Amblypygi

File:AmblypygiDorsal.jpg

File:Phrynichus phipsoni – Pocock, 1900.png

Being arachnids, Amblypygi possess two body-segments; the prosoma and the opisthosoma (often referred to as the cephalothorax and abdomen), four pairs of legs, pedipalps, and chelicerae. Their bodies are broad and highly flattened, with a solid prosoma and a segmented opisthosoma.

Amblypygids range from {{convert|5|to|16|cm|sp=us}} in legspan.{{cite journal |last1=Chapin |first1=KJ |last2=Hebets |first2=EA |year=2016 |title=Behavioral ecology of amblypygids |url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1056&context=bioscihebets |journal=Journal of Arachnology |volume=44 |issue=1 |pages=1–14 |doi=10.1636/V15-62.1 |s2cid=29923727|url-access=subscription }}{{Cite book |last1=Weygoldt |first1=Peter |title=Whip Spiders (Chelicerata: Amblypygi): Their Biology, Morphology and Systematics |publisher=Apollo Books |year=2000 |isbn=8788757463}} Most species have eight eyes; a pair of median eyes at the front of the carapace above the chelicerae and 2 smaller clusters of three eyes each further back on each side.

The first pair of legs act as sensory organs and are not used for walking. The sensory legs are very thin and elongated, have numerous sensory receptors, and can extend several times the length of the body.

Amblypygids have raptorial pedipalps modified for grabbing and retaining prey, much like the forelegs of mantisses.{{cite book |author=Robert D. Barnes |year=1982 |title= Invertebrate Zoology |publisher=Holt-Saunders International |location= Philadelphia, PA |pages= 617–619|isbn= 0-03-056747-5}} The pedipalps are generally covered in spines, used for impaling and capturing prey. They are kept folded in front of the prosoma when not in use. Recent work suggests that the pedipalps display sexual dimorphism in their size and shape.{{cite journal|last1=McLean|first1=C.J.|last2=Garwood|first2=R.J.|last3=Brassey|first3=C.A.|title=Sexual dimorphism in the size and shape of the raptorial pedipalps of Giant Whip Spiders (Arachnida: Amblypygi)|journal=Journal of Zoology|volume=310|issue=1|year=2019|pages=45–54|issn=0952-8369|doi=10.1111/jzo.12726|doi-access=free}}

Pedipalp anatomy varies strongly with species, with configurations often conforming to a particular style of prey capture. The pedipalps of some genera such as Euphrynicus are extremely long, and free of spines until near the extreme distal end of the appendage.

Whip-spiders are covered with a layer of a solidified secretion that forms a super-hydrophobic coating.[https://zoologicalletters.biomedcentral.com/articles/10.1186/s40851-016-0059-y Whip spiders (Amblypygi) become water-repellent by a colloidal secretion that self-assembles into hierarchical microstructures] Studies on the spotted tailless whip-scorpion also show their exoskeleton is enriched with several trace-elements, including calcium, magnesium, manganese, potassium, sodium, and zinc, which tends to accumulate as the individual gets older. The same trace-elements are also present in the exoskeleton of the other members of Tetrapulmonata.[https://bioone.org/journals/the-journal-of-arachnology/volume-49/issue-2/JoA-S-20-048/Elemental-enrichment-of-the-exoskeleton-of-the-whip-spider-Phrynus/10.1636/JoA-S-20-048.short Elemental enrichment of the exoskeleton of the whip spider Phrynus marginemaculatus (Arachnida: Amblypygi)]

File:Damon diadema female.jpg

Amblypygids have eight legs, but use only six for walking, often in a crab-like, sideways fashion. The front pair of legs are modified for use as antennae-like feelers, with many fine segments giving the appearance of a "whip". When a suitable prey is located with the antenniform legs, the amblypygid seizes its victim with large spines on the grasping pedipalps, impaling and immobilizing the prey. This is typically done while climbing the side of a vertical surface and looking downward at their prey.{{Cite journal |last1=Ladle |first1=Richard J. |last2=Velander |first2=Kathryn |date=2003 |title=Fishing behavior in a giant whip spider |url=https://www.researchgate.net/publication/289037904 |journal=The Journal of Arachnology |volume=31 |pages=154–156 |via=ResearchGate|doi=10.1636/0161-8202(2003)031[0154:FBIAGW]2.0.CO;2 |s2cid=86012520 }}

Pincer-like chelicerae then work to grind and chew the prey prior to ingestion. The tailless whip scorpion may go for over a month in which no food is eaten. Often this is due to pre-molt. Due to the lack of venom the tailless whip scorpion is very nervous in temperament, retreating away if any dangerous threat is sensed by the animal.{{Citation needed|reason=Sounds like speculation|date=March 2022}}

File:Amblypygi-legs.jpg

Courtship involves the male depositing stalked spermatophores, which have one or more sperm masses at the tip, onto the ground, and using his pedipalps to guide the female over them.{{Cite journal|author=Peter Weygoldt |year=1999 |title=Spermatophores and the evolution of female genitalia in whip spiders (Chelicerata, Amblypygi) |journal=Journal of Arachnology |volume=27 |issue=1 |pages=103–116 |url=http://www.americanarachnology.org/JoA_Congress/JoA_v27_n1/arac_27_01_0103.pdf |url-status=dead |archive-url=https://web.archive.org/web/20080517002449/http://www.americanarachnology.org/JoA_Congress/JoA_v27_n1/arac_27_01_0103.pdf |archive-date=2008-05-17 }} She gathers the sperm and lays fertilized eggs into a sac carried under the abdomen, or opisthosoma. When the young hatch, they climb up onto the mother's back; any which fall off before their first molt will not survive.

Some species of amblypygids, particularly Phrynus marginemaculatus and Damon diadema, may be among the few examples of arachnids that exhibit social behavior. Research conducted at Cornell University suggests that mother amblypygids communicate with their young with her antenniform front-legs, and the offspring reciprocate both with their mother and siblings. The ultimate function of this social behavior remains unknown.{{cite journal|last1=Rayor|first1=Linda|title=Social Behavior in Amblypygids, and a Reassessment of Arachnid Social Patterns|journal=Journal of Arachnology|date=December 2017|volume=31|issue=12|pages=399–421|doi=10.1636/S04-23.1|s2cid=34165769|url=https://www.biodiversitylibrary.org/part/228950 }} Amblypygids hold territories that they defend from other individuals.{{Cite journal | author1=Chapin KJ | author2=Hill-Lindsay S | year=2015 | title=Territoriality evidenced by asymmetric intruder-holder motivation in an amblypygid | journal=Behavioural Processes | volume=122 | pages=110–115| doi=10.1016/j.beproc.2015.11.014 | pmid=26616673 | s2cid=37584495 }}

The amblypygid diet mostly consists of arthropod prey, but these opportunistic predators have also been observed feeding on vertebrates. Amblypygids generally do not feed for a period of time before, during, and after molting. Like other arachnids, an amblypygid will molt several times during its life. Molting is done while hanging from the underside of a horizontal surface in order to use gravity to assist in separating the old exoskeleton from the animal.

Several genera of Amblypygi are sold and kept as pets, including Acanthophrynus, Charinus, Charon, Damon, Euphrynichus, Heterophrynus, Phrynus, Paraphrynus, and Phrynichus.{{cite web|url=https://www.exotic-pets.co.uk/tail-less-whip-scorpion.html |title=Tail-less Whip Scorpion - Damon medius |publisher=exotic-pets.co.uk|access-date=2019-07-13}}{{Cite book |last=McMonigle |first=Orin |title=Breeding the world's largest living arachnid: amblypygid biology, natural history, and captive husbandry |date=2013 |publisher=Coachwhip Publications |isbn=978-1-61646-183-6 |location=Greenville, Ohio |pages=}} Tailless whip-scorpions are kept in tall enclosures with arboreal climbing surfaces to allow for two things: Enough vertical space for climbing and molting, and enough space for heat to dissipate in order to keep the enclosure between {{convert|70|F|C}} and {{convert|75|F|C}}. {{convert|5|cm|in|sp=us}} of substrate at the bottom of the enclosure is generally sufficient to allow for burrowing and also serves as a method to retain water in order to keep the humidity above 75%. Tailless whip-scorpions live anywhere between 5 and 10 years. Feeding can include small insects such as crickets, mealworms, and roaches.{{cite web |title=Tailless Whip Scorpion Care Sheet |url=https://www.reptilecentre.com/info-tailless-whip-scorpion-care-sheet |website=Reptile Centre |access-date=December 27, 2019}}{{cite web |title=Tailless Whip Scorpion: Facts, Lifespan, Care, Feeding, & Breeding |url=https://allpetsdirectory.com/tailless-whip-scorpion/ |website=AllPetsDirectory |access-date=27 December 2019}}

File:Molting process of Tail-less Whip Scorpion from Sri Lanka.jpg

File:Damon johnstoni – Lydekker, 1879.png from West Africa]]

The following genera are recognised:{{cite book |author=Mark S. Harvey |year=2003 |title=Catalogue of the smaller arachnid orders of the world: Amblypygi, Uropygi, Schizomida, Palpigradi, Ricinulei and Solifugae |publisher=CSIRO Publishing |isbn=978-0-643-06805-6 |chapter=Order Amblypygi |pages=3–58 |chapter-url=https://books.google.com/books?id=I5JNqiORopUC&pg=PA12}}{{cite journal |last1=Engel|first1=M.S. |last2=Grimaldi |first2=D.A. |year=2014 |title=Whipspiders (Arachnida: Amblypygi) in amber from the Early Eocene and mid-Cretaceous, including maternal care |journal= Novitates Paleoentomologicae |volume=9 |pages=1–17}}

• Palaeoamblypygi Weygoldt, 1996
• Paracharontidae Weygoldt, 1996
• Paracharon Hansen, 1921 (1 species, West Africa)
• Jorottui Moreno-González, Gutierrez-Estrada, & Prendini, 2023 (1 species, northern South America)
• Weygoldtinidae Dunlop, 2018{{Cite journal |last=Dunlop |first=Jason A. |date=2018-03-01 |title=Systematics of the Coal Measures whip spiders (Arachnida: Amblypygi) |url=https://www.sciencedirect.com/science/article/pii/S0044523117300967 |journal=Zoologischer Anzeiger |series=In honor of Peter Weygoldt |language=en |volume=273 |pages=14–22 |doi=10.1016/j.jcz.2017.11.004 |issn=0044-5231|url-access=subscription }}
• †Weygoldtina Dunlop, 2018 (2 species, Upper Carboniferous Europe, North America)
• Euamblypygi Weygoldt, 1996
• †Paracharonopsis Engel & Grimaldi, 2014 (1 species, Cambay amber, India, Eocene){{Cite journal |last1=Moreno-González |first1=Jairo A. |last2=Gutierrez-Estrada |first2=Miguel |last3=Prendini |first3=Lorenzo |date=2023-06-28 |title=Systematic Revision of the Whip Spider Family Paracharontidae (Arachnida: Amblypygi) with Description of a New Troglobitic Genus and Species from Colombia |url=https://bioone.org/journals/american-museum-novitates/volume-2023/issue-4000/4000.1/Systematic-Revision-of-the-Whip-Spider-Family-Paracharontidae-Arachnida/10.1206/4000.1.full |journal=American Museum Novitates |issue=4000 |pages=1–36 |doi=10.1206/4000.1 |s2cid=259275494 |issn=0003-0082}}
• Charinidae Weygoldt, 1996
• Charinus Simon, 1892 (33 species)
• Sarax Simon, 1892 (10 species)
• Weygoldtia Miranda, Giupponi, Prendini & Scharff, 2018 (3 species)
• Neoamblypygi Weygoldt, 1996
• Charontidae Simon, 1892
• Catageus Thorell, 1889 (9 species)
• Charon Karsch, 1879 (5 species)
• Unidistitarsata Engel & Grimaldi, 2014
• †Kronocharon Engel & Grimaldi, 2014 (1 species, Burmese amber, Myanmar, Cretaceous)
• †Burmacharon? Hu et al. 2020 (1 species, Burmese amber, Myanmar, Cretaceous)
• Phrynoidea Blanchard, 1852
• Phrynichidae Simon, 1900
• Damon C. L. Koch, 1850 (10 species)
• Euphrynichus Weygoldt, 1995 (2 species)
• Musicodamon Fage, 1939 (1 species)
• Phrynichodamon Weygoldt, 1996 (1 species)
• Phrynichus Karsch, 1879 (16 species)
• Trichodamon Mello-Leitão, 1935 (2 species)
• Xerophrynus Weygoldt, 1996 (1 species)
• Phrynidae Blanchard, 1852
• Acanthophrynus Kraepelin, 1899 (1 species)
• †Britopygus Dunlop & Martill, 2002 (1 species; Crato Formation, Brazil, Cretaceous)
• Heterophrynus Pocock, 1894 (14 species)
• Paraphrynus Moreno, 1940 (18 species)
• Phrynus Lamarck, 1801 (28 species, Oligocene - Recent)
• Incertae sedis:
• † Sorellophrynus Harvey, 2002 (1 species, Upper Carboniferous, North America)
• † Thelyphrynus Petrunkevich, 1913 (1 species, Upper Carboniferous, North America)

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• {{Wikispecies-inline|Amblypygi}}
• [https://web.archive.org/web/20120829192507/http://www.thewildclassroom.com/biomes/speciesprofile/species/amblypigid.html Amblypigid video] summarizing research from University of Nebraska's Eben Gering
• {{usurped|1=[https://web.archive.org/web/20160304030218/http://www.scorpionsetc.com/amblypygi-the-antillean-west-indian-fauna.html Amblypygi. The Antillean (West Indian) fauna.]}}

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Category:Arachnid orders

Category:Amblypygi

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Category:Carboniferous arachnids

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