Molecular analysis of the genus Phelsuma brings more clarity in evolutionary relationships

A new study by Rocha et al. brings some more clarity in Phelsuma evolutionary relationships. Despite extensive work on Phelsuma taxonomy, ecology, biogeography and ethology, the relationships between species is not fully understood. Many species and subspecies descriptions are based only on variations in colour. Polymorphism is common in the genus, so some taxa are non-valid and only based on geographical colour morphs.

A new study by Rocha et al. brings some more clarity in Phelsuma evolutionary relationships. Despite extensive work on Phelsuma taxonomy, ecology, biogeography and ethology, the relationships between species is not fully understood. Many species and subspecies descriptions are based only on variations in colour. Polymorphism is common in the genus, so some taxa are non-valid and only based on geographical colour morphs.

Previous studies of the phenetic characters have led to the recognition of several species groups. Unfortunately these phenetic groups provide unreliable information about the evolutionary relationships among taxa. The main potential dif´Čüculty with Phelsuma taxonomy is thus its reliance on highly variable colouration characters, which has led to the description of a large number of species and subspecies.

This study is the most comprehensive molecular phylogenetic analysis of Phelsuma to date, based on a near-complete taxon sampling of all but the species, subspecies and forms listed below;

Phelsuma borbonica agalegae
Phelsuma borbonica borbonica

Phelsuma hoeschi
recently described (Berghoff & Trautman, 2009)
Phelsuma guimbeaui
Phelsuma laticauda angularis
Phelsuma lineata bombetokensis
Phelsuma lineata elanthana
Phelsuma lineata lineata
from the Terra Typica: Tamatave (Mertens, 1970)
Phelsuma lineata lineata from Perinet
Phelsuma lineata punctulata
Phelsuma
cf. madagascariensis from Sainte-Marie (Berghoff, 2005; Lerner, 1997)
Phelsuma madagascariensis from Andasibe (P. madagascariensis boehmei)
Phelsuma masohoala
Phelsuma pusilla hallmanni
Phelsuma
quadriocellata cf. parva from Nosy Be (Budzinski pers. comm.)
Phelsuma quadriocellata cf. parva from Ampasidava (Van Heygen, 2004)
Phelsuma quadriocellata lepida
Phelsuma quadriocellata bimaculata
Phelsuma sundbergi ladiguensis

Conclusions

The study reveals eight clades that simultaneously differentiated, grouping several species based on evolutionary ancestry and relationships. Most of the clades reflect previously hypothesized relationships.

Clade J (P. lineata group)
Phelsuma antanosy
Phelsuma quadriocellata
cf. bimaculata from Sainte Marie
Phelsuma quadriocelata parva
Phelsuma quadriocellata quadriocellata
Phelsuma pusilla
Phelsuma kely
Phelsuma lineata
cf. lineata from Sainte Luce
Phelsuma comorensis
Phelsuma lineata lineata
from Ranomafana (closest to the Terra Typica)
Phelsuma lineata dorsivittata
Phelsuma lineata
cf. dorsivittata from Marojejy
Phelsuma lineata
cf. dorsivittata from Ibarana

Clade K (P. laticauda group)
Phelsuma laticauda
Phelsuma pasteuri
Phelsuma robertmertensi
Phelsuma v-nigra v-nigra
Phelsuma v-nigra comoraegrandensis
Phelsuma v-nigra anjouanensis


Clade N (P. dubia group)
Phelsuma hielscheri
Phelsuma berghofi
Phelsuma malamakibo
Phelsuma flavigularis
Phelsuma dubia
Phelsuma ravenala
Phelsuma
cf. dubia from Antsalova

Clade P (P. modesta group)
Phelsuma modesta modesta
Phelsuma modesta leiogaster
Phelsuma modesta isakei
Phelsuma nigistriata

Clade Q (P. barbouri group)
Phelsuma barbouri
Phelsuma pronki


Clade M (Mascarene group)
Phelsuma guentheri
Phelsuma rosagularis
Phelsuma borbonica
Phelsuma cepediana
Phelsuma inexpectata
Phelsuma ornata

Clade D (P. mutabilis group)
Phelsuma breviceps
Phelsuma
sp. aff. mutabilis from Bemaraha
Phelsuma mutabilis


Clade E (P. madagascariensis group)
Phelsuma vanheygeni
Phelsuma astriata astriata
Phelsuma astriata semicarinata
Phelsuma sundbergi sundbergi
Phelsuma sundbergi longinsulae
Phelsuma guttata
Phelsuma madagascariensis
Phelsuma seippi
Phelsuma
cf. kochi from Manongarivo?
Phelsuma kochi
Phelsuma grandis
Phelsuma parkeri
Phelsuma abbotti sumptio
Phelsuma abbotti abbotti
Phelsuma abbotti chekei

The recently described Phelsuma vanheygeni is the sister taxon to the Seychelles members of the genus. This means that Phelsuma astriata and Phelsuma sundbergi share a common ancestor with Phelsuma vanheygeni. A similar situation can be found in clade K with Phelsuma laticauda, which is the sister taxon to the Comoro Islands members; Phelsuma pasteuri, Phelsuma robertmertensi and Phelsuma v-nigra. Phelsuma antanosy is a sister taxon to Phelsuma quadriocellata.

Phelsuma serraticauda is not closely related with Phelsuma laticauda and Phelsuma antanosy as previously suggested (Glaw et al.,1999; Austin et al., 2004; Van Heygen, 2004; Raxworthy et al., 2007 and Harmon et al., 2008), but represents an early diverging lineage.

Phelsuma klemmeri is not closely related to Phelsuma barbouri and Phelsuma pronki (Van Heygen 2004) but also represents an earlier diverging lineage. Phelsuma standingi and Phelsuma andmanense are of separate older lineages.

The recently described Phelsuma ravenala (Raxworthy et al., 2007) is probably a synonym of Phelsuma dubia and Phelsuma cf. dubia from Antsalova represents probably a subspecies, or even a species. Further study is necessary.

Phelsuma sp. aff. mutabilis is currently being described (Glaw pers. comm.) from the Tsingy de Bemaraha where it lives sympatric with its close relative Phelsuma mutabilis.


Refferences

Austin, J.J., Arnold, E. N. and Jones, C. G. (2004): Reconstructing an island radiation using ancient and recent DNA: the extinct and living day geckos (Phelsuma) of the Mascarene islands. Molecular Phylogenetics and Evolution 31 (1): 109-122

Berghof, H.-P. (2005): Taggeckos. Die Gattung Phelsuma. Pflege und Vermehrung. Natur und Tier-Verlag, Münster, 142 pp.

Berghof, H.-P. & G. Trautmann (2009): Eine neue Art der Gattung Phelsuma Gray, 1825 (Sauria: Gekkonidae) von der Ostküste Madagaskars. Sauria, Berlin, 31 (1): 5-14

Glaw, F., M. Vences & T. Ziegler (1999): Bemerkungen zu Phelsuma dubia (Boettger, 1881): Wiederentdeckung des Holotypus, Verwandtschaftsbeziehungen und Daten zur Fortpflanzung. Salamandra, 35(4): 267-278.

Lerner, A. (1997): Ein Besuch auf der Insel Ste. Marie (Ostmadagaskar). IG-Rundschreiben 1/97

Mertens, R. (1970): Neues uber einige Taxa der Geckonengattung Phelsuma Senckenb. biol. 51(1/2):1-13.

Raxworthy, C. J., C. M. Ingram, N. Rabibisoa, R. G. Pearson (2007): Applications of Ecological Niche Modeling for Species Delimitation: A Review and Empirical Evaluation Using Day Geckos (Phelsuma) from Madagascar. Systematic Biology, 56:6, 907-923

Rocha, S., M. Vences, F. Glaw, D. Posada and D.J. Harrisa (2009): Multigene phylogeny of Malagasy daygeckos of the genus Phelsuma. Molecular Phylogenetics and Evolution 52 (2009): 530–537

Van Heygen, E.,( 2004): Remarks on the Phelsuma barbouri - and Phelsuma klemmeri- phenetic groups. Phelsuma12, 153–154.