Zoological Studies最新文献

Epifaunal communities inhabiting seaweeds are key components of temperate rocky reef ecosystems, playing vital roles in nutrient cycling and biodiversity maintenance. However, limited research has addressed their seasonal dynamics in the semi-enclosed Sea of Japan. This study examined the seasonal changes in epifaunal communities associated with two dominant brown algae, Sargassum macrocarpum and S. patens, in Tsukumo Bay, Noto Peninsula. Over the course of one year, we recorded fluctuations in seaweed biomass and associated epifaunal abundance and composition. The wet weight of both host seaweed species peaked in spring and winter and declined during summer and autumn, reflecting their life history traits. Seasonal changes in epifaunal communities were more pronounced than differences between host species. Caprellid and gammarid amphipods exhibited synchronized abundance peaks with seaweed growth in spring and winter, while gastropods remained relatively stable year-round, likely favoring understory habitats. Bivalves increased in summer on S. macrocarpum, potentially due to structural differences facilitating larval settlement. Multivariate analyses (PERMANOVA and nMDS) revealed clear seasonal shifts in community composition, with caprellids, gammarids, and gastropods contributing most to these patterns. Our findings highlight the strong coupling between macroalgal phenology and epifaunal dynamics, suggesting that algal bed seasonality significantly shapes coastal community structure.

Stylochoposthia Faubel, 1983 is a genus of acotylean polyclads, and its family-level assignment is controversial. In this study, we inferred the phylogenetic position of the genus represented by Stylochoposthia sp. using the combined data generated from partial sequences of nuclear 18S and 28S ribosomal DNA, mitochondrial 16S ribosomal DNA, and the cytochrome c oxidase subunit I gene. The phylogenetic analysis revealed that Stylochoposthia sp. was nested in a robust clade comprising the species of four genera within Planoceridae Stimpson, 1857 (Aquaplana Hyman, 1953, Heteroplanocera Oya & Kajihara, 2021, Paraplanocera Laidlaw, 1903, and Planocera Blainville, 1828). Specifically, Stylochoposthia sp. was closely related to Planocera pellucida (Mertens, 1833), with high support values. This study revealed that an eversible cirrus with hard structures (numerous spines, thorns, or teeth) in the male copulatory apparatus, a diagnostic characteristic of Planoceridae, has been lost in the lineage of Stylochoposthia.

Based on a comprehensive literature review, we present an analysis of the richness of the subfamily Scarabaeinae and its distribution in Mexico's Chiapas state. The reviewed works provided information from 185 localities where 134 species belonging to 24 genera were recorded. Fourteen species (10.4%) are endemic to Chiapas, mainly restricted to montane forests. The number of species places Chiapas as one of the regions with the highest species richness in Mexico, representing 39.2% of the Scarabaeinae diversity known in the country. Although the sampling effort is relatively high compared to other regions, there is a strong sampling bias, with localities unevenly distributed in the state territory, most of them concentrated in easily accessible areas, with extensive regions with little or no representativeness, including mountainous areas and several natural protected areas. This information may constitute a valuable contribution to future projects on the taxonomy and biodiversity of dung beetles, so considering poorly explored regions constitutes a niche of opportunities that would allow expanding the knowledge on Scarabaeinae at a regional level.

This study describes two new species of Glyptothorax from the Mekong River drainage in Cambodia and Laos. Glyptothorax carnatus can be distinguished from Mekong congeners by its deep body relative to the caudal peduncle (caudal peduncle depth 2.8-3.6 times in body depth at dorsal-fin origin vs. 1.9-3.0) and combination of characters in color pattern, thoracic adhesive apparatus (TAA) morphology, nuchal plate shape, and morphometry. Glyptothorax rhadinus can be distinguished from Mekong congeners by its very slender TAA (width 1.9-2.2 times in its length vs. 1.1-1.9) and a combination of characters in color pattern, thoracic adhesive apparatus (TAA) morphology, nuchal plate shape, and morphometry. Both species have been previously confused with G. fuscus and G. lampris, and comparisons with these two species are provided.

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.