Wikipedia

Pseudis

genus of frogs in the Hylidae family


Pseudis or the swimming frogs are a genus of frogs that live in South America. They are in the family Hylidae.[1] They are important because they have the largest tadpoles of any frog in the world. The adult frogs are not much bigger than other frogs, but the tadpoles are giant. Human beings hear these frogs more than they see them. This is because the frogs sing loud but blend into the water and plants so they are hard to see. The frogs live in lakes, ponds, marshes, and other bodies of waters that have many plants in them. These frogs sit near the top of the water, hiding in the plants or on floating plants. This frog will dive into the water if they see something that looks dangerous to them.[2][3][4]

Pseudis
Pseudis minuta
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Hylidae
Subfamily: Hylinae
Genus: Pseudis
Wagler, 1830
Type species
Rana paradoxa
Species

See text.

Distribution

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Pseudis frogs live in tropical and subtropical South America. Almost all of them live east of the Andes, on the Atlantic side of South America. P. paradoxa is the only species in Pseudis that has any frogs living west of the Andes. These frogs live from Trinidad to northern Argentina but not in Ecuador or Chile. They live in hills and other highland regions, and they live in the southernmost part of South America. All species in this genus are found in Brazil.[1][5]

Description

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Mating P. paradoxa
 
Models of full-grown tadpole and adult P. paradoxa

These frogs have several body parts that help them live in the water. They have eyes that stick up and out, strong hind legs, and fully webbed feet.[6] Scientists say they are still "true" tree frogs, so they are in the family Hylidae.[1]

Breeding and feeding

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Frogs in Pseudis find mates and lay eggs the same way most frogs do. However, their tadpoles are different. The tadpoles start live normal, but they continue growing until they are very, very large, sometimes as large as 22–27 cm (9–11 in) in length in P. paradoxa and P. platensis.[3][5][7][8] They are the longest tadpoles in the world. They are also very large compared to the adult frogs, which are 3.4–7.6 cm (1.3–3.0 in) from nose to rear end.[2][5] Scientists have not seen enough tadpoles from other species to say for sure, they have seen enough to know they are also very large.[9] Their adult frogs are also somewhat smaller with nose-to-rear-end lengths of 2.4–6.6 cm (0.9–2.6 in).[5][10][11] However, P. cardosoi and P. minuta (which could be in the proposed genus Podonectes, see Phylogenetic relationships) have more normal tadpoles that probably do not grow longer than c. 9 cm (3.5 in).[9][11][12] This is still large compared to the adults of these two species. This means that the animal is the largest it will ever be in its life when it is an older tadpole. It is smaller when it becomes a frog.[9] In most of these frogs, tadpoles from different places can be different sizes. Tadpoles that grow in large, temporary bodies of waters with plenty of food and few animals that want to eat them grow larger than those in smaller bodies of water with less food, or year-round bodies of waters that may have fish or other animals that eat tadpoles in them.[5] The very largest tadpoles usually have well-developed organs, including reproductive organs that are almost ready to be used. This means that the frogs are ready to mate very soon after becoming frogs. This is different from most genuses of frogs: In most species, the tadpoles become small frogs and then grow larger before they can mate and lay eggs.[3][5][13]

Pseudis is closely related to the genus, Lysapsus. The frogs in Lysapsus do not have giant tadpoles. In Lysapsus, adults frogs grow to 2.5 cm (1.0 in).[5][6]

Pseudis tadpoles eat algae, many different kinds of algae. They can also eat small animals without bones, for example insects.[14][15] The adult frogs eat land-based insects and spiders, but they also eat other animals without bones and smaller frog. Some frogs in Pseudis can eat plants.[16][17][18][19]

Species

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P. bolbodactyla, one of several species formerly included in P. paradoxa

There are seven species in this genus if we think of Lysapsus as a different genus. Until the late 1990s and early 2000s, most scientists said only P. minuta and P. paradoxa counted as frogs in Pseudis. Scientists wrote the first paper about P. cardosoi. Before that, scientists thought P. cardosoi was the same frog as P. minuta. All the other species remaining were thought to be subspecies, synonyms or populations of P. paradoxa.[1] Not all scientists agree that P. platensis is not the same frog as P. paradoxa.[5]

Binomial name and author Common name
Pseudis bolbodactyla (Lutz, 1925)
Pseudis cardosoi (Kwet, 2000)
Pseudis fusca (Garman, 1883)
Pseudis minuta (Günther, 1858) lesser swimming frog
Pseudis paradoxa (Linnaeus, 1758) paradoxical frog
Pseudis platensis (Gallardo, 1961)
Pseudis tocantins (Caramaschi & Cruz, 1998)

Phylogenetic relationships

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Scientists argue about how these frogs are related to other frogs and toads. In the 19th and 20th centuries, scientists could only looking at animals' bodies, the way they acted, and fossils to figure out how they were related to each other. Then DNA technology became strong enough to help scientists look at the animals' genes. These frogs were very hard for scientists to put in groups before DNA technology became strong.

Over the years, scientists have said theys hould be in Ranidae, Leptodactylidae,[20] Hylidae,[21] and in their own family, Pseudidae, by themselves.[22] It has been difficult for scientists to say where these frogs belong in taxonomy because their bodies are very different from those of other hylid frogs. The bodies of Pseudis frogs are different from other tree frogs' bodies because Pseudis frogs spend much more time living in water than most tree frogs do.

However, in the early 20th century, scientists did more studies. Both body-shape-based[23] and molecular (DNA)[24] scientific experiments showed that these frogs are more closely related to tree frogs than to other frogs. So scientists put them in the subfamily Hylinae with Scarthyla as a sister group.

Since then, two teams of scientists used molecular genetics (DNA) to find how this frog is related to other frogs.[6][23][25] Both teams found the same thing, but they had different ideas about how the frogs should be put into groups: One team said scientists should start using the genus Podonectes again[6] and the other team said they should use Lysapsus as a junior synonym of Pseudis.[25] Later, more teams of scientists said Pseudis was not paraphyletic to Lysapsus, so making Lysapsus a junior synonym would not be good.[1]

References

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  1. ↑ 1.0 1.1 1.2 1.3 1.4 Frost, Darrel R. (2013). "Pseudis Wagler, 1830". Amphibian Species of the World 5.6, an Online Reference. American Museum of Natural History. Retrieved 11 December 2013.
  2. ↑ 2.0 2.1 Halliday, T. (2016). The Book of Frogs: A Life-Size Guide to Six Hundred Species from around the World. University Of Chicago Press. p. 320. ISBN 978-0226184654.
  3. ↑ 3.0 3.1 3.2 Fabrezi, M.; S.I. Quinzio; J. Goldberg (2009). "Giant Tadpole and Delayed Metamorphosis of Pseudis platensis Gallardo, 1961 (Anura, Hylidae)". Journal of Herpetology. 43 (2): 228–243. doi:10.1670/08-028R3.1. hdl:11336/53231. S2CID 83912058.
  4. ↑ Franklyn, D. (2015). Pseudis paradoxa (Paradoxical Frog). The Online Guide to the Animals of Trinidad and Tobago. Retrieved 7 January 2020
  5. ↑ 5.0 5.1 5.2 5.3 5.4 5.5 5.6 5.7 Garda, A. A.; D.J. Santana; V.d. Avelar São Pedro (2010). "Taxonomic characterization of Paradoxical frogs (Anura, Hylidae, Pseudae): geographic distribution, external morphology, and morphometry". Zootaxa. 2666: 1–28. doi:10.11646/zootaxa.2666.1.1.
  6. ↑ 6.0 6.1 6.2 6.3 GARDA, A. A., and D. C. CANNATELLA. 2007. Phylogeny and biogeography of paradoxical frogs (Anura, Hylidae, Pseudae) inferred from 12S and 16S mitochondrial DNA. Molecular Phylogenetics and Evolution. Molecular Phylogenetics and Evolution. 44:104-114.
  7. ↑ Bokermann, W.C.A. (1967). "Girinos de anfíbios brasileiros—3: sôbre um girino gigante de Pseudis paradoxa (Amphibia, Pseudidae)". Revista Brasileira de Biologia. 27: 209–212.
  8. ↑ Emerson, S. B. (1988). "The giant tadpole of Pseudis paradoxa". Biological Journal of the Linnean Society. 34 (2): 93–104. doi:10.1111/j.1095-8312.1988.tb01951.x.
  9. ↑ 9.0 9.1 9.2 Santana, D. J.; F.D. Medeiros Magalhães; V.d. Avelar São Pedro; S. Mângia; T.F. Amado; A.A. Garda (2016). "Calls and tadpoles of the species of Pseudis (Anura, Hylidae, Pseudae)". Herpetological Journal. 26: 141–150.
  10. ↑ Caramaschi, U.; C.A. Gonçalves da Cruz (1998). "Notas taxonômicas sobre Pseudis fusca garman e P. bolbodactyla A. Lutz, com a descrição de uma nova espécie correlata (Anura, Pseudidae)". Rev. Bras. Zool. 15 (4): 929–944. doi:10.1590/S0101-81751998000400011.
  11. ↑ 11.0 11.1 Kwet, A. (2000). "The genus Pseudis (Anura: Pseudidae) in Rio Grande do Sul, southern Brazil, with description of a new species". Amphibia-Reptilia. 21 (1): 39–55. doi:10.1163/156853800507264.
  12. ↑ Sá, R.O.d.; E.O. Lavilka (1997). "The tadpole of Pseudis minuta (Anura: Pseudidae), an apparent case of heterochrony". Amphibia-Reptilia. 18 (3): 229–240. doi:10.1163/156853897X00116.
  13. ↑ Downie, J.R.; K. Sams; P.T. Walsh (2009). "The paradoxical frog Pseudis paradoxa: larval anatomical characteristics, including gonadal maturation". Herpetological Journal. 19: 1–10.
  14. ↑ Arias, M.; P. Peltzer; R. Lajmanovich (2002). "Diet of giant Pseudis paradoxa platensis (Anura, Pseudidade) from Argentina". Phyllomedusa: Journal of Herpetology. 1 (2): 97–100. doi:10.11606/issn.2316-9079.v1i2p97-100.
  15. ↑ Huckembeck, S.; L.T. Alves; D. Loebmann; A.M. Garcia (2016). "What the largest tadpole feeds on? A detailed analysis of the diet composition of Pseudis minuta tadpoles (Hylidae, Dendropsophini)". Anais da Academia Brasileira de Ciências. 88 (3): 1397–1400. doi:10.1590/0001-3765201620150345. PMID 27508992.
  16. ↑ Downie, J.R.; E.G. Hancock; A.P. Muir (2010). "The diet of the paradoxical frog Pseudis paradoxa in Trinidad, West Indies". Herpetological Journal. 20 (2): 111–114.
  17. ↑ Miranda, T.; M. Ebner; M. Solé; A. Kwet (2006). "Spatial, seasonal and intra polulational variation in the diet of Pseudis cardosoi (Anura-Hylidae) from the araucaria Plateau of Rio Grande do Sul". South American Journal of Herpetology. 1 (2): 121–130. doi:10.2994/1808-9798(2006)1[121:SSAIVI]2.0.CO;2. S2CID 85090411.
  18. ↑ Duré, M.I.; A.I. Kehr (2001). "Differential Exploitation of Trophic Resources by Two Pseudid Frogs from Corrientes, Argentina". Journal of Herpetology. 35 (2): 340–343. doi:10.2307/1566129. hdl:11336/47353. JSTOR 1566129.
  19. ↑ de Oliveira Neves, M.; C. José da Silva Morais; A.A. Garda (2014). "Sexual Dimorphism and Diet of Pseudis tocantins (Anura, Hylidae, Pseudae)". South American Journal of Herpetology. 9 (3): 177–182. doi:10.2994/SAJH-D-14-00020.1. S2CID 84254037.
  20. ↑ NOBLE, G. K. 1922. The phylogeny of Salientia. I. The osteology and thigh musculature; their bearing on classification and phylogeny. Bulletin of the American Museum of Natural History. 46:1-87.
  21. ↑ PARKER, H. W. 1935. The frogs, lizards, and snakes of British Guiana. Proceedings of the Zoological Society of London. 505-530.
  22. ↑ SAVAGE, J. M., and A. L. DE CARVALHO. 1953. The family position of neotropical frogs currently referred to the genus Pseudis. Zoologica. 38:193-200.
  23. ↑ 23.0 23.1 DA SILVA, H. R. 1998. Phylogenetic relationships of the family Hylidae with emphasis on the relationships within the subfamily Hylinae (Amphibia: Anura). Department of Systematics and Ecology. University of Kansas.
  24. ↑ DARST, C. R., and D. C. CANNATELLA. 2004. Novel relationships among hyloid frogs inferred from 12S and 16S mitochondrial DNA sequences. Molecular Phylogenetics and Evolution. 31:462-475.
  25. ↑ 25.0 25.1 AGUIAR-JR., O., M. BACCI JR, A. P. LIMA, D. C. ROSSA-FERES, C. F. B. HADDAD, and S. M. RECCO-PIMENTEL. 2007. Phylogenetic relationships of Pseudis and Lysapsus (Anura, Hylidae, Hylinae) inferred from mitochondrial and nuclear gene sequences. Cladistics. 23:455-463.

Other websites

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  • Frost, Darrel R. (2013). "Pseudis Wagler, 1830". Amphibian Species of the World 5.6, an Online Reference. American Museum of Natural History.
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