|
Description
Description:
Amnirana parva is a medium sized frog species, which was described by Griesbaum et al. (2023). It has a long and slender body, is slightly dorsoventrally flattened with a male snout-vent length range of 41.9 - 50.4 mm and a female range of 53.6 - 75.6 mm. The snout is acuminate with a rounded tip in dorsal view, and narrowly rounded in lateral view. The head length is approximately 27% of the snout-vent length. The head width is shorter than the head length. The nostrils are directed laterally and are closer to the snout than to eyes. The canthus rostralis is distinct and sharply protruding, the loreal region is concave. The eye–snout distance is about the same length as the eye diameter. The eye diameter is slightly larger than the tympanum diameter. Approximately one third of the eyes projecting above the dorsal margin of head in lateral view. In males, the anterocranial part of the upper arm has a large protruding gland, which is longer than wide (3.6 mm long, 2.0 mm wide, surface: 7.2 mm2 in the male holotype). The fingers are long and slender, the finger tips broader than the subarticular tubercles, forming discs, which reach 130 - 200% of the finger width. The inner metacarapal tubercle is large and elongated; the outer metacarpal tubercle is smaller and more rounded. Manual webbing is totally absent. The relative finger formula is II < I < III < IV. In males, the nuptial pads on the anteroventral surface of first finger are almost transparent. Thigh length is approximately half of snout-vent length. In the holotype, the crus length is 23.0 mm, and the foot length, including longest toe, is 32.5 mm. The single inner metatarsal tubercle is large and elongated; the single outer metatarsal tubercle small and round. The toes are long and slender, with the tips slightly broader than the subarticular tubercles, forming small discs. The relative toe formula is I < II < V < III < IV. The foot webbing formula is I(0) II(1 - 0) III(1 - 0) IV(2 - 1) V(0). The head and the dorsum are covered with small tubercles, becoming slightly larger from snout to the middle of the dorsum, decreasing in size towards lower back. There is a narrow, distinct dorsolateral ridge extending from posterior corner of eye, reaching to the posterior 1/3 of body, and in the last third becoming broken into isolated small bumps. The ventral skin smooth.
Diagnosis:
In their distribution range A. parva can only be confused with A. fonensis, which is its sister species. Adult male A. parva are smaller in snout-vent-length than male A. fonensis and also show larger humeral glands. In contrast to male A. fonensis, male A. parva do not get brightly yellow during mating season. In females, the identification is not so simple between the two species (Griesbaum et al. 2023). The other West-African Amnirana species, A. galamensis and A. occidentalis both are much larger, very differently colored, and have completely smooth dorsal skin (Rödel and Bangoura 2004, Channing and Rödel 2019).
Coloration:
The dorsal coloration in life is medium brown with few darker spots. The flanks are greenish yellow, becoming paler ventrally with some darker mottling. The arms are slightly lighter brown than the dorsum, marbled with a fine, irregular, dark pattern. The hind limbs are slightly lighter brown than the dorsum, with narrow transverse dark bars. The posterior parts of thighs are marbled, the foot webbing is greyish brown. The throat and belly are white, the ventral side of the legs are pale beige, and the hind limbs are ventrally patterned with indistinct brown spots. The bright, white upper lip (giving the species its common name) extends posterior to angle of mouth, below and posterior to the tympanum (see below for variation in coloration in life). After years in preservation in 75% ethanol, the colors are general less saturated: the brownish dorsal color darkened, there is a greater contrast of marbled limb patterning, the flanks lose their yellow coloration, become beige with small remnants of brownish speckles, the white throat and lip more shiny (Griesbaum et al. 2023).
Variation:
The species displays variation in morphology and coloration, including some sexual dimorphism. Variation is possible in the webbing of the fourth toe. In some individuals, the skin appeared almost smooth at first sight, but tiny granules were always present upon detailed inspection. Female exceeded male snout-vent length by far. Males have humeral glands, with an area that spanned between 3.7 - 14.8 mm2, and nuptial pads. The dorsal skin was covered with small tubercles in all individuals, but females had fewer, smaller, and less spiny tubercles. Among 13 male individuals, the coloration in preservation was very similar. Concerning life coloration, the back shows various shades of brown, sometimes with darker spots (especially in males, most females without darker spots). The flanks in males are greenish yellow to chocolate brown dorsally, usually turning lighter ventrally. The flanks in females are more olive green, but also turning paler ventrally, and becoming almost cream-colored towards the belly (then often with some greenish or brownish mottling). The number of conspicuous dark bars on the hind limbs also varies among individuals (Griesbaum et al. 2023).
Distribution and Habitat
Country distribution from AmphibiaWeb's database: Cote d'Ivoire, Ghana, Guinea, Liberia, Sierra Leone
The species occurs all along the rainforest zone in Western-Africa, which covers parts of Sierra Leone, Guinea, Liberia, Ivory Coast, and Ghana. Apparently, the species is restricted to primary, or only slightly degraded rainforests in the lowland (Griesbaum et al. 2023).Life History, Abundance, Activity, and Special Behaviors
Mostly, A. parva is found close to, or even on the actual banks of small forest streams, mostly on the ground but also on low vegetation (Griesbaum et al. 2023, iNaturalist data).
The frogs seem to be diurnal in close canopy forests but can also be found active at night (especially) in more open forest areas (Griesbaum et al. 2023).
Calling often is done in small choruses, and can be heard in the day and night. The males, despite being hidden well, usually call from exposed sites. The advertisement call consists of a whiney croaking sound with up to five harmonics. The frequency modulation ascends from ~930 to ~1090 Hz (Griesbaum et al. 2023).
Eggs are deposited in ponds or stagnant parts of small streams and clutches can contain more than 1000 eggs (Griesbaum et al. 2023). At least in one case where eggs were deposited in a fish breeding pond, the cichlids did not prey on the eggs (maybe due to toxins).
Adult frogs seem to have strong skin toxins as well, as Griesbaum et al. (2023) report from a personal incident where a scientist touched his eye after handling a frog and was in pain for hours. This might explain, why in Ivory Coast A. parva is often found in close proximity to Dwarf Crocodiles (Osteolaemus tetraspis). Larva
The tadpole of A. albolabris sensu lato, which A. parva was previously thought to be, has been described and illustrated by Lamotte et al. (1957), Guibé and Lamotte (1958), Perret (1977), and Channing et al. (2012). These robust and conspicuously colored tadpoles (with red and black markings) (Figs. 8d, 11e) may reach large sizes up to 60 mm.
In their habitat they are the only tadpoles that can be observed swimming during the daytime. They have several large skin glands, which likely produce skin toxins (Perret 1977).
Tadpoles offered to fish were immediately spat out again. The published descriptions of tadpoles of A. albolabris sensu lato are similar to one another, though definitely refer to multiple distinct taxa. The most detailed description, predominantly based on tadpoles from Mount Nimba in West Africa, was published by Lamotte et al. (1957). Interestingly, these authors already pointed out differences between these tadpoles and ones from A. albolabris from central Africa. Trends and Threats
Because all available data indicate that the species is broadly distributed in West African rainforests, the population should probably be classified as relatively stable (IUCN category ‘Least Concern’). This is based on its likely large range, extending from central Ghana and across the forest zone into eastern Sierra Leone. It seems to be at least a little tolerant to slight forest degradation and also can be found in anthropogenic structured landscape (Griesbaum et al. 2023). However, West African rainforests are still under threat of deforestation and fragmentation, which likely will affect this species as well. The species occurs in numerous protected areas, such as Tai National Park, Banco National Park, Azagny National Park and Tanoé forest reserve in Ivory Coast and Foya Forest Reserve in Liberia, etc. Possible reasons for amphibian decline General habitat alteration and loss
Comments
The species was thought to be just a West-African population of A. albolabris. Jongsma et al. (2018), using Maximum Likelihood and Bayesian methods on 16s mtDNA and DISP2, FICD, KIAA2013, and REV3L nuclear protein-coding DNA sequences, showed that former A. albolabris populations consists of several clades and the West-African population is not even close to their Central-African relatives in the phylogenetic tree. Also based on these analyses, A. parva is sister to A. fonensis (Jongsma et al. 2018, Griesbaum et al. 2023)
The species epithet is "parva," which derives from Latin "parvus" (translates to "small") and refers to A. parva's small body size compared to their congeners.
Following Dubois et al. (2021), Amphibian Species of the World (Frost, 2023) states that the genus Amnirana is not valid and should be placed within Hylarana. References
Channing, A., Rödel, M.-O. and Channing J. (2012). Tadpoles of Africa. The biology and identification of all known tadpoles in sub-Saharan Africa. Edition Chimaira, Frankfurt am Main, Germany, 402 pp.
Channing, A. and Rödel, M.-O. (2019). Field guide to the frogs and other amphibians of Africa. Struik Nature, Cape Town, South Africa, 408 pp.
Dubois, A., Ohler, A., and Pyron, R. A. (2021). New concepts and methods for phylogenetic taxonomy and nomenclature in zoology, exemplified by a new ranked cladonomy of recent amphibians (Lissamphibia). Megataxa 5(1), 1–738.
[link]
Frost, Darrel R. (2023). Amphibian Species of the World: an Online Reference. Version 6.2 (20.11.2023). Electronic Database accessible at https://amphibiansoftheworld.amnh.org/index.php. American Museum of Natural History, New York, USA.
Griesbaum, F., Jongsma, G. F., Penner, J., Doumbia, J., Gonwouo, N. L., Hillers, A., Glos, J., Blackburn, D. C. and Rödel, M.-O. (2023). The smallest of its kind: Description of a new cryptic Amnirana species (Amphibia, Anura, Ranidae) from West African rainforests. Zootaxa, 5254(3), 301–339.
[link]
Guibé, J.and Lamotte, M. (1958). La réserve naturelle intégrale du Mont Nimba. XII. Batraciens (sauf Arthroleptis, Phrynobatrachus et Hyperolius). Mémoires de l’Institut Français d’Afrique Noire, 53, 241–273.
Jongsma, G. F., Barej, M. F., Barratt, C. D., Burger, M., Conradie, W., Ernst, R., Greenbaum, E., Hirschfeld, M., Leaché, A. D., Penner, J., Portik, D. M., Zassi-Boulou, A.-G., Rödel, M.-O. and Blackburn, D. C. (2018). Diversity and biogeography of frogs in the genus Amnirana (Anura: Ranidae) across sub-Saharan Africa. Molecular Phylogenetics and Evolution, 120, 274–285.
[link]
Lamotte, M., Lauwarier, G. and Perret, J.-L. (1957). Contribution à l’étude des batraciens de l’Ouest Africain V.– Le développement larvaires de Rana (Hylarana) albolabris. Bulletin de l’Institut fondamental d’Afrique Noire, Sér. A, 19, 1312–1327.
Perret, J.-L. (1977). Les HylaranaRevue suisse de Zoologie, 84, 841–868.
[link]
Rödel, M.-O., Bangoura, M. A. and Böhme, W. (2004). The amphibians of south-eastern Republic of Guinea (Amphibia: Gymnophiona, Anura). Herpetozoa, 17, 99–118.
[link]
Originally submitted by: Frederic Griesbaum (2023-11-27)
Edited by: Ann T. Chang (2023-11-27)Species Account Citation: AmphibiaWeb 2023 Amnirana parva: Lesser White-Lipped Frog <https://amphibiaweb.org/species/9679> University of California, Berkeley, CA, USA. Accessed Apr 25, 2024.
Feedback or comments about this page.
Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 25 Apr 2024.
AmphibiaWeb's policy on data use.
|
Map of Life