Zoological Studies最新文献

This study compared the changes in benthic community structures of the Shanfu (SF) and Duozaiping (DU) coral reef intertidal zones of Liuqiu Island between 2020 and 2022 after a prolonged precipitation event between late July and early August 2021. The trend of extreme rainfall on the island was also explored using the Standardized Precipitation Index (SPI) for coastal management use. The adjacent study sites of SF and DU have areas of 16,203 and 31,930 m², respectively. Variations in the diversity indexes between sites (SF and DU) and years (2020, 2021, and 2022) were determined by two-way ANOVA tests. SF and DU differed significantly in species density, richness, dominance, diversity, and evenness indexes. Site factor had a more significant effect than year on these indices. The benthic community at DU was distinctly clustered into before, after, and 1-year after rainfall groups, but this was not the case for SF. Echinodermata was the taxon primarily responsible for the differences. Based on the meteorological data from 1997 to 2022, the SPIs varied from -1.83 (severe drought) to +1.90 (severe precipitation). Temporally, precipitation intensity and frequency increased during 2016-2021 compared with 2000-2006, with a peak precipitation event of 1,168 mm rainfall over 14 days in 2021. The broader reef flat at DU may have resulted in thermal and salinity stresses lasting longer for stenohaline echinoderms than at SF. Results from this island highlighted the differential vulnerability of the benthic communities from different sites to natural disturbances for the first time, allowing policymakers and stakeholders to formulate effective regional management strategies to minimize the impact of extreme climate events.

The Amami rabbit (Pentalagus furnessi), endemic to the Amami-Oshima and Tokunoshima Islands, is an endangered species that faces habitat disturbance. This study used fecal DNA metabarcoding to analyze the dietary preferences of Amami rabbits. Fecal samples from six rabbits were collected and analyzed for plant DNA. The results revealed the presence of 85 operational taxonomic units (OTUs) representing different plant species, with individual rabbits consuming 17-38 plant species. The dietary composition varied significantly among individuals, with a notable preference for ferns in some cases. Diet diversity, assessed using Simpson's Diversity Index, ranged from 0.328 to 0.889. This study highlights the importance of a diverse plant diet for Amami rabbits and underscores the need for habitat preservation to ensure a stable food supply. Conservation efforts must focus on maintaining a unique subtropical moist forest ecosystem and mitigating human-wildlife conflicts to promote sustainable coexistence.

Cymothoidae are mainly described based on the morphology of adult females, making species identification difficult because of the limited morphological information on male, juvenile, and manca life stages. In particular, most species in the genus Anilocra Leach, 1818 lack morphological information beyond that of females, highlighting the need to accumulate such data. In the present study, we described the aegathoid stage, male, and transitional morphology of Anilocra prionuri Williams and Bunkley-Williams, 1986 collected from Japanese waters and documented changes in morphology with growth for the first time. With growth, the morphology of A. prionuri changed: 1) body shape becomes rounder, 2) eye length becomes shorter, 3) shortest pereonite changes from 7 to 2, 4) antennular article 3 enlarged, 5) length of dactylus relative to propodus in pereopod 1 becomes longer, 6) pleopod peduncle becomes shorter, 7) decrease robust setae of pereopods, coupling hooks and plumose setae of pleopods, swimming setae of pleotelson, pleopod, and uropod, 8) appendix masculina on the pleopod 2 endopod shortens and disappears, 9) rami of pleopods and uropods become rounded, and 10) endopods of uropods become elongated. The aegathoid stage of A. prionuri was distinguished from that of Anilocra clupei Williams and Bunkley-Williams, 1986, also distributed in Japan by 1) 3-5 and 0-5 plumose setae of pleopods 1 and 2, (5 and 8 plumose setae in A. clupei), 2) uropodal exopod longer than endopod (same length in A. clupei), and 3) triangular uropodal exopod (oval in A. clupei).

The sea urchin Pseudechinus magellanicus is a dominant species in coastal habitats of southern Argentina and Chile. This study investigates its size distribution, abundance, and spatial arrangement in relation to coastal environmental gradients and habitat complexity along a depth gradient in central Patagonia (Argentina) during the austral spring. P. magellanicus exhibited a unimodal response to depth, with lower densities observed at intertidal levels and depths greater than 12 m. Size distribution showed depth-related patterns, with larger individuals prevalent at subtidal levels, intermediate sizes more common in intertidal and shallow depths, and recruits and juveniles most abundant at the infralittoral fringe and subtidal zones. A positive relationship between structural complexity and sea urchin densities was found, especially for smaller size classes. Conversely, larger individuals tended to inhabit areas with lower structural complexity and higher food availability. Sedimentation impacted the vertical distribution, particularly affecting recruits, juveniles, and young adults. Spatial arrangement analysis showed that aggregation is the predominant pattern along the coastal depth gradient. However, at depths of 3-5 m, where the kelp forest (Macrocystis pyrifera) dominates, recruits, juveniles, and intermediate-sized sea urchins displayed a less aggregated, more random distribution. These findings reveal the critical role of habitat complexity and depth in shaping the population dynamics of P. magellanicus and highlight the adaptability of this species to varying habitat conditions and its potential as an indicator of coastal ecosystem health.

In this study, four new species of land hermit crabs (Crustacea: Decapoda: Anomura: Coenobitidae: Coenobita Latreille, 1829) are described from Indonesia. These descriptions are based on evidence from morphological differences as well as mitochondrial 16S rDNA and cytochrome c oxidase subunit I data. Among the new species, Coenobita moluccensis n. sp. (from Aru Island, Maluku), C. patsyae n. sp. (from Central Sulawesi and Southeast Sulawesi), and C. celebensis n. sp. (from Central Sulawesi) form a major clade on the phylogenetic tree, exhibiting similarities in morphology, particularly in the male sexual tubes- a character they share with their closely related counterpart, C. lila Rahayu, Shih & Ng, 2016. Although the four species are similar in overall morphology, they can be distinguished by differences in the left third pereopod, the second article of the antennal peduncles, granulation on the pereopods, as well as their live coloration. Coenobita granularis n. sp., found in Central Sulawesi, shares morphological similarities with the genetically closely related C. pseudorugosus Nakasone, 1988, particularly in the male sexual tubes. However, the two species can be distinguished by differences in the morphology of the male sexual tubes, the presence of tubercles on the left cheliped, the left third pereopod, as well as their live coloration. Additionally, a newly recorded species, C. variabilis McCulloch, 1909, has been confirmed in West Papua. This study brings the total number of Coenobita species known from Indonesia to 13.

Artotrogidae Brady, 1880 is a cosmopolitan family with 23 valid genera and 131 known species. However, a considerable number of these species were subject of reexaminations and redescriptions recently. With the crescent number of new species discovered, it is becoming possible to better understand their boundaries. This study presents a new genus and species of Artotrogidae, recovered from unidentified hosts in debris of benthonic samples from Todos-os-Santos Bay, northeastern coast of Brazil. Kuayguara etymatee gen. et sp. nov. exhibits an underdeveloped first leg, which possess an unsegmented protopod and 1-segmented exopod, a unique set of morphological characteristics that differentiates it from all other genera of the family.

Taiwanese Pseudasphondylia species inducing spherical leaf galls on six Neolitsea hosts, viz, N. acuminatissima, N. daibuensis, N. konishii, N. parvigemma, N. sericea and N. variabillima, was regarded as a species allied to Japanese P. neolitseae Yukawa due to similarity of gall structure and host. The Taiwanese species is morphologically different from P. neolitseae in adult palpus segmental number, shapes of pupal antennal horn, pupal prothoracic spiracle, and larval sternal spatula, resulting in its description as a new species to science, Pseudasphondylia hooki sp. n. The species delimitation (Assemble Species by Automatic Partitioning method) supported that P. hooki sp. n. is distinct from P. neolitseae. The sistership of P. hooki sp. n. and P. neolitseae was also supported in the Maximum likelihood tree based on the 1^st codon of COI region. The speciation event of them is assumed to be geographical isolation because the divergence corresponded to the separation of Taiwan and Japan in the Pleistocene. The patterns of ecological features (host species) on the phylogeny revealed that galling on N. sericea is primitive of Neolitsea-associated Pseudasphondylia lineage. Accordingly, the divergence pathway from north to south in Taiwan is suggested by the distributions of primitive (N. sericea) and most derived hosts (N. daibuensis).

Two freshwater tardigrade populations belonging to the genus Dactylobiotus were investigated using phase contrast microscopy, scanning electron microscopy, and molecular markers commonly employed in tardigrade phylogenetic studies (18S rRNA, 28S rRNA, ITS2, and COI). The population from Taiwan, discovered through social media, represents a new species, described here as Dactylobiotus taiwanensis sp. nov. This species is most similar to Dactylobiotus parthenogeneticus but differs in the presence of singular rings of pores surrounding the egg processes and specific morphometric traits. The second population, from Greenland, was provisionally identified as D. cf. octavi, and its morphological discrepancies are discussed in detail. A revision of the type material for Dactylobiotus caldarellai and Dactylobiotus lombardoi raises questions about their validity due to insufficient data. Finally, a phylogenetic analysis incorporating taxa from the family Murrayidae, along with the newly sequenced populations, is presented. An updated dichotomous key for the genus Dactylobiotus is also provided.

This study investigates the trophic cascades and habitat suitability in Udanti Sitanadi Tiger Reserve (USTR), highlighting the roles of apex predators, subordinate predators, and prey species in maintaining ecosystem balance. Using the Trophic Species Distribution Model (Trophic SDM), we explored prey-predator interactions and habitat suitability, revealing that tigers respond to prey depletion by increasingly relying on cattle, while leopards adapt by preying on smaller species. Additionally, climate change projections for 2021-2040 and 2081-2100 under CMIP6 scenarios SSP245 and SSP585 indicate significant regional habitat shifts, necessitating adaptive management strategies. Kulhadighat is projected to face habitat contraction, while Sitanadi may experience habitat expansion. This study emphasizes the need for effective conservation efforts such as habitat restoration, prey augmentation and predator recovery are the most important steps needed to maintain the purpose of a Tiger reserve and conservation potential of Chhattisgarh-Odisha Tiger Conservation Unit (TCU). To achieve these dynamics, focusing on community participation, anti-poaching measures, and scientific recommendations are the most crucial components to focus on. This comprehensive analysis underscores the critical role of targeted conservation activities in prey-depleted landscapes to ensure the long-term survival of tigers and the overall health of forest ecosystems, enhancing biodiversity and mitigating human-wildlife conflicts in USTR.