Zoological Studies最新文献

A bizarre marine planktonic organism giant phyllosoma with a body length of 79 mm was collected off Taiwanese waters for the first time. The specimen is positively identified as Parribacus antarcticus (Lund, 1793) by DNA barcoding, representing the largest and the first final stage giant phyllosoma with identification confirmed. The characteristics of the phyllosoma from Taiwan is described and illustrated in detail. As morphometric ratios previously proposed for identifying phyllosomae of Parribacus failed to assign correctly the species of the Taiwanese specimen, there is still no reliable morphological character for separating these giant phyllosomae. A key to the different phyllosoma stages of P. antarcticus is provided.

Shih et al. (2024) reported on the detection of Neocaridina species in Japan and their morphological characteristics in Zoological Studies. Eleven taxa were identified based on mitochondrial DNA (mtDNA) analysis and morphological examination. Among these, they identified two taxa that formed sister groups: N. denticulata and N. davidi, which are primarily found in Japan and China. In this commentary, I argue that both species are actually N. davidi. This conclusion was previously drawn by Onuki and Fuke (2022) based on their examination of genome-wide SNPs, mtDNA, and morphological data. The doubts raised about this identification represent a serious issue in terms of conservation, as N. denticulata is a native species, whereas N. davidi is considered an invasive alien species in Japan. Two likely reasons for this misidentification are the oversight of previous studies and the inability to account for the effects of interspecific and intraspecific hybridization. Inaccurate or unsubstantiated identifications pose significant challenges to taxonomy and conservation, underscoring the need for research grounded in reliable methods and well-characterized specimens.

Odontobuthus Vachon, 1950, with nine described species, is a genus of digger scorpions in the Buthidae family, which can be distinguished by having large tooth-like processes on the ventrosubmedian carinae of the second and third metasomal segments. Morphological and molecular investigation of coastal specimens from the Hormozgan province in Iran led to the discovery of a new species named Odontobuthus persicus sp. nov. that is described here. It is closely related to O. chabaharensis morphologically. The new Odontobuthus species has two large and conical tooth-like processes on ventrosubmedian carinae of the second and third metasomal segments, while O. chabaharensis has three or four medium to large tooth-like processes. Based on phylogenetic analysis using partial COI sequences, the new species is placed as a sister taxon of O. brevidigitus. Genetic differences with the other species of Odontobuthus (mean = 0.107) confirmed the validity of this species.

As a prominent group of nonpollinating fig wasps widely distributed in the paleotropics, Sycoscapter Saunders has been subject to limited taxonomic attention. This study presents the first comprehensive taxonomic investigation of Sycoscapter wasps associated with five Taiwanese monoecious fig species, employing both molecular and morphological methods. Phylogenetic analyses using COI and COI+28S data revealed the presence of five species associated with monoecious figs in Taiwan and neighboring regions: Sycoscapter gajimaru (Ishii), Sycoscapter piceoscapus Chou & Tzeng sp. nov., Sycoscapter monticola Chou & Tzeng sp. nov., Sycoscapter ishiianus Chou & Tzeng sp. nov., and Sycoscapter littoralis Chou & Tzeng sp. nov. Morphologically, these five Sycoscapter species possessed distinctive characteristics, including the male head shape, which distinguished them from related species. Furthermore, males of all five species exhibited rudimentary wing vestiges, commonly found in wasps associated with monoecious figs but absent in those associated with dioecious figs. Overall, this study enriches our understanding of chalcidoid fauna in Taiwan and provides insight into the mechanisms that sustain intricate ecosystems.

Species of the family Scorpaenidae are easily misidentified due to their similar appearances, a result of camouflaging to their surroundings. In recent years, many species from this family have been described, and generic placements of some species have been revised. Previously, there were 80 species belonging to 29 genera of the Scorpaenidae recorded in Taiwanese waters. However, their taxonomy has not been revised for decades. It is necessary to update the checklist of the Scorpaenidae occurring in Taiwanese waters based on updated morphological and molecular data. In the present study, we revised the Taiwanese scorpaenids based on 296 specimens and updated the checklist, amounting to a total of 85 species of 29 genera, of which Sebastapistes mauritiana (Cuvier) is a new record, and three species from the genera Phenacoscorpius, Scorpaenopsis, and Sebastapistes are unable to be identified to any species. Using molecular analysis, we conducted the first comprehensive DNA barcoding study of the Scorpaenidae from Taiwanese waters based on a partial cytochrome c oxidase I (COI) gene of 655 bps. A total of 118 COI sequences were generated from voucher specimens of 66 species (28 genera) identified based on morphological characters. The COI sequences of Parascorpaena maculipinnis, Scorpaena pepo, and Scorpaenopsis orientalis are new to online databases. According to the Kimura-2 Parameter (K2P) genetic distance, the mean interspecific variation (15.61%) was distinctly greater than the mean intraspecific variation (0.22%), suggesting a barcoding gap. The maximum likelihood tree showed that all lineages were supported by high bootstrap values.

Selecting ambush sites where prey abundance is high is vital for the foraging success of sit-and-wait predators. Ideal ambush sites, however, could vary due to different prey characteristics and intra-specific competition. We examined whether different life stages of a sit-and-wait predator, Trimeresurus stejnegeri, select different ambush sites, based on the observations of ambush sites of juvenile and adult snakes in three water habitats (lentic, lotic, and temporary pools) in Taiwan throughout the year. Snake stomach contents were compared between life stages in each habitat. Correlations between the monthly number of snakes observed and that of each frog species were analyzed for each habitat. Adult snakes mainly used lentic water as ambush sites and rarely used temporary pools, whereas juvenile snakes used all three habitats with a similar frequency. No clear ontogenetic diet shift was found from juveniles to adults. A high percentage of snakes from lentic water habitats had stomachs containing prey, suggesting this habitat is a better site for foraging by both juveniles and adults. Overall, our study highlights that habitat use and behavior of each prey animal and intraspecific competition as well as prey abundance should be taken into consideration when we investigate the factors that affect ambush site selection by predators.

Wing morphology, one of the most important morphological traits in bats, is closely related to their foraging habitat and strategies and has been explored as a pivotal trait for ecological and conservation studies. However, studies on wing morphology, as well as the ecology of Japanese bats, are largely lacking. In this study, we aimed to enrich the wing morphology data of Japanese bats. The wing variables, including forearm length, aspect ratio, relative wing loading, and wing tip shape index, were assessed using museum and private specimens of 34 Japanese bat species. Hierarchical clustering of the wing variables classified the bats into nine clusters to predict their foraging ecology, including the species for which ecological knowledge was lacking. Based on the ecological knowledge of Japanese bats, the aspect ratio of bats belonging to the open-space foraging guild was significantly higher than that of those belonging to other guilds. In contrast, the wing tip shape index of bats belonging to the narrow-space foraging guild was significantly higher than those belonging to the other guilds. In conclusion, our study sheds light on the complex interplay between wing morphology and foraging ecology in Japanese bats, offering insights for future research and conservation efforts.

Determining how environmental factors influence species occupancy patterns is essential to establish more efficient management strategies and policies for conserving natural populations and habitats. The Yellow-green Grosbeak (Caryothraustes canadensis) is a canopy specialist bird that occurs in the Atlantic Forest and represents a good model for evaluating how changes in regional scale characteristics can affect occupancy patterns of forest specialist species. Increasingly, occupancy models are being used to maximize these predictions because they are statistical methods that account for imperfect detection, which strengthens inferences compared to other approaches. We evaluated how multiple environmental factors affected the large-scale occupancy of C. canadensis over the last 30 years in the far north of the Brazilian Atlantic Forest, a recognized center of endemism and biodiversity. In this study, we collected secondary data from C. canadensis between 1991 and 2020. The occupancy of C. canadensis and several environmental factors that explain the historical occupancy dynamics of the species in the northern Atlantic Forest region were determined, and analyses were conducted with single-season occupancy models. The diurnal temperature range had the most significant impact on occupancy. Climate stability and the forest area were determining factors in the large-scale occupancy of C. canadensis. Other impacts on occupancy were noted as altitude and secondary effects due to precipitation. Records of C. canadensis in the region are probably associated with multiple interaction factors. The preservation of forested and climatically stable habitats of the region should favor the establishment of forest specialist species such as C. canadensis within the study region. The more significant climatic instability present along the final portion of the Sao Francisco River, probably a consequence of the loss of forest cover, can be considered an area that requires more urgent action for the conservation of this forest specialist species. Thus, our data validate the importance of forest remnants and reinforce the adverse effects of habitat fragmentation and degradation on the requirements of endemic bird populations of the Atlantic Forest.

A new species of lizardfish, Saurida weijeni sp. nov., from deep water of the outer slope of the North Macclesfield Bank (Zhongsha), South China Sea, and Guimaras Island, Western Visayas region of the Philippines, is described and figured. The new species is distinguished by the following combination of characteristics: dorsal fin with 11-12 rays; pectorals with 13-15 rays; lateral-line scales 49-52; transverse scale rows above the lateral line 3½, below the lateral line 5½; pectoral fins moderately long (extending to or just beyond a line from origin of pelvic fins to origin of dorsal fin); 2 rows of teeth on outer palatines; 0-3 teeth on vomer; tongue with about 3-4 rows of teeth posteriorly; 47-49 vertebrae; caudal peduncle compressed (depth greater than width); anterior part of stomach dusky or black, posterior extension pale whitish, intestine black. Saurida weijeni sp. nov. is genetically distinct from all other species of Saurida.

A new species of the ostracod genus Elpidium (Timiriaseviinae), a group almost exclusively known from Neotropical bromeliad phytotelmata, is here described and illustrated from the northeast of Argentina. Elpidium chacoense n. sp. represents the first record of the genus in this country and brings the total of described Elpidium species to 19. In view of the recently increased knowledge on the distribution of the species in this Neotropical genus, we discuss potential drivers of speciation that might have led to the high (endemic) diversity of the group: allopatry in bromeliad islands, sexual selection and putative co-evolution between ostracod and bromeliad species. We also point out the biogeographical relevance of the present records, which are amongst the most southern of the genus. Finally, also the fact that species of Elpidium can now also be found in non-bromeliad phytotelmata is of relevance.