Ecological aspects of diet, reproduction, and parasitism of Pseudopaludicola boliviana (Anura, Leptodactylidae) from Corrientes, Argentina. The main objectives of this paper were to update the distribution range of Pseudopaludicola boliviana in Argentina, to determine its diet composition and the feeding patterns, to analyze some reproductive variables as mature ova count and diameter in relation to female snoutvent length, to describe the advertisement call for Argentinean populations, and to identify and to localize its helminth parasites. Eleven prey types were identified; dipterans were more important both in number (23.53%) and in volume (41.30%); other important preys were collembolans, arachnids and coleopterans. The trophic niche width was 7.15 and the standardized trophic niche value was 0.61. Ovarian complement (number of mature ova for female) ranged from 50 to 319 (mean 175.3 ± 86.12), while ovum diameter ranged from 0.2 to 0.4 mm (mean 0.27 ± 0.062). The nuptial call is composed by five notes. The dominant frequency ranged from 3.488 to 5.927 kHz; emphasized frequency fluctuated between 4.942 and 5.224 kHz. A total of 10 helminth species (larvae and adults) were found in 54 (96%) infected frogs. Helminths were represented by Trematoda (7 species), Cestoda (1), Nematoda (1), and Acanthocephala (1).

Natale, G.S., Alcalde, L., Herrera, R., Cajade, R., Schaefer, E.F., Marangoni, F. and Trudeau, V.L. 2011. Underwater acoustic communication in the macrophagic carnivorous larvae of Ceratophrys ornata (Anura: Ceratophryidae). -Acta Zoologica (Stockholm) 92: 46-53.We provide the first evidence for sound production by anuran larvae. In this study, we describe the sounds, their context-specific emission and the structures related to sound production of the carnivorous larvae of Ceratophrys ornata (Amphibia, Anura, Ceratophryidae). Tadpoles emit a brief, clear and very audible metallic-like sound that consists of a short train of notes that occur at all stages of larval development. Tadpoles make sound only when a conspecific tadpole is preying upon it or when touched by an object. Ceratophrys ornata larvae possess the basic required anatomical structures for sound production via expulsion of atmospheric air from the lungs through the open soft-tissue glottis. The glottis is opened and closed via the larval laryngeal muscles (constrictor laryngis and dilatator laryngis). The arytenoid cartilages appear at stage 40 and the cricoid cartilage does at stage 43. Adult laryngeal muscles differentiate from the larval ones at stage 46 together with the vocal sac formation from the adult interhyoideus muscle. We demonstrate (n = 2160 conspecific predator-prey interactions) that larval sounds occur always under predatory attack, probably serving to diminish the chances of cannibalism. These data raise the possibility that other macrophagic carnivorous anuran larvae may produce sound.

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ABSTRACT.-In amphibians from tropical or subtropical regions well-expressed growth marks in bone could be expected because of the existence of strong dry/wet seasons, but little evidence is available. Additionally, temporal patterns of growth-mark formation may be a function of genetic and environmental factors. We used skeletochronology and a laboratory experiment to tease apart both causal sources, establishing direct correspondence between an observed pattern of bone growth and the actual age of Ceratophrys cranwelli and Dermatonotus muelleri from the subtropical Argentinean Chaco. Also, we describe the growth by application of the von Bertalanffy model. Growth rates decreased in both species, tending to reach asymptotic values at age 8-10 months after metamorphosis. Both species clearly exhibited haematoxylinophilic lines of arrested growth (LAG) after one year growing in captivity. These results reinforce the hypothesis that in subtropical climates the LAG formation is ultimately caused by a general intrinsic (genetic) control.

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The ability of an organism to produce different phenotypes under different environmental conditions is a common adaptation in nature. Biotic factors like competition, community structure and predation can influence the survival and time to metamorphosis in amphibians. However, abiotic factors such as the hydroperiod and light intensity can be as important as biotic ones. We examine the influence of abiotic (light, hydroperiod) and biotic (density) factors on the morphology, growth and development of Argenteohyla siemersi pederseni tadpoles. Our main goal was to determine whether the morphology, growth and development vary in relation to changes in water volume, light intensity and number of conspecifics. The experiment was conducted under mesocosm conditions. We used a randomized block design with a factorial combination of two densities of tadpoles, two volumes of water and two light intensity conditions. The main findings were as follows: (1) Tadpole morphology was significantly affected by density and water volume but not by light intensity. Tadpoles maintained at low density increased their tail length and tail depth, tadpoles exposed to low volumes of water increased their tail length and tail muscle depth; (2) The growth rate and development rate of tadpoles were significantly affected by the effects of volume of water and density. Tadpoles maintained at low densities and low volume of water showed a significant increase in growth and development rate; (3) The growth and development rates of tadpoles were significantly affected by the effect of light intensity. Tadpoles exposed to lower light intensity showed an increase in their growth and development rates.

This communication provides notes on 2 species of toads, Chaunus schneideri and Chaunus granulosus, infested with ixodid ticks, Amblyomma rotundatum, from the provinces of Corrientes and Formosa in northern Argentina. Chaunus schneideri is a new amphibian host record for A. rotundatum, a species previously reported to parasitize other anurans and also reptiles. We examined 74 ticks on 5 toads. All ticks were A. rotundatum; all adults were females, and all developmental stages were randomly attached to host body parts. Ticks remained attached to one of the toads for from 7 to 17 days after the host was captured. One toad, encumbered with 33 ticks, was moribund when found and died shortly thereafter.

Here we describe a new species of sarcophagid fly reared from larvae found feeding on three species of leptodactylid frogs collected in subtropical Corrientes Province in northeastern Argentina. Our species description is based on adult male and female external morphology and genitalia. Adult males and females of the new species were associated with certainty because all specimens studied were reared from single clutches of larvae on each of three infested frogs. Thus, adult males and females reared from each clutch were siblings that emerged almost simultaneously. The paper provides line drawings, high-resolution photographs, and SEM images to aid in identifying Lepidodexia (Notochaeta) adelina sp. nov. and to distinguish the new species from its closely related congeners. We include brief notes on the host species and on larval feeding behavior of L. (N.) adelina. This is the first and only species in the genus Lepidodexia reported to parasitize leptodactylid frogs. Further, our observations reported here are the first to fully document a completed life cycle by sarcophagid fly larvae on three different species of leptodactylid frogs and the only well-documented case of myiasis of an amphibian in Argentina.