Abstract:[Objectives] Jellyfish have a complicated life history including the asexual generation of sessile life and the sexual generation of planktonic life. Scyphozoan species usually have an obvious sexual generation, which is commonly named as medusa. However, the asexual generation is the key to ensure the population survival. Almost all jellyfish blooms were related to the strobilation of a large number of polyps in field. Therefore, it is particularly important to understand the asexual reproduction of jellyfish and the development process of ephyrae after strobilation. Although Mastigias papus is a popular ornamental species in aquarium and a common species in warm waters, knowledge about the asexual reproduction of M. papus is still very limited. Therefore, we made a detailed observation of the asexual reproduction including the formation of planuloid, the attachment process and morphological changes from planuloid to polyp, as well as the process of strobilation, and the morphological characteristics from ephyra to juvenile medusa. [Methods] Morphological changes were observed and recorded using stereoscopic microscope or inverted microscope. [Results] The results showed that, as a widely distributed species, M. papus only showed one style of asexual reproduction, producing planuloid at the base of the calyx (Fig. 3). Planuloids metamorphosed into polyps 93 hours after release at 25 ℃ (Fig. 4). When the temperature raised to 27 ℃, constriction emerged on the calyx of the polyp and the polyp transformed into strobila, and then the ephyra larvae were formed at the top of the strobila. The ephyra would release 47 hours after strobilation with more and more frequently pulses. It took 21 days for ephyra to develop into young medusae. [Conclusion] Planuloid producing was the only asexual reproduction mode for M. papus, but the reproductive efficiency was relatively high: each polyp could produce one planuloid in an average of 2 days, and planuloid could metamorphosize to polyp within 4 days. Ephyra in turn could develop into juvenile medusa within 21 days. The rapid asexual reproduction rate makes M. papus a popular species in aquarium and also make jellyfish blooms in nature.

Abstract:[Objectives] To deal with the challenges of the low temperatures and food shortage in winter, animals have evolved different energy strategies such as migration, molting, hoarding, fat storage and torpor, but there may be individual differences and trade-offs among strategies. Some researchers have suggested that there may be trade-offs among energetic strategies such as hoarding and torpor, etc., in Phodopus sungorus. Here we explored whether there are trade-offs among various energy strategies and analyzed the causes of individual differences in energy strategies responding to low temperature and food shortage. [Methods] Under low temperature and short light (10 ± 2 ℃, light︰dark (L︰D) = 8︰16), and ad libitum feeding or food restriction, we used TSE Lab Master system, food hoarding device and Vital View system (by G2 E-Mitter) to detect the basal metabolic rate, food intake, hoarding, core body temperature and activity of P. sungorus. Repeated-measure ANOVA, independent-sample t-test, paired-sample t-test, Fisher's exact test and Pearson correlation analysis were used to analyze differences of P. sungorus in body weight, food intake, hoarding, total intake, basal metabolic rate, core body temperature and activity. [Results] Under the conditions of low temperature and short light (ad libitum feeding), there was no gender difference in food intake (Table 1 and 2). The average body weight of males was larger than that of females (Table 1 and 2), and the core body temperature and activity of males were lower than those of females (Table 2). Some individuals expressed torpor at 40% food restriction (10 ± 2 ℃, L︰D = 8︰16). The activity of torpor individuals was higher than that of non-torpor individuals at ad-libitum-feeding stage (Fig. 4) but not food-restriction stages (Fig. 3c, d), that is, individuals with higher activity levels at ad-libitum-feeding stage were more likely to express torpor. Minimum core body temperature of torpor group was higher than non-torpor group, but tthere was no significant differencein average core body temperature at any stage (Fig. 3a, b, Table 3). There was no difference in basal metabolic rate between torpor and non-torpor individuals (Table 3). However, basal metabolic rate was negatively correlated with torpor frequency, and activity at ad-libitum-feeding stage was negatively correlated with torpor duration of torpor individuals (Fig. 1c, d, e). In the non-torpor individuals, the activity level increased significantly after dietary restriction (Table 5). In contrary to predictions, whether individuals ever hoarded food, hoarding size, or total food intake (including hoarding) did not significantly correlate with torpor. [Conclusion] Trade-offs among different energy strategies were not found between hoarding and torpor, but were found between basal metabolic rate or activity and torpor. That is, non-torpor individuals tend to decrease activity and save energy. Moreover, torpor individuals with higher basal metabolic rate, and those with higher activity at ad-libitum-feeding stage showed lower torpor expression.

Abstract:[Objectives] Melatonin is an important neuroendocrine amine hormone that plays a critical role in regulating gonadal function and germ cell development in seasonal breeding animals. However, the regulatory pathway of melatonin affecting seasonal reproduction through hypothalamic-pituitary-gonadal (HPG) axis is still unclear. [Methods] In the present study, Plateau Pika (Ochotona curzoniae), a representative long-day animal, was used. Adult Pikas from reproductive and non-reproductive stages were captured in May and November, respectively, and assigned to four groups: reproductive male, reproductive female, non-reproductive male and non-reproductive female. Blood samples were collected from Plateau Pikas by posterior orbital venous plexus approach every 2 h within 24 h, and serum melatonin concentrations were detected by enzyme linked immunosorbent assay. Quantitative real-time PCR was used to determine relative expression levels of Mtnr1a and Mtnr1b with reference to Gapdh in hypothalamus, pituitary and gonad of Plateau Pika. The expression and location of MTNR1A and MTNR1B in pika’s gonad were confirmed by immunofluorescence staining with a germ cell specific marker DDX4 and a DNA specific dye Hoechst 33342. The concentration of melatonin and relative expression levels of Mtnr1a and Mtnr1b were compared among groups by one-way ANOVA. [Results] Results showed that serum melatonin concentration of non-reproductive male Pikas was always higher than that of reproductive males (P < 0.05), and the two groups showed distinct diurnal dynamics. Serum melatonin concentration of female pikas was lower than that of males all the time (P < 0.05), although there was no significant difference in female pikas between reproductive and non-reproductive stages (Fig. 1). The mRNA expressions of Mtnr1a and Mtnr1b were detected with similar changing pattern. There were significant seasonal differences in Mtnr1a and Mtnr1b expressions in male hypothalami and pituitaries (P < 0.05), and seasonal differences were also found in Mtnr1a and Mtnr1b expressions in female pituitaries and ovaries (P < 0.05) (Fig. 3). Immunostaining indicated that the two receptors were widely distributed in germ cells and Sertoli cells of testis. Nevertheless, MTNR1A was more extensively expressed in spermatogonia, while more expression of MTNR1B was observed in advanced germ cells at reproductive stage. In the ovary, MTNR1A was found in oocyte cytoplasm and granulosa cells preferentially. MTNR1B expression was observed in both oocyte nucleus and cytoplasm as well as in granulosa cells. Strikingly, distinct high expression of MTNR1B was found in theca cells of growing follicles (Fig. 4). [Conclusion] In conclusion, melatonin showed gender difference effects on seasonal reproduction in Plateau Pikas, implying that its control pattern is not limited to indirect regulation through HPG axis, but it also acts directly on melatonin receptors in gonad to control the fate of germ cells and somatic cells.

Abstract:[Objectives] To enlarge the population size and distribution area of Crested Ibis (Nipponia nippon), 20 individuals were introduced from Yangxian to establish an acclimatizing population in Beidaihe in July 2018. The reproduction of the Crested Ibis has always been the focus of the research for its conservation. Since the introduction of the Crested Ibis into Beidaihe, we have been continuously monitoring the reproduction of this population, and discovered the phenomenon of extramarital mating and intraspecific parasitism for the first time. [Methods] During the breeding period of 2020, three high-definition cameras installed in the cage house were used to observe the Crested Ibis and relevant data were recorded. A nest with laid eggs was recorded as a breeding nest, and when we found that at least one chick fledged out of the nest, it was recorded as a successful nest. Accordingly, the success rate of nesting is defined as the ratio of the number of successful nests to the total number of nests, the reproductive success rate is defined as the ratio of the number of fledglings to the number of eggs laid, and the reproductive productivity is defined as the number of fledglings per nest. The breeding data of Beidaihe and Yangxian in 2020 were analyzed by Excel and SPSS19.0 software. The independent sample t-test and the Mann-Whitney U test were used for comparison, according to if the data were in line with the normal distribution. [Results] During the breeding period in 2020 in Beidaihe, there were altogether 22 Crested Ibis, including 17 adults, with a female-to-male ratio of 1.1. The actual breeding density was 37.8/hm2, the nest density was 40.0/hm2, and the inner diameter of the nest basket was 50cm. Of the 8 pairs of Crested Ibis, 6 pairs were successful in breeding, with a nesting success rate of 75%; a total of 33 eggs were laid, with an average clutch size of 4.1 ± 1.8 eggs; 18 eggs were hatched, with the hatching rate of 54.5%; 13 chicks flew, with the flegling rate of 72.2%. The reproductive success rate was 39.4%, and the reproductive productivity was 2.2 ± 1.2 (Table 1). During the breeding period in 2020, there were 10 pairs of Crested Ibis in Yangxian, all of which were successful in breeding, with a nesting success rate of 100%; a total of 24 eggs were laid, with an average clutch size of 2.4 ± 0.8; 18 eggs were hatched, with the hatching rate of 75%. The fledgling rate was 100%, the reproductive success rate was 75%, and the reproductive productivity was 1.8 ± 0.8 (Table 1). Compared with the breeding population in Yangxian, the spawning time of the first egg of the Beidaihe population was 17 days later, which was consistent with the temperature difference between the two places (Fig.1). Through Mann-Whitney U test, we found that the nest egg number of Beidaihe Crested Ibis was significantly higher than that of Yangxian population, which may be caused by conspecific brood parasitism. Surveillance video showed that the clutch number of eggs of the Crested Ibis in the Beidaihe No. 1 nest was 6, more than twice of the average clutch number of the wild population (2 or 3), and we speculated that the conspecific brood parasitism might be occurred. In addition, it was also observed that the No. 8 nest Crested Ibis had both extra-pair copulations and conspecific brood parasitism. The extramarital female laid eggs in the male's nest, making the clutch number as high as 7. After that, three Crested Ibis were found to incubate their eggs in turn, and two females were found to incubate in the same nest. [Conclusion] The conspecific brood parasitism of Beidaihe Crested Ibis may be caused by high density of artificial nest sites and low concealment in the net cage, while the extra-pair copulations may be related to the high population density and reproductive density. Our results of the abnormal reproduction behavior of the Crested Ibis can provide references for the setting of artificial nest baskets in the acclimatizing cages and the selection of wild provenance, and prompt us to pay more attention to the phenotypic plasticity and ecological adaptability of the Crested Ibis under environmental pressure.

Abstract:[Objectives] The Great Bustard (Otis tarda) is a Class I protected species in China. Analyzing the population trends of the Great Bustard in important habitats will provide a scientific basis for protection and management of the species and its habitat. [Methods] From 2017 to 2020, a total of 33 monitoring sites were selected (Fig. 1) and comprehensive surveys were conducted on spatial and temporal changes in the population and distribution of Great Bustards in the Tumuji National Nature Reserve (eastern Inner Mongolia) and nearby areas. The number, sex and distribution sites of the Great bustard were investigated. [Results] The population of Great Bustard in our area increased from 193 ind in 2017 to 253 ind in 2020. The monthly number of birds varied, with the peaks in May (> 200 ind) and October (> 100 ind) and fewer in December to February of the following year. The winter population was approximately 50﹣70 individuals (Fig. 2). The winter population in January declined from 67 ind in 2017 to 55 ind in 2019 but recovered to 67 ind in 2020. Females were recorded from March of each year, with the peaks in April and May reaching to 50﹣70 individuals; their numbers declined in June but increased again slightly in September. No females were observed in the wild after October. In April, when Great Bustards were easy to observe in the field, the average female-to-male ratio was 1︰2 (Fig. 3). In 2017 and 2018, the population was stable and widely distributed in the Maanshan area of southeastern Tumiji Nature Reserve, but the number of distribution sites decreased in 2019 (Fig. 4), which may be related to the increase of human disturbances. The functional areas of the nature reserve were adjusted in 2020, and the Maanshan area, which had been removed in 2014, was again zoned as part of the protected area; this increased the area of wetlands and grasslands (Table 1), and the number of Great Bustard distribution sites was gradually restored. [Conclusions] The surveys indicated that the population and distribution of Great Bustards are greatly affected by human disturbances. In order to manage the ongoing problems in Tummuji National Nature Reserve and strengthen the protection of the Great Bustard populations and their habitat, some protective measures are needed, such as restoring farmland to grasslands, strengthening the management of conservation gaps and banning grazing.

Abstract:[Objectives] In China, Myotis horsfieldii was only to know distributed in Guangdong, Hainan and Hong Kong. This study aims to expand knowledge of geographical range of this species. [Methods] Two bat specimens (2♂: 211521 and 211540) were captured in the crack of the Datuo Station Interchange Bridge (112°57′24.4″ E, 28°3′18.1″ N, 44 m above sea level) and the Zhaohua Xiangjiang River Bridge (112°59′33.9″ E, 27°56′8.7″ N, 39 m above sea level) in August, 2021 in Changsha City, Hunan Province, respectively. The morphological and skull features of the two specimens were measured using electronic digital caliper and combined with the data of NCBI for constructed phylogenetic tree using maximum likelihood in MEGA7.0 based on Cyt b gene sequences. [Results] The main diagnosis characteristics of the two specimens as follows. Medium to small body size, forearm lengths of 36.1 mm (211521) and 33.1 mm (211540) and head body lengths of 44.0 mm and 41.2 mm, respectively. Hind-foot lengths of 10.5 mm and 10.4 mm more than half of the tibia lengths of 16.4 mm and 16.2 mm, respectively (Fig. 1, Table 2). Narrow and long skull, greatest lengths of skull 15.5 mm and 15.0 mm, breadths of braincase 7.8 mm and 7.5 mm, respectively. Delicate skull with a marked inclination at the frontal bone, and the braincase is higher than the maxilla. Zygomatic arch is thinner (Fig. 2, Table 2). Phylogenetic analysis based on Cyt b gene sequences showed that the captured bats were well clustered with M. horsfieldii formerly discovered in Hong Kong, China or Malaysia, and the genetic distance was only 0.9% to the specimen from Hong Kong, China (Fig. 3, Table 1). [Conclusion] Therefore, the two bats were confirmed to M. horsfieldii, a new record for Hunan Province. The specimens were kept in Institute of Zoology, Guangdong Academy of Science.

Abstract:Rumen ciliates are important components of rumen microorganisms and play an important role in maintaining rumen microecology and supplying energy to the host animal. [Objectives] This study aims to clarify rumen ciliate species diversity in Holstein cows. [Methods] In this study, rumen fluid samples of five healthy mid-lactation Chinese Holstein (Bos taurus) cows were collected. For each cow, three samples were collected, and each sample includes 2 ml of rumen fluid which were fixed and stained with 8 ml MFS (methyl-green-formalin-saline) solution. The density of rumen ciliates was counted by hemocytometer: The sample was gently shaken repeatedly, and 6.5 μl of samples were immediately aspirated onto a hemocytometer plate (size: XB.K.25) to fill the counting cell, covered with a clean coverslip for 5-10 min, and the density of rumen ciliates was counted under a 10 × 10 microscope (NEXCOPE NE610, USA). Each sample was randomly counted 6 times. And the means and standard deviation of the acquired data were calculated. Total genera and percentage composition of genera of rumen ciliates were counted under light microscopy: The sample was gently shaken repeatedly, 20 μl was pipetted onto a clean slide with coverslip and 300 rumen ciliates cells were counted under a 10 × 40 microscope. The number of rumen ciliates of different genera was recorded. Each sample was randomly counted 3 times. The percentage composition of genera (%) was obtained by counting the number of each genus out of the total 300 rumen ciliates in each count and then the mean and standard deviation were calculated; the frequency of detectable genera (%) was calculated from the frequency of each genus in the total times of counts. We observed and described the common genera of rumen ciliates in the rumen of Chinese Holstein (Fig. 1), aiming to understand the rumen ciliates biodiversity [Results] The results show that the average density of ciliates in rumen fluid of Chinese Holstein was (3.2 ± 3.4) × 108 ind/L, and 13 genera of rumen ciliates were identified. Table 1 shows the results of density (× 108 ind/L) and total genera of rumen ciliates in five Chinese Holsteins. Table 2 reveals the results of the frequency of detectable genera (%) and percentage composition of genera (%) in five Chinese Holsteins. Of which three genera with the highest frequency of detection were Entodinium, Eremoplastron and Diplodinium, and three genera with the lowest frequency of detection were Elytroplastron, Metadinium and Polyplastron. In terms of the percentage composition of genera, Entodinium was the most abundant genus in the rumen fluid of Chinese Holstein, with an average percentage composition of 84.0% ± 10.2%, while the percentage compositions of all other genera were less than 5%. In Table 3 and Table 4, we also compared the results in the present study with reported data on rumen ciliates of Holstein cattle. [Conclusion] Our results reveal that rumen ciliates in rumen fluid of Chinese Holstein have rich species diversity.

Abstract:[Objectives] The growth of the gladius is irreversible throughout the entire life cycle, which can completely record the life information of cephalopod. It is a good material for the study of the age and growth of cephalopod. This study used the gladius to analyze the individual growth of Berryteuthis magister shevtsovi, and provided a research basis for the subsequent exploration of its migration route, stock assessment, and rational development and utilization [Methods] In December 2018, 261 samples of B. m. shevtsovi were collected in the Sea of Japan by the Chinese Jigging fishing fleets. Linear regression or power function regression was used to evaluate the relationships between gladius length, proostracum length and individual growth, and frequency analysis was used to study the relationship between greatest width of conus, greatest width of vanes and sex maturity. We also analyzed the growth characteristics between proostracum, vanes and conus, by the analysis of covariance to test whether there were significant differences in various parameters between males and females. [Results] The results showed that gladius length and proostracum length both had a linear relationship with mantle length (ML) (R2 > 0.76), and a power function relationship was best for the growth with body weight (BW) (R2 > 0.77) (Fig. 4, 5). Greatest width of conus and greatest width of vanes both showed a significant increase after sex maturity reaching stage III (Fig. 6, 7). For individuals at stage III, greatest width of conus was not less than 5 mm, and greatest width of vanes was not less than 6 mm. The coefficient of the linear relationship between the standardized vanes length and the standardized length of greatest width of proostracum was slightly less than “1”. The coefficient of the linear relationship between the standardized proostracum length and standardized conus length was much less than “1”. Moreover, the ratio of vanes length to the length of greatest width of proostracum and the ratio of conus length to proostracum length were all similar, about 0.77 and 0.27, respectively. This showed that the growth rate of proostracum and vanes of B. m. shevtsovi was basically the same, which was much faster than that of the conus. [Conclusion] The study show that it is feasible to use the gladius to analyze the individual growth of B. m. shevtsovi, especially when the body ia damaged, and the width of gladius grows mainly after the individual has matured.

Abstract:[Objectives] After long-term natural selection, the Bactrian Camel (Camelus bactrianus) has many special biological characteristics, such as strong thirst tolerance, hunger tolerance and the ability to adapt to bad weather. Nesfatin-1 is a peptide composed of 82 amino acids. It is derived from the protein hydrolysis of its precursor NUCB2 in prohormone convertases (PCS) at Lys 83 - Arg 84 site. It can regulate the efficiency of energy metabolism and inhibit appetite. To study the distribution and expression of NUCB2/Nesfatin-1 in Bactrian camels, in order to explore whether Bactrian camels have a unique way of energy metabolism and whether it is related to the absence of metabolic diseases. [Methods] The hapten polypeptide of specific epitope of Bactrian camel NUCB2/Nesfatin-1 protein was synthesized by chemical synthesis method. The hapten was coupled with keyhole limpet hemocyanin (KLH) by maleimide method, and polyclonal antibody against single antigenic epitope of NUCB2/Nesfatin-1 protein was prepared by immunizing animals, Western blot was used to detect the expression of NUCB2/Nesfatin-1 protein in the hypothalamus (arcuate nucleus, solitary tract nucleus, ventromedial nucleus), anterior peak fat, posterior peak fat, stomach (tissue around gastric fundus gland), duodenum, jejunum, ileum, cecum, colon, rectum, pancreas, liver and abdominal adipose tissue of Bactrian camel. The expression of NUCB2/Nesfatin-1 mRNA in the above tissues o was also detected by fluorescence quantitative PCR. T-test analysis was used to analyze the results by using graphpad prism 5.0 software. [Results] The synthesized Bactrian Camel NUCB2/Nesfatin-1 protein had few polypeptide heteropeaks at specific epitopes, and its purity was calculated to be more than 95%. The mass charge ratio [M + 4H]4+ and [M + 3H]3+ of the polypeptide was in line with its expectation (Fig. 1, 2). The titer of the polyclonal antibody against NUCB2/Nesfatin-1 protein determined by indirect ELISA was 5.12 ′ 105, and the polyclonal antibody was successfully prepared (Fig. 4). The prepared polyclonal antibody of NUCB2/Nesfatin-1 was used to detect the distribution of NUCB2/Nesfatin-1 protein various tissues and organs mentioned above. It was significantly expressed in adipose tissue and pancreas of Bactrian Camel (Fig. 7, 8). The distribution of NUCB2/Nesfatin-1 mRNA in Bactrian camel was detected by fluorescence quantitative PCR. It was found that the gene was expressed in the detected tissues, especially in abdominal fat and liver tissues (Fig. 9). [Conclusion] In this study, a specific antibody against Bactrian Camel NUCB2/ Nesfatin-1 protein was successfully prepared by analyzing antigen epitopes and synthesizing peptides, and the antibody has high titer and strong specificity. The distribution of NUCB2/Nesfatin-1 in Bactrian Camels was detected at the protein level by the successfully prepared specific antibody, and then the distribution of NUCB2/Nesfatin-1 in Bactrian Camels was detected at mRNA level by fluorescence quantitative PCR. Through the analysis of the results, it is found that NUCB2/Nesfatin-1 is highly expressed in the peripheral adipose tissue, and it may play a role in inhibiting appetite in the regulation of thirst and hunger tolerance mechanism of Bactrian camel, so that Bactrian Camel can endure long-term hunger. It is speculated that NUCB2/Nesfatin-1 protein may inhibit the differentiation of adipocytes, promote the hydrolysis of lipid droplets in adipocytes and provide energy for the body in Bactrian Camel. Its specific function in adipocytes needs our further study.

Abstract:[Objectives] Recently, many ciliopathy-associated proteins are found in the basal body of cilia, and these proteins are also located in ciliates, Euplotes amieti. Ciliates have thousands of basal bodies of cilia and a complicated microtubular cytoskeleton, therefore, it is an ideal material for studying the interaction between the basal body and the microtubular cytoskeleton. [Methods] In this experiment, immunofluorescence and immuno-electron microscopy were used to observe the cellular and subcellular localization of Centrosomal protein 43 (CEP43) and Coiled-coil domain-containing 13 protein (CCDC13) in Euplotes amieti. [Results] The results showed that the cilia microtubular organelles of Euplotes amieti were composed of the adoral zone of membranelles, caudal cirrus, marginal cirrus, frontoventral cirrus, transverse cirrus, radiating microtubule, and dorsum bristle (Fig. 2). Immunofluorescence showed that CCDC13 was mainly located in the basal body and rod of cilia microtubular organelles and the silverline system (Fig. 3a, b), while CEP43 was mainly located in the basal body of cilia microtubular organelles, and cirrus accessory microtubules and nucleus (Fig. 3c). CEP43 and γ-tubulin were co-localized in the regions mentioned above (Fig. 4), while CCDC13 and γ-tubulin were only located in the same regions on the ventral side of Euplotes amieti (Fig. 5a, b). On the dorsum, CCDC13 was located in the silverline system (Fig. 5d), while γ-tubulin was located in the basal body of the dorsal cirri (Fig. 5e). During the cell division, CEP43 was not located in the nucleus, but in the basal body and the adoral zone of membranelles (Fig. 6a, b), while CCDC13 was observed in the adoral zone of membranelles (Fig. 6c, d). Further, the immuno-electron microscopy showed that CEP43 and CCDC13 were located in the basal bodies of the cilia, the adoral zone of membranelles, the base of the frontoventral cirrus, and the base of the transverse cirrus (Fig. 7), and the amount of colloidal gold at the base of frontoventral cirrus of CCDC13 was much more than that of CEP43 (Fig. 7h), while CCDC13 was not observed in the nucleus (Fig. 7j). [Conclusion] 1) CCDC13 and CEP43 are involved in the formation of cilia and basal body; 2) CEP43 can form complexes with CAP350 to provide attachment points for microtubule extension; 3) the excess CEP43 will be regulated and recruited to the nucleus after the formation of cilia; 4) the CCDC13 participates in the formation of the silverline system, in addition, it will affect the rate of microtubule regeneration. However, in order to increase the regeneration off the anterior longitudinal microtubules of Euplotes amieti during the growth period, CCDC13 is not required. The results provide basic data for further research on the roles and mechanisms of the above proteins in regulating and maintaining the assembly and stability of the cortical microtubule cytoskeleton in hypotrichous ciliate.

Abstract:[Objectives] The winged pearl oyster (Pteria penguin) is one of the large marine economic molluscs that are used to produce mabé pearls. It relys on strong byssus to anchor itself to substrate and resist the impact of water flow and predators. The byssus secretion behavior and byssal properties are easily affected by the environmental factors. Therefore, this research aims to study the effect of salinity on byssus secretion and mechanical properties of P. penguin. [Methods] In this experiment, three different salinities (low salinity group of 30, control salinity group of 35, high salinity group of 40) were used to study the effects of different salinities on byssus secretion, diameter and breaking force of P. penguin. Mustcam USB digital microscope was used for measuring and recording the diameters of the proximal, middle and distal regions of newly secreted byssus to an accuracy of 0.01 mm. Tensile tester (HP-10, Handpi) was used for byssus breaking force determination without affecting the structural properties of the byssus. One-way ANOVA (LSD method) was used to analyze whether there were significant differences for the three byssus-related parameters among the three salinity groups. [Results] The results showed that there were no significant differences in the byssus attachment rates of P. penguin among different salinity groups (Fig. 2), but the total number of byssus secretion in the control salinity group (48.7 ± 15.1) was significantly higher than that in the low salinity group (24.7 ± 5.0) and the high salinity group (13.3 ± 1.5) throughout the whole experimental period of 72 h. During the first 6 h of the experiment, the byssus first attachment rate in the control salinity group was significantly higher than that in the low salinity and high salinity groups (P < 0.05), but no significant difference was identified in the following hours (12 h, 18 h, 30 h, 42 h, 54 h and 66 h) in the byssus first attachment rate in the three salinity groups (Fig. 3). The measurement results of byssus diameter showed that the distal diameter of byssus was significantly different from the middle or proximal diameter (P < 0.05) under the same salinity. Therefore, when investigating the effect of salinity on the diameter of byssus, the whole byssus was still divided into three parts. There was no significant difference in the diameter of the same part (proximal, middle and distal diameter) of the byssus under 3 different salinities (Fig. 4), while salinity had significant effects on the byssus breaking force (Fig. 5), and the byssus breaking force in the control salinity group was significantly higher than that in the low salinity and high salinity groups (P < 0.05). [Conclusion] The above results show that in high salinity of 40 or low salinity of 30, byssus secretion is inhibited in the initial stage, probably due to the need to close the shell and reduce energy consumption to adapt to the environment. There is no significant difference in the first attachment rate among the three salinity groups. Salinity significantly affects the byssus re-attachment rate and breaking force, but not the byssus diameter. This study would provide valuable information for P. penguin culture and nucleus-inserting and pearl production.

Abstract:[Objectives] Exploring the effects of different particle sizes (50, 200 and 1 000 nm) and different concentrations (zero, low, moderate and high) of fluorescent polystyrene microsphere solutions on the body size and internal organ indices of Pelophylax nigromaculatus at Gosner stage 37 tadpoles. [Methods] The Gosner stage 37 tadpoles were exposed to any combination of any particle size and any concentration solution for 7 days, then were transfered into dechlorinated tap water and fed without fluorescent polystyrene microsphere solution for an additional 7 or 14 days. The variations of ratio of body mass to total body length (ratio of BM to TBL), the length of small intestine, and the wet masses of heart and liver were continuously measured. All statistical analyses were performed using SPSS software packages (SPSS 19.0 for windows). For any particle size (50, 200 or 1 000 nm), two-way ANOVA (concentration × day) and multiple comparisons were used to compare the differences of ratio of BM to TBL, the length index of small intestine, and the wet mass indexes of heart and liver. Then, one-way ANOVA and multiple comparisons were further used to compare the differences of the parameters mentioned above among different concentration groups from the same day, or among different days from the same concentration group. Results were presented as means ± standard error, and P < 0.05 was considered to be statistically significant. [Results] Ratio of BM to TBL was not affected by polystyrene microsphere exposure and clearance under the conditions of 200-nm solution (Table 3, P > 0.05); The BM to TBL ratio was significantly lower in clean water group than that of any other concentration group on day 14 when exposed to 50-nm solution (Table 2, P > 0.05); When exposed to 1000-nm solution, the ratio was significantly higher on days 7 and 14 than on day 21 for moderate concentration group, which was lower in high concentration group than that of any other concentration group on day 7, and was higher in clean water group and low concentration group than that of moderate concentration group on day 21 (Table 4, P < 0.05). When exposed to 200-nm solution with high concentration, small intestine length index was significantly changed with days, being greatly increased from day 7 to day 14, and sharply declined by day 21 (Table 3, P < 0.05); On day 7 or 14, exposure to 1 000-nm solution with moderate concentration, the index was greatly higher than on day 21, while it was greatly lower in high concentration group than that of any other concentration group (Table 4, P < 0.05), but not for 50-nm (Table 2, P < 0.05) or 200-nm solution group (Table 3, P < 0.05). The wet mass indexes of heart and liver did not greatly change (Table 2﹣4, P > 0.05); The heart wet mass index was only significantly changed under the conditions of 50-nm solution on day 14, which was highest in clear water group, followed by high and moderate concentration groups, and lowest in low concentration group (Table 2, P < 0.05); The liver wet mass index was only significantly lower in clean water group than that of any other concentration group on day 14 from 50-nm or 200-nm solution group (Table 2 and 3, P < 0.05). [Conclusion] Ratio of BM to TBL, indexes of heart and liver wet masses, small intestine length index combined with liver wet mass index, and ratio of BM to TBL combined with small intestine length index were affected by 50-nm, 200-nm or 1000-nm polystyrene microspheres solution, respectively, but polystyrene particle size and concentration are not linear with their potential hazards.

Abstract:Three tailless amphibian specimens were collected in Puhe Wetland Park (41°41′54″ N, 122°52′19″ E, elevation 35 m) in Shenyang in September 2021 (Fig. 1, with Fig. 3 showing the habitat). In this study, the morphological characteristics of the collected specimens were compared and analyzed in detail with P. chosenicus and P. plancyi. The 12S rRNA and 16S rRNA gene of 3 samples were amplified and sequenced by second-generation high-throughput sequencing. The 12S rRNA and 16S rRNA gene information of 19 species of Pelophylax distributed in China and abroad (including a species of Rana as an outgroup) were obtained in NCBI GenBank database and existing reports. Phyml 3.0 to construct maximum likelihood phylogenetic tree. Morphological analysis shows that there are interspecific differences between our specimens and P. plancyi, which is consistent with the type origin species of P. chosenicus. The results of ML phylogenetic tree show that the Pelophylax specimens collected in Shenyang Puhe Wetland Park and the type origin (Korea) specimens of P. chosenicus gather into one branch (Fig. 2), with a high support rate (95%). By comprehensive comparison with morphological and phylogenetic analysis, the specimens we collected should be the P. chosenicus of the genus Pelophylax in the family Anura, and be a new record of amphibian distribution in China.

Abstract:Olfactory organ is one of the important chemical sensory organs in fish, which plays an important role in foraging, reproduction and migration. In order to understand the structure and early development characteristics of olfactory sac of Siniperca chuatsi, the morphological structure of olfactory organ, structure and early development of olfactory epithelium were observed by paraffin section, H.E staining, Massorn staining, immunohistochemistry, scanning and transmission electron microscopy. The results showthat Siniperca chuatsi has two pairs of nostrils, and the anterior and posterior nostrils are closely linked, with flaps (Fig. 1a). The olfactory sac is located in the olfactory cavity, which is composed of 16﹣20 primary olfactory lamellas (Fig. 1b). It is a G-type olfactory sac, and the primary olfactory lamellas generate secondary olfactory lamellas through folds (Fig. 1c). The distal edge of olfactory lamella is a non-sensory area, and the sensory area is mainly located at the middle and proximal ends of olfactory lamellas. Olfactory epithelial cells can be divided into six categories: ciliated non-sensory cells, ciliated receptor cells, microvilli sensory cells, supporting cells, basal cells and mucous cells (Fig. 1e﹣g). Under the scanning electron microscope, there are a large number of cilia coverings on the surface of sensory area, and microvilli on the surface of secondary olfactory lamellas (Fig. 1h, i). There are convex ridges on the surface of the non-sensory region (Fig. 1j). From larvae to young fish, the olfactory substrate of 1﹣7 days old larvae is thin and the cells are loosely arranged (Fig. 2a). At 7 days of age, the olfactory base plate is thickened to form an olfactory fossa with cilia on the surface of olfactory epithelium (Fig. 2b). At 10 days of age, the olfactory base continues to sink into the olfactory fossa and forms an olfactory cavity (Fig. 2c). At 26 days old, juveniles form the first pair of primary olfactory lamellas (Fig. 2e), and at 55 days old, juveniles form eight pairs of primary olfactory lamellas (Fig. 2h). Before 55 days of age, the olfactory sac of S. chuatsi develops slowly, the primary olfactory lamellas are arranged laterally, and the secondary olfactory plate is not formed.

Abstract:[Objectives] Animal social network analysis can provide a flexible toolbox for describing the social system of species or populations in a directly quantitative and comparable manner. However, it requires careful consideration of differentiating real from observed networks and controlling for inherent biases that are common in social data. To investigate the species diversity and its community characteristics at the Dongzhai National Reserve, Henan Province, China. [Methods] We carried out 5.5 days of bird banding using mist nets in 2021. Using animal social network analysis, we investigate the social network of species in this reserve. With the network of species implanting species’ life-history traits (i.e. trophic niche and migration), we investigate the impact of these life-history traits on the network's structure. Animal social network analysis was done using the R packages ‘asnipe’ and ‘igraph’. [Results] 33 species of birds from 12 families were banded among which the most banded species were Vinous-throated Parrotbill (Sinosuthora webbiana), Chestnut-flanked White-eye (Zosterops erythropleurus) and Brown-flanked Bush Warbler (Horornis fortipes) (Table 1). As to the trophic niche of these 33 species, 12 belong to invertivore glean arboreal, 8 to invertivore ground, and 6 to generalist (Table 1, Fig. 1). Seventeen species of the ringed birds are residential and 16 species are migratory. We found that common species appeared in the central of the social network. Moreover, species with the same trophic niche are grouped together in the social network. However, species with the same migration feature (either resident or migratory) appeared randomly in the network (Fig. 1). [Conclusions] These patterns indicated that the population size and trophic niche, but not migration, are important factors that influence the social network of species. In short, social network analysis is an advanced method for describing the structure of multi-species groups and investigating the mechanisms underlying collective behavior.

Abstract:Tool use was once considered as unique ability for humans. However, in the past 50 years, tool use has been widely observed throughout the animal kingdom, and therefore is more common than previously thought. Tool use in animals usually has certain purposes, and most animals use tools to achieve short-term goals instead of long-term goals. The tool-use behaviors may be influenced by environmental, cognitive, and physiological factors, and individual differences in tool use may be observed. For some animals, the tool use is an innate behavior. However, for most higher vertebrates, tool use usually involves the trial-and-error learning. Through social learning, some tool-use behaviors can spread and evolve, thus being widely distributed in the population. Tool use is one of the central concepts in animal cognition. Researches in tool use would enhance the understanding of cognitive abilities and behavioral evolution of animals.

Abstract:

Abstract: