Zoological Studies最新文献

he Arctic warbler (Phylloscopus borealis) species complex is commonly present in the Palearctic region. By 2014, the three bird subspecies were split into three species, Arctic warbler (P. borealis), Japanese leaf warbler (P. xanthodryas), and Kamchatka leaf warbler (P. examinandus), based on different breeding areas and distinct vocalizations. However, their similar coloration and body size make it difficult to distinguish these species in the nonbreeding season. Taiwan is located in the potential migration routes of the Arctic warbler species complex; however, no confirmed record of P. xanthodryas and P. examinandus exists. In this study, we compared the mitochondrial cytochrome c oxidase subunit 1 (CO1) sequences of samples from breeding sites during the breeding season and confirmed that the three species could be distinguished based on CO1 gene sequences. We also examined the species of the Arctic warbler species complex samples collected from eastern Taiwan. For the first time, we confirmed that all three species visited Taiwan during migration season. In the Taiwanese samples, no clear distinction could be made between species based on plumage coloration and size, indicating that these traits are not reliable for species identification. Reassessment of the CO1 gene sequences of the three species deposited in the Barcode of Life Data System revealed that the taxonomic status needs to be updated for 31.8% of the samples.

The isotopic discrimination between a mother and her hatchlings has been modelled in various vertebrates, including sea turtles. In addition to the linear relation between δ¹³C and δ¹⁵N isotope values of the mother - hatchling couple, there is missing data on the combined effects of both isotopes, which represent ecological niches of a species. The stable δ¹³C and δ¹⁵N isotope signatures of live hatchlings and their mother's epidermis tissues were used in green turtles. The samples were taken from three main breeding beaches, Akyatan, Sugözü and Samandağ in Türkiye during the 2020 nesting season. δ¹⁵N and δ¹³C values of hatchlings were not significantly different from those of mothers. Significant relationships were found between hatchlings and their mothers in terms of δ¹³C value. Furthermore, when the hatchling isotopic niche size is known, the condition probabilities of estimating the mother's isotopic niche size were 85.16% and 92.88% with the 0.95 and 0.99 alpha levels. In addition to showing a linear relationship between hatchlings and their mother's single isotopic composition, the current study offers a novel insight that proposes a niche overlap concept using two isotopes to comprehend the mother-hatchling relationship of green turtles living in the eastern Mediterranean.

Fig pollinating wasps (Hymenoptera: Chalcidoidea: Agaonidae) constitute a key ecological role since they are the only known pollinators to Ficus (Moraceae), founding complex food webs. Taxonomy of Agaonidae is relatively well known due to their ecological importance and their mutualistic closed relationship with Ficus. However, the spatial and temporal patterns that have influenced the agaonid distribution as well as the species description record of this family are yet unknown. Here, we aim to study the taxonomical and nomenclatural knowledge status of Agaonidae (following Burks et al. 2022) in each biogeographical region and globally. We analyse taxonomic factors, such as the number of described species or the amount of non-valid binominals, together with their historical description process. By retrieving and analysing all available geographical and nomenclatural data in fig wasps of the Universal Chalcidoidea Database, we have found that the diversity of Agaonidae is underestimated, exhibiting a high potential dark biodiversity, especially in the tropical areas where the highest diversity is observed. The species richness of Agaonidae varies depending on the biogeographical region, being more unknown in the Neotropical region, and higher and better represented other tropical areas such as the Afrotropical or Oriental realms. Our results indicate that there is a strong need for increasing sampling efforts and research for a better understanding of Agaonidae diversity and interspecific relationships, as well as inventory revisions to correct potentially redundant binominal names.

This study elucidates the species diversity of marine fishes in the Exclusive Economic Zone (EEZ) of Peninsular Malaysia (PM) using an integrative approach combining DNA barcoding and morphological identification. Our focus was on demersal surveys conducted on the east coast of PM in the South China Sea. We re-evaluated the diversity of 475 specimens across 93 putative species (92 barcoded morphospecies), from 16 orders and 41 families, including two IUCN vulnerable species. A total of two species - Saurida isarankurai and Oxyurichthys auchenolepis - are presented as new record, and three species - Nemipterus balinensoides, Gymnothorax reevesii and Synodus hoshinonis - as the first specimen-based records in Malaysian waters. Cytochrome c oxidase subunit I (COI) sequence analyses delineated 95 consensus Molecular Operational Taxonomic Units (MOTUs), exceeding morphological diversity. Interestingly, the barcode analysis revealed several MOTUs delimited within one morphologically identified fish species, with both intraspecific and interspecific genetic divergences exceeding 2%, indicating substantial intraspecific genetic divergence within species groups or the existence of morphologically cryptic species within our dataset. These findings highlight the complexity of species delimitation and the value of genetic methods. Our study provides valuable insights into marine fish diversity from the east coast of Peninsular Malaysia and enhances our understanding of genetic diversity, distribution, and conservation needs of ecosystems through DNA barcoding. By integrating DNA barcoding with morphology, we present a comprehensive framework for future research to develop conservation and management strategies for Malaysia's marine biodiversity. The expansion of the genetic barcode database generated in this study will facilitate future molecular taxonomy research.

Molecular and morphological methods are used to describe the rhizocephalan Briarosaccus hoegi sp. nov. from Russian waters of the Sea of Japan, parasitizing the stone crab Hapalogaster dentata (De Haan, 1849). Briarosaccus hoegi sp. nov. has minor differences by gross morphology from the closely related species B. tenellus, parasitizing H. mertensii in British Columbia and Alaska. Briarosaccus hoegi sp. nov. and B. tenellus are identified as distinct species by genetic markers. These two species have different hosts and different areas of distribution. Moreover, nauplii of Briarossacus hoegi sp. nov. have naupliar eyes not present in B. tenellus larvae. The presence/absence of larval eyes may be a clear character separating the two species. The prevalence of Briaroaccus hoegi sp. nov. on H. dentata in Peter the Great Bay is about 6%.

Quantifying the abundance and diversity of small insects, especially those with specific environmental associations or hidden habitats, can be challenging using direct methods. Galls are specialized microhabitats that host a wide range of interactions between species. However, assessing their abundance and associated community diversity takes time and effort. In this study, we propose an indirect approach using the size of gall emergence holes to estimate the abundance of gall wasps (Cynipini) and their associated wasp species. We examined eight different types of gall structures collected in the temperate forest of Mexico. We identified every gall-emerging individual, classifying them as gall inducer, inquiline, or parasitoid. Kruskal-Wallis tests, correlation analysis and a mixed linear model (LMM) were used to evaluate differences between mesosoma size and gall hole size for each emerged species in each gall type. Our results showed that mesosoma and hole size significantly differed between Cynipini wasps and their associated wasp species. LMM showed a significant relationship between the size of the mesosoma and the diameter of the emergence hole among the analyzed wasp species. Upon validating the method, a low emergence rate and low abundance of the studied Cynipini wasps were observed, attributed to negative interactions and inadequate development of the wasps. We emphasize the potential of gall emergence hole size as an indicator of species abundance and emergence rates within Cynipini gall complexes. Furthermore, strategies are discussed to improve their effectiveness and reliability in future studies to increase our understanding of the ecological dynamics and evolutionary processes of gallforming wasps.

The occurrence of cyclic morphological alternation in male crayfish of the family Cambaridae following molting is widely acknowledged. However, there remains a contentious issue within the genus Cambaroides: Some previous studies have proposed that male Cambaroides exhibit a pair of noncorneous Form II gonopods during the non-breeding season, while others argue that these species lack Form II in adult males. This study examined the color and shape of the corneous tips on the gonopod to determine its form. Additionally, morphometric methods were utilized to distinguish between Form II adults and juveniles. The results of the study confirm the presence of Form II adults in Cambaroides dauricus and Cambaroides similis. The Form I gonopod is characterized by four golden-colored corneous terminal elements, whereas the Form II gonopod features blunt, non-corneous terminal elements, on which the color is the same as that of the surrounding surface. Furthermore, cyclic dimorphism on the gonopod of C. dauricus was observed seasonally, and distinct morphological differences in the chela were noted between Form I and Form II adults.

Terpios hoshinota Rützler & Muzik, 1993 is a poriferan species that competes with corals and is known as a coral-killing sponge. However, limited information is available on its biology, including morphological traits. This study aims to examine the arrangement and development of spicules in various body parts of the sponge, including settled larvae. Spicules were found to appear on the second day after settlement and were present in all individuals on the fifth day. The spicules in the thread-like tissue of the growth portion were oriented in the direction of growth, with their pointed tips facing forward to support the elongated pioneer tissue. Furthermore, the spicules in the surface layer of the sponge tissue were perpendicular, with outward-facing tips associated with collagens. The study indicates that the spicules of T. hoshinota are arranged to support both encrusting basal tissue and pioneering tissue to colonize corals.

Confined by the Mid-Atlantic Ridge and the European continental shelf, the deep-sea acorn barnacle Bathylasma hirsutum (Hoek, 1883) lives in the northeast Atlantic deep sea, where it has been frequently reported in high current areas. Cemented to a solid substrate during its entire adult life, the species can only disperse by means of planktotrophic nauplius larvae. This study reports on the occurrence, ecology and genetic connectivity of B. hirsutum from four sites within the northeastern Iceland Basin and presents the first record of the species living affiliated with hydrothermal vent field on the Reykjanes Ridge axis. Vent-associated specimens were found to differ extrinsically from their naturally shaded conspecifics by a prominent brown-black shell precipitate. Energy Dispersive Spectroscopy revealed ferromanganese oxides to be the main component of these shell precipitates. Morphometric measurements of shell plates revealed specimens from the vent-associated habitat to be smaller compared to non-venting sites. Molecular species delimitation based on the mitochondrial COI and nuclear EF1 genetic markers aided species identification and revealed a low intraspecific genetic variability. Our findings suggest a pronounced genetic connectivity of B. hirsutum within the studied region and provide a first step towards a biogeographic study. As such, habitats of hydrothermal influence along the Mid-Atlantic Ridge are discussed as possible niches, as are deep-sea basins in the western Atlantic. In light of the reported affiliation with hydrothermal activity, we elaborate on the potential for the sister species Bathylasma corolliforme (Hoek, 1883) and Bathylasma chilense Araya & Newman, 2018 to utilise equivalent habitats in the Antarctic and Pacific Ocean, respectively. Our record of the unacquainted ecological niche occupation for B. hirsutum emphasises the need for further research on bathylasmatid acorn barnacles along the extensive Mid-Atlantic Ridge, where many biological communities remain to be discovered.

Two new amphipod species from Iran, Niphargus sahandensis sp. nov. and Niphargus chaldoranensis sp. nov., are described based on their morphological characteristics and molecular analyses. Bayesian inference analyses of COI and 28s rDNA sequence data provided evidence for the validity of the two species and their placement in the Niphargus genus. N. sahandensis sp. nov. primarily differs from similar species by having more than two hook-like retinacles on the inner surface of pleopods I-III, the presence of two spines at the base of uropod I and rectangular-shaped propodi in both gnathopods. N. chaldoranensis sp. nov. is distinguished by the trapezoidal-shaped propodi in gnathopods I to II, the equal sizes of pereopods V and VI, and the proportional size of periopod VII in relation to the total body (60%). Morphological descriptions with illustrations of the new species, as well as a DNA-based phylogeny generated from analyses of a multigene dataset, are provided to better understand species relationships.