Myrmarachne+plataleoides+(Kerengga+Ant-like+Jumper)

You think that it’s an ant? Look again! It’s an Ant-mimicking spider!

Scientific name: [|Myrmarachne plataleoides (O. P.-Cambridge, 186][|9)]

Common name: Kerengga Ant-like Jumper ==

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Etymology
- Origin of the genus In Anci//e//nt Greek myrmex means “ant” and “arachne” means spider.

1. How can a spider look like an Ant?!
A typical spider has two segmented body – the abdomen and cephalothorax. For Myrmarachne plataleoides, the carapace is skinny; giving it a three-segmented body look similar to a typical ant look (Mclver & Stonedahl 1993). It also has black pigments at the sides of the heads to resemble the larger eyes of the ants (Maderspacher, 2011).To reinforce their mimicry, they wave their first pair of legs in the air while moving so as to portray an “antennal illusion” (Mathew 1954; Edmunds, 1978; Jackson 1986).

[Image of a comparison of typical spider and //Myrmarachne plataleoides]//

1.2 What is the purpose for looking like an ant?
Myrmarachne plataleoides are batesian mimics of Ant Weaver (Oecophylla smaragdina) which are known to be aggressive, give painful bites and attack together (Holldobler and Wilson 1990). Batesian mimics mean that harmless mimics (Myrmarachne plateleoides) look like their unpalatable models (Ant Weavers) (Edmunds 1972, 1993; Cushing 1997).

With the combination of both behavioural and morphological mimicry, they deceive potential araneophagic (spider-eating) predators and gain protection (Edmunds 1993; Nelson et al. 2004; Nelson et al. 2005).

[Video of //Mp// locomotion]

1.3 Do you know that Juveniles (Young Myrmarachne plataleoides) look like other ant species?
Juveniles mimic different ant species at different stages of growth. This is known as transformational mimicry (Mathew, 1934, 1940, 1954; Bhattacharya, 1938; Marson, 1947).

What is more fascinating is that: They seem to display different transformational mimicry in different parts of Asia.


 * In one part of India, early instars being dark brown or blackish are found to resemble small black ant Prenolepis (Mathew, 1934) while larger instars resemble Solenopsis
 * In another part of India, the first three instars mimic Solenopsis geminata whereas the fourth instars mimic Plagiolepis longipes (Bhattacharya, 1938)
 * In Malaysia and Singapore, the late instars (developmental stage between each molt until sexual maturity is reached) appear to mimic small Ocecophylla and the orange ant Anoplolepis which is associated with Oecophylla (Edmunds, 2006).

1.4 You can actually tell differentiate adults Female and Male at one look!
Their genders could only be determined when they are sexually matured adults.

The males have enlarged and elongated chelicerae of about five times longer than those of females. This can increase the male’s length by 50-70% (Pollard, 1994)! Due to their elongated chelicerae, they resemble Ant Weavers less. In addition, thetips of their chelicerae have a black spot which has been suggested that they look like ants’ eyes so the males actually mimic worker Ant Weaver carrying a dead ant.

For females, look at: Epigyne (on the underside of female’s abdomen) For males, look at: Pedipalps of the males under the microscope for accurate differentiation.
 * One can also look at their genitals under the microscope to tell if it is a boy or a girl! **

[Image of the Epigyne and Pedipalps drawings]

In the family Salticidae (Jumping spiders), Myrmarachne is one of the largest genera with currently 217 species described (Platnick, 2013). You can identify different Myrmarachne species by looking at their epigyne or pedipalps too!
 * Do you know?: **

[Images of other species Epigyne and pedipalp drawings]

1.5 Learn to recognize Myrmarachne plataleoides from Ant Weavers
Although they live close to their hostile ant model – Ant Weavers and mimic ants, this close association can be life-threatening for them. Hence they will avoid ants upon sighting.

Their first pairs of legs come from beneath their cephalothorax to act as antenna || Present Come out from the top of their heads ||
 * || **Kerengga Ant-like Jumper** || **Ant Weavers** ||
 * Antenna || Absent
 * Abdomen ||  ||   ||
 * Eyes and location || Two pairs of eyes at the front of the head

Two pairs of eyes at the side || Only one pair of eyes at the side ||
 * Ability to Jump || Yes

Being part of the Salticidae (Jumping spiders) family, they have the ability to jump while leaving a dragline. This enables them to escape from potential predators quickly upon sighting any with their exceptional spatial acuity (Nelson & Jackson, 2006a).

However jumping is usually their last resort escape plan as they do not want to be detected as non-Ant (Jackson, 1994). || No || Run to the underside of the leaves (Marson, 1946) or jump away and do not bite! || Aggressive and defensive Open up their jaws in an erected posture ||
 * Personality || Gentle and timid
 * Sociality || Usually solitary

|| Form colonies

||
 * Nest || * Silk produced from individual spinnerets
 * On the underside or upper side of just one leaf
 * Tend to have a woolly and fluffy texture (Jackson,1994) || * Silk produced from last instar ant larvae (Wilson & Holldobler, 1980)
 * A cluster of leaves stuck together

||

[Image of Mp among ant weaver]
 * Now let's spot the Ant-mimic spider and share your new knowledge with your friends! **

2. Habitats
They can be found on shrubs or tree trunks at the forest edges or at the parks.

2.1 Countries
They are widely distributed in India,Sri Lanka,Kerala, China, Singapore, Malaysia, Thailand and Southeast Asia (Hill, 2010). Usually when you see Ant Weavers, you can try to look out for them too!

2.2 In Singapore
[Map]

3. Feeding behavior
They are generalist predators of insects but do not prey on ants (Jackson & Pollard 1996).

3.1 Prey capture (Pollard, 1994)
Due to the modified chelicerae in male Myrmarachne plataleoides, their fang ducts have been lost and they cannot immobilize prey with venom. Furthermore, they cannot insert fangs into prey as soon as they land on them. As a result, large and moving prey can escape from males more easily than females (Jackson, 1986).


 * || Females || Males ||
 * Fang duct on the tip of each fang || Present || Absent ||
 * Capture to Feeding |||| Prey ||  ||   ||   ||   ||
 * || [[image:http://taxo4254.wikispaces.com/site/embedthumbnail/placeholder?w=200&h=50]] ||
 * ||^  ||   || [[image:http://taxo4254.wikispaces.com/site/embedthumbnail/placeholder?w=200&h=50]] ||




 * || Insert fangs into prey’s body
 * || Insert fangs into prey’s body

↓

Immediately inject venom

↓

Digestive fluid enter into the prey’s cuticle through openings between the junction of the basal segments and fangs || Basal segments of chelicerae spread apart by 45o and the fangs extend out from their relaxing position

↓

Cephalothorax on top of the prey’s body to restrain prey and chelicerae extended forward of the prey’s body

↓

Fangs penetrate the cuticle of the prey until the tip of the fangs protrude through the other side into the spider’s mouth

↓

Digestive fluid exit from fang tips into the skewered prey ||
 * ^  |||| Digestion and extract nutrients! ||

4.2 Predators
They get eaten by araneophagic (spider-eating) predators such as Ants, mantises and even salticids (Nelson et al., 2006).

They also deceive myrmecophagic (ant-eating) spiders hence they get eaten by these mymecophagic salticids. However, if they manage to fully extend their forelegs 45o to the side and elevate their legs at 45 degrees (also known as the erect-legs posture (Jackson, 1982)) to show ant-eating spiders that they are not ants in time, they can escape (Nelson et al., 2006)!
 * Do you know? **

5. Conservation status
The IUCN red list has not evaluated Myrmarachne plataleoides threat status.

** 6.11 Cohabitation **
Males will build a translucent nest beside the densely woven and completely opaque nest of a sub-adult (one more moult to become sexually matured) female. After the female moults to become sexually matured, the male will enter her nest to mate with her. Females are more willing to mate at the nests rather than away.



** 6.12 Courtship away from the nest **
The males will arch their palps and lower their bodies, twitching their abdomens when they face the females. Then they will continue posturing either stationary or walking. They will chase or block the females if they run away. Sometimes they will even do a Zigzag dance to mesmerize the females.

media type="custom" key="24405624" width="389" height="389" align="center"
 * Watch how the male Jumping spider charms the female Jumping spider to mate with him! It is more than just visual display!**

** 6.13 Mating **
Mating occurs when the palps of the male applies to the epigyne of the female. When this happens, the male is always beside the female and orientated 180 degree to each other. Sometimes, the male will alternate different sides of his palps by freeing from her and moving to the other side of her. The females will remain stationary when the males apply their palps.

** 6.14 Male-male competition **
**Two male ant-mimic spiders wrestling! See how fierce they can be.** media type="custom" key="24406546" width="368" height="368" align="center"

** 6.15 Parental care **
The female will weave dense opaque nest over her nest first followed by another layer over herself. She will then continue to stay in the nest until the eggs hatch into spiderlings and come out occasionally to hunt. Upon hatching, the spiderlings will to continue to stay in the nest for a week or so to develop until they are ready to leave! As they are really tiny, they will feed on nectar and they can actually weave really tiny nest over themselves too!



7. Taxonavigation

 * Kingdom || Animalia ||
 * Phylum || Arthropoda ||
 * Class || Arachnida ||
 * Order || Araneae ||
 * Suborder || Araneomorphae ||
 * Family || Salticidae ||
 * Subfamily || Myrmarachninae ||
 * Genus || Myrmarachne ||
 * Species || Myrmarachne plataleoides ||

8. Taxonomy history
Myrmarachne plataleoides (Pickard-Cambridge O., 1869)is an accepted name. (Catalogue of life)

8.1 Synonymised taxa
Only one correct scientific name is accepted at any one time in taxonomy. However, sometimes, the same taxon is named more than once independently or there is a change in the existing taxa (for instance, two genera are merged to become one). This results in synonyms (inappropriate scientific name of the same species). Myrmarachne daitarensis Prószynski, 1992 (synonym) Myrmarachne plataleoides Simon, 1901 (synonym) Salticus plataleoides Pickard-Cambridge O., 1869 (synonym)

** 8.2 Type information **
Holotype information is unknown. However one specimen can be found in Salticidae (Araneae) of India in the collection of the Hungarian National Natural History Museum in Budapest.

9. References
Bhattacharya, G.C., 1938. On the moulting and metamorphosis of Myrmarachne plataleoides, Camb. Transactions of the Bose Institute, Calcutta 12: 103–114. Cushing PE. 1997. Myrmecomorphy and myrmecophily in spiders:a review. Fla Entomol 80:165–93. Edmunds ME. 1972. Defensive behavior in Ghanaian preying mantids. Zool J Linn Soc 51:1–32. Edmunds, M., 1978. On the association between Myrmarachne spp. (Salticidae) and ants. Bulletin of the British Arachnological Society 4: 149–160. Edmunds, M., 2006. Do Malaysian Myrmarachne associate with particular species of ant? Biological Journal of the Linnean Society 88: 645–653 Edmunds, M., 1993. Does mimicry of ants reduce predation by wasps on salticid spiders? Memoirs of the Queensland Museum 33:507-512. Hill, D.E., 2010. Sunda to Sahul: Trans-Wallacean distribution of recent salticid genera (Araneae: Salticidae). PECKHAMIA 80.1: 1―60 Holldobler B, Wilson EO. 1990. The ants. Heidelberg, Germany: Springer-Verlag. Jackson, R.R., 1982. The biology of ant-like jumping spiders: Intraspecific interactions of Mymarachne lupata (Araneae: Salticidae). Zoological Journal of the Linnean Society 76: 293-319. Jackson, R.R., 1986. The biology of ant-like jumping spiders (Araneae:Salticidae): prey and predatory behaviour of Myrmarachne with particular attention to M. lupata from Queensland. Zoological Journal of the Linnean Society 88:179-190. Jackson, R.R, 1994. The comparative study of the predatory behaviour of Myrmarachne, ant-like jumping spiders (Araneae: Salticidae).Zoological Journal of the Linnean Society 110: 77-102. Jackson, R. R. & Pollard, S. D., 1996. Predatory behavior of jumping spiders. Annu. Rev. Entomol. 41:287–308 Marson, J.E., 1947. The ant mimic Myrmarachne plataleoides. Journal of the East African Natural History Society 19: 62– 63. Mathew, A.P., 1934. The life-history of the spider (Myrmarachne plataleoides) (Cambr). Journal of the Bombay Natural History Society 37: 369–374. Mathew, A.P., 1940. A study of the courting habits of Myrmarachne plataleoides (Cambr.) − a spider mimic of the Indianred-ant Oecophylla smaragdina. Journal of the Bombay Natural History Society 42: 171–180. Mathew, A.P., 1954. Observations on the habits of two spider mimics of the red ant, Oecophylla smaragdina (Fabr.). Journal of the Bombay Natural History Society 52: 249–263. Maderspacher, F., 2011. Myrmecomorphomania. Current Biology 21: R291-R293. Mclver, J.D. & G. Stonedahl. 1993. Myrmecomorphy: morphological and behavioural mimicry of ants. Annual Review of Entomology 38:351-379. Nelson, X.J.,Jackson, R.R, Pollard, S.D, Edwards, G.B & Barrion, A.T., 2004. Predation by ants on jumping spiders (Araneae : Salticidae) in the Philippines. New Zealand Journal of Zoology 31:45-56. Nelson, X.J., Jackson, R.R, Pollard, S.D, Edwards, G.B & Barrion, A.T., 2005. Living with the enemy: jumping spiders that mimic weaver ants. Journal of Arachnology 33:813-819. Nelson, X.J., Jackson, R.R. & Li, D., 2006. Conditional use of honest signaling by a Batesian mimic. Behavioral Ecology 17: 575-580. Nelson, X. J. & Jackson, R. R., 2006a. Vision-based innate aversion to ants and ant mimics. Behav. Ecol. 17: 676–681 Nelson, X.J., Jackson, R.R., Li, D., Barrion, A.T. & Edwards, G.B., 2006. Innate aversion to ants (Hymenoptera: Formicidae) and ant mimics: experimental ﬁndings from mantises (Mantodea), Biological Journal of the Linnean Society 88: 23–32 Platnick, N. I., 2013. The world spider catalog, version 14.0. American Museum of Natural History, online at http: research.amnh.org/entomology/spiders/catalog/index.html. Pollard, S.D., 1994. Consequences of sexual selection on feeding in male jumping spiders (Araneae: Salticidae). The Zoological Society of London 234 :203-208 Wilson, E.O. & Holldobler, B., 1980. Sex differences in cooperative silk-spinning by weaver ant larvae. National Academy of Sciences of the United States of America 77: 2343-2347. Conservation status of Myrmarachne// plataleoides. The IUCN Red List of threatened species. [Online] Accessed from http://www.iucnredlist.org/search []