Arum frog

{{Short description|Species of amphibian}} {{speciesbox | name = Arum lily reed frog | image = Hyperolius horstockii.jpg | status = LC | status_system = IUCN3.1 | status_ref = <ref name="iucn status 17 November 2021">{{cite iucn |author=IUCN SSC Amphibian Specialist Group |date=2013 |title=''Hyperolius horstockii'' |volume=2013 |article-number=e.T56142A18374911 |doi=10.2305/IUCN.UK.2013-2.RLTS.T56142A18374911.en |access-date=17 November 2021}}</ref> | taxon = Hyperolius horstockii | authority = ([[Hermann Schlegel|Schlegel]], 1837) | synonyms = ''Hyla horstockii'' <small>Schlegel, 1837</small> | synonyms_ref = <ref name=Frost/> }}

The '''arum frog''', '''arum lily reed frog''', '''Horstock's arum-frog''', '''arum lily frog''', or '''Horstock's reed frog''' ('''''Hyperolius horstockii''''') is a species of [[frog]] in the family [[Hyperoliidae]]. It is [[Endemism|endemic]] to [[South Africa]].<ref name="iucn status 17 November 2021" /><ref name=Frost/>

==Identification==

Adults grow to 40 mm in length. They have bright orange feet and can change their colour to camouflage themselves. The top of the body is cream to brown, sometimes with small black spots. A distinctive, pale, dorsolateral line runs from the snout along the flanks, with a dark-brown lateral band underneath. A fine, dark line usually separates the pale line from the brown band. The concealed surfaces of limbs, webbing, and discs are orange to red. Underneath, the frog is creamy white and slightly granular. The gular flap in males is bright ochre. their pupils are horizontal.<ref name = Amphibiaweb>{{cite web | url = http://amphibiaweb.org/cgi/amphib_query?where-genus=Hyperolius&where-species=horstockii&account=amphibiaweb | title = ''Hyperolius horstockii'' | access-date = 2016-11-19 |publisher = Amphibiaweb}}</ref>

Tadpoles reach 40 mm. They are brown with longitudinal, darker bands on their tails.<ref name = Amphibiaweb/>

==Distribution and habitat== The arum frog is found in the southern coastal plain of South Africa from [[Cape Town]] in the [[Western Cape]] to [[Port Elizabeth]] in the [[Eastern Cape]].<ref name = Carruthers>{{cite book | author1 = Vincent Carruthers | year = 2005 | title = The Wildlife of Southern Africa: A Field Guide to the Animals and Plants of the Region | url = https://books.google.com/books?id=QygFIjP9jYUC&pg=PT95 | publisher = Struik | page = 79 | isbn = 978-1-86872-451-2}}</ref>

Its natural [[habitat]]s are Mediterranean-type shrubby vegetation, [[river]]s, [[swamp]]s, intermittent freshwater [[lake]]s, freshwater [[marsh]]es, intermittent freshwater marshes, and [[pond]]s. It is frequently found lying at the bottom of arum lilies (''[[Zantedeschia aethiopica]]''), trying to catch pollinating insects.<ref>{{Cite book | last = Kingdon | first = Jonathan | author-link = Jonathan Kingdon | title = Island Africa: The Evolution of Africa's Rare Plants and Animals | location = Princeton, New Jersey | publisher = Princeton University Press | year = 1989 | pages = [https://archive.org/details/islandafricaevol0000king/page/55 55–58] | isbn = 978-0-691-08560-9 | url = https://archive.org/details/islandafricaevol0000king/page/55 }}</ref>

It is assessed as [[least concern]] but some populations are threatened by [[habitat loss]] through the invasion of alien vegetation and fire.<ref name="iucn status 17 November 2021" /> Contrary to popular belief it is not threatened by the collection and sale of arum lilies.<ref name = SANBI>{{cite web | url = http://www.sanbi.org/news/setting-facts-straight-arum-lilies-and-frogs | title = Setting the facts straight on arum lilies and frogs | access-date =2016-11-19 | publisher = SANBI}}</ref>

==Behaviour== These frogs are sometimes found in arum lily flowers where they can change colour to perfectly match their surroundings. This makes them virtually invisible to predators, as well as to their insect prey. Their pale colour camouflages them in the white flowers, helped by hiding their bright orange feet and legs under their bodies during the day. Contrary to popular belief they do not use the pollen of the flowers to camouflage themselves.<ref name = SANBI/>

The breeding habitat of the arum frog includes large or small pans, dams, vleis and slow-flowing, quiet streams where there is sufficient emergent vegetation. Males usually call at night from elevated positions above water, normally in the emergent vegetation such as [[sedge]]s, [[reed (plant)|reed]]s, shrubs and grasses, although they may sometimes call from the pads of water lilies. The usually start calling just after sunset, but will call sporadically in the late afternoon on cloudy, rainy days. The arum frog occurs mostly in a winter rainfall region; however, its breeding season occurs over the spring and summer, in September–January. After mating the female lays clutches of 10–30 eggs which are attached to the submerged roots and stems of plants.<ref name = Amphibiaweb/>

==References== {{Reflist|30em|refs= <ref name=Frost>{{cite web |url=http://research.amnh.org/vz/herpetology/amphibia/Amphibia/Anura/Hyperoliidae/Hyperolius/Hyperolius-horstockii |title=''Hyperolius horstockii'' (Schlegel, 1837) |author=Frost, Darrel R. |year=2016 |work=Amphibian Species of the World: an Online Reference. Version 6.0 |publisher=American Museum of Natural History |access-date=19 November 2016}}</ref> }}

[[Category:Hyperolius]] [[Category:Frogs of Africa]] [[Category:Endemic amphibians of South Africa]] [[Category:Taxa named by Hermann Schlegel]] [[Category:Amphibians described in 1837]] [[Category:Taxonomy articles created by Polbot]]