Nyctibatrachus major

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Nyctibatrachus major
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Amphibia
Order: Anura
Family: Nyctibatrachidae
Genus: Nyctibatrachus
Species:
N. major
Binomial name
Nyctibatrachus major
Boulenger, 1882
Range of N. major; reports of the species from Maharashtra are probably erroneous[2]
Synonyms[3]

Nyctibatrachus major, the Malabar night frog, large wrinkled frog, or Boulenger's narrow-eyed frog[3] is a species of frog in the family Nyctibatrachidae, commonly known as the robust frogs. It was described in 1882 by the zoologist George Albert Boulenger, and is the type species of the genus Nyctibatrachus. It is a large frog for its genus, with an adult snout–vent length of 31.5–52.0 mm (1.24–2.05 in) for males and 43.7–54.2 mm (1.72–2.13 in) for females. It is mainly brownish to greyish in colour, with a dark greyish-brown upperside, a greyish-white underside, and light grey sides. It also has a variety of grey or brown markings. When preserved in ethanol, it is mostly greyish-brown to grey, with whitish sides. Sexes can be told apart by the presence of the femoral glands (bulbous glands near the inner thigh) in males.

The species is

nitrate pollution
caused by fertiliser overuse.

Taxonomy

Black-and-white illustration of frog viewed from above
Illustration of N. major from the 1882 description

The zoologist

lectotype to avoid subsequent taxonomic uncertainty and ensure that the genus Nyctibatrachus could be tied to a single type species.[5]

There are no

N. sylvaticus. The clade of these five species is sister to N. radcliffei, and these six species are sister to N. indraneili.[10][11] A study from 2014 found a slightly different relationship, with major being sister to gavi, and acanthodermis being sister to that clade.[12] The following cladogram shows relationships within this clade based on a phylogeny from the 2017 study by Sonali Garg and colleagues:[10]

N. indraneili

N. radcliffei

N. grandis

N. sylvaticus

N. acanthodermis

N. gavi

N. major

The species had its

microsatellite markers could offer tools for assessing genetic variation and population dynamics, further informing conservation strategies for this species.[13]

Description

Nyctibatrachus major is a large species of night frog, with an adult

vomerine teeth along each vomerine ridge and a bluish-black liver that can be seen through the skin of the underside.[5] Male frogs also have two vocal sacs,[4] which are seen as an internal pair of slits at the back of the lower jaw. The sacs expand towards the sides and to a large size when inflated.[5]

The species may be confused with several other species in its genus, namely

N. vrijeuni. It can be distinguished from these species by its large size; well-developed toe and finger discs; the absence of a groove on the third finger disc; the presence of a groove on the fourth toe disc; conspicuous wrinkling and glandular protrusions on the skin of the upperside; medium-sized webbing between the fingers; and a prominent Y-shaped ridge from the upper lip to the nostrils.[5]

  • Dorsal view
    Dorsal view
  • Ventral view
    Ventral view

Tadpoles

Tadpoles of the species are mainly black, with a brown body, brown underside of head, and a mostly white tail. There are two long pale marks on the lower back, and the tail has darks bands near the front. Tadpoles have a maximum length of 5.2 cm (2.0 in), of which one-half to two-thirds is the tail. Their heads and bodies are roughly egg-shaped and somewhat flattened, and the mouth is small with no teeth. After reaching a length of 1.5–1.9 cm (0.59–0.75 in), tadpoles have only a tail stump and begin metamorphosing; they can be distinguished from adults by the lack of grooves on the fingers.[15]

Vocalizations

modulating calls significantly at the higher end of this range, although some calls are also delivered at a frequency of around 2.43 kHz.[16]

Habitat and distribution

The species is

leaf litter.[18] Tadpoles have been found at elevations up to 825 m (2,700 ft).[15]

Ecology

Adults are mostly

nocturnal and spend most of their time in aquatic environments, most commonly being seen on rocks near water. During the day, adults typically conceal themselves below rocks, but subadults are more active. When disturbed or threatened, they scramble through the mud of the streambed and stay underwater for some time before coming to the surface again.[15] Other observers have found that they rarely bury themselves in mud or try to exit the water and hide in nearby undergrowth.[9]

Diet

brownish frog
N. major feeds on several species of frog, such as Fejervarya limnocharis (pictured)[19]

Nyctibatrachus major mainly feeds on insect larvae and other frogs. It consumes insects like dragonflies in the genus

springtails in the genus Sminthurinus. Frogs that N. major feeds on include Fejervarya limnocharis, Euphlyctis cyanophlyctis, and Micrixalus saxicola; the especially high rates at which the species predates F. limnocharis and E. cyanophlyctis may be due to the fact that all of these species share the same microhabitat.[19]

Reproduction

The species' life cycle and breeding behaviour are poorly known. Females with mature eggs have been collected from May to June; tadpoles have been collected in October.[15] Femoral glands are only present in males and seem to show subtle seasonal variation, being longer proportional to total body length from February to September (before and during the monsoon) than from October to January (after the monsoon). This may indicate that these glands have a reproductive function and aid in amplexus (mating).[14] Males also have extremely small testes proportional to their body size, although the reasons for this are unclear.[16] The sperm of the species is rather distinctive, with a loosely coiled, S-shaped head and an unusually thin tail.[20]

Mature eggs are pigmented and have an outer diameter of 4.1 mm (0.16 in). Immature eggs are smaller and colourless. Females possess egg cells undergoing several stages of maturity at any time; this suggests that they lay multiple small clutches of eggs over several days or weeks, instead of one large clutch at once.

froglets by 98 days.[21]

Conservation

Nyctibatrachus major is classified as being

habitat degradation.[1] It is threatened by habitat loss caused by factors such as deforestation, wood and timber harvesting, and conversion of land for agricultural use. It is also threatened by the construction of check dams, road construction, and an increase in tourism in its range. Adults and tadpoles of N. major are highly sensitive to changes in their microhabitat.[17][18] Consequently, increased human activities that alter their habitat may lead to declines in the species' population, as has occurred in the related N. aliciae.[18]

The species may also be threatened by

micrograms (μg) per litre over a 30-day period; nitrate concentrations in streams with N. major tadpoles have been collected vary from 110 to 6,000 μg per litre. Even sub-lethal concentrations of nitrates in the water lead to adverse effects such as paralysis, restlessness, abnormal swimming patterns, and swollen body parts.[21][22]

References

  1. ^
    doi:10.2305/IUCN.UK.2004.RLTS.T58401A11773366.en. Retrieved 17 August 2023.{{cite journal}}: CS1 maint: multiple names: authors list (link
    )
  2. ^
    ISSN 2581-8686. Archived from the original on 14 November 2023. Retrieved 14 November 2023.{{cite journal}}: CS1 maint: DOI inactive as of January 2024 (link
    )
  3. ^
    doi:10.5531/db.vz.0001. Archived
    from the original on 24 October 2023. Retrieved 17 August 2023.
  4. ^
    OCLC 182918804. Archived
    from the original on 3 November 2023. Retrieved 14 November 2023.
  5. ^
    ISSN 1175-5334. Archived
    from the original on 3 March 2021. Retrieved 17 August 2023.
  6. ISSN 0006-324X. Archived from the original on 5 November 2023. Retrieved 14 November 2023 – via Biodiversity Heritage Library
    .
  7. ^
    doi:10.5531/db.vz.0001. Archived
    from the original on 7 June 2023. Retrieved 17 August 2023.
  8. S2CID 251650759. Archived
    from the original on 18 August 2023. Retrieved 18 August 2023.
  9. ^
    ISSN 0255-9587. Archived
    (PDF) from the original on 1 November 2023. Retrieved 14 November 2023.
  10. ^
    PMID 28243532
    .
  11. ISSN 0974-7907. Archived
    from the original on 7 February 2023. Retrieved 18 August 2023.
  12. PMID 24870664. Archived
    from the original on 10 October 2022. Retrieved 18 August 2023.
  13. S2CID 35880867. Archived
    from the original on 18 August 2023. Retrieved 18 August 2023.
  14. ^
    ISSN 0970-4140. Archived
    from the original on 17 August 2023. Retrieved 17 August 2023.
  15. ^
    OCLC 475620800. Archived
    from the original on 24 October 2023. Retrieved 14 November 2023.
  16. ^
    ISSN 1881-1019. Archived
    from the original on 17 August 2023. Retrieved 17 August 2023.
  17. ^
    ISSN 2713-1467
    .
  18. ^
    ISSN 1827-9643. Archived
    from the original on 17 August 2023. Retrieved 17 August 2023.
  19. ^
    ISSN 0018-084X. Archived
    from the original on 11 January 2022. Retrieved 17 August 2023.
  20. S2CID 82682100. Archived
    from the original on 14 November 2023. Retrieved 17 August 2023.
  21. ^
    ISSN 1303-6114. Archived
    from the original on 17 August 2023. Retrieved 17 August 2023.
  22. ISSN 1323-3475
    .

External links
Retrieved from "https://en.wikipedia.org/w/index.php?title=Nyctibatrachus_major&oldid=1207320755"