Jump to content

Hula painted frog

From Wikipedia, the free encyclopedia

Hula painted frog
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Alytidae
Genus: Latonia
Species:
L. nigriventer
Binomial name
Latonia nigriventer
Synonyms

Discoglossus nigriventer Mendelssohn and Steinitz, 1943

The Hula painted frog (Latonia nigriventer) is a species of frog endemic to the Lake Hula marshes in northern Israel. It is the only living member of the genus Latonia, which is otherwise known from fossils from Europe spanning from the Oligocene through Pleistocene.[2] The Hula painted frog was thought to be extinct as a result of habitat destruction during the 1950s until the species was rediscovered in 2011.

The draining of Lake Hula and its marshes in the 1950s was thought to have caused the extinction of this frog, along with the cyprinid fish Mirogrex hulensis and cichlid fish Tristramella intermedia.[3] Only five individuals had been found prior to the draining of the lake. Environmental improvements in the Hula reserve have been cited as a possible reason for the frog's reemergence.[4]

Taxonomy

[edit]

On March 22, 1940, the biologists Heinrich Mendelssohn and Heinz Steinitz discovered two specimens apparently belonging to a new species of the frog genus Discoglossus on the eastern shore of Lake Hula in Safed, in the Northern District of Mandatory Palestine. The largest of the frogs swallowed the smaller one while they were kept in a terrarium. Two tadpoles of the species from the same locality were discovered by Seinitz in August 1940. In 1943, Mendelssohn and Steinitz named the new species Discoglossus nigriventer, designating a female of the captured specimens by then housed at the Hebrew University in Jerusalem as the holotype specimen and the tadpoles as the paratype specimens.[5]

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.[6]

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.[7]

Fossil of the prehistoric relative Latonia seyfriedii

This frog was originally proposed to be a member of the genus Discoglossus, but further genetic and morphological assessment after the rediscovery of the species led a reassignment to genus Latonia, for which no other living examples are known. Fossils of Latonia are known in Europe spanning from the Upper Oligocene until the Early Pleistocene.[8] The closest relative of Latonia is considered to be Discoglossus. On this basis, the Hula painted frog has been labeled a living fossil, the only extant representative of an ancient genetic split.[9][10][11]

The cladogram below is based on the 2013 genetic analysis by Biton and colleagues:[9]

Description

[edit]
Specimen in hand seen from the upper and underside

The Hula painted frog shows variation in size; while the adult female type specimen measured only 40.0 millimetres (1.57 in), other females have been recorded to reach greater lengths of 69.0–128.4 millimetres (2.72–5.06 in), while males are slightly smaller and grow 66.6–121.3 millimetres (2.62–4.78 in) long.[5][12] This species has a dark belly with small white spots, with adults having more of these spots than juveniles.[13] It is colored ochre above with a rusty colour grading into dark olive-grey to greyish-black on the sides.[5] A band of lighter color stretching down the middle of the back is present near the hind part of the animal. Although the distinctness and contrast varies between individuals, the general color pattern is largely the same throughout the species. There is no significant sexual dimorphism in this frog, though the webbing of the feet may be slightly weaker in females.[12]

The head is flattened and about as wide as it is long, with no canthal ridge (a ridge connecting the snout tip to the front edge of the eye, present in some other frogs). The distance between the eyes is at least equal to the width of the eyelid, a feature distinguishing it from the Mediterranean painted frog (Discoglossus pictus) whose eyes are closer together. The nostrils are located closer to both the tip of the snout and to each other than to the eyes, and each has a rectangular shape with rounded corners. The tympana are taller than they are wide, but not distinctly visible. The snout protrudes forward beyond the mouth, though not as far as that of the Mediterranean painted frog, while the angle of the mandible has a process which corresponds to a hollow in the upper jaw. Inside the mouth are a pair of vomerine teeth, each located behind a rectangular choana with rounded corners. The tongue has a roundish triangular shape, with smooth edges and no furrows, and is adhesive aside from a small margin. A pair of glandular ridges extends from the back of each eye, one over the tympanum towards the base of the arm, and the other stretches straight backwards and splits into multiple warts at the shoulder level. The whole upper surface of the animal is dotted with warts, some of which are arranged in rows or groups. The fingers may have rounded or pointed tips and are not webbed, though the toes are partly webbed at the base. The length of the hind legs with the feet included exceeds the snout-vent length, while the foot itself is slightly shorter than the shin.[5] In both sexes the arms are long and robust, with well-developed muscles; this is unusual among frogs as typically only male frogs have robust arms, which are used to grasp the female during amplexus. In Hula painted frogs, the robustness of the arms is believed to be an adaptation for digging or feeding.[14]

Tadpoles

[edit]

The tadpoles of the Hula painted frog are small, with total lengths of 14 millimetres (0.55 in) and 24 millimetres (0.94 in) at Gosner stages 25 and 34 respectively. The main body (excluding the tail) of the tadpole has an oval shape when viewed from above, with the body being widest about a third of its length away from the rounded snout. When viewed from the side, the snout slopes downwards. The upper surface is a medium brown color with golden speckles and a network of black lines forming a net-like pattern. The underbelly is translucent and lacks pigment, allowing the internal anatomy to be seen through it, and possesses a single crescent-shaped spiracle located in its middle.[12] The width of this spiracle is about a quarter the width of the mouth. The oral disc contains teeth arranged into double rows surrounding the serrated, partly keratinized jaw sheaths, with two upper double rows and three lower double rows present, of which one of the lower rows is split in the middle to accommodate the jaw sheath. A series of papillae (small fleshy protrusions) is present on the margins the lips, and is split in the middle of the upper lip.[5] The nostrils are small and rounded, located closer to the snout than to the eyes, and each has a dark spot behind it. The eyes are located on top of the head and oriented sideways, making them invisible when the tadpole is viewed from below. The tail is a slightly lighter color than the main body and grows long, being around 169% the length of the main body. Moderately high caudal fins are located on the upper and lower sides of the tail. These fins are translucent and bear irregular dark brown spots of varying sizes.[12] The musculature of the tail does not reach the tail tip.[5]

Distribution and habitat

[edit]

The Hula painted frog is endemic to Hula Valley of Israel and has an extremely limited range, known only from an area of less than 6.5 km2 (2.5 sq mi). It has only been recorded from two localities, the Hula National Reserve and the village of Yesud HaMa'ala, located about 1 kilometre (0.62 mi) apart from each other.[12] It was formerly more widespread, as evidenced by fossil remains of this species found at the Ubeidiya prehistoric site in the Jordan Valley, dating back to the Early Pleistocene epoch (around 1.5 million years ago).[14][15] The Hula Valley had survived as an area containing major water bodies such as Lake Hula throughout the Pleistocene epoch, when geological activity and climatic changes led to a dramatic decline in suitable habitat for Latonia frogs, allowing the valley to serve as a refugium for this species while the genus became extinct elsewhere.[14] Although a 2017 study found that environmental DNA of this frog was also present in the Agamon Ha-Hula nature park and the Ein Te’o nature reserve, it was also noted that since most water bodies in the Hula Valley are interconnected via streams and canals, the presence of DNA at a site could be due to it being washed downstream from a different area and is not definitive evidence that the frog itself is present.[16]

This species is semiaquatic (though mainly terrestrial) and is known to inhabit both terrestrial and aquatic habitats. Adults have been recorded in damp, peaty soil underneath 20–30 centimetres (7.9–11.8 in) of decomposed leaf litter amongst thickets of common reed, holy bramble and occasionally fig trees, as well as beneath dried grass or in burrows near water. In Yesud HaMa'ala, the Hula painted frog is known from a single ditch approximately 600 metres (2,000 ft) long, with slow-flowing water that reaches a maximum depth of about 150 centimetres (4.9 ft). This ditch is supplied by a small permanent spring and has a thick layer of mud at its bottom, while dense vegetation occurs both in and around the water, with the present plant species including common reed, water lettuce and common duckweed.[12]

Status

[edit]

Decline

[edit]
Swamps near Lake Hula in the late 1930s (above) and later water management installations there (below)

The draining of Lake Hula and its marshes in the 1950s was thought to have caused the extinction of this frog, along with the cyprinid fish Mirogrex hulensis and cichlid fish Tristramella intermedia.[17] Only five individuals had been found prior to the draining of the lake. Environmental improvements in the Hula reserve have been cited as a possible reason for the frog's reemergence.[4]

In 1996, the IUCN classified this species as "extinct in the wild", the very first amphibian to be given that designation by the IUCN.[1][11] Israel continued to list it as an endangered species in the slim hope that a relict population may be found in the Golan Heights or in southern Lebanon. Following the rediscovery of the species in 2011, the IUCN now considers the frog to be critically endangered as its known habitat occupies less than 2 km2.[1]

In 2000, a scientist from the Lebanese nature protection organisation A Rocha claimed he had seen a frog species which could be Latonia 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.[18] 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.[19]

The female specimen found in the 2011 rediscovery

In 2013, a study published in Nature Communications revealed that in 2011 during a routine patrol at the Hula Nature Reserve, ranger Yoram Malka found the frog, which he immediately suspected as being the Hula painted frog, as he claimed he has been on the lookout for it for many years. Scientists confirmed that it was one of this rare species.[4][9][10] An ecologist with the Israel Nature and Parks Authority credited the rehydration of the area for the frog sighting.[20] On November 29, a second specimen was located in the same area.[4] 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.[7] Since the discovery of the first specimen, at least ten more individuals have been found, all in the same area.[21]

In 2016, a team led by Professor Sarig Gafni of the Ruppin Academic Center's School of Marine Sciences discovered populations totaling several hundred individuals by searching in water at night, instead of in marsh mud, finding populations in 17 of the 52 Hula Valley water holes they surveyed.[22]

Conservation

[edit]

In 2017, an article published in the Molecular Ecology Journal, mentions of a group of scientists who investigated the suitable aquatic habitats for Hula painted frogs using the environmental DNA (eDNA) approach.[16] The Hula Lake once provided a habitat for many rare species including this frog. Since, the 2011 rediscovery of this species in this region (in the Hula nature reserve), consequent efforts to study and protect it started. However, these efforts have been hampered by the elusive nature of this species (that also prevented it being found from the 1950s-2010s). Since, there is a lack of systematic and efficient methodology to detect a rare amphibian or aquatic species, including this Hula painted frogs, they were designated “extinct”; until their rediscovery at a later stage.

Environmental DNA (eDNA) is becoming a ‘go-to’ tool for detecting species presence in aquatic environments. eDNA extraction (genetic material extracted through water filtrate) followed by quantitative Polymerase Chain Reaction (qPCR is a technique to amplify genetic material in real time) are highly sensitive methods which can increase the detection probability of rare organisms. To be more reliable the researchers concluded a site to be positive for the presence of Hula painted frogs if the water contains eDNA and if the physical presence of frog is detected as well. Thus, these researchers sampled 52 sites and found that 22 sites were positive for the presence of Hula painted frogs. Most of the positive sites were located in the regions around Hula Nature Reserve, Agamon ha-Hula, and Ein Te’o Nature Reserve. These regions overlap with the former Hula Lake region, and also contain organic, and colluvial-alluvial soils.

The Hula National Reserve at the beginning of the 21st century

Such findings in the regions around reserved parks indicate the importance of nature parks in conservation of wild-life. The suitable habitats predicted by employing the eDNA are of great importance for identifying potential sites for future translocation to save this rare frog.

In 2018, another article published in Nature Scientific Reports, mentioned that this species has low abundance and dispersal capability, calling for urgent conservation measures.[23] The total estimate of potentially reproducing adults in this population (Nad) is found to be 234-235 individuals. They determined the population genetics of this species through a capture-recapture study on 118 adult frogs, and through micro-satellite analysis. Surprisingly, this frog has high genetic diversity (HO = 0.771) and low inbreeding coefficient (FIS = −0.018) with an effective population size estimate (Ne) of ~16–35. It could be due to the presence of one more unknown population or genetic admixture leading to a high genetic diversity and low inbreeding in spite of a less population.

Future research calls for understanding the habitat locations of another population which is not well studied, or different spots within the Hula valley location in which the frog species can be present. The aquatic habitats of this species are prone to disturbance and anthropogenic hazards which could imperil the survival of endangered Hula frogs. Thus outcomes of any future research dealing with prediction of the favorable dwelling habitats of this rare species, and their habitat characterization will be vital to protect the only living member of genus Latonia, by recommending characteristics of safer spots.

See also

[edit]

References

[edit]
  1. ^ a b c IUCN SSC Amphibian Specialist Group (2021). "Latonia nigriventer". IUCN Red List of Threatened Species. 2021: e.T6715A177694004. doi:10.2305/IUCN.UK.2021-3.RLTS.T6715A177694004.en. Retrieved 24 May 2023.
  2. ^ "Amphibian Species of the World: An Online Reference (Version 6)". Reference Reviews. 28 (6): 32. 2014-08-12. doi:10.1108/rr-05-2014-0125. ISSN 0950-4125.
  3. ^ "Hula Painted Frog Bounces Back From Extinction". Wired UK. 2011-11-21. Retrieved 2013-06-04.
  4. ^ a b c d Zafrir, Rinat (November 17, 2011). "Long thought extinct, Hula painted frog found once again in Israeli nature reserve". Haaretz.
  5. ^ a b c d e f Mendelssohn, Heinrich; Steinitz, Heinz (1943). "A New Frog from Palestine". Copeia. 1943 (4): 231–233. doi:10.2307/1438135. ISSN 0045-8511. JSTOR 1438135.
  6. ^ "Frog jumps back from extinction". News24. Retrieved 2013-06-04.
  7. ^ a b Rinat, Zafrir (2011-11-29). "Second of frog species long thought extinct found in Israel nature reserve Israel News | Haaretz Daily Newspaper". Haaretz.com. Retrieved 2013-06-04.
  8. ^ Rocek, Z. (1994). "Taxonomy and distribution of Tertiary discoglossids (Anura) of the genus Latonia v. Meyer, 1843" (PDF). Geobios. 27 (6): 717–751. Bibcode:1994Geobi..27..717R. doi:10.1016/s0016-6995(94)80058-8.
  9. ^ a b c Biton, Rebecca; Geffen, Eli; Vences, Miguel; Cohen, Orly; Bailon, Salvador; Rabinovich, Rivka; Malka, Yoram; Oron, Talya; Boistel, Renaud; Brumfeld, Vlad; Gafny, Sarig (4 June 2013). "The rediscovered Hula painted frog is a living fossil". Nature Communications. 4. Article 1959. Bibcode:2013NatCo...4.1959B. doi:10.1038/ncomms2959. PMID 23736869.
  10. ^ a b Morelle, Rebecca (2013-06-04). "Rediscovered Hula painted frog 'is a living fossil'". BBC. Retrieved 2013-06-04.
  11. ^ a b Than, Ker (4 June 2013). "Frog Long Thought Extinct Is Rediscovered in Israel". National Geographic. Archived from the original on June 8, 2013.
  12. ^ a b c d e f Perl, R. G. Bina; Gafny, Sarig; Malka, Yoram; Renan, Sharon; Woodhams, Douglas C.; Rollins-Smith, Louise; Pask, James D.; Bletz, Molly C.; Geffen, Eli; Vences, Miguel (2017-02-13). "Natural history and conservation of the rediscovered Hula painted frog, Latonia nigriventer". Contributions to Zoology. 86 (1): 11–37. doi:10.1163/18759866-08601002. ISSN 1875-9866.
  13. ^ Perl, R.; Gafny, S.; Geffen, E.; Malka, Yoram; Renan, Sharon; Vences, M. (2018-05-28). "Notes on post-metamorphic colour pattern changes in the Hula painted frog ( Latonia nigriventer ) – how realistic is a re-identification of juveniles?". Herpetology Notes. 11: 475–480. S2CID 194795168.
  14. ^ a b c Biton, Rebecca; Boistel, Renaud; Rabinovich, Rivka; Gafny, Sarig; Brumfeld, Vlad; Bailon, Salvador (2016). "Osteological Observations on the Alytid Anura Latonia nigriventer with Comments on Functional Morphology, Biogeography, and Evolutionary History". Journal of Morphology. 277 (9): 1131–1145. doi:10.1002/jmor.20562. ISSN 1097-4687.
  15. ^ Haas, Georg (1966). On the Vertebrate Fauna of the Lower Pleistocene Site ‘Ubeidiya, Jerusalem. The Israel Academy of Sciences and Humanities. p. 67.
  16. ^ a b Renan, Sharon; Gafny, Sarig; Perl, R. G. Bina; Roll, Uri; Malka, Yoram; Vences, Miguel; Geffen, Eli (December 2017). "Living quarters of a living fossil-Uncovering the current distribution pattern of the rediscovered Hula painted frog (Latonia nigriventer) using environmental DNA". Molecular Ecology. 26 (24): 6801–6812. doi:10.1111/mec.14420. ISSN 0962-1083. PMID 29117632. S2CID 20984317.
  17. ^ "Hula Painted Frog Bounces Back From Extinction". Wired UK. 2011-11-21. Retrieved 2013-06-04.
  18. ^ Tron, François (April 2005) Second Discoglossus nigriventer rediscovery expedition in the Central Bekaa valley, Lebanon, A Rocha Lebanon.
  19. ^ Black, Richard (2010-08-09). "Global hunt begins for 'extinct' species of frogs". BBC. Retrieved 2010-08-09.
  20. ^ Fleischman, Danielle (2011-11-17). "'Extinct' frog rediscovered in Israel | Jewish Telegraphic Agency". Jta.org. Retrieved 2013-06-05.
  21. ^ Ed Yong (2013-06-04). "'Extinct' frog is last survivor of its lineage". Nature. doi:10.1038/nature.2013.13135. S2CID 88427695. Retrieved 2013-06-07.
  22. ^ Shpigel, Noah (30 April 2016). "Scientists Discover Hula Painted Frog Hasn't Croaked After". Haaretz. Retrieved 1 May 2016.
  23. ^ Perl, R. G. Bina; Geffen, Eli; Malka, Yoram; Barocas, Adi; Renan, Sharon; Vences, Miguel; Gafny, Sarig (2018-04-03). "Population genetic analysis of the recently rediscovered Hula painted frog (Latonia nigriventer) reveals high genetic diversity and low inbreeding". Scientific Reports. 8 (1): 5588. Bibcode:2018NatSR...8.5588P. doi:10.1038/s41598-018-23587-w. ISSN 2045-2322. PMC 5882862. PMID 29615810.
[edit]
Wikispecies has information related to Discoglossus nigriventer.

Additional data and discoveries were published in Haaretz newspaper on 15/04/2016

Among the discoveries are Tadpole data, which is very small, up to 2.5 cm, and becomes even smaller as adult, the largest adult caught was 13 cm long which suggest it was several decades old. Also sound was first noticed and it is a very weak one.

Retrieved from "https://en.wikipedia.org/w/index.php?title=Hula_painted_frog&oldid=1265673247"