera. ...
s, and
caddisflies.
Species
, the
World Spider Catalog
The World Spider Catalog (WSC) is an online searchable database concerned with spider taxonomy. It aims to list all accepted families, genera and species, as well as provide access to the related taxonomic literature. The WSC began as a series of ...
recognizes the following nine species:
* ''
P. bicolor''
— Brazil
* ''
P. bruneti''
— Trinidad
* ''
P. ferriferus''
— Brazil
* ''
P. guacharo''
— Venezuela
* ''
P. juberthiei''
— French Guiana
* ''
P. miranda''
— Venezuela
* ''
P. novalima''
— Brazil
* ''
P. striatus''
— Brazil
* ''
P. troglodita''
— Ecuador
Taxonomic history
Jonathan A. Coddington
Jonathan A. Coddington is an American museum scientist and biologist. From 2009 to 2014 he was the Associate Director for Science at the Smithsonian National Museum of Natural History (NMNH), located in Washington, D.C., United States. , he is th ...
, a biologist at the
National Museum of Natural History
The National Museum of Natural History is a natural history museum administered by the Smithsonian Institution, located on the National Mall in Washington, D.C., United States. It has free admission and is open 364 days a year. In 2021, with 7 ...
,
circumscribed
In geometry, the circumscribed circle or circumcircle of a polygon is a circle that passes through all the vertices of the polygon. The center of this circle is called the circumcenter and its radius is called the circumradius.
Not every polyg ...
the genus ''Plato'' in a 1986 revision of the family
Theridiosomatidae
The ray spiders (Theridiosomatidae) are a family of spiders first described by Eugène Simon in 1881. They are most recognizable for their construction of cone-shaped webs.
The family contains several genera which actively hunt for prey by using ...
. He designated ''P. troglodita'', which he
described in the same work, to be the
type species
In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...
of the genus. The other species he included in his initial circumscription had been initially described in the genera ''
Maymena
''Maymena'' is a genus of spiders in the family Mysmenidae. It was first described in 1960 by Gertsch. , it contains 13 species.
Species
''Maymena'' comprises the following species:
*''Maymena ambita'' (Barrows, 1940)
*''Maymena calcarata'' (Sim ...
'' (''P. bruneti'') and ''
Wendilgarda
''Wendilgarda'' is a genus of ray spiders that was first described by Eugen von Keyserling in 1886.
Species
it contains fourteen species and one subspecies, found in Asia, the Caribbean, Central America, São Tomé and Príncipe, Brazil, and Me ...
'' (''P. miranda'', ''P. guacharo'', and ''P. bicolor'').
André Lopez at the
Centre national de la recherche scientifique described ''P. juberthiei'' in 1996,
and Pedro H. Prete and colleagues at the
Instituto Butantan described the three species ''P. novalima'', ''P. ferriferus'', and ''P. striatus'' in 2018.
Coddington named the genus after the ancient Greek philosopher
Plato
Plato ( ; grc-gre, Πλάτων ; 428/427 or 424/423 – 348/347 BC) was a Greek philosopher born in Athens during the Classical period in Ancient Greece. He founded the Platonist school of thought and the Academy, the first institution ...
. Coddington's reasoning were their "strikingly cubical egg sacs" and their "partiality for caves."
These relate to the philosopher by way of the
Platonic solid
In geometry, a Platonic solid is a convex, regular polyhedron in three-dimensional Euclidean space. Being a regular polyhedron means that the faces are congruent (identical in shape and size) regular polygons (all angles congruent and all edges c ...
s and the
Allegory of the Cave, respectively. The
generic name is masculine in
gender
Gender is the range of characteristics pertaining to femininity and masculinity and differentiating between them. Depending on the context, this may include sex-based social structures (i.e. gender roles) and gender identity. Most cultures u ...
.
Coddington placed ''Plato'' in a new subfamily
Platoninae, alongside the genus ''
Chthonos
''Chthonos'' is a genus of South American ray spiders that was created by Jonathan A. Coddington in 1986 because the previous name was preoccupied. Originally placed with the Orb-weaver_spiders under the name ''Tecmessa'', it was transferred to ...
''.
In 2011, the German arachnologist changed the status of Platoninae to be the tribe Platonini in the subfamily
Theridiosomatinae instead,
although Prete and colleagues followed Coddington in having ''Plato'' in the subfamily ''Platoninae''.
See also
*
List of organisms named after famous people (born before 1800)
References
{{taxonbar, from=Q2667476
Araneomorphae genera
Theridiosomatidae