Between 1970 and 2012, vertebrate abundance has declined by 58% with an average annual decline of 2%, calling for serious action to prevent a mass extinction and an irreversible loss of biodiversity. Cryobanks and cryopreservation have the potential to assist and improve ex situ and in situ conservation strategies by storing valuable genetic material. A great deal of studies concerning cryopreservation have been performed within the class Mammalia, although no systematic overview has previously been presented. The objective of this study is therefore to evaluate the status, pattern and future of cryopreservation within Mammalia. A strong disproportional distribution of studies in examined orders is displayed. For the majority of examined orders less than 10% of species has been examined. However, the cryopreservation of germplasm has in several cases been successful and resulted in successful applications of assisted reproductive techniques (ARTs). Various obstacles are associated with the development of cryopreservation protocols, and among them the most prominent is interspecific differences in cryotolerance. Extrapolation of protocols in closely related species is considered the most applicable procedure, and a future supplement to overcome this problem is the examination and comparison of cryobiological traits. Successful protocols have been developed for the vast majority of domesticated mammals, which gives incentive for the further extrapolation of protocols in threatened species.

Males of many animals exhibit conspicuous secondary sexual traits, which are often the result of sexual selection. During the breeding period of the pale chub (Pisces: Cyprinidae), males show various sexual traits, such as long anal fins, breeding tubercles on the head, and/or conspicuous red and greenish-blue nuptial colorations. Although these conspicuous sexual dimorphisms and dichromatisms indicate that this can serve as a model species for understanding sexual selection, it is unclear whether these male sexual traits are related to female mate choice. This study examined the relationships between female mate choice and male sexual traits under laboratory conditions. In a dichotomous choice experiment, no relationship was found between female preference and male body size, anal fin length or number of breeding tubercles. In addition, female preference was not detected for traits related to the greenish-blue nuptial color of males. Instead, females chose males based on the degree of expression of red nuptial coloration. Such female preference may be useful for selecting high-quality males with good foraging abilities or good immune function related to carotenoids and sexual hormones. The present study suggests that red nuptial coloration of the male pale chub evolved in part through female mate choice.

Without the establishment of effective culturing systems, little can be known about the late developmental stages of polyclad flatworms. Here, we report a laboratory culturing system for three polyclad species: Comoplana pusilla, Notocomplana koreana, and Pseudostylochus obscurus, and we describe changes in their morphology from hatching to reproductive maturity. These species hatch out as lobe-less larvae with four eyespots, but the number of eyespots increases in later development. Cross-like and triangularly shaped larvae are observed in N. koreana and P. obscurus, respectively. After settlement, a pale area appears on the body of juveniles and then develops into the copulatory complexes. All three species could be successfully reared on brine shrimp, but only C. pusilla and N. koreana achieved reproductive maturation in such a culturing system. In P. obscurus, switching the food to the gastropod Monodonta labio induced sexual maturation.

The taxonomic status of two populations of stream toads of the genus Ansonia from Thailand, previously suspected to be specifically distinct on the basis of molecular data, are assessed using morphological and additional genetic data. In mtDNA phylogeny, each of the two Thai lineages, one from Pilok Subdistrict, Kanchanaburi, and another from Phuket Island, are separated from other congenerics from the Thai—Malay Peninsula by large genetic distances, comparable with those observed between other species in the genus. Although each of the two lineages is superficially similar to other species morphologically, they are distinguishable in several morphological traits and are considered to represent valid, independently evolving species. We therefore describe them as A. pilokensis sp. nov. and A. phuketensis sp. nov.

Maternal effects play important evolutionary and ecological roles. Amictic female mothers of monogonont rotifer Brachionus calyciflorus can transmit predatory information of Asplanchna brightwellii in their environment to their offspring by changing the offspring's defensive morphology to increase their fitness. However, it remains unclear whether such maternal effects also exist during sexual reproduction of a mictic mother. This study explored the maternal effect in mictic mothers using the B. calyciflorus and A. brightwellii as a prey-predator model. We collected resting eggs from two groups of mictic mothers that previously experienced environments with (P environment) or without (NP environment) Asplanchna kairomones. Stem females from the resting eggs of each maternal group were also hatched and reared in P and NP environments. The population growth rate of offspring who experienced the same environment as their mictic mothers was significantly higher than those that experienced a different environment. When exposed to a gradient of predator kairomone levels, the posterolateral spine of the offspring elongated with increasing kairomone concentration. Offspring from the P mictic mother showed significantly shorter posterolateral spines than those from the NP mictic mother at each predator kairomone level. Offspring originating from NP mictic mothers clearly elongated their posterolateral spines at low concentrations of predator kairomones, while those from P mothers elongated their posterolateral spines only at the highest levels of predator kairomone. Our findings highlight the existence of anticipatory maternal effects during the sexual process via resting eggs of B. calyciflorus in response to predator kairomone.

Indian gaur (Bos gaurus) is one of nine species of wild oxen found in the world. They are largely confined to evergreen, semi-evergreen, and moist deciduous forests, but also occur in dry deciduous forest areas at the periphery of their range. According to the IUCN Red List (2017), the estimated population of gaur in India is between 15,000 and 35,000 individuals, and probably due to this, despite the gaur's vast range of distribution, they are listed as a vulnerable species by IUCN and listed as schedule-I of the Indian Wildlife Protection Act (1972) as well as in appendix-I in CITES (2003). Gaur is not a well studied species, and baseline data are thus needed to support conservation efforts. We studied the feeding habits of gaur in Pench Tiger Reserve. Pench Tiger Reserve is the 19th tiger reserve in India, situated in the Seoni and Chhindwara districts of MP, India (21°41′35″N 79°14′54″E). Diet composition of gaur was studied by micro-histological examination of 32 dung piles collected from different sampling plots in different seasons. For this purpose, 169 sampling plots were established at an interval of 200 m. To locate gaur faecal matter, a circular plot of 10 m radius was laid within each sampling plot. Eighty-eight permanent reference slides of available plants were prepared and used for plant fragment identification from the dung piles. A total of 29 plant species were identified from dung piles of gaur. On average, 44.51% of grass-fragments were detected in the diet of gaur, suggesting that gaurs are primarily grazers in the Pench Tiger Reserve.

We studied the food habits of the Japanese marten (Martes melampus) and the raccoon dog (Nyctereutes procionoides) at the Tama Forest Science Garden, western Tokyo, Japan by fecal analysis in 2014/15. Martens were dependent on fruits throughout the year and showed less marked seasonal changes. Raccoon dogs were less dependent on fruits than martens were, and more dependent on mammals in spring, insects in summer and winter, and seeds throughout the year. Martens fed on more fruits containing tiny seeds, such as Actinidia arguta and Stachyurus praecox, whereas raccoon dogs fed on more large-seeded fruits, such as Ginkgo biloba and Diospyros kaki. Martens fed on more fruits that grew at the forest edges, whereas raccoon dogs fed on more fruits growing inside the forest.

Enteroendocrine cells (EEs) are evolutionarily conserved gastrointestinal secretory cells that show scattered distribution in the intestinal epithelium. These cells classified into several subtypes based on the hormones they produce in both mammals and insects. In the fruit fly Drosophila, it has been suggested that nearly equal numbers of two subtypes of EEs (Allatostatin A: AstA and Diuretic hormone 31 : Dh31) are alternately produced from the intestinal stem cells in the posterior midgut. However, we found that these two subtypes are not always present in this manner, but are rather distributed in a complementary frequency gradient along the posterior midgut. We show that midgut-preferential RNA knockdown of the peptide hormones AstA or Dh31 respectively results in decreased or increased adult lifespan. This effect on longevity is apparently correlated with the midgut senescence phenotypes as a result of direct hormone action through both hormone receptors expressed in the enteroblasts or other midgut cell types. However, gut senescence does not appear to be the direct cause for longevity regulation, as knockdown of both hormone receptors did not affect adult lifespan. Furthermore, these senescence phenotypes appear to be independent of insulin signaling and manifest in an organ-specific manner. These results indicate that the two intestinal secretory peptides antagonistically regulate adult lifespan and intestinal senescence through multiple pathways, irrespective of insulin, which implicates a complementary gradient distribution of each of the hormone-producing EEs, consistent with local requirements for cell activity along the posterior midgut.

I analyzed the association between the reflectance spectra and melanin rod arrangement in barbules of the eyespot of peacock feathers. The reflectance spectra from the yellow-green feather of the eyespot indicated double peaks of 430 and 540 nm. The maximum reflectance spectrum of the blue feather was 480 nm, and that of the dark blue feather was 420 nm. The reflectance spectra from brown feathers indicated double peaks of 490 and 610 nm. Transmission electron microscopic analysis confirmed that melanin rods were arranged fanwise in the outer layer toward the barbule tips. In addition, using polarized light microscope, I attempted to determine whether the turning angles of melanin rods in the barbules reflected different colors. The turning angle of the polarizing axis of the barbules was supported by that of the melanin rods, observed using transmission electron microscopic images. To compare the turning angle of melanin rods in the respective barbules, I calculated the opening width of the fanwise melanin rods by dividing the width of the barbules by the turning angle of the polarizing axis of barbules and obtained a positive correlation between the reflectance spectra and opening width of the fanwise melanin rods. Moreover, the widely spreading reflection from the barbules may occur because of the fanwise melanin rod arrangement.

Sea urchins have a globiferous pedicellaria that stands from a test with a stalk on which lies a head made of three movable jaws with venom-injecting teeth. The globiferous pedicellariae of the flower sea urchin Toxopneustes pileolus, one of the most developed among sea urchins, are unique in that the jaws are provided with a jaw membrane that gives the pedicellaria an appearance of a flower when the jaws are open. We observed this membrane in an ionic liquid that does not require processes, such as fixation, dehydration, or coating with conductive materials, for observation with a scanning electron microscope. Using this technique, we discovered dumbbell-shaped ossicles, which consist of two spheres of similar size connected by a cylinder. The diameter of the sphere is 4–8 µm, and the total length of the ossicle is 10–20 µm. The jaw membrane is trimmed with an edge zone. The ossicles were found sparsely in the connective tissue of general part of the membrane, but in the edge zone their density was so high that neighboring ossicles were in close contact with each other. Some neighboring ossicles crossed their cylinders and some inserted one of their spheres to snugly fit in the gap between the spheres of neighboring ossicles. Their structural role is very likely in strengthening the jaw membrane, probably serving as fillers in the general part of the membrane; in the edge zone the interlocking of adjacent ossicles forms a loose network providing a firm frame for the head of the globiferous pedicellaria. When opened, the stiff frame prevents the membrane from sagging. When clasped, it works as a closed door, firmly keeping prey trapped.

The order Anura (frogs and toads) is a group of amphibians and contains over 6500 extant species living in a variety of environments. Each frog species evolved body form adaptive for living and breeding in their own habitats. In Japan, four taxa of Bufo are living: Western-Japanese common toad (Bufo japonicus japonicus), Eastern-Japanese common toad (B. japonicus formosus), Miyako toad (B. gargarizans miyakonis) and Japanese stream toad (B. torrenticola). The former three taxa breed in still water as many other species of Bufo do. In contrast, B. torrenticola breeds in running water such as streams in mountainous area. Corresponding to their breeding in a stream environment, both adult and larva of B. torrenticola acquired unique morphological characters. However, few study have explored differences in the body form between B. torrenticola and closely-related Bufo species quantitatively, remaining the details about the morphological adaptation to a stream environment in this toad species poorly understood. In this study, we quantitatively compared the shape of the foot and skull between the adult male of B. torrenticola and its close relative B. j. formosus using landmark-based geometric morphometrics. Our analyses revealed that B. torrenticola has relatively longer toe phalanges with relatively larger foot webs and relatively shorter metatarsals and a narrower and more streamlined skull, compared to closely-related B. j. formosus. These morphological characteristics are considered adaptive for their breeding in mountain torrents.