RESUMEN
With open-access publishing authors often pay an article processing charge and subsequently their article is freely available online. These charges are beyond the reach of most African academics. Thus, the trend towards open-access publishing will shift the business model from a pay-wall model, where access to literature is limited, to a pay-to-publish one, where African scholars cannot afford to publish. We explore the costs of publishing and the ability of African scholars to afford to publish via open access in top journals. Three-quarters of the 40 top ecology journals required payment for open-access publishing (average cost $3150). Paying such fees is a hardship for African scholars as grant funding is not available and it is not feasible to pay the fees themselves as salaries are low. We encourage funders and publishers to facilitate an equitable publishing model that allows African scholars to make their research available through open-access publishing.
Asunto(s)
Ecología , EdiciónRESUMEN
How environmental factors shape patterns of biotic diversity in tropical ecosystems is an active field of research, but studies examining the possibility of ecological speciation in terrestrial tropical ecosystems are scarce. We use the isolated rainforest herpetofauna on the Montagne d'Ambre (Amber Mountain) massif in northern Madagascar as a model to explore elevational divergence at the level of populations and communities. Based on intensive sampling and DNA barcoding of amphibians and reptiles along a transect ranging from ca. 470-1470 m above sea level (a.s.l.), we assessed a main peak in species richness at an elevation of ca. 1000 m a.s.l. with 41 species. The proportion of local endemics was highest (about 1/3) at elevations >1100 m a.s.l. Two species of chameleons (Brookesia tuberculata, Calumma linotum) and two species of frogs (Mantidactylus bellyi, M. ambony) studied in depth by newly developed microsatellite markers showed genetic divergence up the slope of the mountain, some quite strong, others very weak, but in each case with genetic breaks between 1100 and 1270 m a.s.l. Genetic clusters were found in transect sections significantly differing in bioclimate and herpetological community composition. A decrease in body size was detected in several species with increasing elevation. The studied rainforest amphibians and reptiles show concordant population genetic differentiation across elevation along with morphological and niche differentiation. Whether this parapatric or microallopatric differentiation will suffice for the completion of speciation is, however, unclear, and available phylogeographic evidence rather suggests that a complex interplay between ecological and allopatric divergence processes is involved in generating the extraordinary species diversity of Madagascar's biota. Our study reveals concordant patterns of diversification among main elevational bands, but suggests that these adaptational processes are only part of the complex of processes leading to species formation, among which geographical isolation is probably also important.
RESUMEN
The Lygodactylus madagascariensis species group, constituting the subgenus Domerguella, currently contains five valid species of inconspicuous dwarf geckos from Madagascars humid forests, but at least 18 deep genetic lineages have been revealed by recent molecular studies. Given the high morphological similarity of these lineages, taxonomic resolution of this astonishing diversity requires efforts to correctly delimit species, as well as assigning the available nomina to the species-level lineages identified. We here combine DNA sequences of one mitochondrial and two nuclear-encoded gene fragments with morphometric measurements and scale counts, and report evidence for a species status of most of the previously identified lineages. In particular, we rely on sympatric and often even syntopic occurrence of several of these lineages without evidence for genetic admixture, and consistent with subtle morphological differences. Furthermore, the very high divergences of 7.423.8% pairwise distances in the relatively conserved mitochondrial 16S rRNA gene, combined with a lack of haplotype sharing in the nuclear-encoded genes and differences in scale counts convinced us that most of the other, allopatrically distributed lineages also represent distinct species. We elevate L. madagascariensis petteri to species level and formally name eight new species: L. salvi sp. nov., a species from the Sambirano region in northern Madagascar, previously called L. sp. 8; L. tantsaha sp. nov. (L. sp. 10), a species occurring sympatrically with L. madagascariensis and L. petteri on Montagne dAmbre in far northern Madagascar; L. roellae sp. nov. (L. sp. 17), a species characterized by a striped coloration in all known specimens, from northern Madagascar; L. winki sp. nov. (L. sp. 18), an unstriped species from northern Madagascar but belonging to a subclade mostly distributed in the eastern rainforests of the island; L. ulli sp. nov. (L. sp. 21), a species from the same subclade as L. winki but known only from the Marojejy Massif in the North East; L. fritzi sp. nov. (L. sp. 11), a further species of this subclade from coastal lowlands in the Northern Central East; L. hodikazo sp. nov. (L. sp. 23) known from a single specimen collected at the Tsingy de Bemaraha and therefore the only Domerguella species known from the West region of Madagascar; and L. hapei sp. nov. (L. sp. 26), an enigmatic species from the Sambirano region characterized by a striped pattern on the throat that is otherwise unknown in the subgenus. Three additional deep mitochondrial lineages of Domerguella were identified in our analysis, but could not be further analyzed due to the lack or scarcity of voucher specimens. More field work and collection of voucher specimens is needed to understand their status. Furthermore, the taxonomy of the Domerguella subclade occurring in eastern Madagascar, with three described species (L. guibei, L. miops, L. fritzi), two synonyms (L. septemtuberculatus, Microscalabotes spinulifer) and at least two further deep genetic lineages co-occurring in a relatively small area, requires further revisionary work, possibly aided by target-enrichment sequencing of the respective name-bearing types.
Asunto(s)
Lagartos , Animales , Anuros , Lagartos/genética , Madagascar , Filogenia , ARN Ribosómico 16S , Bosque LluviosoRESUMEN
Evolutionary reduction of adult body size (miniaturization) has profound consequences for organismal biology and is an important subject of evolutionary research. Based on two individuals we describe a new, extremely miniaturized chameleon, which may be the world's smallest reptile species. The male holotype of Brookesia nana sp. nov. has a snout-vent length of 13.5 mm (total length 21.6 mm) and has large, apparently fully developed hemipenes, making it apparently the smallest mature male amniote ever recorded. The female paratype measures 19.2 mm snout-vent length (total length 28.9 mm) and a micro-CT scan revealed developing eggs in the body cavity, likewise indicating sexual maturity. The new chameleon is only known from a degraded montane rainforest in northern Madagascar and might be threatened by extinction. Molecular phylogenetic analyses place it as sister to B. karchei, the largest species in the clade of miniaturized Brookesia species, for which we resurrect Evoluticauda Angel, 1942 as subgenus name. The genetic divergence of B. nana sp. nov. is rather strong (9.9â14.9% to all other Evoluticauda species in the 16S rRNA gene). A comparative study of genital length in Malagasy chameleons revealed a tendency for the smallest chameleons to have the relatively largest hemipenes, which might be a consequence of a reversed sexual size dimorphism with males substantially smaller than females in the smallest species. The miniaturized males may need larger hemipenes to enable a better mechanical fit with female genitals during copulation. Comprehensive studies of female genitalia are needed to test this hypothesis and to better understand the evolution of genitalia in reptiles.
Asunto(s)
Evolución Biológica , Genitales/anatomía & histología , Lagartos/anatomía & histología , Animales , Biodiversidad , Femenino , Lagartos/clasificación , Lagartos/genética , Madagascar , Masculino , Tamaño de los Órganos , Filogenia , FilogeografíaRESUMEN
The northern part of Madagascar is well known for its high species diversity and endemism. Exceptional species richness is related to the existence of large forest blocks and mountain complexes. These areas shelter a diverse variety of habitats occupied by a wide diversity of species, including leaf-tailed geckos of the genus Uroplatus. Based on morphological and molecular evidence, we here formally name two evolutionary lineages as new species that previously had been considered as candidate species (Uroplatus spp. Ca3 and Ca4), both small-sized species of the Uroplatus ebenaui group. Genetically, both new species are related to U. finiavana with a genetic divergence (uncorrected pairwise distance) of 10.3-12.8% in a fragment of the mitochondrial 16S rRNA gene, and separated from each other by 10.3-10.7%. Uroplatus fangorn sp. nov. is described from the Marojejy massif and is also known from Andrevorevo, Lohanandroranga and Sorata; it is similar to U. ebenaui and U. fetsy but is distinguishable by its rather short tail and only partially black pigmented oral mucosa. Uroplatus fivehy sp. nov. is described from the Sorata Massif and is wider-ranging, occurring in an area from Marotandrano and Makira to Sorata, comprising Marojejy, Anjanaharibe-Sud, Ankitsika and Betaolana; it is morphologically similar to U. finiavana but distinguishable by tail size and shape. Both newly described species are found in rainforest from mid to high elevation and range respectively from 840-1417 m for U. fivehy sp nov. and 1300-1800 m for U. fangorn sp. nov. According to their respective geographical distributions, we propose to classify the two new species as Vulnerable under the IUCN Red List criteria, due to their occurrence in some forests outside of the protected area network plus the continuing decline of forest patches in the north of Madagascar.
Asunto(s)
Lagartos , Animales , Lagartos/genética , Madagascar , Filogenia , ARN Ribosómico 16S/genética , Bosque LluviosoRESUMEN
Previous studies on leaf-tailed geckos of the genus Uroplatus identified a lineage from the Ankarana karst massif in northern Madagascar as genetically highly divergent, but only fragmentary information was available on these geckos. Here, we provide an integrative analysis based on molecular and morphological data, including a newly collected specimen from this locality. Phylogenetic analysis placed the Ankarana lineage sister to U. ebenaui, but with a surprisingly high genetic divergence of over 19% uncorrected pairwise distance in the mitochondrial 16S rRNA gene. We formally describe the Ankarana lineage as Uroplatus fetsy sp. nov. and provide new information on the distribution and genetic differentiation of its sister species, Uroplatus ebenaui. Based on DNA sequences of newly examined samples this latter species is confirmed as widespread, ranging from low-elevation dry forests from Beanka in western Madagascar to Forêt d'Ambre and Analalava/Fanambana in northern Madagascar, and thus far has not been found in the Ankarana Massif, where U. fetsy occurs.
Asunto(s)
Lagartos , Animales , Lagartos/genética , Madagascar , Parques Recreativos , Filogenia , ARN Ribosómico 16SRESUMEN
The Tsaratanana Massif is the highest mountain massif of Madagascar and is characterized by a high species-level endemism of its biota. Here we describe two new small-sized species of leaf-tailed geckos of the Uroplatus ebenaui group from this region. Named in a preliminary way as confirmed candidate species Uroplatus ebenaui [Ca1] and [Ca2] in previous studies, we here provide detailed data on their molecular and morphological differentiation and describe them as Uroplatus fotsivava sp. nov. and Uroplatus kelirambo sp. nov. Their closest relatives are U. fiera and U. finiavana, respectively, as revealed by a phylogeny based on DNA sequences of four mitochondrial genes. However, integration of various lines of evidence confirms that the new species are independent evolutionary lineages, differing from other Uroplatus by high mitochondrial divergences, lack of haplotype sharing in the nuclear CMOS gene, and shape and relative size of the tail. While U. fotsivava is known from multiple sites at elevations between 1100-1538 m above sea level, U. kelirambo was found only at high elevations between 2000-2200 m a.s.l.; it therefore is the only known forest-dwelling nocturnal gecko reaching such high elevations in Madagascar, and might be narrowly endemic to montane forests of the Tsaratanana Massif.
Asunto(s)
Lagartos , Animales , ADN , Haplotipos , Madagascar , FilogeniaRESUMEN
A new species of the hitherto monotypic genus Chalarodon is described from southern Madagascar and a lectotype (ZMB 4360) is designated for C. madagascariensis Peters, 1854. The new species of terrestrial iguana, Chalarodon steinkampi sp. nov., is defined by several morphological characters and by concordant differentiation in mitochondrial and nuclear DNA with >5% uncorrected pairwise genetic distance in the 16S rRNA gene. It can be most clearly recognized by the presence of smooth (vs. keeled) gular and ventral scales, a spotted pattern extending from flanks onto belly, and an unpigmented throat. The new species is known from only a small area between the villages of Amboasary Sud and Esomony, located west of the Andohahela Massif, while C. madagascariensis appears to be widespread over much of southern and western Madagascar. We highlight the need for further exploration of this unprotected region which might host several other microendemic species.
Asunto(s)
Iguanas/anatomía & histología , Iguanas/clasificación , Animales , Femenino , Iguanas/genética , Madagascar , Masculino , ARN Ribosómico 16S , Análisis de Secuencia de ADN , Especificidad de la EspecieRESUMEN
BACKGROUND: An understanding of the conservation status of Madagascar's endemic reptile species is needed to underpin conservation planning and priority setting in this global biodiversity hotspot, and to complement existing information on the island's mammals, birds and amphibians. We report here on the first systematic assessment of the extinction risk of endemic and native non-marine Malagasy snakes, lizards, turtles and tortoises. METHODOLOGY/PRINCIPAL FINDINGS: Species range maps from The IUCN Red List of Threatened Species were analysed to determine patterns in the distribution of threatened reptile species. These data, in addition to information on threats, were used to identify priority areas and actions for conservation. Thirty-nine percent of the data-sufficient Malagasy reptiles in our analyses are threatened with extinction. Areas in the north, west and south-east were identified as having more threatened species than expected and are therefore conservation priorities. Habitat degradation caused by wood harvesting and non-timber crops was the most pervasive threat. The direct removal of reptiles for international trade and human consumption threatened relatively few species, but were the primary threats for tortoises. Nine threatened reptile species are endemic to recently created protected areas. CONCLUSIONS/SIGNIFICANCE: With a few alarming exceptions, the threatened endemic reptiles of Madagascar occur within the national network of protected areas, including some taxa that are only found in new protected areas. Threats to these species, however, operate inside and outside protected area boundaries. This analysis has identified priority sites for reptile conservation and completes the conservation assessment of terrestrial vertebrates in Madagascar which will facilitate conservation planning, monitoring and wise-decision making. In sharp contrast with the amphibians, there is significant reptile diversity and regional endemism in the southern and western regions of Madagascar and this study highlights the importance of these arid regions to conserving the island's biodiversity.