The inappropriate delimitation of species may lead to inflated species lists, with implications for biodiversity research, management, and conservation. In this paper, we reassess and discuss the taxonomic status of the lizards Liolaemus montanezi Cabrera and Monguillot, 2006 and L. cinereus Monguillot et al., 2006, members of the L. boulengeri species group (Liolaemidae). These taxa have been treated as syntopic and endemic to a hyper-arid desert from central‑western Argentina, but are hereafter considered synonyms. Evidence supporting their conspecificity relies on the comparison of morphological characters, including scale counts, morphometry, and body‑shape traits, which showed extensive overlap. Further, a comprehensive phylogenetic analysis comprising 84 terminals from the L. boulengeri group (plus seven outgroups) and 155 morphological characters (34 continuous and 121 discrete) recovered L. montanezi and L. cinereus as sibling species with no autapomorphic traits. These lizards coexist in a small area of approximately 2 km² where no clear structural or ecological differences were detected. The essentially identical ecology of L. montanezi and L. cinereus is interpreted as an additional index of their status as a single taxonomic entity. With the proposed synonymy, the name L. montanezi has priority over L. cinereus, and species accounts of the L. boulengeri species group should be updated accordingly.

La inadecuada delimitación de especies puede conducir a una inflación de las listas taxonómicas con implicaciones para la investigación, el manejo y la conservación de la biodiversidad. En este trabajo, reevaluamos y discutimos el estatus taxonómico de las lagartijas Liolaemus montanezi Cabrera y Monguillot, 2006 y L. cinereus Monguillot et al., 2006, miembros del grupo de L. boulengeri (Liolaemidae). Estos taxones han sido tratados como sintópicos y endémicos de un desierto hiperárido del centro-oeste de Argentina, pero en lo sucesivo se considerarán sinónimos. La evidencia que respalda su sinonimización proviene de la comparación de caracteres morfológicos, incluidos recuentos de escamas, morfometría y rasgos de la forma del cuerpo que mostraron una notable superposición. Además, en un análisis filogenético amplio que incluyó a 84 terminales del grupo L. boulengeri (más 7 grupos externos) y 155 caracteres morfológicos (34 continuos y 121 discretos) L. montanezi y L. cinereus fueron recuperadas como especies hermanas sin rasgos autapomórficos. Estas lagartijas coexisten en una pequeña superficie de aproximadamente 2 km² donde no se detectaron claras diferencias fisionómicas ni ecológicas. La ecología esencialmente idéntica de L. montanezi y L. cinereus es interpretada como un indicador adicional de su estatus como entidad taxonómica única. Con la sinonimia propuesta, el nombre L. montanezi tiene prioridad sobre L. cinereus, y las enumeraciones de especies del grupo de L. boulengeri deben actualizarse como corresponde.

The auditory sensitivity of frogs Discoglossus (Alytidae) was measured and compared with the known spectral characteristics of their vocalizations, to assess evolutionary patterns of sound communication in these primitive anurans. Multi-unit recordings in the Torus semicircularis of 6 D. pictus, and 2 D. galganoi show two regions of enhanced sensitivity, below 0.5 kHz and at ca. 1.6 kHz, with minimum thresholds at ca. 40 and 50 dB SPL, respectively. The high frequency sensitivity region is tuned to frequencies higher than the calls reported for this genus, with dominant frequencies below 1 kHz. These audiogram characteristics were similar to those measured in a former study in Iberian Alytes toads. However, auditory thresholds to calls of Alytidae were higher in Discoglossus relative to those measured in A. cisternasii, A. obstetricans and A. dickhilleni in response to vocalizations of one Discoglossus and two Alytes species. The relatively high auditory thresholds of Discoglossus, together with the low amplitude of their vocalizations and the detuning between call spectra and auditory sensitivity restrict their sound communication to short distances. Such mismatch is likely a derived trait in the evolutionary history of the genus, as occurs in other anuran groups.

Most records of camallanid species are from fish, being poorly studied in South American turtles. This paper reports several species of Camallanus and one Serpinema parasitizing freshwater turtles in Argentina. We also describe two new nematode species of Camallanus from the Chaco Side-necked turtle Acanthochelys pallidipectoris, the Hilaire's Side-necked turtle Phrynops hilarii, and the Black Spine-neck Swamp turtle Acanthochelys spixii. These two new nematode species differ from their previously described congeners mainly in the shape of the buccal capsule, spicules, number and distribution of caudal papillae in males, and number of mucrons in females. We provide 18S rDNA sequences of the new species of Camallanus and Camallanus sp. and report interspecific distances for the Camallanus species. Further, we report C. emydidius from Trachemys dorbigni and Camallanus sp. and Serpinema sp. from Kinosternon scorpioides, constituting the first parasitological records for these turtles in Argentina. Also, C. pallidipectoris sp. nov. is the first global parasitological report for the endangered turtle A. pallidipectoris.

Vocalizations can vary in relation to individuals and species, and their function is highly dependent on social context. Parental care can influence calling behavior because of the energetic constraints imposed by performing both tasks simultaneously. However, little is known about the association of acoustic traits with parental care across species that continue to call and accumulate multiple clutches while attending their offspring. In this study, we quantified variation in temporal and spectral call traits in relation to paternal care under natural field conditions in a glassfrog species (Centrolenidae) from the Costa Rican Atlantic rainforest. Specifically, we explored if the calls of males observed in egg-attendance activities differ from those of single individuals not displaying parental care in their call rate, call duration, and dominant frequency. In a second series of analyses generated by additional field observations, we assessed variation in the same acoustic traits in relation to call type by comparing the call of single non-attending males (advertisement call) with that of individuals participating in male–male, long-range acoustic disputes (aggressive call). Our results demonstrate that adult males engaged in egg-attendance or territorial encounters have a different call rate but not dominant frequency or call duration relative to individuals not engaged in these activities. Our findings show that non-attending individuals call more often than attending individuals, but that individuals involved in male–male interactions exhibited the highest call rates overall. Based on these results, we discuss the hypothetical role of call rate as an indicator of male condition with respect to both male–male and male–female interactions. The findings of this study are expected to be helpful for future taxonomic assessments of Hyalinobatrachium talamancae and increase our understanding on the evolution of bioacoustics and natural history aspects associated with paternal care and territoriality in neotropical frogs.