Integrative zoology最新文献

Plague, a zoonotic disease caused by Yersinia pestis, remains a major public health threat in several parts of the world, including Madagascar. Factors underlying long-term persistence and emergence of the pathogen remain poorly understood. We implemented a longitudinal survey to provide insights into plague reservoir ecology within an endemic focus. Six trapping sessions (TS) were conducted in six different localities of the Ankazobe district from 2018 to 2020 in order to monitor small mammal communities. A total of 2762 individuals composed of six species (Rattus rattus, Rattus norvegicus, Mus musculus, Setifer setosus, Suncus murinus and Tenrec ecaudatus) were caught over the six successive TS. R. rattus represented 88% of all captures, with the highest relative abundances observed during the dry season (June to August 2019). None of the micromammals tested positive for the presence of Y. pestis, neither with qPCR nor bacterial culture. However, 11 seropositive individuals (6 R. rattus, 2 M. musculus and 3 S. murinus) were retrieved following ELISA, thus leading to a global seroprevalence of 0.4%. Our study highlighted the significant influence of climatic data on the seasonal variations of R. rattus abundance and suggest that black rat control should be conducted before the dry season, that is, during high reproduction period of rats, in order to reduce the number of reproducing animals and prevent subsequent increase in abundance. As three S. murinus and two M. musculus plague seropositive were identified in the present study, their potential role in plague eco-epidemiology in Madagascar should be explored further.

The burrow microhabitats created by burrowing mammals, as a hotspot for biodiversity distribution in ecosystems, provide multiple critical resources for many other sympatric species. However, the cascading effects of burrow resources on sympatric animal community assemblages and interspecific interactions are largely unknown. During 2020-2023, we monitored 184 Chinese pangolin (Manis pentadactyla) burrows using camera traps to reveal the burrow utilization patterns of commensal species. We totally recorded up to 57 species, with 19 mammal species, 32 bird species, and 1 reptile species recorded in the burrows revisited by Chinese pangolin, with 19 mammal species and 25 bird species in the non-revisited burrows. Among them, most bird species as peripheral species primarily utilize soil mounds while most mammal species as burrow-used species utilize burrow tunnels. The structure of animal communities in the burrows revisited by Chinese pangolins is more complex than that in the burrows not revisited. Furthermore, the positive correlation between community species in pangolin-revisited burrows is also stronger. Our results demonstrate that the presence and repeated visitation by Chinese pangolins could enhance positive interactions (i.e., the emergence of one species promotes the emergence of another) among species that utilize the burrow resources (particularly, burrow-used species). Our study provides the first evidence that the ecological role of the Chinese pangolin and its associated burrow microhabitats in promoting the coexistence of burrowing commensals and the restoration of Chinese pangolin populations may potentially contribute to the restoration of local biodiversity and ecological processes.

Pomacea canaliculata is recognized as a globally invasive aquatic species. Analyses of intestinal microbiota, dietary composition, and metabolism of invasive species can enhance our understanding of their feeding strategies and physiological adaptation strategies to the environment. Intestinal content samples were collected from P. canaliculata inhabiting three distinct environments including a pond, a river, and a ditch. These samples were subjected to 16S rRNA gene sequencing analysis and multiple metabarcoding analyses, including eukaryotic 18S rRNA, mitochondrial cytochrome c oxidase I (COI), and chloroplast rbcL genes. In addition, metabolomics analysis was conducted on the intestinal content samples to investigate metabolic change. The highest dietary diversity in P. canaliculata was observed in the ditch, and females exhibited a higher dietary diversity than males in the pond. The 18S rRNA gene has a high potential for identifying the dietary components of omnivorous species. The intestinal microbiota of P. canaliculata from different habitats displayed significant variations, attributed to differences in food resources and other environmental factors. Bacteria in the aquatic environment had minimal impact on the intestinal microbiota of P. canaliculata. Overall, P. canaliculata exhibited adaptive changes in physiological characteristics across different habitats, including alterations in diet, which, in turn, influence microbiota and metabolic pathways such as amino acid biosynthesis in the intestine. The present study investigated the physiological mechanisms that enable P. canaliculata to adapt to diverse habitats, considering various factors including diet, which is important for comprehending its invasive potential and the subsequent threats it poses to aquatic ecosystems.

The invasion of cane toads (Rhinella marina) across tropical Australia has resulted in the rapid evolution of traits that enable higher rates of dispersal, and that adapt toads to hot dry climates. In anurans, a larger heart facilitates both locomotor activity and desiccation tolerance. Heart size is also often affected, either directly or indirectly, by parasite infections. To test the effects of invasion history and parasite exposure on heart size, we studied common garden-reared toads whose parents were sourced from diverse locations, and experimentally exposed them to larvae of a nematode lungworm (Rhabdias pseudosphaerocephala). Offspring of invasion-front parents had larger hearts than did conspecifics from long-established populations. Exposure to infective lungworm larvae decreased heart mass in toads from all populations. Our study suggests that cardiovascular function, like other traits, has evolved rapidly during the toad invasion; and that lungworm parasites can modify the cardiovascular function and hence aerobic capacity of their host.

Australia is urgently confronted with the need to develop and implement an integrated national strategy for managing Varroa mite (Varroa destructor), external parasites that pose a severe threat to honeybee colonies. The manuscript advocates for immediate action, emphasizing the importance of importing expertise and strengthening educational programs to build long-term resilience against Varroa mite infestations.

The conspecific encounter index can be further decomposed into two components, which represent two ecological processes.

Bird eggs can be spherical, ellipsoid, ovoid, or pear-shaped (pyriform), the latter being the most complex. There is however no unambiguous evolutionary/adaptive explanation for this final, exotic shape. We hypothesized that pyriform eggs have a larger surface area-to-volume ratio (S/V) that may be a criterion for increased embryo metabolism. By integrating mathematical approaches, we confirmed this to be the case and developed a model of the egg metabolic rate defined as the ratio of S/V to its maximum possible value, depending on egg length. We found this to be inversely proportional to the egg incubation period and concluded that the complex pyriform shape is most likely due to embryo metabolism increase and, as a result, a reduction in the incubation period and shortened hatching time. As a result of this study, we conclude that some avian eggs are pyriform as this may attain a larger S/V ratio making them grow and hatch quicker.

This essay was originally prepared for a special commemorative volume to celebrate the International Zoological Congress (established 135 years ago) and the International Society of Zoological Sciences (ISZS, established 20 years ago). These two institutions underpin international cooperation and promote excellence in zoological research without which the science of zoology would be very much the poorer.

The genus Typhlomys comprises six species that all exhibit exceptional climbing agility in arboreal habitats, of which five have been established to use ultrasonic echolocation in the 80-120-kHz frequency range to navigate among tree branches. Here, we investigated the ultrasonic vocalizations of the remaining and recently recognized species, T. fengjiensis, and compared its ultrasonic and morphological traits with its sibling species T. daloushanensis. Both species produced frequency-modulated (FM) ultrasonic calls that lacked harmonic structure, consistent with echolocating calls established for other members of this genus Typhlomys. This FM echolocation call structure is well-adapted to navigating along branches in dense foliage conditions in the forest understory. Importantly, however, the specific call structures of T. fengjiensis and T. daloushanensis exhibited significantly different ultrasonic characteristics, with different numbers of pulse groups, in support of phonic speciation. T. fengjiensis was on average larger than T. daloushanensis and vocalized at a lower frequency and for a longer duration, in support of the signal-size allometry hypothesis. Furthermore, T. fengjiensis has the lowest ultrasonic call frequency among Typhlomys spp., corresponding with it being the largest member of this genus. Bergmann's law does not provide a compelling explanation of the body mass differences between T. fengjiensis and T. daloushanensis, due to the likely overlap in their elevational distribution. Further research is needed to establish if differences in habitat selection and diet, or differences in social and reproductive behavior, might best explain this local species divergence based on phonic traits.

Gut mycobiota are part of the gut microbiome, typically derived from the host diet and living environment. In this study, we examined the gut mycobiota of three snub-nosed monkeys: Rhinopithecus roxellana, R. bieti, and R. strykeri using next-generation amplicon sequencing targeting the fungal internal transcribed spacer. The alpha diversity indexes of gut mycobiota in R. bieti were significantly higher than R. roxellana and R. strykeri, the beta diversity indicated that R. roxellana and R. bieti had more similar feeding habits. Core mycobiota demonstrated commonalities among the three species and potentially associated with feeding habits. Mycobiota displaying significant differences exhibited the respective characteristics of the host, likely associated with the hosts' living environment. Among them, animal and plant pathogenic fungi and lichen parasites are potential threats to the survival of snub-nosed monkeys for their pathogenicity to both monkeys and their food plants. Functionally, fungal trophic modes and functional guilds revealed a strong association between gut mycobiota and host diet. We found a higher abundance and more significant correlations with lichen parasitic fungi in R. strykeri than the other two species, indicating potential threats to their foods. Accordingly, this study revealed the basic structures of gut mycobiota of three wild Rhinopithecus species and highlighted the associations between gut mycobiota and their feeding habits and living environments. Furthermore, due to the close connection between fungi and the environment, animals could ingest fungi from their diet; thus, we speculate that gut mycobiota may serve a role in environmental monitoring for wildlife.