[Herpetology • 2023] Hyperolius ukaguruensis • Diversification of Spiny-throated Reed Frogs (Anura: Hyperoliidae) with the Description of A New, Range-restricted Species from the Ukaguru Mountains, Tanzania

Hyperolius ukaguruensis 

 Lawson, Loader, Lyakurwa & Liedtke, 2023

DOI: 10.1371/journal.pone.0277535

  uc.edu 

Abstract

The spiny-throated reed frog species group is a small radiation of Hyperolius frogs from East Africa. Unlike many members of the genus which have relatively wide distributions, these species tend to be small-range endemics found in montane and submontane forests. Recent discovery of a golden-hued frog with the clade-specific traits of spines on their gular discs prompted a morphological and genetic exploration of the distinctness of this new lineage and relationships to other members of the clade. Genetic (mitochondrial and nuclear loci) results resolved many sister-relationships, but deeper nodes in the phylogeny were poorly resolved. A reduced-representation genome-wide Single Nucleotide Polymorphism (SNP) dataset was able to fully resolve the phylogenetic relationships within this clade, placing this new lineage, here named after the mountain range in which is it found–Hyperolius ukaguruensis sp. nov., as an early diverging lineage within the group. This new species is distinct from all other spiny-throated reed frogs, necessitating further understanding as a single-mountain endemics vulnerable to habitat loss and potential decline. Morphometric analyses identify clear morphological characteristics that are distinct for the herein described species, most noticeably in that the eyes are significantly smaller than other members of the genus for which we have samples.

Photos in life of Hyperolius ukaguruensis sp. nov.
 A,B) Male (BMNH 2022.7682; holotype) and female (BMNH 2022.7683; paratype) in vivo,
C) H. ukaguruensis sp. nov. male and female in axillary amplexus, and D) Type locality habitat.

Photos by C. Liedtke. 

Hyperolius ukaguruensis sp. nov.

 

Diagnosis.— Horizontal pupil with distinctive gular flap in males. As with most other members of the spiny-throated group (H. spinigularis, H. burgessi, H. davenporti, H. minutissimus, H. ruvuensis, H. ukwiva), H. ukaguruensis sp. nov. also has the presence of dermal asperities (including the body and chin region) on the ventrum. This trait is unique amongst members of the genus Hyperolius. The presence of asperities on the gular flap diagnoses H. ukaguruensis sp. nov. from H. tanneri, for which they are absent. Hyperolius ukaguruensis sp. nov. primarily has asperities anteriorly positioned (closer to the mouth), which differentiates it from H. spinigularis, H. burgessi and H. davenporti which have an even distribution of dermal asperities on the gular flap. Hyperolius minutissimus and H. ukwiva have a similar distribution of asperities to H. ukaguruensis sp. nov.. Furthermore, in males, H. ukaguruensis sp. nov has a distinctively shaped gular flap, differentiating it from H. davenporti, H. tanneri and H. burgessi (Figs 4 & 5). Quantification of differences in gular shape from the H. ukwiva were not possible due to inability to locate the only known male specimen, but should be investigated in future studies.

Etymology.— Hyperolius ukaguruensis sp. nov. is named after the forested mountain block (Ukaguru Mountains) where the type series was collected. The species name is a masculine Latin singular adjective in the nominative case.

 

 Lucinda P. Lawson, Simon P. Loader, John V. Lyakurwa and H. Christoph Liedtke. 2023. Diversification of Spiny-throated Reed Frogs (Anura: Hyperoliidae) with the Description of A New, Range-restricted Species from the Ukaguru Mountains, Tanzania.  PLoS ONE. 18(2): e0277535.  DOI: 10.1371/journal.pone.0277535 

 uc.edu/news/articles/2023/01/biologists-speak-up-to-save-voiceless-african-frog.html

[Herpetology • 2022] Afrixalus phantasma & A. lacustris • Systematics of the Central African Spiny Reed Frog Afrixalus laevis (Anura: Hyperoliidae), with the Description of Two New Species from the Albertine Rift

 Afrixalus phantasma Dehling, Greenbaum, Kusamba & Portik, 

in Greenbaum, Portik, Allen, Vaughan, Badjedjea, ... et Dehling, 2022.  

DOI: 10.11646/zootaxa.5174.3.1

  twitter.com/EliGreenbaumPhD 

fieldnotes.nationalgeographic.org/expedition/congoquest

Abstract

The geographically widespread species Afrixalus laevis (Anura: Hyperoliidae) currently has a disjunct distribution in western Central Africa (Cameroon, Equatorial Guinea, Gabon, and possibly adjacent countries) and the area in and near the Albertine Rift in eastern Democratic Republic of the Congo and neighboring countries. At least two herpetologists have previously suggested that these disjunct populations represent distinct species, and herein, we utilize an integrative taxonomic approach with molecular and morphological data to reconcile the taxonomy of these spiny reed frogs. We sequenced 1554 base pairs of the 16S and RAG1 genes from 34 samples of A. laevis and one sample of A. orophilus (sympatric with eastern populations of A. laevis), and combined these data with previously sequenced GenBank Afrixalus samples via the bioinformatics toolkit SuperCRUNCH. Phylogenetic trees, dated phylogenetic analyses, and species-delimitation analyses were generated with RAxML, BEAST, and BPP, respectively. Eleven mensural characters were taken from multiple specimens of A. laevis and A. orophilus, and compared with paired t-tests and analyses of covariance. These combined results suggested populations of A. laevis in western Central Africa (Cameroon and Bioko Island, Equatorial Guinea) represent one species, whereas populations from the Albertine Rift and nearby forests represent two undescribed taxa that are sister to A. dorsimaculatus. The two new species (A. lacustris sp. nov. and A. phantasma sp. nov.) are distinguished by our phylogenetic and species-delimitation analyses, significant differences in several mensural characters, qualitative morphological differences, and by their non-overlapping elevational distribution.

Keywords: Amphibia, Afromontane, Endemism, Conservation, Species Delimitation, Phylogeny

 

 Photos of Afrixalus phantasma sp. nov. in life.
Adult male holotype, ZFMK 103454 (field no. JMD 723), from Gishwati-Mukura National Park, Rwanda, in the habitat showing nighttime coloration (A), adult male paratype, ZFMK 103460 (field no. JMD 679) from Kamiranzovu Swamp, Nyungwe National Park, showing daytime coloration in dorsal (B) and ventral views (C), adult male paratype UTEP 20802 (EBG 1198) from Kahuzi-Biega National Park, DRC (D), photographed the morning after capture.

Afrixalus phantasma Dehling, Greenbaum, Kusamba & Portik sp. nov.

Ghost Spiny Reed Frog 

Etymology. The species epithet derives from the Greek noun φάντασμα (phántasma), meaning ghost or phantom, in allusion to the coloration and general appearance of the new species. The epithet is used as an invariable noun in apposition.

Afrixalus lacustris Greenbaum, Dehling, Kusamba & Portik sp. nov.

Great Lakes Spiny Reed Frog

Etymology. The species epithet is the Latin adjective “ lacustris,” meaning belonging to or dwelling in lakes; in allusion to the distribution of the new species in the region of the African Great Lakes.

Eli Greenbaum, Daniel M. Portik, Kaitlin E. Allen, Eugene R. Vaughan, Gabriel Badjedjea, Michael F. Barej, Mathias Behangana, Nancy Conkey, Bonny Dumbo, Legrand N. Gonwouo, Mareike Hirschfeld, Daniel F. Hughes, Félix Igunzi, Chifundera Kusamba, Wilber Lukwago, Franck M. Masudi, Johannes Penner, Jesús M. Reyes, Mark-Oliver Rödel, Corey E. Roelke, Soraya Romero and J. Maximilian Dehling. 2022. Systematics of the Central African Spiny Reed Frog Afrixalus laevis (Anura: Hyperoliidae), with the Description of Two New Species from the Albertine Rift. Zootaxa. 5174(3); 201-232. DOI: 10.11646/zootaxa.5174.3.1

  twitter.com/EliGreenbaumPhD/status/1557375490859470850

 fieldnotes.nationalgeographic.org/expedition/congoquest

 twitter.com/mindje/status/1557321194797502465

Researchgate.net/publication/362604907_Systematics_of_Afrixalus_laevis_with_the_description_of_two_new_species_from_the_Albertine_Rift

[Herpetology • 2022] Systematic Position of the Clicking Frog (Kassinula Laurent, 1940), the Problem of Chimeric Sequences and the Revised Classification of the Family Hyperoliidae

Clicking Frog (Kassinula Laurent, 1940)

in Nečas, Kielgast, ... & Gvoždík, 2022. 

 DOI: 10.1016/j.ympev.2022.107514

 

Highlights: 

• Phylogeny and systematics of the African frog family Hyperoliidae.

• Kassinula included for the first time in a multilocus phylogenetic reconstruction.

• Kassinula merits the genus-level status.

• Chimeric sequences are phylogenetically placed at misleading positions.

• Revised suprageneric taxonomy of the Hyperoliidae.

Abstract

The systematics of the African frog family Hyperoliidae has undergone turbulent changes in last decades. Representatives of several genera have not been genetically investigated or with only limited data, and their phylogenetic positions are thus still not reliably known. This is the case of the De Witte's Clicking Frog (Kassinula wittei) which belongs to a monotypic genus. This miniature frog occurs in a poorly studied region, southeastern Democratic Republic of the Congo, northern Zambia, Angola. So far it is not settled whether this genus belongs to the subfamily Kassininae as a relative of the genus Kassina, or to the subfamily Hyperoliinae as a relative of the genus Afrixalus. Here we present for the first time a multilocus phylogenetic reconstruction (using five nuclear and one mitochondrial marker) of the family Hyperoliidae, including Kassinula. We demonstrate with high confidence that Kassinula is a member of Hyperoliinae belonging to a clade also containing Afrixalus (sub-Saharan Africa), Heterixalus (Madagascar) and Tachycnemis (Seychelles). We find that Kassinula represents a divergent lineage (17–25 Mya), which supports its separate genus-level status, but its exact systematic position remains uncertain. We propose to name the clade to which the above four genera belong as the tribe Tachycnemini Channing, 1989. A new taxonomy of the family Hyperoliidae was recently proposed by Dubois et al. (2021: Megataxa 5, 1–738). We demonstrate here that the new taxonomy was based on a partially erroneous phylogenetic reconstruction resulting from a supermatrix analysis of chimeric DNA sequences combining data from two families, Hyperoliidae and Arthroleptidae (the case of Cryptothylax). We therefore correct the erroneous part and propose a new, revised suprageneric taxonomy of the family Hyperoliidae. We also emphasize the importance of inspecting individual genetic markers before their concatenation or coalescent-based tree reconstructions to avoid analyses of chimeric DNA sequences producing incorrect phylogenetic reconstructions. Especially when phylogenetic reconstructions are used to propose taxonomies and systematic classifications.

 

Keywords: Afrotropics, Amphibians, Congo Basin, Suprageneric classification, Systematics

 

Tadeáš Nečas, Jos Kielgast, Zoltán T. Nagy, Zacharie Kusamba Chifundera and Václav Gvoždík. 2022. Systematic Position of the Clicking Frog (Kassinula Laurent, 1940), the Problem of Chimeric Sequences and the Revised Classification of the Family Hyperoliidae. Molecular Phylogenetics and Evolution. In Press, 107514. DOI: 10.1016/j.ympev.2022.107514

[Herpetology • 2018] Sky, Sea, and Forest Islands: Diversification in the African Leaf‐folding Frog Afrixalus paradorsalis (Anura: Hyperoliidae) of the Lower Guineo‐Congolian Rain Forest

Afrixalus paradorsalis  Perret, 1960

in Charles, Bell, Blackburn, et al., 2018. 

 DOI: 10.1111/jbi.13365

photo: Daniel M. Portik

Abstract

Aim: 

To investigate how putative barriers, forest refugia, and ecological gradients across the lower Guineo‐Congolian rain forest shape genetic and phenotypic divergence in the leaf‐folding frog Afrixalus paradorsalis, and examine the role of adjacent land bridge and sky‐islands in diversification.

Location: The Lower Guineo‐Congolian Forest, the Cameroonian Volcanic Line (CVL), and Bioko Island, Central Africa.

Taxon: Afrixalus paradorsalis (Family: Hyperoliidae), an African leaf‐folding frog.

Methods: 

We used molecular and phenotypic data to investigate diversity and divergence among the A. paradorsalis species complex distributed across lowland rain forests, a land bridge island, and mountains in Central Africa. We examined the coincidence of population boundaries, landscape features, divergence times, and spatial patterns of connectivity and diversity, and subsequently performed demographic modelling using genome‐wide SNP variation to distinguish among divergence mechanisms in mainland (riverine barriers, forest refugia, ecological gradients) and land bridge island populations (vicariance, overwater dispersal).

Results: 

We detected four genetically distinct allopatric populations corresponding to Bioko Island, the CVL, and two lowland rain forest populations split by the Sanaga River. Although lowland populations are phenotypically indistinguishable, pronounced body size evolution occurs at high elevation, and the timing of the formation of the high elevation population coincides with mountain uplift in the CVL. Spatial analyses and demographic modelling revealed population divergence across mainland Lower Guinea is best explained by forest refugia rather than riverine barriers or ecological gradients, and that the Bioko Island population divergence is best explained by vicariance (marine incursion) rather than overseas dispersal.

Main conclusions: 

We provide growing support for the important role of forest refugia in driving intraspecific divergences in the Guineo‐Congolian rain forest. In A. paradorsalis, sky‐islands in the CVL have resulted in greater genetic and phenotypic divergences than marine incursions of the land bridge Bioko Island, highlighting important differences in patterns of island‐driven diversification in Lower Guinea.

Keywords: Africa amphibian, historical demography, land bridge island, Lower Guinea, phylogeography

Figure 1: Sampling localities of Afrixalus paradorsalis paradorsalis (circles) and A. p. manengubensis (triangles) in the Lower Guinean forests of continental Central Africa and Bioko Island. Sampling localities are coloured according to the mitochondrial (mtDNA) haplotype groups and distinct genetic lineages identified in analyses of the ddRADseq (nuDNA) dataset (Figure 2). Symbols with white borders reflect localities with only mtDNA sequence data and symbols with no border reflect localities with only morphological data. The right panel depicts the locations of key mountains along the Cameroon Volcanic Line

 twitter.com/JBiogeography

Kristin L. Charles, Rayna C. Bell, David C. Blackburn, Marius Burger, Matthew K. Fujita, Václav Gvoždík, Gregory F.M. Jongsma, Marcel Talla Kouete, Adam D. Leaché and Daniel M. Portik. 2018. Sky, Sea, and Forest Islands: Diversification in the African Leaf‐folding Frog Afrixalus paradorsalis (Anura: Hyperoliidae) of the Lower Guineo‐Congolian Rain Forest. Journal of Biogeography. DOI: 10.1111/jbi.13365

 osf.io/fvh9k/wiki/home blackburnlab.org/publications.html

 twitter.com/JBiogeography/status/1011641073314254848

[Herpetology • 2018] Hyperolius stictus • A New Reed Frog (Hyperoliidae: Hyperolius) from coastal northeastern Mozambique

Hyperolius stictus 

Conradie, Verburgt, Portik, Ohler, Bwong & Lawson, 2018

 DOI:  10.11646/zootaxa.4379.2.2 

Abstract

A new species of African reed frog (genus Hyperolius Rapp, 1842) is described from the Coastal Forests of the Eastern Africa Biodiversity Hotspot in northeastern Mozambique. It is currently only known from less than ten localities associated with the Mozambican coastal pans system, but may also occur in the southeastern corner of Tanzania. Phylogenetic reconstructions using the mitochondrial 16S marker revealed that it is the sister taxon of Hyperolius mitchelli (>5.6% 16S mtDNA sequence divergence) and forms part of a larger H. mitchelli complex with H. mitchelli and H. rubrovermiculatus. The new species is distinguished from other closely related Hyperolius species by genetic divergence, morphology, vocalisation, and dorsal colouration.

Keywords: Amphibia, Amphibian, endemic, coastal pans

 Werner Conradie, Luke Verburgt, Daniel M. Portik, Annemarie Ohler, Beryl A. Bwong and Lucinda P. Lawson. 2018. A New Reed Frog (Hyperoliidae: Hyperolius) from coastal northeastern Mozambique. Zootaxa. 4379(2); 177–198.   DOI:  10.11646/zootaxa.4379.2.2

facebook.com/EnviroInsightSA/photos/1607331866026107
facebook.com/PEMHerp/posts/1783215375098676

[Herpetology • 2017] Hyperolius ruvuensis • A New, Narrowly Distributed, and Critically Endangered Species of Spiny-throated Reed Frog (Anura: Hyperoliidae) from A Highly Threatened Coastal Forest Reserve in Tanzania

Hyperolius ruvuensis 

Barratt, Lawson & Loader, 2017 

 thebhs.org

Abstract

 Amphibians are in decline globally due to increasing anthropogenic changes, and many species are at risk of extinction even before they are formally recognised. The Coastal Forests of Eastern Africa is a hotspot of amphibian diversity but is threatened by recent land use changes. Based on specimens collected in 2001 we identify a new species from the coastal forests of Tanzania. The new species belongs to the spiny-throated reed frog complex that comprises a number of morphologically similar species with highly fragmented populations across the Eastern Afromontane Region, an adjacent biodiversity hotspot comprising of numerous isolated montane forests. The new species is the first coastal forest member of this otherwise montane clade. We formally describe this species, assess its distribution and conservation threat, and provide a revised key to species of the spiny throated reed frog complex. We highlight the most important characters distinguishing the new species from the other similar reed frog species. Recent surveys at the type locality and also more broadly across the region failed to find this new species. The conservation threat of this species is critical as the only known locality (Ruvu South Forest Reserve) is currently subjected to devastating land use changes.

Key words: Coastal Forests of Eastern Africa, conservation, habitat destruction, Hyperolius ruvuensis sp. n., Hyperolius spinigularis, Tanzania Ruvu South Forest Reserve

Fig. 3. Dorsal (A) and ventral (B) views of the holotype of Hyperolius ruvuensis sp. n. BMNH 2002.410.

Scale bar = 1 cm. 

Hyperolius ruvuensis sp. n. Barratt, Lawson and Loader 

Ruvu Spiny Reed Frog

Etymology.— The species is named after Ruvu South Forest Reserve where the specimens were collected and is the current extent of the species occurrence.

  Christopher D. Barratt, Lucinda P. Lawson, Gabriela B. Bittencourt-Silva, Nike Doggart, Theron Morgan-Brown, Peter Nagel and Simon P. Loader. 2017. A New, Narrowly Distributed, and Critically Endangered Species of Spiny-throated Reed Frog (Anura: Hyperoliidae) from A Highly Threatened Coastal Forest Reserve in Tanzania. Herpetological Journal.  27; 13-24.

Newly discovered Tanzanian frog already facing extinction
https://news.mongabay.com/2017/03/newly-discovered-tanzanian-frog-already-facing-extinction/ via @mongabay