University of Antananarivo

About: University of Antananarivo is a education organization based out in Antananarivo, Madagascar. It is known for research contribution in the topics: Population & Lemur. The organization has 1561 authors who have published 1703 publications receiving 30922 citations. The organization is also known as: Tananarive University & Antananarivo University.

Soil flooding and rice straw addition can increase isotopic exchangeable phosphorus in P-deficient tropical soils

Abstract: Soil flooding increases phosphorus (P) availability due to reductive dissolution of P-bearing Fe(III) minerals. It is, however, unclear whether such processes also act in P-deficient soils of the tropics that have large Fe/P ratios (dithionite- and oxalate-extractable P and Fe). The objective was to identify the extent of P release induced by flooding in such soils and the soil characteristics involved. Six topsoils (0.4–5% Fe) from rice fields in Madagascar were incubated aerobically and anaerobically for 66 days amended with factorial combinations of (0, 50 mg P/kg); half of the flooded soils were also amended with 1 g rice straw/kg prior to flooding to stimulate soil oxygen depletion. The release of P after flooding was measured at day 40 with 33P isotopic exchange, which detects both changes of labile P (exchangeable P) and changes in P solubility. Flooding increased labile P concentration in soil compared with aerobic soils by 1.4–60 mg P/kg, effects being significant in 6 of the 12 soil samples. Rice straw addition further increased the labile P in 5 of the 12 flooded soil samples by 2–27 mg P/kg. The release of labile P by flooding increased with soil oxalate-extractable P concentration. Flooding combined with rice straw addition can increase the labile P in soil, even in soils with large amount of Fe; however, this release in unfertilized soils is likely insufficient for optimal nutrition of rice plants when evaluated against critical values for P solubility.

Species distribution and assembly patterns of frog larvae in rainforest streams of Madagascar

Abstract: Many tropical rainforests harbour species-rich assemblages of frogs and, consequently, of tadpoles. These larvae are often morphologically highly diverse, especially in their oral structures. Whether this might represent an important axis of ecological partitioning in frog assemblages remains an untested hypothesis. In general, it is poorly known how diverse tadpole assemblages are organised. Using information from Madagascar’s remarkably species-rich stream tadpole assemblages, we analysed the distribution and co-occurrence of 44 species. We also assessed the importance of phylogenetic history and eco-morphological adaptation for habitat selection at two functional and two spatial levels. We show that both rare and common species exist in most morphological clusters and phylogenetic groups of tadpoles. Habitat characteristics of the streams and surrounding forest influence species composition. Whereas there is a general trend in preferring wide and deep streams without a steep slope for most species, some of the morphological clusters separate along specific habitat variables. Stream choice is influenced both by phylogenetic history and morphological adaptation. Within streams, tadpoles partition microhabitat mainly according to their morphological cluster but without phylogenetic signal. Species dissimilarities of habitat selection on both spatial scales are not correlated. We found no evidence for competition in the tadpole assemblages studied.

Late Cretaceous bird from Madagascar reveals unique development of beaks.

Abstract: Mesozoic birds display considerable diversity in size, flight adaptations and feather organization1–4, but exhibit relatively conserved patterns of beak shape and development5–7. Although Neornithine (that is, crown group) birds also exhibit constraint on facial development8,9, they have comparatively diverse beak morphologies associated with a range of feeding and behavioural ecologies, in contrast to Mesozoic birds. Here we describe a crow-sized stem bird, Falcatakely forsterae gen. et sp. nov., from the Late Cretaceous epoch of Madagascar that possesses a long and deep rostrum, an expression of beak morphology that was previously unknown among Mesozoic birds and is superficially similar to that of a variety of crown-group birds (for example, toucans). The rostrum of Falcatakely is composed of an expansive edentulous maxilla and a small tooth-bearing premaxilla. Morphometric analyses of individual bony elements and three-dimensional rostrum shape reveal the development of a neornithine-like facial anatomy despite the retention of a maxilla–premaxilla organization that is similar to that of nonavialan theropods. The patterning and increased height of the rostrum in Falcatakely reveals a degree of developmental lability and increased morphological disparity that was previously unknown in early branching avialans. Expression of this phenotype (and presumed ecology) in a stem bird underscores that consolidation to the neornithine-like, premaxilla-dominated rostrum was not an evolutionary prerequisite for beak enlargement. A crow-sized stem bird, Falcatakely forsterae, possesses a long and deep rostrum—a beak morphology that was previously unknown among Mesozoic birds and is similar to that of some crown-group birds, such as toucans.

Diversity and Use of Edible Grasshoppers, Locusts, Crickets, and Katydids (Orthoptera) in Madagascar.

Abstract: Madagascar has a long history of using Orthoptera as food and feed. Our understanding of the biological diversity of this resource, its contemporary use, and its future potentials in Madagascar is extremely limited. The present study contributes basic knowledge of the biological diversity and local uses of edible Orthoptera in Malagasy food cultures. Data was collected with key informants in 47 localities covering most of the ecoregions of Madagascar and corresponding to 12 of the 19 ethnic groups. Orthoptera are consumed throughout Madagascar. We report 37 edible Orthoptera species, of which 28 are new species records of edible Orthoptera in Madagascar and 24 are new species records of edible Orthoptera in the world. Most species are endemic and occur in farming zones. Children are the primary collectors and consumers of edible Orthoptera. The insects are eaten both as snacks and main meals. Edible Orthoptera are primarily collected casually and marketing is rare, with the notable exceptions of the large cricket Brachytrupes membranaceus colosseus and during locust outbreaks (e.g., Locusta migratoria). The use of Orthoptera as feed seems rare. Further investigations of cultural and personal preferences are required to assess the future potential roles of Orthoptera in Malagasy food habits.

Les larves des Scarabaeoidea (Insecta, Coleoptera) en riziculture pluviale des régions de haute et moyenne altitudes du Centre de Madagascar

Abstract: Randriamanantsoa R., Aberlenc H.-P., Ralisoa O. B., Ratnadass A. & Vercambre B. 2010. — Les larves des Scarabaeoidea (Insecta, Coleoptera) en riziculture pluviale des regions de haute et moyenne altitudes du Centre de Madagascar. Zoosystema 32 (1): 19-72.