Myrmarachne plataleoides
Encyclopedia
Myrmarachne plataleoides, also called the Kerengga Ant-like Jumper, is a jumping spider that mimic
Mimic
In evolutionary biology, mimicry is the similarity of one species to another which protects one or both. This similarity can be in appearance, behaviour, sound, scent and even location, with the mimics found in similar places to their models....

s the Kerengga or weaver ant
Weaver ant
Weaver ants or Green ants are eusocial insects of the family Formicidae . Weaver ants are obligately arboreal and are known for their unique nest building behaviour where workers construct nests by weaving together leaves using larval silk...

 (Oecophylla smaragdina
Oecophylla smaragdina
Oecophylla smaragdina is a species of arboreal ant found in Asia and Australia. They make nests in trees made of leaves stitched together using the silk produced by their larvae.Weaver ants may be red or green...

) in morphology and behaviour. This species is found in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...

, Sri Lanka
Sri Lanka
Sri Lanka, officially the Democratic Socialist Republic of Sri Lanka is a country off the southern coast of the Indian subcontinent. Known until 1972 as Ceylon , Sri Lanka is an island surrounded by the Indian Ocean, the Gulf of Mannar and the Palk Strait, and lies in the vicinity of India and the...

, China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...

 and many parts of Southeast Asia
Southeast Asia
Southeast Asia, South-East Asia, South East Asia or Southeastern Asia is a subregion of Asia, consisting of the countries that are geographically south of China, east of India, west of New Guinea and north of Australia. The region lies on the intersection of geological plates, with heavy seismic...

.

Unlike the weaver ants, M. plataleoides does not bite people, and indeed seems rather timid.

Description

M. plataleoides, especially the females, mimic
Mimic
In evolutionary biology, mimicry is the similarity of one species to another which protects one or both. This similarity can be in appearance, behaviour, sound, scent and even location, with the mimics found in similar places to their models....

 the Weaver Ants in size, shape and colour. The body of the M. plataleoides appears like an ant, which has three body segments and six legs, by having constrictions on the cephalothorax
Cephalothorax
The cephalothorax is a tagma of various arthropods, comprising the head and the thorax fused together, as distinct from the abdomen behind. The word cephalothorax is derived from the Greek words for head and thorax...

 and abdomen
Abdomen
In vertebrates such as mammals the abdomen constitutes the part of the body between the thorax and pelvis. The region enclosed by the abdomen is termed the abdominal cavity...

. This creates the illusion of having a distinct head, thorax
Thorax
The thorax is a division of an animal's body that lies between the head and the abdomen.-In tetrapods:...

 and gaster
Gaster
The gaster is the bulbous posterior portion of the metasoma found in Apocrita Hymenoptera . This begins with abdominal segment III on most ants, but some make a postpetiole out of segment III, in which case the gaster begins with abdominal segment IV....

 of the weaver ant, complete with a long and slender waist. The large compound eyes of the weaver ant are mimicked by two black patches on the head. The males resemble a larger ant carrying a smaller one.

The scientific name of the genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 literally translates as "ant spider".

Sexual dimorphism

Kerengga Ant-like Jumpers are sexually dimorphic
Sexual dimorphism
Sexual dimorphism is a phenotypic difference between males and females of the same species. Examples of such differences include differences in morphology, ornamentation, and behavior.-Examples:-Ornamentation / coloration:...

. Female jumpers, measuring about 6–7 mm, are the best mimics of the weaver ants while the males which usually measure about 9–12 mm in length give the appearance of a weaver ant carrying a minor worker due to their elongated chelicerae
Chelicerae
The chelicerae are mouthparts of the Chelicerata, an arthropod subphylum that includes arachnids, Merostomata , and Pycnogonida . Chelicerae are pointed appendages which are used to grasp food, and are found in place of the chewing mandibles most other arthropods have...

which may be as long as one-third to half their body length. These elongated chelicerae are a secondary sexual characteristic of the males. The males use their long fangs like swords to fight off rivals. They can split their jaws, normally held close, to unfold their fangs when required.

Behaviour

The spiders live in trees and bushes where the weaver ants live in colonies. By mimicking the ants they are able to stay close to them and gain protection from predators. Since weaver ants have a painful bite and also taste bad, this strategy appears to be successful. Though these spiders mimic the weaver ants very well they are known to stay away from them. They weave a thin web on leaves, hide under their webbing and ambush their prey.

The Kerengga Ant-like Jumper also mimics ant-like behaviour by the style of locomotion and by the way they wave their front legs like antennae to mimic the ants. These jumping-spiders jump only when their safety is threatened.
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