Eleutherodactylus barlagnei

Number of Pages: 3Integrative BiologyGeological Science

Eleutherodactylus pinchoni

Number of Pages: 3Integrative BiologyGeological Science

Frog origins: inferences based on ancestral reconstructions of locomotor performance and anatomy

Frogs are the most species-rich and ecologically diverse group of amphibians and are characterized by a unique body plan including long legs, elongated ilia, and fused caudal vertebrae. Stem anurans such as Triadobatrachus or Czatkobatrachus have been suggested to have used jumping or hopping as part of their locomotor repertoire based on their anatomy. The earliest known true frog, Prosalirus bitis was suggested to have been a proficient jumper. However, data on jumping performance in frogs have never been used to attempt reconstruction of ancestral features at the base of the radiation. Here we provide data on jumping performance (forces and acceleration) in 20 species of extant frogs including representatives of most of the early radiating clades. We next use ancestral character value inferences to assess ancestral features. Our analyses suggest that frog ancestors were of small to medium size, had relatively short limbs, produced rather low jump forces, yet were capable of relatively high acceleration. Given the short limbs and low forces, the unique frog bauplan with a reduced vertebral column and a mobile ilio-sacral joint may not have been an adaptation for powerful jumping

Rhabdias (Nematoda: Rhabdiasidae) from Chamaeleonidae (Sauria): two new species from Trioceros ellioti in East Africa and one from Brookesia superciliaris in Madagascar.

International audience; Rhabdias casiraghii n. sp. and R. kibiraensis n. sp. are described from Trioceros ellioti from Burundi and co-infection was observed in one of the host specimens. Distinctive characters between these species are, among others, the mouth and buccal capsule in front view, both of which are round in the former and laterally flattened in the latter species. Both species have a complete set of submedian head papillae (three in each submedian axis) as observed in the fourth stage larva of R. americanus from anurans. This primitive character opposes them to other species parasitic in Chamaeleonidae that have a single papilla per axis. The third species is the first described from the primitive chamaeleonid genus Brookesia; R. brygooi n. sp. from B. superciliaris from Madagascar can be distinguished from other Rhabdias in Chamaeleonidae by the small diameter of its mouth and buccal capsule. In this character, it resembles parasites from anurans. However, its infective larva has a rounded caudal extremity ornated with buds, as described in species of Rhabdias parasitic in Chamaeleonidae

Addenda and errata to “Description of a new species of the genus Adenomera (Amphibia, Anura, Leptodactylidae) from French Guiana"

In the first issue of Acta Herpetologica, Boistel et al. (2006) described a new species of Adenomera (Amphibia, Anura, Leptodactylidae). Because of an unfortunate set of events, there are several aspects of this paper that have to be corrected, or elaborated on. We address these issues herein

Eikonal phase retrieval: Unleashing the fourth generation sources potential for enhanced propagation based tomography on biological samples

The evolution of synchrotrons towards higher brilliance beams has increased the possible sample-to-detector propagation distances for which the source confusion circle does not lead to geometrical blurring. This makes it possible to push near-field propagation driven phase contrast enhancement to the limit, revealing low contrast features which would otherwise remain hidden under an excessive noise-to-signal ratio. Until today this possibility was hindered, in most objects of scientific interest, by the simultaneous presence of strong phase gradient regions and low contrast features. The strong gradients, when enhanced with the now possible long propagation distances, induce such strong phase effects that the linearisation assumptions of current state-of-the-art single-distance phase retrieval filters are broken, and the resulting image quality is jeopardized. Our work provides an innovative algorithm which efficiently performs the phase retrieval task over the entire near-field range, producing images of exceptional quality for mixed objects

Whispering to the Deaf: Communication by a Frog without External Vocal Sac or Tympanum in Noisy Environments

Atelopus franciscus is a diurnal bufonid frog that lives in South-American tropical rain forests. As in many other frogs, males produce calls to defend their territories and attract females. However, this species is a so-called “earless” frog lacking an external tympanum and is thus anatomically deaf. Moreover, A. franciscus has no external vocal sac and lives in a sound constraining environment along river banks where it competes with other calling frogs. Despite these constraints, male A. franciscus reply acoustically to the calls of conspecifics in the field. To resolve this apparent paradox, we studied the vocal apparatus and middle-ear, analysed signal content of the calls, examined sound and signal content propagation in its natural habitat, and performed playback experiments. We show that A. franciscus males can produce only low intensity calls that propagate a short distance (<8 m) as a result of the lack of an external vocal sac. The species-specific coding of the signal is based on the pulse duration, providing a simple coding that is efficient as it allows discrimination from calls of sympatric frogs. Moreover, the signal is redundant and consequently adapted to noisy environments. As such a coding system can be efficient only at short-range, territory holders established themselves at short distances from each other. Finally, we show that the middle-ear of A. franciscus does not present any particular adaptations to compensate for the lack of an external tympanum, suggesting the existence of extra-tympanic pathways for sound propagation

Le buzz de la cigale : comment Cidada Orni produit-elle son chant ?

Les mâles des cigales produisent des chants d’appels sexuels tous les étés. Ces insectes produisent des sons intenses malgré leur taille relativement petite. Une paire de muscles dans leur cavité abdominale antérieure qui tirent et déforment les membranes cymbales cuticulaires à nervures rigides situées sous les ailes repliées. Ces muscles dans la littérature sont identifiés comme des muscles striés super rapides chez certaines espèces de cigales, voir même chez des vertébrés comme l'organe émetteur du serpent à sonnettes ou de la vessie natatoire du poisson- crapaud. Connus sous le nom de muscles « soniques », ils fonctionnent généralement à des fréquences supérieures à 50 fois par seconde (Hz), des taux qui sont 2 à 3 fois supérieurs à ceux pouvant être atteints par un muscle squelettique typique. La plupart des muscles soniques sont synchrones ou neurogènes. Ceci contraste avec d'autres muscles à haute fréquence tels que certains muscles du vol des insectes qui sont asynchrones ou myogéniques. Nous avons exploré l'anatomie fonctionnelle de l’appareil émetteur de Cicada orni. Elle produit un son avec une fréquence dominante de 4,51 kHz. Comment peut- on produit un sont de plus de 4000 Hz alors que les muscles ne peuvent atteindre une fréquence supérieure à 50Hz ? Est-ce que les cymbales sont synchrones ? A quelle fréquence vibrent-elles ? Est-ce que l’abdomen vibre à quelle fréquence ? Quelle est la fréquence de résonance de la cavité abdominale ? Nous avons tenté de répondre à ces questions grâce à une imagerie multimodale (caméra rapide, microtomographie par rayon X in vivo et synchrotron) et examiné les propriétés structurelles et fonctionnelles sur la façon dont il produit le son en faisant vibrer les cymbales et résonner la cavité abdominale. Nous avons modélisé le comportement de résonance de la cavité abdominale de la cigale

Is Bocourt’s Terrific Skink Really So Terrific? Trophic Myth and Reality

Many scientists argue that our planet is undergoing a mass extinction event that is largely due to human influences. In this context, rediscoveries of species presumed to be extinct are encouraging and of great potential interest. During a 2003 expedition to New Caledonia, Bocourt’s terrific skink, Phoboscincus bocourti, was unexpectedly rediscovered on a small islet by one of us. This skink species had been described from a single specimen collected around 1872 in New Caledonia. Since that time, however, no data on the species’ biology, trophic interactions, or role in the ecosystem have been collected, making it difficult to follow the established conservation plan. In this study, we used a multidisciplinary approach involving natural history, anatomy, morphology, genetics, and stable isotopes to elucidate the ecology of Bocourt’s terrific skink. Over the course of three different expeditions to the islet (total of 55 days across 2005 and 2012), we captured 4 individuals and observed another 4 individuals. The species’ dentition and trophic ecology suggest that it is a top predator in its ecosystem and a major consumer of small terrestrial reptiles. Its high degree of genetic relatedness to another New Caledonian skink, which has a broad distribution, suggests that P. bocourti underwent genetic isolation at a geographical remote location, where dispersal or colonization was highly improbable. Moreover, the lack of genetic variation among the four individuals we captured may imply that a unique lineage, characterized by few inter-island exchanges, exists on the islet. Bocourt’s terrific skink may be the largest terrestrial squamate predator alive in New Caledonia today. As a result, it is likely vulnerable to habitat modifications and especially the invasive rodents found on this islet. Further information is necessary to assess the conservation plans and practices in place as no concrete changes have been made since the species’ rediscovery almost 10 years ago.Peer reviewe

Push and bite: trade-offs between burrowing and biting in a burrowing skink (**Acontias percivali**)

International audienc