Aim
Disentangling historical and ecological effects on different components of species diversity is key to understanding the assembly and maintenance of communities over space and time. Historical ...factors may be stronger predictors of the community composition at regional scales, while ecological factors may be more important predictors at local scales. Here, we evaluate multiple biodiversity dimensions to investigate riverine barrier and aridity effects on the assembly and structure of lizard assemblages.
Location
Semi‐arid region of northeastern Brazil.
Taxon
Lacertilia (lizards).
Methods
We used data describing 63 lizard assemblages from Caatinga habitats to investigate the effects of a riverine barrier and eight environmental gradients on estimates of taxonomic, phylogenetic and functional diversity. At the regional scale, we compared communities between the banks of the SFr, assuming that differences could emerge from regionally interrupted dispersal in some of the sampled species. At local scales, we evaluated the patterns of phylogenetic and functional structure of the lizard assemblages from Caatinga, and investigated the influence of aridity‐related gradients on species richness, taxonomic, phylogenetic and functional diversity.
Results
Lizard assemblages were regionally structured by the SFr acting as a barrier to 47% of the species sampled. We detected phylogenetic signal in 88% of the functional traits. Lizard assemblages were phylogenetic and functionally overdispersed. Moreover, we detected evidence of aridity gradients intensifying the overdispersion of phylogenies and functional traits.
Main conclusions
Lizard assemblages showed high variation at both regional and local scales. Riverine barriers played a stronger role as a historical factor structuring assemblages on a regional scale. The interaction of historical constraints with competition enhanced by aridity on a local scale may play a role in structuring lizard assemblages across multiple scales.
Spalerosophis
Jan, 1865, is a colubrid snake genus distributed in arid and semiarid regions from northwestern Africa to northern India. Six species of
Spalerosophis
are identified based on ...traditional morphology; however, there are arguments about their systematic status. We performed the first molecular phylogenetic analyses for this genus using nucleotide sequences of c. 2278 bp from three mitochondrial genes (12S rRNA, 16S rRNA, and cyt b) to investigate the phylogenetic relationships and historical evolution of the poorly known
Spalerosophis
species and doubtful populations. We used fossil calibrations for dating divergences. Our phylogenetic analyses clearly showed five separate species with high support values, including
S. arenarius
,
S. atriceps
,
S. microlepis
,
S. diadema schirasianus
, and
S. diadema cliffordii
. Bayesian calibrated molecular clock suggested that the genus
Spalerosophis
diverged from the common ancestor in the Paleogene around 35.28 Mya (25.89–44.66). Our analysis indicated that isolated
S. atriceps
was separated around 21.72 Mya (10.86–33.04) as the basal diverged species of the genus. This suggested that the species of
Spalerosophis
probably originated from an ancestor somewhere in the Iranian Plateau and then dispersed to its current geographical range.
Spalerosophis arenarius
and
S. atriceps
were identified as the two last diverged members of the genus, separated from
S. d. schirasianus
during the Middle Miocene about 13.31 Mya (5.52–22.33). These results indicate that the separation of
Spalerosophis
species coincided with the orogenic events of the Zagros Mountains in western Iran and the Sulaiman Mountains in Afghanistan, India, and Pakistan. Their diversification may therefore be the result of vicariance events that promoted their current distribution. This work provides a foundation for future studies on the phylogeny, diversity, and evolution of the genus
Spalerosophis
and highlights the need for more molecular studies on unknown snakes.
Spatial patterns of genetic variation can help understand how environmental factors either permit or restrict gene flow and create opportunities for regional adaptations. Organisms from harsh ...environments such as the Brazilian semiarid Caatinga biome may reveal how severe climate conditions may affect patterns of genetic variation. Herein we combine information from mitochondrial DNA with physical and environmental features to study the association between different aspects of the Caatinga landscape and spatial genetic variation in the whiptail lizard Ameivula ocellifera. We investigated which of the climatic, environmental, geographical and/or historical components best predict: (1) the spatial distribution of genetic diversity, and (2) the genetic differentiation among populations. We found that genetic variation in A. ocellifera has been influenced mainly by temperature variability, which modulates connectivity among populations. Past climate conditions were important for shaping current genetic diversity, suggesting a time lag in genetic responses. Population structure in A. ocellifera was best explained by both isolation by distance and isolation by resistance (main rivers). Our findings indicate that both physical and climatic features are important for explaining the observed patterns of genetic variation across the xeric Caatinga biome.
Spatial and temporal variations can influence the abundance and biology of parasite species and even the transmission process, as well as the diet, reproduction and distribution of hosts. We studied ...the influence of seasonality on the diet and endoparasites of the lizard Strobilurus torquatus. The lizards were collected during a period of one year, in the Engenho Gargaú Private Reserve of Natural Heritage, located in the municipality of Santa Rita, in the state of Paraíba, Northeast Brazil. Thirty-three lizards were analysed, of which 30 were parasitised (overall prevalence of 90%) with the helminths Physaloptera lutzi (prevalence of 69.6%), Spauligodon loboi (51.5%), Strongyluris oscari (15.1%) and Haplometroides odhneri (3.0%). Our analysis showed that endoparasite abundance was influenced by host body size (R2m: 0.95; R2c: 0.95; Z-value: 11.521; P < 0.0001). Host sex also influenced endoparasite abundance, where males were parasitised more than females (Z-value: 6.260; P < 0.001). When comparing the two seasons (dry and rainy), we observed that the greatest endoparasites abundance occurred during the rainy season (Z- value: -2.422; P < 0.05). Regarding the lizards’ diet, we observed a high niche overlap (overlap index of 0.999), which indicates that males and females of S. torquatus consumed practically the same prey during the analysed period. The life cycle of the endoparasites found in S. torquatus was linked to seasonal variation, and the behavioural and physiological differences between sexes may have influenced the variations in endoparasite abundance.
We compared lizard endoparasite assemblages between the Atlantic Forest and naturally isolated forest enclaves to test the ecological release hypothesis, which predicts that host specificity should ...be lower (large niche breadth) and parasite abundance should be greater for parasites from isolated forest enclaves (poor assemblages) than for parasites from the coastal Atlantic Forest (rich assemblages). Parasite richness per specimen showed no difference between the isolated and non-isolated areas. Parasite abundance did not differ between the isolated and non-isolated areas but showed a positive relationship with parasite richness considering all areas (isolated and non-isolated). Furthermore, host specificity was positively related to parasite richness. Considering that host specificity is inversely proportional to the host range infected by a parasite, our results indicate that in assemblages with greater parasite richness, parasites tend to infect a smaller range of hosts than do those in simple assemblages. In summary, our study partially supports the ecological release hypothesis: in assemblages with greater parasite richness, lizard parasites from Atlantic Forest are able to increase their parasite abundance (per host), possibly through facilitated infection; however, the amplitude of infected hosts only expands in poor assemblages (lower parasite richness).
Chikungunya virus (CHIKV) is the causative agent of chikungunya fever, a disease that can result in disability. Until now, there is no antiviral treatment against CHIKV, demonstrating that there is a ...need for development of new drugs. Studies have shown that thiosemicarbazones and their metal complexes possess biological activities, and their synthesis is simple, clean, versatile, and results in high yields. Here, we evaluated the mechanism of action (MOA) of a cobalt(III) thiosemicarbazone complex named Co
III
(L
1
)
2
Cl based on its in vitro potent antiviral activity against CHIKV previously evaluated (80% of inhibition on replication)
.
Furthermore, the complex has no toxicity in healthy cells, as confirmed by infecting BHK-21 cells with CHIKV-
nanoluciferase
in the presence of the compound, showing that Co
III
(L
1
)
2
Cl inhibited CHIKV infection with the selective index of 3.26. Co
III
(L
1
)
2
Cl presented a post-entry effect on viral replication, emphasized by the strong interaction of Co
III
(L
1
)
2
Cl with CHIKV non-structural protein 4 (nsP4) in the microscale thermophoresis assay, suggesting a potential mode of action of this compound against CHIKV. Moreover, in silico analyses by molecular docking demonstrated potential interaction of Co
III
(L
1
)
2
Cl with nsP4 through hydrogen bonds, hydrophobic and electrostatic interactions. The evaluation of ADME-Tox properties showed that Co
III
(L
1
)
2
Cl presents appropriate lipophilicity, good human intestinal absorption, and has no toxicological effect as irritant, mutagenic, reproductive, and tumorigenic side effects.
Graphical abstract
Neryl butyrate is a constituent of volatile oils obtained from aromatic plants. Aliphatic organic compound analogues chemically close to neryl butyrate possess vasodilator properties in rat aorta. To ...evaluate whether neryl butyrate has relaxing properties, this study tested its effects on isolated rat aorta. Unlike the analogues, neryl butyrate did not show relaxant profile in aortic rings precontracted with phenylephrine, but induced a contraction when it stimulated aortic rings under resting tonus. The contractile effect augmented in endothelium-denuded aortic rings. Treatment of endothelium-intact preparations with the nitric oxide synthase inhibitor L-NAME or the guanylyl cyclase inhibitor ODQ also augmented the contractile effect of neryl butyrate. Such phenomenon was absent in the presence of the cyclooxygenase inhibitor indomethacin. Contractile responses decreased in the presence of verapamil, a L-type Ca
2+
channel blocker, or when Ca
2+
was removed from the extracellular solution. Antagonists of α-adrenergic receptors (prazosin and yohimbine), but not the thromboxane-prostanoid receptor seratrodast, reversed the contraction induced by neryl butyrate. The α
1A
selective antagonist RS-17053 antagonized the neryl butyrate-induced contraction. The contraction caused by neryl butyrate was decreased by inhibiting the phospholipase C or the rho-associated kinase with U-73122 or Y-27632, respectively. Injected intravenously to awake rats, neryl butyrate induced arterial hypotension and bradycardia. Decreased frequency was also present in isolated right atrium preparations. In conclusion, the contractile effects of neryl butyrate were inhibited by α-adrenergic antagonists, indicating the involvement of α-adrenoceptors in the mechanism of action. In vivo, neryl butyrate caused hypotension, suggesting that other systemic influence than vasoconstriction may occur.
ABSTRACT Currently, plastics are recognized as a major pollutant of the marine environment, representing a serious threat to ocean wildlife. Here, we examined the occurrence and effects of plastic ...ingestion by sea turtles found stranded along the coast of Paraíba State, Brazil from August 2009 to July 2010. Ninety-eight digestive tracts were examined, with plastic found in 20 (20.4%). Sixty five percent (n = 13) of turtles with plastic in the digestive tract were green turtles (Chelonia mydas), 25% (n = 5) were hawksbills (Eretmochelys imbricata), and 10% (n = 2) were olive ridley (Lepidochelys olivacea). More plastic was found in the intestine (85%) than in other parts of the gastrointestinal tract. We observed complete blockage of the gastrointestinal tract due to the presence of plastic in 13 of the 20 turtles that had ingested plastic. No correlation was found between the curved carapace length (CCL) and the number or mass of the plastic ingested items. Significant differences were found between the intake of hard and soft plastic and the ingestion of white/transparent and colored plastic, with soft and white/transparent plastics being more commonly ingested. This study reveals the serious problem of plastic pollution to sea turtles at the area.
RESUMO Atualmente, os plásticos são reconhecidos como um dos principais poluentes do ambiente marinho, representando uma séria ameaça para a vida marinha. Neste trabalho, nós examinamos a ocorrência e os efeitos da ingestão de plástico por tartarugas marinhas encontradas encalhadas ao longo da costa do estado da Paraíba, Brasil, de agosto de 2009 a julho de 2010. Noventa e oito tratos gastrointestinais foram examinados e plásticos foram encontrados em 20 (20,4%). Sessenta e cinco por cento (n = 13) das tartarugas com plástico no trato gastrointestinal eram da espécie verde (Chelonia mydas), 25% (n = 5) eram da espécie pente (Eretmochelys imbricata) e 10% (n = 2) eram da espécie oliva (Lepidochelys olivacea). Foi encontrado mais plástico no intestino (85%) do que em outras partes do trato gastrointestinal. Observou-se o completo bloqueio do trato gastrointestinal, devido à presença de plástico, em 13 das 20 tartarugas que ingeriram plástico. Não foi encontrada correlação entre o comprimento curvilíneo de carapaça (CCC) e o número ou massa dos itens plásticos ingeridos. Diferenças significativas foram encontradas entre a ingestão de plástico rígido e flexível e entre a ingestão de plástico branco/transparente e colorido, com os flexíveis e brancos/transparentes sendo ingeridos com mais frequência. Este estudo revelou o grave problema da poluição por resíduos plásticos para as tartarugas marinhas nesta área.
Vegetable peels are rarely used in food preparation, causing the loss of several nutrients. Such residues caproduce flour as a possible food source with added nutritional and economic value. Thus, ...the objective wasto evaluate the nutritional quality and the color of the flours obtained from the peels of potato, carrot, andchayote subjected to drying at the temperatures of 40, 50, 60, and 70 °C, as well as analyzing the dryingkinetics. The peels were removed, packed in an isothermal box with ice, and taken to the laboratory. Thenthey were washed in running water to remove dirt and unwanted parts and sanitized. After this stage, theywere broken into 2 cm lengths. The drying was carried out in 150 g of peels in triplicate for each raw material.Subsequently, nutritional quality, color, and drying models were determined. Flours obtained from drying athigher temperatures showed higher protein content and lower lipid content. The higher the temperature, theshorter the drying time for the flour. All flours presented excellent nutritional quality. Among the models studiedfor potato peels, Wang and Singh, Midilli, and Logarithmic are the most suitable. For chayote and carrot peels,the Midilli model is the most adequate. Using vegetable residues added to food formulations presents itself asan excellent nutritional source, besides adding flavor and texture to foods.
Abstract
The Caatinga is the largest seasonal dry tropical forest in South America and it has been historically neglected in terms of its biodiversity. Regarding lizards, different studies led to the ...current knowledge of diversity and endemism in Caatinga, but detailed syntheses are scarce in the literature. We present the most detailed and up-to-date synthesis of knowledge about Caatinga lizards by providing a detailed (i) list of species; (ii) taxonomic richness patterns; (iii) knowledge gaps and spatial biases; and (iv) detailed distribution maps of all species that contain at least one occurrence record within Caatinga limits. We created a distribution database using occurrences of lizards in Caatinga based on scientific collections, field collection, and literature. We produce up-to-date distribution maps, calculate the Extent of Occurrence and provide the environmental and bioclimatic profile for each species recorded. We draw taxonomic richness and sampling gap maps. Our database has 20,538 records of occurrence of lizards of the Caatinga. We recorded 93 lizard species (13 families), 52.7% of which are endemic. Forthy-four percent of the species present restricted distributions. We identified that 53% of the Caatinga area (or 70% of the municipalities) has no record of occurrence of lizards. The data presented are an important step towards synthesizing in detail the accumulated knowledge about Caatinga lizards and is crucial for accurate strategies for the conservation planning. It directs actions to advance our knowledge on Caatinga lizards: to concentrate inventories in sample void areas; continuous update of the species occurrence database, advance in the generation of autoecology data for species.
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