Posts tagged madagascar.
Geckolepis typica Grandidier, 1867
Geckolepis typica is generally considered to be broadly distributed across southern and western Madagascar, ranging as far north as Mahajanga, and as far east as the Anosy Mountains, but never particularly far inland (Köhler et al. 2009). It is a low-altitude specialist, and is not found above 650 m above sea level. Its habitat consists of a variety of dry and spiny forests. Geckos belonging to the strict G. typica (clade K in Lemme et al. 2012) are only found in southern Madagascar.
Morphology & Colouration:
Geckolepis typica has a medium-sized gecko, not exceeding 53 mm in body length. The tail is usually as long as or longer than the body. The innermost postmental scales do not make substantial contact with one another (this is important). It possess 28-32 scale rows at midbody. Like all Geckolepis species, it has large scales covering slippery skin, and these are shed easily upon capture to facilitate its escape.
The body colouration is uniform grey/brown, occasionally with longitudinal dark lines, but without heavy dark spots.
Geckolepis typica is an arboreal, nocturnal species. It typically roosts beneath loose bark on dead trees, or, less commonly, under rocks at the base of trees. It eats a variety of insects. Eggs are laid under tree bark or beneath stones as well. These geckos may aestivate, storing fat in the base of their tails.
Geckolepis typica is listed as Least Concern by the IUCN Red List, as it is widely distributed and is quite common.
Systematics and Taxonomy:
The taxonomy of the genus Geckolepis is complicated. G. anomala and G. petiti were moved into synonymy with G. typica by Köhler et al. (2009), and generally differed from G. typica only in characters of the postmental scale arrangement. G. typica is smaller than G. maculata and has fewer scale rows at mid body. It is larger than G. polylepis, and that species also has its postmental scales in broad contact, unlike those of G. typica.
Geckolepis typica is thought to refer to clade K from Lemme et al. (2012). It is clear that at least three species from this genus remain undescribed, with a possible diversity of up to 10 total species. Characters here are therefore given for G. typica sensu stricto, and reference to Lemme et al. (2012) is recommended.
First photo by Mark Scherz, second by Alejandro Lozano.
Köhler, G., H.-H. Diethert, R.A. Nussbaum and C.J. Raxworthy. 2009. A revision of the fish scale geckos, genus Geckolepis Grandidier (Squamata, Gekkonidae) from Madagascar and the Comoros. Herpetologica 65:419-435
Lemme, I., M. Erbacher, N. Kaffenberger, M. Vences and J. Köhler. 2012. Molecules and morphology suggest cryptic species diversity and an overall complex taxonomy of fish scale geckos, genus Geckolepis. Organisms Diversity & Evolution 13:87-95
Giant Leaftail Gecko | ©Giovanni Mari (Nosy Mangabe, Madagascar)
Endemic to Madagascar, the Giant Leaftail Gecko or Common Flat-tail Gecko, Uroplatus fimbriatus (Gekkonidae) can reach a total length of 330 mm. This large nocturnal gecko, is found in eastern Madagascar and on the islands Nosy Bohara and Nosy Mangabe.
According to the assessment of the IUCN Red List of Threatened Species (2013.2):
There is uncertainty about the number of species represented under the names Uroplatus fimbriatus and U. giganteus (F. Glaw and M. Vences pers. comm. January 2011). Raxworthy et al. (2008) consider U. giganteus to be a synonym for U. fimbriatus; however it has also been argued that additional undescribed species may be revealed within U. giganteus and/or U. fimbriatus by future molecular study (F. Glaw pers. comm. January 2011).
The scheme followed here is that of Glaw et al. (2006), which considers this group to consist of two species, U. fimbriatus and U. giganteus, which correspond to the southern and northern clades of U. fimbriatus respectively (Raxworthy et al. 2008; F. Glaw, pers. comm. January 2011).
Due to the geographical proximity of the U. fimbriatus type locality, Nosy Mangabe, to genetic U. giganteus, further research is needed to establish whether the assignment U. fimbriatus to the southern clade treated here under that name is valid, or whether this name should instead be applied either to a single species including both presently recognized clades, or to a northern form presently included under the name U. giganteus (C. Raxworthy pers. comm. January 2011).
This situation is a little clearer now:
In 2013, Ratsoavina et al. performed a diversity assessment of the genus Uroplatus. They showed, among other things, that one species (U. ebenaui) is actually ~9 cryptic species. They considered all of thegiant leaftails from Nosy Mangabe southward as U. fimbriatus, and U. giganteus northward of Nosy Mangabe. They did, however, highlight the fact that far more data will be needed before their taxonomic situation can be cleared up.
Ratsoavina, F.M., N.R. Raminosoa, E.E. Louis Jr., A.P. Raselimanana, F. Glaw and M. Vences. 2013. An overview of Madagascar’s leaf tailed geckos (genus Uroplatus): species boundaries, candidate species and review of geographical distribution based on molecular data. Salamandra 49:115-148
Langaha madagascariensis (Colubridae), commonly called Madagascar leaf‐nosed snake, is endemic to Madagascar, as its common and scientific names point out.
Langaha is a medium-sized, slender, arboreal, mostly diurnal Malagasy colubrid genus comprised of three species, all of which can be quickly identified by the presence of a large leaf like rostral appendage.
A report published in 2008 demonstrates that L. madagascariensis is a potentially harmful snake capable of envenoming humans.*capable of envenomating scientists who purposefully allow the snake to chew on their hand for a little bit to see the effect of its venom. These snakes are not dangerous at all; certainly no more so thanHeterodon spp., and almost infinitely harder to find.
Calumma tarzan Gehring, Pabijan, Ratsoavina, Köhler, Vences & Glaw, 2010
The Tarzan Chameleon
Calumma tarzan is found in only a tiny area of fragmented forest in central eastern Madagascar.
Morphology & Colouration:
Calumma tarzan is a medium-sized chameleon, reaching a maximum total length of 15 cm. It possesses a unique rostral ornamentation, consisting of a small spade-like projection, which is larger in males than females.
Ground colouration ranges from green to bright yellow. In males, the back of the head and neck are brown to blackish in colouration. When stressed, dark transverse bands appear along the body. A single white/yellow spot is present on each flank. A pair of white ventral bands runs the length of the body, as is typical for the C. furcifer group of chameleons.
Like most chameleons, C. tarzan is an arboreal, diurnal species. It roosts at night at the tips of branches at a height of 1-4 metres above the ground - apparently lower in juveniles.
Calumma tarzan is currently listed as Critically Endangered in the IUCN Red List. It is thought to inhabit an area of less than 10km2, which is under heavy threat from deforestation.
Calumma tarzan does not closely resemble any other chameleon species, even those it is most closely related to, because of its unique rostral appendage, and stress colouration. A population of chameleons from a nearby forest fragment was described by Gehring et al. (2010), which may be conspecific with C. tarzan, but this remains unclear.
Photos are of the male holotype of the species, from Gehring et al. 2010.
Gehring, P.-S., M. Pabijan, F.M. Ratsoavina, J. Köhler, M. Vences & F. Glaw (2010) ‘A Tarzan yell for conservation: a new chameleon, Calumma tarzan sp. n., proposed as a flagship species for the creation of new nature reserves in Madagascar' Salamandra 46(3):167-179
TSA Turtle Tuesday: Spider Tortoise
Did you know that the spider tortoise (Pyxis arachnoides) gets its common name from the beautiful pattern on its shell that resembles a spider web?
Endemic to the dry, coastal areas of western and southern Madagascar, this small tortoise is partial to eating grasses, young leaves, and succulent plants, as well as insects. This shy chelonian is most active during the wet season (November through April) when the vegetation that it thrives on is lush. During the dry season, the spider tortoise buries itself deep in the sand and becomes dormant as the weather gets colder. This is believed to be an energy saving mechanism which allows the tortoise to retain necessary moisture until the wet season and the lush vegetation returns!
The TSA has been active in conservation programs in Madagascar, specifically with critically endangered spider tortoises and radiated tortoises, since 2007… read more here.
(via: Turtle Survival Alliance)
One of Madagascar’s four endemic tortoise species. They are also sometimes called pixie tortoises because they are are so small and adorable.
The Malagasy leaf-nosed snake, Langaha madagascariensis (1790)
Phylum : Chordata
Class : Reptilia
Order : Squamata
Suborder : Serpentes
Family : Colubridae
Genus : Langaha
Species : L. madagascariensis
Malagasy leaf-nosed snake is a medium-sized highly cryptic arboreal species. It is endemic to Madagascar and found in deciduous dry forests and rain forests. There is considerable sexual dimorphism within the species; the males are dorsally brown and ventrally yellow with a long tapering snout while the females are mottled grey with a leaf shaped snout.
Malagasy leaf-nosed snake is largely a sit-and-wait predator. It may show curious resting behaviour, hanging straight down from a branch.
Malagasy leaf-nosed snake is generally calm and reluctant to bite unless provoked. Envenomation by the snake causes severe pain in humans but is not deadly.
Parastenophis betsileanus - the genus changed from Stenophis based on the work of Nagy et al. 2010.
Nagy, Z. T., Glaw, F. & Vences, M. 2010. Systematics of the snake genera Stenophis and Lycodryas from Madagascar and the Comoros. Zoologica Scripta 39:426–435.
Giant Malagasy Hognose Snake (Leioheterodon madagascariensis)
…a large species of Hognose Snake that is native to Madagascar and the Nosy Be, Nosy Saktia and Comoros Islands. True to their common name L. madagascariensis is quite large and can reach lengths of around 180 cm (6 ft). L. magagascariensis is diurnal and occupies a wide range of habitats, including humid and dry forests, shrublands and grasslands. They feed mainly on small birds and rodents, and are known to take reptile eggs as well.
Image: Frank Vassen
Uroplatus phantasticus (Boulenger, 1888)
The Satanic Leaf-tailed Gecko.
Asked by libutron
This is a fantastic question, and one that is rather contentious, and takes quite a lot of answering. So I’m sorry this has taken weeks to put together, but here is the extremely long answer to the question:
Until recently, it was believed that mainland Africa had only pythons and a single group of boas (sandboas, genus Eryx), while the rest of the boas boas were restricted to the Americas… and Madagascar.
Madagascar’s large constricting snakes were assigned in their early descriptions to the Boidae. Indeed, so alike are Madagascar’s boas to those of the Americas that it misled phylogenetic reconstructions of them:
In 1991, based solely on morphological characters (molecular phylogenetics was in its infancy), Kluge found Acrantophis and Sanzinia to be sister to the South American genus Boa. And so he synonymised them, transferring the Malagasy boas to the South American genus, thus rendering a genus Boa with the following members: Boa constrictor (and subspecies thereof), B. madagascariensis, B. dumerili, and B. manditra - Sanzinia madagascariensis obviously couldn’t become Boa madagascariensis, because Acrantophis madagascariensis had already taken that name, so he erected a new name for this species.
As it turns out, moving Madagascar’s boas to the genus Boa was a huge mistake. But Madagascar’s boas are boas (Family Boidae: Subfamily Sanziniinae), they just don’t belong in the genus Boa. A phylogeny produced by Noonan & Chippindale (2006a) showed that the genus Boa belongs to a neotropical clade, together with Epicrates, Eunectes, and Corallus. These are closest related to a group containing Afro-Indian Eryx plus Candoia from Papua New Guinea. These together are then related to the North and Central American boas (Exiliboa+Lichanura+Charina). Finally, sister to this whole group of New World+Australiasian boas is a clade containing Calabaria, Acrantophis, and Sanzinia. This whole group is formalised as Boidae, and is sister to the Pythonidae in the Noonan & Chippindale phylogeny.
Until this point, Calabaria were thought to be allied to pythons and not to boas, but the molecular work of this and subsequent studies showed that to be quite incorrect. So boom, another group of boas is present in Africa. Woo.
All subsequent phylogenies (and several earlier ones that I can’t be bothered to go find) have supported this view that Madagascar’s boas belong in their own genera (Sanzinia and Acrantophis), and yet still Wikipedia would have you believe that they are in Boa. I will fix this in the next few weeks, but in the mean time, ignore it. Focus on my argument here.
In light of more complete taxonomic and genetic sampling by Pyron et al. (2013), it was shown that boas and pythons aren’t even sister groups (which we knew before, but never with quite such nice resolution and such high taxon sampling). Rather Boidae+Calabaridae are sister to a group containing Anomochilidae+Cylindrophiidae+Uropeltidae+Xenopeltidae+Loxocemidae+Pythonidae. Together, these two clades comprise the superfamily Henophidia (ancient snakes), which is paraphyletic with regards to all other snakes except the blind snakes, but shh we can ignore that for now.
Anyway, the important thing is that both of these reports (Noonan & Chippindale 2006a and Pyron et al. 2013) agree on one key point: Madagascar’s boas are unequivocally the oldest radiation of boas.
How, then, did Madagascar’s boas get to Madagascar? Well, Noonan & Chippindale (2006a, 2006b) suggested a vicariant origin; that they were in Madagascar when it broke off from Gondwana as it split. This vicariant origin is further supported by the rapid diversification in deep branches in the boids (Noonan & Chippindale 2006a).
However, the age of the African clade (Calabaria+Acrantophis+Sanzinia) suggested by Noonan & Chippindale (2006a, 2006b) is 30 million years after Madagascar lost contact with Antarctica, and through Antartica, South America; and 11 million years after Madagascar lost contact with India and became isolated (Samonds et al. 2013). It would be prudent therefore to interpret this as either incorrect inferrence by Noonan & Chippindale in both papers, or indication of oceanic dispersal. I lean towards the results of Noonan & Chippindale being wrong because of the way they calculated their clade ages (poor outgroup choice with an incorrect date).
After the split from Africa, Madagascar maintained connection with India and, through a land bridge connecting to Antarctica, was connected to South America, and could continue to exchange species with it for at least a few million years (Noonan & Chippindale 2006a; Samonds et al. 2013). This left Madagascar with its own boas, one of which apparently dispersed to Africa to give rise to Calabaria. Not until much later did Madagascar’s modern boa genera arise on the island.
Today, most authors (e.g. Pyron et al. 2013; Reynolds et al. 2014) tend to assume that Calabaria, which is a troublesome group, genetically, is actually basal to all boas, and do not include it in the true boas. They do not, however ,make any comment on the implications of this, in terms of origins.
Bizarrely, the Round Island Boa (Casarea dussumieri) is not related to those of Madagascar at all (Round Island is very close to Madagascar - just north of Mauritius), but is instead most closely related to a Malaysian lineage, and only distantly related to other constrictors at all (Reynolds et al. 2014). How it fits into this picture is very unclear.
The implication then is that pythons and boas split long before Madagascar broke off from Africa. Very recent (read: not yet physically published but available online) research by Reynolds et al. (2014) has suggested an origin for the modern pythons in what is today northern Africa, whence they then spread south, north, and east. The boas, on the other hand, are suggested to have arisen in southern Gondwana by some authors (Reynolds et al. 2014) and Asia by others (Noonan & Sites 2010).
But the problem is that Reynolds et al. (2014), and indeed all authors working on the relationships of the Henophidian snakes, have not attempted to figure out where and when the other families arose. Thus, we have no idea where the ancestors were at the time of the split of Gondwana. All we can postulate is that Madagascar had boas when it split off (perhaps getting them after Africa was isolated from the rest of Gondwana via land bridges to Antarctica+South America; Samonds et al. 2013), while pythons were further up in Africa somewhere. Then, when pythons radiated down into Africa, they didn’t make it across to Madagascar - or if they did, they went extinct soon afterwards.
tl;dr: Nobody knows for sure. Nobody has really even tried to find out. Probably because it’s not a very interesting question (relatively speaking).
Kluge, A. G. (1991) ‘Boine snake phylogeny and research cycles' Miscellaneous Publications, Museum of Zoology, University of Michigan 178:1-58
Noonan, B. P. & P T. Chippindale (2006a) ‘Dispersal and vicariance: The complex evolutionary history of boid snakes' Molecular Phylogenetics and Evolution 40:347-358
Noonan, B. P. & P T. Chippindale (2006b) ‘Vicariant Origin of Malagasy Reptiles Supports Late Cretaceous Antarctic Land Bridge' The American Naturalist 168(6):730-741
Noonan, B. P. & J. W. Sites Jr. (2010) ‘Tracing the origins of iguanid lizards and boine snakes of the Pacific' The American Naturalist 175(1):61-72
Pyron, R. A., F. T. Burbrink & J. J. Wiens (2013) ‘A phylogeny and revised classification of Squamata, including 4161 species of lizards and snakes' BMC Evolutionary Biology 13:93
Reynolds, R. G., M. L. Niemiller & L. J. Revell (2014) ‘Toward a Tree-of-Life for the boas and pythons: Multilocus species-level phylogeny with unprecedented taxon sampling' Molecular Phylogenetics and Evolution 71:201-213
Samonds, K. E., L. R. Godfrey, J. R. Ali, S. M. Goodman, M. Vences, M. R. Sutherland, M. T. Irwin & D. W. Krause (2013) ‘Imperfect isolation: factors and filters shaping Madagascar’s extant vertebrate fauna' PLoS One 8(4):e62086
Calumma vohibola Gehring, Ratsoavina, Vences & Glaw, 2011
The Vohibola Short-nosed Chameleon
This species is currently only known from the primary and secondary littoral forest of Vohibola in the north-central range of Madagascar’s eastern rainforest belt.
Morphology & Colouration:
Calumma vohibola is a fairly small chameleon, reaching a total length of nearly 10 cm. It has a low casque (brain case) and a very small, soft rostral (nose) appendage, which is almost completely absent in females. This species lacks axillary pits (arm pits), a useful character to distinguish it from several closely related and superficially similar species.
A dorsal crest of seven well-spaced spines is present only in some males of the species. The reason for this intra-specific variation is unclear.
Calumma vohibola is typically brown to greyish in colour. Females exhibit a distinct stress colouration of dark-red/brownish with irregularly arranged blueish spots.
Little to nothing is known about the habits of this species, other than the typical hallmarks of Calumma chameleons: it is a diurnal, arboreal insectivore, which roosts at night at the tips of branches.
Calumma vohibola has not been assessed for the IUCN Red List. Its habitat is highly threatened and fragmented however, so it may be a threatened species. Nonetheless, it appears to be relatively tolerant to forest disturbance, so its survival may not be so threatened.
Calumma vohibola is a member of the C. nasutum species complex. These chameleons have a very characteristic body shape, but identification between species is often difficult. This group contains several candidate species.
Photo is the male holotype of the species, and is taken from Gehring et al. 2011.
Gehring, P.-S., F. Ratsoavina, M. Vences & F. Glaw (2011) ‘Calumma vohibola, a new chameleon species (Squamata: Chameleonidae) from the littoral forests of eastern Madagascar' African Journal of Herpetology, 60(2):130-154
Thamnosophis mavotenda Glaw, Nagy, Köhler, Franzen & Vences, 2009
This species is known only from one individual found in the Tsingy de Bemaraha karstic massif in central western Madagascar. A possible second individual was found 300km north, in the Tsingy de Namoroka Special Reserve.
Morphology & Colouration:
Like all members of the genus Thamnosophis, T. mavotenda has 19 scale rows at midbody. This species has more ventral and subcaudal scales than any other members of the genus however.
T. mavotenda receives its name from the characteristic yellow colouration of its throat (Malagasy: mavo = yellow, tenda = throat).
When disturbed, this species can flatten its neck and expand its body, revealing the shocking white colouration of the borders of its dorsal scales.
This is a diurnal snake species. Nothing else is known about its habits.
T. mavotenda is listed as Near Threatened on the IUCN Red List due to its apparently small range which is declining in quality.
Genetically, T. mavotenda is closest related to T. martae, a species found in far northern Madagascar. Glaw et al. (2009) argue that these sister species exemplify historical biogeographical links between western and northern Madagascar, as have been recovered with weaker support for several other species pairs.
Photo is of the male holotype of the species, and is from Glaw et al. 2009
Glaw, F., Z.T. Nagy, J. Köhler, M. Franzen & M. Vences (2009) ‘Phylogenetic relationships of a new species of pseudoxyrhophiine snake (Reptilia: Lamprophiidae: Thamnosophis) suggest a biogeographical link between western and northern Madagascar' Organisms, Diversity & Evolution 9:13-22
Phelsuma borai Glaw, Köhler & Vences 2009
This species is currently known exclusively from the Tsingy de Bemaraha National Park and surrounding forest in western Madagascar. However, it is probably more widely distributed.
Morphology & Colouration:
P. borai is a medium-sized day gecko. It has an unusually large number of supralabial (upper-lip) scales (9-10), but is best distinguished from all closely related species by peculiarities of the throat scalation.
Like all Phelsuma species, P. borai has highly reduced first digits on its hands and feet.
Unlike most members of the genus Phelsuma, P. borai has (a) highly cryptic colouration and (b) an astonishing capacity for colour change. The two photos above are the same individual - a male (the holotype of the species) - under different conditions. The cryptic phase blends well with mottled tree surfaces. The so-called ‘brilliant’ phase with the blue tail is expressed under conditions of bright sunlight.
P. borai is a diurnal, arboreal gecko, like almost all other members of the genus Phelsuma. Very little else is known about its habits.
P. borai is currently listed as ‘Data Deficient’ in the IUCN Red List.
Genetically, this species is very distinct from all other species of Phelsuma. It groups together with P. mutabilis and P. breviceps, which have similar cryptic colouration, at the base of the Phelsuma tree.
Images are of the holotype of the species, and are from Glaw et al. 2009.
Glaw, F., J. Köhler & M. Vences (2009) ‘A new species of cryptically coloured day gecko (Phelsuma) from the Tsingy de Bemaraha National Park in western Madagascar' Zootaxa 2195:61-68