Some seabirds commonly use artificially reclaimed lands, which are frequently located next to mainland environments, for breeding. Nest predation risk caused by birds or mammals from the mainland has negative influence on fitness-related costs and distribution of seabirds. Here, we sought to link potential factors, specifically those related to nest predation and nest environment, with breeding performance and colony movements of the Saunders's gull (Saundersilarus saundersi), a vulnerable species, on a large reclaimed area (1350 ha) in Incheon in Republic of Korea. This reclaimed area has experienced rapid changes in communities of nest predators from the mainland and vegetation ranging from halophytes to terrestrial plants after reclamation. Additionally, changes in the surrounding of used nest sites were retrospectively examined to determine whether colony movement was reversible in this reclaimed area. Our results indicated that high nest predation in a previous year induced colony movements in a consecutive year while the breeding colony exhibited a gradual reduction in clutch size. However, such movement after high nest predation seemed to be irreversible due to ongoing habitat degradation caused by construction and vegetation alteration. This study highlights that high nest predation may exert strong pressure on breeding colonies of Saunders's gulls. It also has anthropogenic impacts, leading to continuous dispersal of colonies to new areas for this vulnerable seabird in a reclaimed land.

The bitterling Acheilognathus melanogaster is a critically endangered primary freshwater fish endemic to the Pacific side of eastern Japan. To elucidate A. melanogaster genetic structure, we investigated phylogeography in nine populations, using gene sequences of mitochondrial Cytochrome b (Cytb), as well as nuclear Rhodopsin (Rho) and glycosyltransferase (Glyt). We found four Cytb-based geographical clusters unevenly divided between the northern and southern regions, with smaller groups in the south. Of the nuclear genes, Glyt did not show geographical differentiation, whereas Rho formed two clusters: one widely occurring and another restricted to central regions. Genetic diversity was generally higher in southern than in northern populations. Our results suggest that conservation of southern local populations is particularly important in maintaining the genetic diversity of this endangered fish.

To assess the genetic diversity of the red fox (Vulpes vulpes) population on Hokkaido Island, northern Japan, we examined genotypes of exon 2 of the major histocompatibility complex (MHC) class II DRB1 gene for 232 individuals and identified 17 novel alleles. The subpopulation in the Southern area was genetically differentiated from those in all other areas on Hokkaido, suggesting isolation in southern Hokkaido. In addition, the Southern subpopulation is lower in genetic diversity than the other subpopulations, possibly resulting from purifying selection and/or a recent bottleneck. The non-synonymous substitutions exceeded the synonymous substitutions for codons encoding antigen-binding sites (ABSs) in exon 2, indicating that the red fox DRB1 alleles have evolved under positive selection. In a Bayesian phylogenetic tree, although most of the DRB1 alleles from the Hokkaido red fox were contained within a red fox-like canid (Vulpes) clade, some belonged to another canid clade. This means trans-species polymorphism maintained by balancing selection. Our results showed the local variability and the presence of selection on the MHC gene in this population, which contributes to the understanding of the historical background and the molecular evolution.

The fish genus Sinocyclocheilus contains many different species that inhabit diverse natural environments, such as surface water layer, cave, or intermediate. As a result of these different habitats there are some differences in their sensory systems. Microscopic and submicroscopic structures of olfactory systems in six representative species of Sinocyclocheilus were studied, including one surface-dwelling species (S. grahami), two intermediate species (S. jii and S. macrophthalmus) and three cave-dwelling species (S. brevibarbatus, S. anshuiensis, and S. tianlinensis). Due to adaptive evolution under extreme environmental conditions, cave-dwelling species have more developed olfactory systems. We observed that, compared with surface-dwelling species, the olfactory sac of the cave-dwelling Sinocyclocheilus species has the following characteristics: higher density of cilia, greater length of sensory cilia, many other special structures (micro-ridge, olfactory islet, rod cilia). These results reveal different levels of olfactory system development, consistent with the view that that cave-dwelling species have more developed olfactory systems than intermediate and surface-dwelling species.

Male peacock (Pavo cristatus) tail feathers have an eyespot pattern with an inconspicuous black or dark blue center surrounded by brilliant, structural colors, such as blue, light brown, and yellow-green. Under ultraviolet A (UVA), the central part of the eyespot reflects UVA better than the surrounding parts. Herein, I examined various areas of eyespots on paraffin sections of feathers using an optical microscope, and characterized positional relationships between barbs and barbules. These analyses confirmed that barbules in the central part of the eyespot are in a horizontal position with respect to the barb, and that light transmission from the central part is less than that from the other parts. In addition, I compared microstructures of barbules in the central part of eyespot with those in surrounding areas using transmission electron microscope analysis. The melanin rods in the barbules reflecting yellow-green color comprise several ordered lattice structures. In contrast, melanin rods in the central part of the eyespot were only distributed in 1–3 layers on a part of the front side of the barbules. I also demonstrated that keratin structures of barbules are homogeneous in the central part of the eyespot, but have fibrous structures with many voids in the yellow-green parts. Collectively, the present observations suggest that feathers in the central part of the eyespot reflect UVA depending on the direction of irradiation, and these properties are governed by configurations of barbules relative to barbs, melanin rod distributions, and the presence of keratin structures with gaps.

The Japanese clouded salamander (Hynobius nebulosus) is a lentic-breeding species distributed throughout western Japan. Threats, such as habitat loss, have led to it being categorized as a vulnerable species. To explore the phylogeographic features and population differentiation among clouded salamanders in Shiga prefecture, we analyzed sequences of the mitochondrial cytochrome b gene. DNA samples were collected from 29 distinct breeding sites, and 53 cytochrome b haplotypes were identified. On the basis of comparison of the composition and frequency of haplotypes in each breeding site, salamanders in each habitat appeared to have distinct characteristics. Significant genetic differentiation was observed in 93.3% of possible pairs of habitats in Shiga prefecture, and 67.7% of habitat pairs within the same locality were found to be significantly different. These results suggest that the salamanders' poor locomotion combined with topographic effects may have contributed to the diversity of locally distributed salamanders in Shiga. Phylogenetic analysis showed that haplotypes of H. nebulosus in Shiga can be divided into five groups (the Nagahama-Maibara group, Otsu group, Konan group 1, Konan group 2, and Takashima group), each with a distinct geographical distribution. Haplotypes of the Otsu group, however, were exceptionally widely distributed. The results of the present study will contribute to the future of H. nebulosus conservation management in Shiga.

Capitellids have emerged as monophyletic in most but not all recent molecular phylogenies, indicating that more extensive taxon sampling is necessary. In addition, monophyly of most or all capitellid genera was questionable, as some diagnostic characters vary ontogenetically within individuals. We tested the monophyly of Capitellidae and eight capitellid genera using phylogenetic analyses of combined 18S, 28S, H3, and COI gene sequences from 36 putative capitellid species. In our trees, Capitellidae formed a monophyletic sister group to Echiura, and Capitella was also monophyletic, separated by a long branch from other capitellids. Well-supported clades each containing representatives of different genera, or containing a subset of species within a genus, indicated that Barantolla, Heteromastus, and Notomastus are likely not monophyletic. We mapped three morphological characters traditionally used to define capitellid genera (head width relative to width of first segment, number of thoracic segments, and number of segments with capillary chaetae) onto our tree. While Capitella showed unique character states, states in the other genera were decidedly not phylogenetically informative. Morphology-based capitellid taxonomy will require a fine-scale reevaluation of character states and detection of new characters.

The adult male accessory gland in insects is an internal reproductive organ analogous to the mammalian prostate, and secretes various components in the seminal fluid. Products of the accessory gland in the fruit fly Drosophila melanogaster are known to control reproductive behaviors in mated females, such as food uptake, oviposition rate, and rejection of re-mating with other males, all of which increase male reproductive capacity. Production of larger amounts of accessory gland products is thus thought to result in higher male reproductive success. The epithelium of the Drosophila accessory gland lobe is composed of a unique population of binucleate cells. We previously predicted, based on measurements of cell size in mono/binucleate mosaic accessory glands, that binucleation results in a higher plasticity in cell shape, enabling more effective ejection of seminal fluid. However, the actual effect of binucleation on ejection of seminal fluid or reproductive capacity remained unclear, as we were unable to generate an organ with uniformly mononucleate cells. In the present study, we generated organs in which most of the epithelial cells are mononucleate by manipulating aurora B or fizzy-related to block binucleation. Mononucleation resulted in a less elastic accessory gland lobe, which decreased ejection volume and the oviposition of mated females; these effects were particularly pronounced over the long term. These results suggest that binucleation in accessory gland epithelial cells contributes to higher plasticity in the volume of this organ, and enhances male reproductive success through enabling ejection of larger amounts of seminal fluid.

The systematic status of the stygobitic amphipod, Paramoera relicta Uéno, 1971, was revisited based on morphological examination of the paratypes, and molecular phylogenetic analyses using a newly collected specimen from its type locality. The paratypes clearly showed that this species does not possess the “sinusoid” antennal sinus in the head, which was erroneously described in the original description of this species; P. relicta is unquestionably classified within the genus Paramoera Miers, 1875. Molecular phylogenetic trees obtained with nuclear histone H3 and mitochondrial 16S rRNA demonstrated that P. relicta clearly belongs to the clade consisting of Paramoera species. Since the genus Relictomoera Barnard and Karaman, 1982 was erected according to the “sinusoid” characteristic of its type species P. relicta, this genus is no longer valid, and should be treated as a junior subjective synonym of Paramoera. One of the paratypes of P. relicta is herein designated as a neotype for the species to clarify its taxonomic status and emend the morphological characteristics of this pontogeneiid amphipod.

We examined the morphology of Daphnia individuals maintained in our laboratory for several years, originally collected in Lake Inbanuma, Chiba, Japan. We determined partial sequences of the mitochondrial cytochrome c oxidase subunit I and 12S rRNA genes from specimens in the cultured material. These animals are morphologically similar to D. obtusa Kurz, 1874, but genetically distinct from this species. Our detailed observation shows that the morphological characteristics in the female and male individuals of our material are highly congruent with those of D. mitsukuri Ishikawa, 1896, which has not been identified positively for more than 120 years since its original description, with its taxonomic identity having been questioned for almost 90 years. Based on our morphological and genetic data, we conclude that D. mitsukuri should be regarded as a taxonomically valid species. A search among public DNA sequence databases suggests D. mitsukuri is also distributed in China, although these Chinese sequences have been labeled as ‘Daphnia pulex’, representing misidentification.

A new species of pachychilid freshwater gastropod, Sulcospira hunanensis sp. nov., is described from Hunan Province, China, based on morphological and molecular evidence. The new species is distinguished from its congeners by a combination of characters, including elongated shell with eight to nine whorls, spiral whorls with ribs, and stomach with outer and inner crescentic pads not connected to each other. Sulcospira hunanensis sp. nov. is the first confirmed report of this genus from Hunan Province, China. It is anticipated that further species will be found in this region, which currently remain unknown. Furthermore, based on morphological and molecular evidence, this study is the first record of Sulcospira tonkiniana in Guangxi Zhuang Autonomous Region, China, with Sulcospira krempfi supported as a synonym of Sulcospira tonkiniana.