Hula painted frog
The draining of Lake Hula and its marshes in the 1950s was thought to have led to the extinction of this frog, along with the cyprinid fish Acanthobrama hulensis and cichlid fish Tristramella intermedia. Only five individuals have been found prior to the draining of the lake and subsequent disappearance of the frog. Environmental improvements in the Hula reserve have been cited as a possible reason for the frog's re-emergence.
The Hula painted frog has a dark belly with small white spots. It is colored ochre above with a rusty colour grading into dark olive-grey to greyish-black on the sides. Differences from the common painted frog (Discoglossus pictus) include its greater interocular distance, longer forelimbs, and a less projecting snout. The type specimen was an adult female with a body length of 40 mm.
Little is known about its history, because few specimens have been found by scientists. Two adults and two tadpoles were collected in 1940 and a single specimen was found in 1955. This would prove to be the last record of this species until 2011.
The four 1940 specimens were to be used as types, but the smaller, half-grown frog was eaten by the larger one in captivity. The latter eventually became the holotype (HUJZ Amphib. Discogl. 1) for the species' description and this or the individual collected in 1955 apparently is the only material remains of the species known today; the two tadpole paratypes (HUJZ Amphib. Discogl. 2 and 2a) appeared to have been lost.
According to an ecologist of the Israel Nature and Parks Authority, the frog's Hebrew name, agulashon shehor-gahon (Black-bellied round-tongued), derives from its black belly and round tongue. The scientific name of the species reflects these details as well. Unlike the tongues of other frogs, it is not used to catch prey.
In 2000, a scientist from the Lebanese nature protection organisation A Rocha claimed he had seen a frog species which could be Discoglossus nigriventer in the Aammiq Wetland south of the Beqaa Valley in Lebanon. Two French-Lebanese-British expeditions in the years 2004 and 2005 yielded no confirmation as to the further existence of this species. In August 2010, a search organised by the Amphibian Specialist Group of the International Union for Conservation of Nature set out to look for various species of frogs thought to be extinct in the wild, including the Hula painted frog.
In 2011, a routine patrol at the Hula nature reserve found an unknown frog and scientists confirmed that it was one of this rare species. An ecologist with the Israel Nature and Parks Authority credited the rehydration of the area for the frog sighting. On November 29, a second specimen was located in the same area. The second Hula painted frog, a female, was found in swampy weeds twenty centimeters deep. It weighed 13 grams, half the weight of its male counterpart. Since the discovery of the first specimen, at least ten more individuals have been found, all in the same area.
- Papenfuss, Theodore; Disi, Ahmad; Anderson, Steven; Kuzmin, Sergius; Gasith, Avital; Sadek, Riyad A.; Werner, Yehudah (2004). "Discoglossus nigriventer". The IUCN Red List of Threatened Species. International Union for Conservation of Nature. http://www.iucnredlist.org/apps/redlist/details/6715/0. Retrieved 2011-09-12.
- Mendelssohn, Heinrich and Steinitz, Heinz (1943). A new frog from Palestine. Copeia. 1943 (4): 231-233. doi:10.2307/1438135
- Painted Frog Bounces Back From Extinction
- Zafrir, Rinat (November 17, 2011). "Long thought extinct, Hula painted frog found once again in Israeli nature reserve". Haaretz. http://www.haaretz.com/print-edition/news/long-thought-extinct-hula-painted-frog-found-once-again-in-israeli-nature-reserve-1.396000.
- Frog jumps back from extinction
- Second of frog species long thought extinct found in Israel nature reserve
- The Eastern spadefoot Toad (Pelobates syriacus) : A new amphibian species for Lebanon The international expedition of herpetological research in South Lebanon, April 2005, Francois Tron, A Rocha France
- Black, Richard (2010-08-09). "Global hunt begins for 'extinct' species of frogs". BBC. http://www.bbc.co.uk/news/science-environment-10859989. Retrieved 2010-08-09.
- ‘Extinct’ frog rediscovered in Israel
- Paz, U. (1975): [The Rehabilitation of the Hula Nature Reserve]. Nature Conservation in Israel: Research & Surveys 1: 116-206 [Article in Hebrew].
- Steinitz, Heinz (1955): Occurrence of Discoglossus nigriventer in Israel. Bulletin of the Research Council of Israel B 5: 192-193.