71 research outputs found
The First Bromeligenous Species of Dendropsophus (Anura: Hylidae) from Brazil\u27s Atlantic Forest
We describe a new treefrog species of Dendropsophus collected on rocky outcrops in the Brazilian Atlantic Forest. Ecologically, the new species can be distinguished from all known congeners by having a larval phase associated with rainwater accumulated in bromeliad phytotelms instead of temporary or lentic water bodies. Phylogenetic analysis based on molecular data confirms that the new species is a member of Dendropsophus; our analysis does not assign it to any recognized species group in the genus. Morphologically, based on comparison with the 96 known congeners, the new species is diagnosed by its small size, framed dorsal color pattern, and short webbing between toes IV-V. The advertisement call is composed of a moderate-pitched two-note call (~5 kHz). The territorial call contains more notes and pulses than the advertisement call. Field observations suggest that this new bromeligenous species uses a variety of bromeliad species to breed in, and may be both territorial and exhibit male parental care
Riqueza e distribuição temporal de anuros (Amphibia: Anura) em um fragmento de Floresta Ombrófila Mista
Morphology and anatomy of the flower and anthesis of Metrodorea nigra St. Hill. (Rutaceae)
Ecological Guild Evolution and the Discovery of the World's Smallest Vertebrate
Living vertebrates vary drastically in body size, yet few taxa reach the extremely minute size of some frogs and teleost fish. Here we describe two new species of diminutive terrestrial frogs from the megadiverse hotspot island of New Guinea, one of which represents the smallest known vertebrate species, attaining an average body size of only 7.7 mm. Both new species are members of the recently described genus Paedophryne, the four species of which are all among the ten smallest known frog species, making Paedophryne the most diminutive genus of anurans. This discovery highlights intriguing ecological similarities among the numerous independent origins of diminutive anurans, suggesting that minute frogs are not mere oddities, but represent a previously unrecognized ecological guild
Riqueza, abundùncia relativa e håbitat de reprodução de espécies de anuros terrestres na região do Triùngulo Mineiro, bioma Cerrado, sudeste do Brasil
Based on field observations and pitfall sampling, we determined the species richness, relative abundance, and reproductive habitat of terrestrial frogs in three municipalities in the TriĂąngulo Mineiro region, south Cerrado biome, in southeastern Brazil. We found thirty-two species of terrestrial frogs, belonging to the families Brachycephalidae, Bufonidae, Cycloramphidae, Dendrobatidae, Leiuperidae, Leptodactylidae and Microhylidae. Most of the species were found in open areas and reproduced in human-generated environments, such as artificial lakes (10 species) and ponds (14 species). Dominance was high, with Physalaemus cuvieri Fitzinger, 1826 (Leiuperidae) representing 48% of sampled frogs. A larger number of individuals was captured in the wet season, when most of the species were reproducing. Compared to other areas of Cerrado biome, the TriĂąngulo Mineiro sites presented a larger number of species, which may be attributed to the larger sampled area and greater sampling effort, lower altitude and presence of human generated habitats. The richness of terrestrial frogs was also larger than that in some forested localities in southeastern Brazil, indicating that the number of species cannot be explained only by precipitation and type of vegetation cover. The greater abundance of individuals during the wet season may be related to a greater movement of adults to breeding sites and to juvenile recruitment/dispersion. The heterogeneity of environments in the Cerrado biome, including its several isolated highlands, contributes to its high (local and regional) diversity of frogs.Neste estudo foram determinados a riqueza, abundĂąncia relativa e hĂĄbitat de reprodução de anuros terrestres em trĂȘs municĂpios do TriĂąngulo Mineiro, sul do Bioma Cerrado, sudeste do Brasil, baseados em observaçÔes de campo e armadilhas de interceptação e queda. Foram encontradas 32 espĂ©cies pertencentes Ă s famĂlias Brachycephalidae, Bufonidae, Cycloramphidae, Dendrobatidae, Leiuperidae, Leptodactylidae e Microhylidae. Muitas dessas espĂ©cies foram encontradas em ĂĄreas abertas e se reproduziram em ambientes artificiais gerados por ação antrĂłpica, tais como lagos (10 espĂ©cies) e poças (14 espĂ©cies). Physalaemus cuvieri Fitzinger, 1826 (Leiuperidae) foi a espĂ©cie dominante, representando 48% do total amostrado. Um grande nĂșmero de indivĂduos de diferentes espĂ©cies foi capturado na estação chuvosa, quando muitas das espĂ©cies estavam reproduzindo. As ĂĄreas amostradas na regiĂŁo do TriĂąngulo Mineiro apresentaram um maior nĂșmero de espĂ©cies quando comparadas com outras ĂĄreas do bioma Cerrado, o que pode ser atribuĂdo Ă maior ĂĄrea amostrada, ao maior esforço de coleta, baixa altitude e presença de hĂĄbitats gerados por ação antrĂłpica. A riqueza de anuros terrestres tambĂ©m foi maior do que Ă quela encontrada em localidades florestadas no sudeste do Brasil, indicando que o nĂșmero de espĂ©cies nĂŁo pode ser explicado somente pela precipitação e tipo de cobertura vegetal da ĂĄrea. A grande abundĂąncia de indivĂduos durante a estação chuvosa pode estar relacionada ao maior movimento de adultos para hĂĄbitats de reprodução e ao recrutamento e dispersĂŁo de juvenis. A heterogeneidade dos ambientes no bioma Cerrado, incluindo algumas de suas ĂĄreas com maiores altitudes, contribui para a alta diversidade (local e regional) de espĂ©cies de anuros
Auto-ecologia de Hypsiboas albopunctatus (Anura, Hylidae) em ĂĄrea de Cerrado no sudeste do Brasil
Study of pallial neurogenesis in shark embryos and the evolutionary origin of the subventricular zone
The dorsal part of the developing telencephalon is one of the brain areas that has suffered most drastic changes throughout vertebrate evolution. Its evolutionary increase in complexity was thought to be partly achieved by the appearance of a new neurogenic niche in the embryonic subventricular zone (SVZ). Here, a new kind of amplifying progenitors (basal progenitors) expressing Tbr2, undergo a second round of divisions, which is believed to have contributed to the expansion of the neocortex. Accordingly, the existence of a pallial SVZ has been classically considered exclusive of mammals. However, the lack of studies in ancient vertebrates precludes any clear conclusion about the evolutionary origin of the SVZ and the neurogenic mechanisms that rule pallial development. In this work, we explore pallial neurogenesis in a basal vertebrate, the shark Scyliorhinus canicula, through the study of the expression patterns of several neurogenic markers. We found that apical progenitors and radial migration are present in sharks, and therefore, their presence must be highly conserved throughout evolution. Surprisingly, we detected a subventricular band of ScTbr2-expressing cells, some of which also expressed mitotic markers, indicating that the existence of basal progenitors should be considered an ancestral condition rather than a novelty of mammals or amniotes. Finally, we report that the transcriptional program for the specification of glutamatergic pallial cells (Pax6, Tbr2, NeuroD, Tbr1) is also present in sharks. However, the segregation of these markers into different cell types is not clear yet, which may be linked to the lack of layering in anamniotesThis work was supported by the Spanish Ministerio de EconomĂa y Competitividad-FEDER (BFU2014-5863-1P)S
The peatland map of Europe
Based on the âEuropean Mires Bookâ of the International Mire Conservation Group (IMCG), this article provides a composite map of national datasets as the first comprehensive peatland map for the whole of Europe. We also present estimates of the extent of peatlands and mires in each European country individually and for the entire continent. A minimum peat thickness criterion has not been strictly applied, to allow for (often historically determined) country-specific definitions. Our âpeatlandâ concept includes all âmiresâ, which are peatlands where peat is being formed. The map was constructed by merging national datasets in GIS while maintaining the mapping scales of the original input data. This âbottom-upâ approach indicates that the overall area of peatland in Europe is 593,727 kmÂČ. Mires were found to cover more than 320,000 kmÂČ (around 54 % of the total peatland area). If shallow-peat lands (< 30 cm peat) in European Russia are also taken into account, the total peatland area in Europe is more than 1,000,000 km2, which is almost 10 % of the total surface area. Composite inventories of national peatland information, as presented here for Europe, may serve to identify gaps and priority areas for field survey, and help to cross-check and calibrate remote sensing based mapping approaches
Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences
The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & NemĂ©sio 2007; Donegan 2008, 2009; NemĂ©sio 2009aâb; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported
by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on
18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based
researchers who signed it in the short time span from 20 September to 6 October 2016
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