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Conservation Genetics

, Volume 16, Issue 1, pp 235–240 | Cite as

DNA barcoding of Cameroon samples enhances our knowledge on the distributional limits of putative species of Osteolaemus (African dwarf crocodiles)

  • Nicole L. Smolensky
  • Luis A. Hurtado
  • Lee A. Fitzgerald
Short Communication

Abstract

Recent genetic and morphological evidence indicates that the African dwarf crocodile (O. tetraspis) is comprised of three highly divergent lineages: O. sp. nov., O. tetraspis and O. osborni. Their putative distributional limits correspond with the Cameroon volcanic line (CVL) and the Congo River basin. In this study, we expanded on previous phylogeographic work by conducting detailed sampling of this crocodile in Cameroon and around the CVL. We tested whether O. tetraspis is the only lineage occurring in Cameroon and whether the CVL represents the distributional limit between O. sp. nov. and O. tetraspis. We collected 65 tissue samples from individuals located throughout Cameroon, and the eastern and western sides of the CVL. We sequenced fragments of two mitochondrial genes (CO1 and 12S rDNA) and one nuclear gene (LDH-A). We found that O. tetraspis extends west beyond the CVL and, thus, this mountain chain does not represent the distributional limit of this lineage. We also found O. osborni in Cameroon. Our findings have important implications for the conservation and management of O. tetraspis lineages.

Keywords

Conservation units Crocodylia Phylogeography Volcanic mountain chain 

Notes

Acknowledgments

We attained approval and permits issued by Texas A&M University (TAMU) IACUC (AUP# 2010-123), Cameroon Ministries (MINRESI # 000064-2010, 000098-2011 and MINFOF# 0738-2010, 2149-2011) and US Fish and Wildlife Services (# 10US164015/9 – 2010, 11US47878A/9 - 2011). Funding was provided by TAMU Diversity Fellowship, Alfred P. Sloan Foundation Minority Ph.D. Program in Mathematics, Science and Engineering, Rufford Small Grants for Conservation of Nature, Student Research Assistance Scheme of the Crocodile Specialist Group-IUCN, and the L.T. Jordan Fellowship for International Awareness (TAMU). This is publication number 1475 of the Biodiversity Research and Teaching Collections.

Supplementary material

10592_2014_639_MOESM1_ESM.pdf (6 kb)
Supplementary material 1 (PDF 5 kb)
10592_2014_639_MOESM2_ESM.pdf (36 kb)
Supplementary material 2 (PDF 36 kb)
10592_2014_639_MOESM3_ESM.pdf (58 kb)
Supplementary material 3 (PDF 58 kb)

References

  1. Bickford D, Lohman DJ, Sodhi NS, Ng PK, Meier R, Winker K, Ingram KK, Das I (2007) Cryptic species as a window on diversity and conservation. Trends Ecol Evol 22:148–155PubMedCrossRefGoogle Scholar
  2. Clement M, Posada D, Crandall KA (2000) TCS: a computer program to estimate gene genealogies. Mol Ecol 9:1657–1659PubMedCrossRefGoogle Scholar
  3. Djeukam R (2012) The Wildlife law as a tool for protecting threatened species in Cameroon. Ministry of Forestry and Wildlife MINFOF, Yaounde, Cameroon, p 90Google Scholar
  4. Eaton MJ (2010) Dwarf Crocodile Osteoalemus tetraspis. In: Manolis SC, Stevenson C (eds) Crocodile Specialist Group. Darwin, Australia, pp 127–132Google Scholar
  5. Eaton MJ, Martin A, Thorbjarnarson J, Amato G (2009) Species-level diversification of African dwarf crocodiles (Genus Osteolaemus): a geographic and phylogenetic perspective. Mol Phylogenet Evol 50:496–506PubMedCrossRefGoogle Scholar
  6. Franke FA, Schmidt F, Borgwardt C, Bernhard D, Bleidorn C, Engelmann W-E, Schlegel M (2013) Genetic differentiation of the African dwarf crocodile Osteolaemus tetraspis Cope, 1861 (Crocodylia: Crocodylidae) and consequences for European zoos. Org Divers Evol 13(2):1–12CrossRefGoogle Scholar
  7. Hekkala E, Shirley MH, Amato G, Austin JD, Charter S, Thorbjarnarson J, Vliet KA, Houck ML, Desalle R, Blum MJ (2011) An ancient icon reveals new mysteries: mummy DNA resurrects a cryptic species within the Nile crocodile. Mol Ecol 20:4199–4215PubMedCrossRefGoogle Scholar
  8. IUCN (2012) The IUCN red list of threatened species. Version 2012.2. http://www.iucnredlist.org. Accessed 06 June 2013
  9. Linder HP, de Klerk HM, Born J, Burgess ND, Fjeldså J, Rahbek C (2012) The partitioning of Africa: statistically defined biogeographical regions in sub-Saharan Africa. J Biogeogr 39:1189–1205CrossRefGoogle Scholar
  10. Maddison D, Maddison W (2005) Macclade 4.08 for OSX. Sinauer Associates, Sunderland, MAGoogle Scholar
  11. Moretti S, Armougom F, Wallace IM, Higgins DG, Jongeneel CV, Notredame C (2007) The M-Coffee web server: a meta-method for computing multiple sequence alignments by combining alternative alignment methods. Nucleic Acids Res 35:W645–W648PubMedCentralPubMedCrossRefGoogle Scholar
  12. Nicolas V, Missoup AD, Denys C, Kerbis Peterhans J, Katuala P, Couloux A, Colyn M (2011) The roles of rivers and Pleistocene refugia in shaping genetic diversity in Praomys misonnei in tropical Africa. J Biogeogr 38:191–207CrossRefGoogle Scholar
  13. Ronquist F, Teslenko M, van der Mark P, Ayres DL, Darling A, Höhna S, Larget B, Liu L, Suchard MA, Huelsenbeck JP (2012) MrBayes 3.2: efficient Bayesian phylogenetic inference and model choice across a large model space. Syst Biol 61:539–542PubMedCentralPubMedCrossRefGoogle Scholar
  14. Ryberg WA, Fitzgerald LA, Honeycutt RL, Cathey JC (2002) Genetic relationships of American alligator populations distributed across different ecological and geographic scales. J Exp Zool 294:325–333PubMedCrossRefGoogle Scholar
  15. Schmitz A, Mansfeld P, Hekkala E, Shine T, Nickel H, Amato G, Bohme W (2003) Molecular evidence for species level divergence in African Nile Crocodiles Crocodylus niloticus (Laurenti, 1786). C R Palevol 2:703–712CrossRefGoogle Scholar
  16. Shirley MH, Vliet KA, Carr AN, Austin JD (2014) Rigorous approaches to species delimitation have significant implications for African crocodilian systematics and conservation. Proc R Soc B: Biol Sci 281:20132483CrossRefGoogle Scholar
  17. Silvestro D, Michalak I (2012) raxmlGUI: a graphical front-end for RAxML. Org Divers Evol 12:335–337CrossRefGoogle Scholar
  18. Stewart KM (2001) The freshwater fish of Neogene Africa (Miocene–Pleistocene): systematics and biogeography. Fish Fish 2:177–230CrossRefGoogle Scholar
  19. Tamura K, Peterson D, Peterson N, Stecher G, Nei M, Kumar S (2011) MEGA5: molecular evolutionary genetics analysis using maximum likelihood, evolutionary distance, and maximum parsimony methods. Mol Biol Evol 28:2731–2739PubMedCentralPubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media Dordrecht 2014

Authors and Affiliations

  • Nicole L. Smolensky
    • 1
  • Luis A. Hurtado
    • 1
  • Lee A. Fitzgerald
    • 1
  1. 1.Department of Wildlife and Fisheries SciencesTexas A&M UniversityCollege StationUSA

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