We studied the sexual dimorphism and reproductive cycle of Amphisbaena brasiliana, based on specimens from the municipality of Santar & eacute;m, Par & aacute; state, Brazil, and tested whether precipitation affects the cycle. We accessed and analysed 143 individuals (73 males, 70 females), deposited in scientific collections between 1999 and 2021. We analysed: snout-vent length (SVL), testicular length, width and height, condition of the ductus deferens (convoluted or non-convoluted), diameter of the ductus deferens in the medial and distal portion, condition of the oviducts (convoluted or non-convoluted), length of the largest follicle and number of primary and secondary follicles (vitellogenic follicles). The SVL of females ranged from 149.10-363.11 mm, with 46 specimens (66%) being mature (smallest adult female = 246.46 mm). Male SVL ranged from 123.31-337.26 mm, with 42 (58%) being mature (smallest adult male = 242.0 mm). The sample does not present significant variation in sexual dimorphism analysed in SVL (Mann-Whitney: P = 0.932). Testicle volume and ductus deferens diameter varied seasonally, with the highest values recorded from August to December, during the low rainfall period. Spermatozoa were recorded in the ductus deferens during the low rainfall months in the region, especially in September, when we observed more individuals with ductus deferens convoluted, which may indicate spermatozoa storage. The testicular volume and the diameter of the ductus deferens in the medial and distal portions are related to the period of lower precipitation (ANOVA: P = 2.1 x 10-5; P = 5.18 x 10-6; P = 1.56 x 10-5, respectively). We recorded oviductal eggs in one specimen in December, in addition to the record of vitellogenic follicles in September, October and December, which allows us to interpret a peak of development in the period of lower precipitation, coinciding with the results for males of the species. Our results suggest that the reproductive cycle of the population of A. brasiliana analysed may be influenced by regional rainfall, being seasonal.
The Boulenger's spiny frog Quasipaa boulengeri G & uuml;nther, 1889, is known from only Vietnam and China. It was listed as Vulnerable (VU) in the IUCN Red List and as Endangered (EN) in Vietnam Red Data Book. Knowledge about natural history of this species is virtually lacking. In this study, we analysed the diet of Q. boulengeri based on stomach contents of frogs collected from Cao Bang and Ha Giang Provinces, northern Vietnam. In addition, we also compared food contents between sexes and seasons. We found a total of 892 prey items belonging to 30 prey categories, including 11 orders of insects and four prey categories of invertebrates. There were no positive correlations between the body size of frogs and the minimum prey volume, while there were correlations between the body size of frogs and maximum prey item volume, mean prey item volume and total prey volume. The most important prey groups of Q. boulengeri were Blattidae (IRI = 40.58%), followed by Acrididae (9.27%), other Coleoptera (7.41%) and Tettigoniidae (4.95%). There was an overlap of 67.39% in the diet between males and females. Despite differences in diet compositions between the sexes, Blattidae, beetles and Acrididae make up a majority of prey for all of them. We also compared diet composition between seasons, with a higher number of prey categories recorded in the rainy season (28) than the dry season (15).
Living caecilian are apodal amphibians that present mainly fossorial and secretive habits, making the usual sampling methods ineffective. Therefore, data on the species and their ecology are scarce. In the Atlantic Forest, there are only 13 species, and anecdotal information is available for just three. The Metropolitan Region of S & atilde;o Paulo is highly fragmented, resulting in local extinction of several species. The first record of caecilians on S & atilde;o Paulo, the largest megalopolis in South America, was in 1905, whereas the last record dates back to 1960. Herein, we report the discovery a Luetkenotyphlus brasiliensis population at Parque da Previd & ecirc;ncia, a small urban park in S & atilde;o Paulo, with vegetation in the primary stage of succession. This park is the smallest Atlantic Forest remnant housing caecilians, and surprisingly, it shows the third largest relative abundance of individuals ever registered in this forest fragments for species conservation.
The Lao sucker frog Amolops cremnobatus is known from Laos and Vietnam while the chloronate huia frog Odorrana chloronota has been recorded from Bangladesh, China, India, Laos, Myanmar, Thailand and Vietnam. However, the diet of the two species is still poorly understood. In this study, we investigate the diet composition and niche overlap in the two species living in sympatry at three streams in Vu Quang National Park, Ha Tinh Province, Vietnam. We use the stomach-flushing method to obtain the stomach contents of 83 individuals, including 51 of A. cremnobatus and 32 of O. chloronota. In total, 21 prey categories from 101 food items of invertebrates, and 18 prey categories from 103 food items of invertebrates are identified in the diet of A. cremnobatus and O. chloronota, respectively. Generally, A. cremnobatus consume more diverse prey types than those taken by O. chloronota, and beetles, cockroaches, grasshoppers and crickets represented the most important prey categories in both species. Our results also strongly corroborate the gape hypothesis by demonstrating that O. chloronata with a larger body size can ingest both larger prey items and greater food volumes. Furthermore, our findings show that body size and foraging behaviour play a significant role in selecting prey categories between the sympatric frog species.
Taxonomic and spatial biases limit the understanding of biodiversity patterns, particularly in the Neotropics, with consequences in systematics, biogeography and conservation. Here, we address the impact of these biases by focusing on the widespread species Trachycephalus typhonius. Despite its common occurrence across its range, misidentifications and cryptic diversity have obscured its true phylogenetic and biogeographic histories. Through extensive field sampling and molecular analysis of cis-and trans-Andean localities, we revealed substantial genetic divergence within T. typhonius, which suggests the presence of multiple cryptic species. The samples from Orinoquia (cis-Andes) and Magdalena Valley (trans-Andes) in Colombia, differ from T. typhonius sensu stricto in Guyana. At least three lineages were observed for T. typhonius across the continent, suggesting a complex diversification pattern shaped by major Neotropical barriers. Our results show the influence of both Andes and Amazon-Orinoquia on the phylogeographic structure and provide insights into the biogeographic history of T. typhonius sensu lato. We discuss the importance of addressing taxonomic and spatial biases, and highlight how geographic barriers and historical processes have influenced diversification in the Neotropics. Our findings illustrate the need for comprehensive sampling and molecular studies for 'common' species, to unravel hidden diversity, which is crucial for accurate biodiversity assessments, understanding evolutionary processes, refine biogeographic models, reassess species distributions and inform conservation strategies. Este resumen traducido al espa & ntilde;ol est & aacute; disponible en supplementary materials.
