Zoological Studies最新文献

In nature, survival is affected by many ecological factors, with ambient temperature (Ta) being one of the most important, as it determines the energy metabolism of animals. In endothermic bird species, exposure to colder temperatures significantly increase metabolic thermogenesis. However, whether prior exposure to cool temperatures exacerbates birds' response to warm temperatures and affects tissuespecific physiological response rates in the context of temperature fluctuations remains unclear. Our study examined the effects of cool-warm thermal acclimation on metabolic thermogenesis in different tissues of Chinese bulbuls (Pycnonotus sinensis). Adult Chinese bulbuls were captured in Wenzhou City, Zhejiang, China. After 4 weeks of acclimation at a Ta of 10°C, the birds were divided into a control group (10°C) and an experimental group (30°C). The experimental group was further subdivided into four groups according to the duration of acclimation: 1 day, 3 days, 7 days, and 28 days. After each acclimation period, the body mass, basal metabolic rate (BMR), energy budget, organ mass, state 4 respiration (S4R), and the activity of cytochrome c oxidase (COX) in the liver and muscle were measured. Prolonged exposure to warm acclimation resulted in significant decreases in body mass, energy intake, BMR, tissue mass, S4R, and COX activity in both the liver and muscle, whereas the digestibility of food increased. Interestingly, the small intestine mass and liver metabolism rapidly decreased on the first day of transfer to a warm environment, while the muscle response to such thermal changes was relatively slow, suggesting tissuespecific differences in the physiological response rates to warm temperatures. Overall, these results revealed the influence of changing ambient temperature on the metabolism in Chinese bulbuls and offered valuable insights into the regulation of diverse biological processes that mediated the physiological adjustments of Chinese bulbuls during the seasonal temperature fluctuations.

Anthopleura nigrescens (Verrill 1928) is a common sea anemone typically encountered in the rocky crevices of shallow-water intertidal zones in the West Pacific. Despite its ubiquity, little is known about the biology of this species, with research on them hindered due to difficulties in distinguishing Indo-Pacific Anthopleura species. The original description of A. nigrescens was sparse, and while there have been two focused redescriptions of this species, data presented in those accounts were conflicting (e.g., acrorhagi appearance and cnidom), thus the species cannot be identified accurately. In this study, we report the unusual occurrence of A. nigrescens beside hydrothermal vents in Taiwan and conducted transcriptomic analyses to better understand the adaptive biology of this species. We also performed a contemporary redescription of A. nigrescens, integrating morphological and molecular evidence from both museum specimens and fresh material collected from Taiwan and Singapore, while also incorporating data from earlier descriptions of the species. Transcriptomic analyses revealed a unique A. nigrescens adaptive strategy, characterized by the enrichment of metal ion binding genes and the activation of thermal resistance pathways, enabling adaptation to the hydrothermal vent environment compared to individuals inhabiting intertidal shores. Transcriptomic data also provided additional insights to the systematics of Anthopleura Duchassaing & Michelotti, 1860, concurring to previous observations that biogeographic patterns are a good predictor of its phylogeny than the current state of the genus' taxonomy. Overall, while we found that taxonomic characters of material we had examined to agreed, we also found intra-specific morphological deviations particularly concerning occurrence of cnidae documented for the species. Collectively, our findings refined our understanding of the species' taxonomy and support its placement within a biogeographically coherent clade, contributing to a broader understanding of its evolutionary and ecological context.

Two new troglobitic species of pseudoscorpion genus Pseudochthonius are described from Bahia State, Brazil. Detailed morphological descriptions, diagnostic features, and illustrations of Pseudochthonius cesarioensis sp. nov. and Pseudochthonius gonssaloensis sp. nov. are provided. Additionally, we discuss future research directions for these species and provide a key to distinguish the Brazilian Pseudochthonius species.

This study investigates the presence and biodiversity of tardigrades in a newly identified anthropogenic habitat (holes in concrete blocks) in periurban environments in Bologna, Italy. A total of 13 concrete blocks were sampled and the abundance and diversity of tardigrades present were assessed by both manual counting and DNA metabarcoding. Abundant tardigrades populations were found, with densities reaching up to 5752 individuals per gram of dry sediment. Four tardigrade operational taxonomic units (OTUs) were identified, including species previously associated with freshwater rock pools from Italian Apennines (Ramazzottius cf. varieornatus and Ramazzottius claudii), suggesting that these concrete holes may serve as ecological analogues to such habitats. The findings highlight the potential of anthropogenic environments, specifically concrete anthrotelmata, to support diverse biological communities and provide insights into urban biodiversity conservation strategies. This research underscores the importance of accounting for and integrating artificial habitats into urban planning to enhance biodiversity.

Two new species of Aegla, A. tamanduatei sp. nov. and A. curucutu sp. nov., are described from loworder streams from Alto Tietê microbasin, headwater section of the Tietê River watershed. Description and validation of the new species are based on morphological and molecular features. Posterior probability and maximum likelihood bootstrap values strongly support the two new species as sister groups. Molecular data and the sharing of notable combination of morphological traits suggest a coherent phylogenetic and distributional relationship among all valid species of Aegla from the Tietê River watershed, save Aegla perobae. A key to all presently known aeglid species from the Tietê River watershed is provided.

Niche restriction is observed in tandem with the life history traits of parasites, reflecting their response to changing host conditions. Mesidionema praecomasculatis predominantly inhabits the anterior intestine of the host earthworm African nightcrawler, whereas Thelastoma endoscolicum, a pinworm, resides in the hindgut, which is characterized by a higher population of resident bacteria. Control experiments indicate that both intestinal nematodes are sensitive to environmental residues of the anthelmintic mebendazole. However, reductions in T. endoscolicum infection were observed only after host exposure to food limitation or the antibiotic streptomycin, both of which also reduced gut bacterial abundance. These findings underscore the strong correlation between T. endoscolicum infection dynamics and the host's bacterial abundance, aligning with previous research on the potential relationship between pinworms, host digestion, and the resident bacterial population. Given that African nightcrawler is a widely used compost earthworm, the influence of intestinal nematodes, along with varying prevalence under different farming conditions, may significantly affect the efficiency of earthworm composting-an aspect that has been relatively underexplored in the composting industry.

Medusae of the genus Cassiopea are common components of tropical and subtropical coastlines globally. Despite the broad distribution of this benthic scyphozoan, much about their ecology remains poorly described. Here, we collected over 100 adult Cassiopea individuals from Panama, the eastern United States, Cuba, the Philippines, Italy and Australia to examine continuity and differences in their diet across space, and to investigate whether their unique lifestyle is reflected in their diet. We found the majority of prey items to be associated with the epibenthos. The recovered prey were supermajority crustaceans, mainly harpacticoid copepods, with pteropods, nematodes, and miscellaneous eggs common as secondary components. Within the gastrovascular cavity of a single medusa, we found up to 379 items. There was a limited relationship between medusa size and prey items. Location had an impact on gut content diversity and medusa size had a small impact on the number of taxa found within the gut. In some sites, prey were scarce or absent from all medusae sampled. Overall, we reaffirm the diet previously recorded for small medusae in Puerto Rico and show that similar components are common in large and small medusae from throughout the East and West Atlantic and the Philippines.

A new genus, Supraguinea gen. nov. Cumberlidge, Mvogo Ndongo, and Fitch, is established to accommodate four species of freshwater crabs from West Africa that were previously included in Liberonautes Bott, 1955 s. l. (Liberonautinae). These are: Supraguinea lugbe (Cumberlidge, 1999) comb. nov., S. constantini (Cumberlidge, Fitch and Clark, 2023) comb. nov., S. rubigimanus (Cumberlidge and Sachs, 1989) comb. nov., and S. nimba (Cumberlidge, 1999) comb. nov. This new genus is defined based on previously-published molecular evidence (Mvogo Ndongo et al., 2024: fig. 8) that indicated the presence of a deep phylogenetic split within Liberonautes s. l., and on a set of distinctly different morphological characters of the carapace, third maxillipeds, and chelipeds. The species included in the new genus are found in Liberia, Cote d'Ivoire, and Guinea, and are here compared with, and distinguished from, other freshwater crabs occurring in this part of West Africa. The removal of these four species from Liberonautes s. l. leaves the latter genus with eight species, L. latidactylus (De Man, 1903), 1989, L. paludicolis Cumberlidge and Sachs, 1989, L. chaperi (A. Milne-Edwards, 1887), and L. grandbassa Cumberlidge, 1999, L. kasonko Mvogo Ndongo, von Rintelen, Clark and Cumberlidge, 2024, L. njala Mvogo Ndongo, von Rintelen, Clark and Cumberlidge, 2024, L. schubarti Mvogo Ndongo, von Rintelen, Clark and Cumberlidge, 2024, and L. sugarloaf Mvogo Ndongo, von Rintelen, Clark and Cumberlidge, 2024, which are all compared with the new genus. Identification keys to the four species of Supraguinea gen. nov. Cumberlidge, Mvogo Ndongo, Fitch and to the six genera now included in the Liberonautinae are provided.

Among the mechanisms of insecticide resistance, knockdown resistance (kdr), causes alterations in the functioning of the voltage-gated sodium channel (Nav), which is the target site for pyrethroids (PYs) and dichloro diphenyl chloroethane (DDT). In Aedes aegypti, 13 kdr mutations associated with PYs resistance have been identified, with V₄₁₀L, V₁₀₁₆I, V₁₀₁₆G, and F₁₅₃₄C being the most reported mutations in the literature. To assess global and temporal trends in the allelic frequencies of these V₄₁₀L, V₁₀₁₆I/G and F₁₅₃₄C mutations, a PRISMA-guided systematic review was conducted to analyzed their distribution and frequency, incorporating new genotyping data from five southeastern Brazilian populations. Genotyping in these populations was performed using allele-specific PCR (AS-PCR), thereby complementing the findings of the review. The results revealed that, out of a total of 187 studies, the F₁₅₃₄C mutation is the most studied (144 studies) and has the widest geographical distribution (47 countries, 4 continents), followed by the V₄₁₀L, V₁₀₁₆I, and V₁₀₁₆G mutations. In southeast Brazil, resistant alleles were detected both individually and in co-occurrence (e.g., V₄₁₀L + V₁₀₁₆I + F₁₅₃₄C), and were associated with PY resistance. These mutations alter Nav, reducing insecticide binding affinity and leading to high-level resistance-particularly when specific genotypic combinations are present. Their global spread poses a significant threat to A. aegypti control efforts, as PYs remain a cornerstone of public health interventions. Urgent, systematic monitoring of kdr allele frequencies and their synergistic effects is essential to optimize insecticide rotation strategies and prevent operational failures. This calls for coordinated international efforts to develop adaptive control strategies.

Aedes albopictus, a vector of arboviruses of medical and veterinary importance, has undergone a remarkable global expansion over the past five decades. This worldwide study analyzes the phylogeography, invasion routes, and demographic history of this mosquito species, tracing its spread from its native range in Asia to Oceania, Europe, America, and Africa. To this end, genetic datasets with distribution patterns aligned with the species' global spread were identified and extracted from publicly available databases. Phylogeographic analyses were conducted at a global level, invasion scenarios were tested, and the demographic history of populations involved in the spread was reconstructed. The mitochondrial genes COI (n = 3896), ND5 (n = 597), and the complete mitogenome (n = 79) were analyzed, revealing higher genetic diversity within the native range and genetic connectivity across all invaded regions, including the Americas, Africa, Europe, and Asia. All genetic markers indicate that the invasion dynamics followed a panmictic population structure, characterized by random mating and high gene flow among populations. Demographic analyses confirm Asia as the ancestral source population and identify multiple introduction events into Europe, the Americas, and Africa. This invasion pattern, combined with the evidence of panmixia, suggests that anthropogenic factors-particularly global trade-play a pivotal role in shaping the genetic connectivity and dispersal of A. albopictus, underscoring the influence of increasing global commerce on the spread of medically and veterinary-relevant species.