ZOBODAT - www.zobodat.at Zoologisch-Botanische Datenbank/Zoological-Botanical Database Digitale Literatur/Digital Literature Zeitschrift/Journal: Zoosystematics and Evolution Jahr/Year: 2019 Band/Volume: 95 Autor(en)/Author(s): Griesbaum Frederic, Hirschfeld Mareike, Barej Michael F., Schmitz Andreas, Rohrmoser Mariam, Dahmen Matthias, Mühlberger Fabian, Liedtke H. Christoph, Gonwouo Nono L., Doumbia Joseph, Rödel Mark-Oliver Artikel/Article: Tadpoles of three western African frog genera: Astylosternus Werner, 1898, Nyctibates Boulenger, 1904, and Scotobleps Boulenger, 1900 (Amphibia, Anura, Arthroleptidae) 133-160 Creative Commons Attribution 4.0 licence (CC-BY); original download https://pensoft.net/journals Zoosyst. Evol. 95 (1) 2019, 133–160 | DOI 10.3897/zse.95.32793 Tadpoles of three western African frog genera: Astylosternus Werner, 1898, Nyctibates Boulenger, 1904, and Scotobleps Boulenger, 1900 (Amphibia, Anura, Arthroleptidae) GenBank Frederic Griesbaum1, Mareike Hirschfeld2, Michael F. Barej1, Andreas Schmitz2, Mariam Rohrmoser1, Matthias Dahmen1, Fabian Mühlberger1, H. Christoph Liedtke3, Nono L. Gonwouo4, Joseph Doumbia5, Mark-Oliver Rödel1 1 Museum für Naturkunde, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstr. 43, 10115 Berlin, Germany 2 Natural History Museum of Geneva, UREC-Herpetology & Ichthyology, Route de Malagnou 1, 1208 Genève, Switzerland 3 Ecology, Evolution and Developmental Group, Department of Wetland Ecology, Estación Biológica de Doñana (CSIC), 41092 Sevilla, Spain 4 Cameroon Herpetology – Conservation Biology Foundation (CAMHERP-CBF), PO Box 8218, Yaoundé, Cameroon 5 ONG EnviSud Guinée, Quartier Kipé T2, Commune de Ratoma, 030 BP 558 Conakry, République de Guinée http://zoobank.org/3447C059-0FE0-482F-81D0-9F91BC1ED7EC Corresponding author: Mark-Oliver Rödel ([email protected]) Abstract Received 2 January 2019 Accepted 11 March 2019 Herein, we describe the tadpoles of six Astylosternus species, A. fallax, A. cf. fallax, A. Published 5 April 2019 laurenti, A. montanus, A. perreti, A. ranoides, and Scotobleps gabonicus, and redescribe the tadpoles of A. batesi, A. diadematus, A. laticephalus, A. occidentalis, A. rheophilus, Academic editor: and Nyctibates corrugatus. All Astylosternus tadpoles are adapted to torrent currents and Johannes Penner share a long, oval body, slightly flattened in lateral view, with very long muscular tails with narrow fins. The jaws are massive, serrated, and often show a tooth-like medial pro- Key Words jection (fang) in the upper jaw. Body proportions of Astylosternus tadpoles are extremely similar. The best characters to distinguish species might be life coloration and potentially Barcoding the shape of labial papillae. The tadpole of Scotobleps gabonicus is similar to Astyloster- larval stages nus and differs only slightly by a narrower body with a shorter and rounder head. The Lower Guinea forest upper jaw of Scotobleps carries two or three lateral fangs instead of one medial one. The rainforest tadpole of Nyctibates corrugatus is easily distinguishable from the other two genera on Upper Guinea forest the basis of their very long, eel-shaped body and tail and the bluish-black color. western Africa Introduction lenger, 1900 is restricted to western and central Africa and has stream-dwelling tadpoles with special morpho- The anuran family Arthroleptidae comprises eight gen- logical characteristics like an eel-shaped body and an era, all being endemic to sub-Saharan Africa (Frost elongated spiraculum (Hirschfeld et al. 2012). The genus 2018). The species-rich genera, Arthroleptis Smith, 1849 Leptodactylodon Andersson, 1903, is restricted to the and Leptopelis Günther, 1859, are widespread and oc- western part of central Africa. The tadpoles are likewise cur in forest and open habitats (Blackburn 2008; Schiøtz stream dwellers, but presumably live in the interstitial 1999). Whereas all Arthroleptis seem to reproduce by ter- spaces between pebbles and have special funnel mouths restrial, direct development (Guibé and Lamotte 1958a; (Mapouyat et al. 2014). The tadpoles of the Hairy Frog, Lamotte and Perret 1963; Wager 1986; Schweiger et Trichobatrachus Boulenger, 1900, live in torrent, moun- al. 2017), Leptopelis deposit their clutches in soil, from tainous streams from eastern Nigeria, south to northern where the hatched, long and slender, exotrophic tadpoles Angola (Ernst et al. 2014). They are comparatively short move into lentic or lotic waters (Rödel 2000; Channing and robust with a huge oral sucker and numerous rows 2008; Barej et al. 2015). The genus Cardioglossa Bou- of keratodonts (Mertens 1938; Channing et al. 2012). Copyright Frederic Griesbaum et al. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Creative Commons Attribution 4.0 licence (CC-BY); original download https://pensoft.net/journals 134 Frederic Griesbaum et al.:Tadpoles of three western African frog genera Two of the three remaining genera, Astylosternus Werner, (horizontal nostril diameter), IOD (interorbital distance), 1898 and Nyctibates Boulenger, 1904, have large, long IND (inter-nasal distance), SN (nostril-snout distance), and very muscular stream-dwelling tadpoles, as far as is EN (eye-nostril distance), ES (eye-snout distance), MW known (Amiet 1971; Channing et al. 2012). The tadpole (mouth width), SP (spiracle length) and SSD (snout-spira- of Scotobleps Boulenger, 1900, a monotypic genus rang- cle distance). Based on these measures the following pro- ing from south-eastern Nigeria to Gabon and the Repub- portions were calculated: BL/TL, BH/BL, BW/BL, BH/ lic of the Congo (Portik et al. 2017) is unknown, as are MTH, TMW/BW, TMH/MTH, VFH/DFH, IND/IOD, ED/ the tadpoles of various Astylosternus species. BL. All measurements are provided in Appendix 1. During the last 15 years we collected numerous tad- In the text, measurements or ratios are usually summa- poles of morphologically similar, torrenticolous arth- rized (for N ≥ 3) and given as: mean ± standard deviation roleptid tadpoles, apparently belonging to 10 species of and range (min–max). As we tried to predominately use Astylosternus, Nyctibates corrugatus, and Scotobleps genotyped specimens for the descriptions and the tail tips gabonicus. We present re-descriptions of tadpoles of six were missing in most of them (see above), the total length species (A. batesi, A. diadematus, A. laticephalus, A. oc- was either determined in comparison with alternative cidentalis, A. rheophilus, and N. corrugatus) and new specimens of the same series and developmental stage tadpole descriptions for six additional species, amongst or estimated based on the usual tail shape of the group. them the first from the genusScotobleps . The mouthpart formulae are in accordance with Dubois (1995). In addition, the number, form and arrangement of the labial papillae were accessed and described. We Material and methods further checked for a lateral line system. As all tadpoles proved to possess such organs in an identical arrange- Collection, preservation, deposition and barcodes ment, we excluded it from the species-specific tadpole descriptions and instead present a summary description Tadpoles were collected with dip nets and anesthetized at the end of the result section. The terminology of lateral in chlorobutanol solutions before being either preserved lines follows Escher (1925). The staging of tadpoles was in formalin (5–10%) or ethanol (75%). All were finally according to Gosner (1960). Whenever possible we tried stored in 75% ethanol. Prior to preservation tail tips of rep- to choose tadpoles of Gosner stages 25–30 for descrip- resentative specimens were preserved separately in 96% tions. Descriptions of life coloration are based on photos ethanol for genetic investigations. All tadpole vouchers taken in the field. and tissue samples are deposited at the collection of the Museum für Naturkunde Berlin (ZMB; see descriptions). Illustrations For comparisons we examined further adult frogs and cor- Photos of entire tadpoles were taken with a Canon EOS responding sequences from the collections of Natural His- 50D digital camera and a 50 mm 1:2.5 lens. Mouth- tory Museum of Geneva (MHNG; Geneva, Switzerland) part pictures were taken with a stacking camera (Leica and the Zoological Research Museum A. Koenig (ZFMK; DFC490) on a Leica Z16 APO A microscope. Single ex- Bonn, Germany). Tadpoles were assigned to species by posures were combined using the Automontage® soft- DNA-barcoding, using up to 558 bp of the mitochondri- ware v. 5.03.0061 (Syncroscopy). All pictures were edit- al 16S rRNA gene; for exact laboratory procedures see ed with Adobe Photoshop v. 18.1.0. Schematic sketches Mapouyat et al. (2014) and Barej et al. (2015). All se- of the keratodont formulae are usually based on several quences of tadpoles and adults have been produced for this individuals of the respective species. study and deposited at GenBank (for accession numbers see tadpole descriptions). Comparisons between sequenc- Analysis of morphological differences es were carried out using BioEdit 7.0.9.0 (Hall 1999). To test, if and how the tadpoles of the different species Character assessment can be distinguishable, we plotted indices of our various measures against each other and ran a Principle Compo- All measurements were taken by FG and MR. Measure- nent Analysis