Stenaelurillus Modestus
   HOME

TheInfoList



OR:

''Stenaelurillus modestus'' is a
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
jumping spider Jumping spiders are a group of spiders that constitute the family (biology), family Salticidae. , this family contained over 600 species description, described genus, genera and over 6,000 described species, making it the largest family of spide ...
in the
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
'' Stenaelurillus'' that lives in South Africa. The species is a specialist that preys on '' Odontotermes'' termites, although its venom is also effective against other prey. The spider is medium-sized, with a brown
cephalothorax The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cepha ...
between in length and a black
abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...
between long. It is generally black or dark brown in colour. The
carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...
has a border of white hairs and the abdomen is edged with bristles. The male has white patches on its abdomen. The male has darker
legs A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element cap ...
, generally dark brown or black, while the female has brownish-yellow legs. It is distinguished from other members of the genus by the male's elongated
palpal bulb The two palpal bulbs – also known as palpal organs and genital bulbs – are the copulatory organs of a male spider. They are borne on the last segment of the pedipalps (the front "limbs" of a spider), giving the spider an appearance often descr ...
and straight
embolus An embolus (; : emboli; from the Greek ἔμβολος "wedge", "plug") is an unattached mass that travels through the circulatory system, bloodstream and is capable of creating blockages. When an embolus Vascular occlusion, occludes a blood vess ...
, and the horseshoe-shaped depression in the female's
epigyne The epigyne or epigynum is the external genital structure of female spiders. As the epigyne varies greatly in form in different species, even in closely related ones, it often provides the most distinctive characteristic for recognizing species. ...
. It was first described in 2014 by
Wanda Wesołowska Wanda Wesołowska (born 11 August 1950) is a Polish zoologist known for her work with jumping spiders. She has described more species of jumping spider than any contemporary writer, and is second only to Eugène Simon in the history of arachnolo ...
.


Taxonomy

''Stenaelurillus modestus'' is a
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
of
jumping spider Jumping spiders are a group of spiders that constitute the family (biology), family Salticidae. , this family contained over 600 species description, described genus, genera and over 6,000 described species, making it the largest family of spide ...
, a member of the
family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...
Salticidae Jumping spiders are a group of spiders that constitute the family (biology), family Salticidae. , this family contained over 600 species description, described genus, genera and over 6,000 described species, making it the largest family of spide ...
, that was first described by the Polish
arachnologist Arachnology is the scientific study of arachnids, which comprise spiders and related invertebrates such as scorpions, pseudoscorpions, harvestmen, ticks, and mites. Those who study spiders and other arachnids are arachnologists. More narrowly ...
Wanda Wesołowska Wanda Wesołowska (born 11 August 1950) is a Polish zoologist known for her work with jumping spiders. She has described more species of jumping spider than any contemporary writer, and is second only to Eugène Simon in the history of arachnolo ...
in 2014. It is one of over 500 species identified by the Polish
arachnologist Arachnology is the scientific study of arachnids, which comprise spiders and related invertebrates such as scorpions, pseudoscorpions, harvestmen, ticks, and mites. Those who study spiders and other arachnids are arachnologists. More narrowly ...
. She placed it in the
genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
'' Stenaelurillus'', which was first
circumscribed In geometry, a circumscribed circle for a set of points is a circle passing through each of them. Such a circle is said to ''circumscribe'' the points or a polygon formed from them; such a polygon is said to be ''inscribed'' in the circle. * Circum ...
by
Eugène Simon Eugène Louis Simon (; 30 April 1848 – 17 November 1924) was a French naturalist who worked particularly on insects and spiders, but also on birds and plants. He is by far the most prolific spider Taxonomy (biology), taxonomist in history, ...
in 1886. The name relates to the genus name '' Aelurillus'', which itself derives from the Greek word for cat, with the addition of a Greek stem meaning narrow. The
species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
name is a
Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
word that can be translated modest.
Wayne Maddison Wayne Paul Maddison (born 1958) is a Canadian evolutionary biologist, arachnologist, and biological illustrator. He is Canada Research Chair in Biodiversity and a professor at the departments of zoology and botany at the University of British ...
placed the genus in the subtribe Aelurillina in the
tribe The term tribe is used in many different contexts to refer to a category of human social group. The predominant worldwide use of the term in English is in the discipline of anthropology. The definition is contested, in part due to conflict ...
Aelurillini in his 2015 study of spider phylogenetic classification, which was allocated to the
clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...
Saltafresia. In 2017,
Jerzy Prószyński Jerzy Prószyński (born 1935 in Warsaw) is a Polish arachnologist specializing in systematics of jumping spiders (family Salticidae). He is a graduate of the University of Warsaw, a long-term employee of the Siedlce University of Natural Sc ...
grouped it with nine other genera of jumping spiders under the name Aelurillines.


Description

The spider is medium-sized. The spider's body is divided into two main parts: a rather rounded almost rectangular
cephalothorax The cephalothorax, also called prosoma in some groups, is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. (The terms ''prosoma'' and ''opisthosoma'' are equivalent to ''cepha ...
and more pointed and ovoid
abdomen The abdomen (colloquially called the gut, belly, tummy, midriff, tucky, or stomach) is the front part of the torso between the thorax (chest) and pelvis in humans and in other vertebrates. The area occupied by the abdomen is called the abdominal ...
. The male has a cephalothorax that measures between in length and between in width. The spider's
carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...
, the hard upper part of the cephalothorax, is a black oval that is covered in dense dark hairs. It has a border of white hairs on the edge and two white streaks that stretch from eye field back. The underside of the cephalothorax, or
sternum The sternum (: sternums or sterna) or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major bl ...
, is yellow-brown. The clypeus and cheeks are brown, crossed with two stripes of white hairs and narrow stripes of white hairs on the sides. The spider's mouthparts, including the
chelicerae The chelicerae () are the arthropod mouthparts, mouthparts of the subphylum Chelicerata, an arthropod group that includes arachnids, horseshoe crabs, and sea spiders. Commonly referred to as "jaws", chelicerae may be shaped as either articulated ...
, labium and
maxillae In vertebrates, the maxilla (: maxillae ) is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxillar ...
, are brown. Dark brown hairs cover the chelicerae. The spider's abdomen is shaped like a shield, black with large white patches. Some specimens have a pattern of six large pale yellow spots in two rows and two white patches in the middle. It is between long and wide. It has long bristles on its edge. The
spinnerets A spinneret is a silk-spinning organ of a spider or the larva of an insect. Some adult insects also have spinnerets, such as those borne on the forelegs of Embioptera. Spinnerets are usually on the underside of a spider's opisthosoma, and ar ...
are black or yellow and brown. The
legs A leg is a weight-bearing and locomotive anatomical structure, usually having a columnar shape. During locomotion, legs function as "extensible struts". The combination of movements at all joints can be modeled as a single, linear element cap ...
are dark brown or brown. The
pedipalp Pedipalps (commonly shortened to palps or palpi) are the secondary pair of forward appendages among Chelicerata, chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to ...
s are also brown. The spider has distinctive male copulatory organs. It has a dark brown cymbium that is covered in dark hairs. The
palpal bulb The two palpal bulbs – also known as palpal organs and genital bulbs – are the copulatory organs of a male spider. They are borne on the last segment of the pedipalps (the front "limbs" of a spider), giving the spider an appearance often descr ...
is elongated and has a pointed projection to its base and another to the top. The thin
embolus An embolus (; : emboli; from the Greek ἔμβολος "wedge", "plug") is an unattached mass that travels through the circulatory system, bloodstream and is capable of creating blockages. When an embolus Vascular occlusion, occludes a blood vess ...
projects from inside and loops around to run straight along the bulb. There is a pointed projection, or apophysis, on the palpal tibia. It can be distinguished from other members of the genus by its elongated palpal bulb, and straight embolus. Its embolus resembles that in species of the genus '' Phlegra''. The female is very similar to the male in colouration and shape. It is slightly larger, with a cephalothorax between long and wide and an abdomen between long and wide. It has a brown carapace with two lines of white scales running down it. The eye field is dark brown. The sternum is brown-yellow, as is the labium. Its clypeus and cheeks are light brown and have a scattering of light brown hairs on them. The spinnerets, legs and pedipalps are all brownish-yellow. Some specimens have brown legs with blackish rings on them. The abdomen lacks the white patch that is found on the male. In some specimens, the underside is mottled. The female copulatory organs are distinctive. The
epigyne The epigyne or epigynum is the external genital structure of female spiders. As the epigyne varies greatly in form in different species, even in closely related ones, it often provides the most distinctive characteristic for recognizing species. ...
as an ovoid plate on it and a deep pocket in a deep notch along its back edge. There are two copulatory openings that are spaced far from each other that lead to short insemination ducts and bean-like
spermatheca The spermatheca (pronounced : spermathecae ), also called ''receptaculum seminis'' (: ''receptacula seminis''), is an organ of the female reproductive tract in insects, e.g. ants, bees, some molluscs, Oligochaeta worms and certain other in ...
e. It is distinguishable from other species by the presence of a horseshoe-shaped depression in the epigyne and the particular path of the insemination ducts. The notch at the edge of the epigynal plate is also characteristic.


Behaviour

The species is a specialist hunter and preys on termites in the genus '' Odontotermes''. The spider captures its prey by a process of grasping and holding, injecting its capture with venom. Despite the spider being a specialist hunter, the venom is equally effective against other prey. It has been seen to attack and eat other species, including those of the
order Order, ORDER or Orders may refer to: * A socio-political or established or existing order, e.g. World order, Ancien Regime, Pax Britannica * Categorization, the process in which ideas and objects are recognized, differentiated, and understood ...
Isopoda Isopoda is an order of crustaceans. Members of this group are called isopods and include both aquatic species and terrestrial species such as woodlice. All have rigid, segmented exoskeletons, two pairs of antennae, seven pairs of jointed l ...
like ''
Porcellio scaber ''Porcellio scaber'' (otherwise known as the common rough woodlouse or simply rough woodlouse), is a species of woodlouse native to Europe but with a cosmopolitan distribution. They are often found in large numbers in most regions, with many spec ...
'' and '' Reticulitermes santonensis'' and both adults and lavae of
flies Flies are insects of the Order (biology), order Diptera, the name being derived from the Ancient Greek, Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwin ...
like ''
Drosophila hydei ''Drosophila hydei (mosca casera)'' is a species of Diptera, or the order of flies, in the family Drosophilidae. It is a species in the ''hydei'' species subgroup, a group in the ''repleta'' species group. Bizarrely, it is also known for having ...
''.


Distribution and habitat

The
distribution Distribution may refer to: Mathematics *Distribution (mathematics), generalized functions used to formulate solutions of partial differential equations *Probability distribution, the probability of a particular value or value range of a varia ...
is
endemic Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...
to South Africa. The
holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...
was identified in the Ndumo Game Reserve in
KwaZulu-Natal KwaZulu-Natal (, also referred to as KZN) is a Provinces of South Africa, province of South Africa that was created in 1994 when the government merged the Zulu people, Zulu bantustan of KwaZulu ("Place of the Zulu" in Zulu language, Zulu) and ...
based on a specimen collected in 2012. It prefers areas of leaf litter in broadleaf woodlands.


References


Citations


Bibliography

* * * * * * * * * {{Taxonbar, from=Q27505142 Endemic spiders of South Africa Salticidae Spiders described in 2014 Spiders of South Africa Taxa named by Wanda Wesołowska