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1.
Brookesia dwarf chameleons, endemic to Madagascar, were surveyed at the following localities in northern Madagascar (north of 16°S): Montagne d'Ambre, Ankarana, Manongarivo, Tsaratanana, Marojejy and Masoala. A total of 15 species occur in this region. Six new species are described and five new synonyms are identified. The genus Brookesia , the most speciose chamaeleontid genus in Madagascar, contains 23 species.
Almost all the northern Brookesia species are restricted to rainforest and occupy a relatively narrow elevational range. Although the northern rainforests represent just one-third of the total rainforest and about 5% of the total island area, 65% of the Brookesia species occur in this region, and 52% are endemic to the northern rainforest. Five new biogeographic regions of the northern rainforest are identified based on centres of Brookesia endemicity: Montagne d'Ambre, Northwest, Tsaratanana, Northeast and East. Speciation is thought to have been facilitated in the north through geographic isolation, with the Tsaratanana mountain range and the dry forests south of Montagne d'Ambre forming barriers to dispersal, and the Tsaratanana mountains acting as a centre of isolation. The fragmented distribution of several Brookesia species of low altitude rainforest suggests a period in Madagascar's history when the climate was wetter and low altitude rainforest much more widespread.  相似文献   

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We describe a new species of the pseudoxyrhophiine snake genus Thamnosophis from a dry forest of the karstic massif Tsingy de Bemaraha in central western Madagascar. Thamnosophis mavotenda sp. n. is characterised by 19 dorsal scale rows, 188 ventrals, 110 subcaudals, and by colouration (e.g. yellow head sides). Morphological and molecular phylogenetic data indicate that the species is most closely related to the recently described Thamnosophis martae from the far north of the island which inhabits dry karstic forest and subhumid lowland rainforest. This species pair represents a well-supported example of a sister-group relationship in snakes between northern Madagascar and the Tsingy de Bemaraha plateau, and corroborates preliminary observations in other reptile species. We discuss this finding in the light of recent hypotheses on the biogeographic zonation of Madagascar.  相似文献   

4.
The males of three new and rare species of the Malagasy endemic genus Paractenopsyllus Wagner, 1938 are described. Paractenopsyllus beaucournui, P. oconnori and P. raxworthyi have been collected on endemic small mammals and the black rat. As for others species of the genus, biotopes are rain-forests of the central highlands or the northern mountains of Madagascar. Two of the described species were collected at elevations lower than typical for the genus and below the limits of the highland bioclimatic zone. Morphological affinities between these new species and those already described provide taxonomic framework for the genus. An updated identification key is provided for the diagnosis of all the 20 Malagasy species of Leptopsyllinae.  相似文献   

5.
Five new species of the malagasy endemic genus Paractenopsyllus Wagner, 1938, are described. Paractenopsyllus rouxi, P. ratovonjatoi, P. duplantieri, P. juliamarinus and P. gemelli have been collected on endemic small mammals and the black rat. Biotopes are mid-elevation rain-forests of the central highlands or the northern mountains of Madagascar. Morphological affinities between these new species and those already known provide taxonomic links within the genus. Differences in the spatial and altitudinal distributions and host ranges allow discussion of the potential factors important in the species distribution of this genus.  相似文献   

6.
Recent field studies revealed two new species of the genus Aglyptodactylus (Amphibia: Anura: Ranidae), which was hitherto considered as monotypic and confined to humid eastern Madagascar. Both new species, Aglyptodactylus laticeps sp. n. and Aglyptodactylus securifer sp. n. , occur syntopically in the deciduous dry forest of Kirindy in western Madagascar. In comparison to Aglyptodactylus madagascariensis from eastern rainforests, the new species A. laticeps shows a remarkable morphological divergence, which may be partly due to adaptations to burrowing habits in dry environments. Despite of the morphological differentiation, advertisement calls and osteology indicate that all three species of Aglyptodactylus are closely related. A phylogenetic analysis of the Madagascan ranid genera Aglyptodactylus, Mantella, Mantidactylus, Boophis , and Tomopterna (the latter including species from Madagascar, Africa, and Asia) strongly supports a sister group relationship of Aglyptodactylus with the ranine genus Tomopterna . We therefore transfer Aglyptodactylus from the Rhacophorinae to the Raninae and discuss implications of this rearrangement for ranoid systematics. The existence of the endemic genus Aglyptodactylus in Madagascar as well as its close phylogenetic relationships to Tomopterna confirm that the Raninae were already present on the Madagascan plate before its separation from Africa. The Madagascan Tomopterna labrosa shows several important differences both to Asian and to African species of the genus, and is therefore transferred from the subgenus Sphaerotheca (now restricted to Asia) to a new subgenus Laliostoma subgen. n .  相似文献   

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The missing Madagascan mid-domain effect   总被引:1,自引:0,他引:1  
Species richness varies enormously across geographical gradients, a well-known phenomenon for which there are many hypothesized explanations. One recent hypothesis uses null models to demonstrate that random re-distribution of species' ranges within a given domain leads to a 'mid-domain effect' (MDE): increasing species richness towards the centre of the area. Madagascar is especially well-suited for empirical evaluation of mid-domain models by virtue of its large endemic fauna and its clearly defined boundaries. Lees et al. [ Biol. J. Linn. Soc. 67 (1999) 529] observed patterns of species richness consistent with MDEs in the Madagascan rainforest (a slim, north–south belt). In this study, we test one-dimensional and two-dimensional mid-domain model predictions for the birds and mammals of the entire island of Madagascar. When only latitudinal extents of species' distribution are considered, patterns of richness in Madagascar show an MDE. However, this pattern disappears for both taxa after accounting for the tendency of latitudinal bands nearer the middle of the country to be larger. Two-dimensional mid-domain model predictions of species richness are qualitatively opposite to observed patterns. Instead, island-wide spatial gradients of species richness in Madagascar relate strongly to patterns of primary productivity and amount of remaining natural habitat. Earlier work that showed a mid-domain peak within the rainforest biome (effectively after controlling for climate and natural habitat) seems likely to have reflected methodological artefacts. The classic case in which MDEs should occur is, in fact, inconsistent with the mid-domain hypothesis.  相似文献   

9.
In Madagascar, Anopheles gambiae has been found below altitudes of 1,000 m. We sampled An. gambiae sensu lato (sl) between 2008 and 2010 in the Central Highlands of Madagascar at altitudes over 1,200 m. The study site consists of rainforest, rainforest edge, and an open savanna biotope. Anopheles gambiae and An. arabiensis, as well as molecular forms of An. gambiae, were identified molecularly. An. gambiae accounted for 26.7% at the edge of the rainforest and 2.3% in the open savanna biotope. One specimen of this species was caught in the forest. An. arabiensis accounted for 66.3% at the edge of the rainforest and 97.7 % in the open savanna biotope. All An. gambiae adults tested belonged to the S molecular form. An. gambiae is present at high altitudes in Madagascar, with a high prevalence at the rainforest edge. Several factors, including the appearance of new favorable biotopes, recolonization after a reduction of indoor vector control, and climate change, may contribute to its distribution. The changing distribution of An. gambiae may have consequences for the distribution and incidence of malaria in the Malagasy Highlands.  相似文献   

10.
Uromunna naherba sp. nov. is described from eelgrass beds (Zostera marina and Z. noltii) of the NW Iberian Peninsula. This is the second species of the genus reported from the NE Atlantic, after U. petiti. The new species was more abundant on rhizomes than on the leaves of the plants. Seasonal samples show that ovigerous females are present throughout the year, but become more abundant in late spring and summer, when adult males decrease in frequency. Ovigerous females appear in only one size class. Owing to the yearly productivity cycle of the eelgrasses, these data suggest that the species is semelparous and completes its lifecycle within 1 year. The taxonomic characters of the genus are discussed.  相似文献   

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The pseudoxyrhophiine snake genus Liopholidophis Mocquard, 1904 is endemic to Madagascar and consists of two distinct species groups. We performed molecular phylogenetic analyses using nucleotide sequences of c . 2200 bp from two mitochondrial genes (16S rRNA, cyt b ) and one nuclear gene (c-mos) to test the monophyly of the genus Liopholidophis and to investigate the relationships of the known species and an unidentified Liopholidophis population. Our phylogeny strongly supports the polyphyly of the genus Liopholidophis , confirms the monophyly of both species groups, and reveals that the unidentified population belongs to a new species. We therefore transfer the species of the former L. stumpffi group ( L. epistibes , L. infrasignatus , L. lateralis , L. martae , and L. stumpffi ) to a new genus Bibilava gen. n. and describe Liopholidophis dimorphus sp. n. from the rainforests of Montagne d'Ambre National Park in northern Madagascar. Finally, we compare our phylogeny with previous hypotheses and discuss the evolution of the extreme sexual dimorphism in tail length of Liopholidophis s. str.  相似文献   

13.
Abstract. Tasphorura , a new genus of onychiurid Collembola, is erected for an unusually coloured species, Tasphorura vesiculata n.sp., found at a single locality in Tasmanian Nothofagus rainforest. Its isolated phyletic position is noted and extremely high densities are recorded. The conservation implications of the restricted distribution shown by this species, which is typical of many rainforest invertebrates, are discussed with reference to increasing utilization and fragmentation of these forests.  相似文献   

14.
Six species of Brookesia dwarf chameleons were recorded during two rainforest expeditions in Madagascar. One of these is described as a new species Brookesia valerieae based on the arrangement of the nine pairs of dorso-lateral spines, the lack of a pelvic shield, and dorsal chevron markings. Observations were made on the defence and roosting behaviours shown by these six species. Aspects concerning the evolution and conservation in Madagascar are discussed for this poorly studied group of endemic Malagasy reptiles.  相似文献   

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Data on longevity is a prerequisite to understand the life-history strategies of a species. For Malagasy songbirds no information has been previously published. Therefore, we studied their longevity in a capture–recapture effort in a rainforest in eastern Madagascar (Maromizaha, Andasibe) between 2003 and 2016. We present first data on the longevity of 23 species of Malagasy songbirds. A female Dark Newtonia Newtonia amphichroa (Vangidae) and a Grey-crowned Greenbul Bernieria cinereiceps (Bernieridae) attained an age of at least 12 years, followed by two male Madagascar Brush Warblers Nesillas typica (Acrocephalidae), female Madagascar Bulbul Hypsipetes madagascariensis (Pycnonotidae) and Madagascar Drongo Dicrurus forficatus (Dicruridae) that attained at least 10 years. There was much variation within some taxonomic groups, longevity did not increase with the mass of a bird species and most insectivorous birds lived longer than granivorous ones.  相似文献   

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New comments are proposed on the geographic distribution of genus Opisthacanthus, and the Gondwanian model is further supported. The diversity of the genus is extraordinary in Madagascar, with the same number of species as in continental Africa, but sub-Saharan Africa is home to six out of the nine groups currently recognized of Opisthacanthus. Given the affinities of the Opisthacanthus groups and their current distribution, a center of origin in Africa could be favored for these ancient scorpions. The proposed Gondwana model suggests that the Madagascar Opisthacanthus are closer to those of the New World, which is consistent with the affinities observed in morphological characters. A new species, Opisthacanthus titanus sp. n., is described from the Torotorofotsy Forest, located in Eastern Madagascar. The new species shows affinities with both Opisthacanthus madagascariensis Kraepelin, 1894 known from dry regions in the western portion of the island and Opisthacanthus lavasoa Lourenço, Wilmé & Waeber, 2016 only known from the extreme southeast of the island. The new species and O. madagascariensis have similar external morphologies but the morphometric values are markedly distinct. Moreover, O. madagascariensis is exclusively found in spiny forest thickets and open woodlands, whereas the new species was found in the humid forest of Torotorofotsy. The total number of species in Madagascar is now raised to twelve. Biogeographical scenarios are also proposed to infer the origin of the Opisthacanthus and better understand its distribution in the New World, in Africa and Madagascar.  相似文献   

19.
Wesener T  Raupach MJ  Decker P 《PloS one》2011,6(12):e28035
To elucidate the speciation mechanisms prevalent within hotspots of biodiversity, and the evolutionary processes behind the rise of their species-rich and endemic biota, we investigated the phylogeny of the giant fire-millipede genus Aphistogoniulus Silvestri, 1897, a Malagasy endemic. This study is the first comprehensive (molecular and morphological) phylogenetic study focusing on millipede (class Diplopoda) speciation on Madagascar. The morphological analysis is based on 35 morphological characters and incorporates ten described as well as two newly described species (A. rubrodorsalisn. sp. and A. jeekelin. sp.) of Aphistogoniulus. The molecular analysis is based on both mitochondrial (COI and 16S), and nuclear genes (complete 18S rDNA), together comprised of 3031 base pairs, which were successfully sequenced for 31 individual specimens and eight species of Aphistogoniulus. In addition to the null-model (speciation by distance), two diversification models, mountain refugia and ecotone shift, were discovered to play a role in the speciation of soil arthropods on Madagascar. Mountain refugia were important in the speciation of the A. cowani clade, with three species occurring in the Andringitra and Ranomafana Mountains in the southeast (A. cowani), the Ambohijanahary and Ambohitantely Mountains in the mid-west (A. sanguineus), and the Marojejy Mountain in the northeast (A. rubrodorsalisn. sp.). An ecotone shift from the eastern rainforest to the unique subarid spiny forest of Mahavelo was discovered in the A. vampyrus-A. aridus species-pair. In the monophyletic A. diabolicus clade, evidence for divergent evolution of sexual morphology was detected: species with greatly enlarged gonopods are sister-taxa to species with normal sized gonopods. Among the large-bodied Spirobolida genera of Madagascar, Colossobolus and Sanguinobolus were found to be close sister-genera to Aphistogoniulus. Forest destruction has caused forest corridors between populations to disappear, which might limit the possible resolution of biogeographic analyses on Madagascar.  相似文献   

20.
A new thelastomatid, Aoruroides queenslandensis, is described from two native Australian cockroaches, Panesthia tryoni tryoni Shaw and P. cribrata Saussure, from sub-tropical rainforest in south-eastern Queensland. Species of Aoruroides Travassos & Kloss, 1958 have previously been reported from cockroaches found in Brazil and the Philippines, but A. queenslandensis n. sp. is the first species of this genus found in Australia. The new species differs from the other members of Aoruroides principally in the position of the nerve-ring and egg morphology.  相似文献   

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