There is an urgent need to find a way to improve the genetic diversity of captive South China tiger (SCT, Panthera tigris amoyensis), the most critically endangered taxon of living tigers, facing inbreeding depression. The genomes showed that 13 hybrid SCTs from Meihuashan were divided into two groups; one group included three individuals who had a closer relationship with pureblood SCTs than another group. The three individuals shared more that 40% of their genome with pureblood SCTs and might be potential individuals for genetic rescuing in SCTs. A large-scale genetic survey based on 319 pureblood SCTs showed that the mean microsatellite inbreeding coefficient of pureblood SCTs decreased significantly from 0.1789 to 0.0600 (p = 0.000009) and the ratio of heterozygous loci increased significantly from 38.5% to 43.2% (p = 0.02) after one individual of the Chongqing line joined the Suzhou line and began to breed in the mid-1980s, which is a reason why the current SCTs keep a moderate level of microsatellite heterozygosity and nucleotide diversity. However, it is important to establish a back-up population based on the three individuals through introducing one pureblood SCT into the back-up population every year. The back-up population should be an important reserve in case the pureblood SCTs are in danger in the future.

<!-- *** Custom HTML *** --> The red goral is an endangered species with a small population and narrow distribution in China. The only captive population (21 individuals) is held in Shanghai Zoo, China. Demographic and genetic analyses were carried out to assess the status of this captive population and put forward conservation and management proposals. Population status was assessed on the basis of studbook records from 1981 to 2016. The population size grew from seven (three males, four females) to 31 (19 males, 12 females) in 2012 (λ = 1.06) and 21 (17 males, four females) in 2016 (λ = 0.91). From 1981 to 2016, a total of 81 births (45 males, 36 females) and 68 deaths (32 males, 32 females, four unknown) occurred. The mean kinship (MK) of the population is 0.2614 and the average inbreeding index is 0.2037. Parturition mainly occurs in May, June and July, and deaths occurred in January, February, July and November. In addition, the genetic diversity of this population was analysed on the basis of nine microsatellite loci. The results revealed that 14 primer-amplified bands were found; nine of them were stable, with four loci highly polymorphic (polymorphic information content, PIC > 0.05), three moderate (0.25 < PIC < 0.5), one low (PIC < 0.25) and one monomorphic (PIC = 0). In total, 34 alleles were detected from eight microsatellite loci, with the number of alleles per locus (A) ranging from 3-6 (x̄ = 4.250), and the effective number of alleles (Ne) from 1.245 to 3.862 (x̄ = 2.529). The observed heterozygosity (H0) varied from 0.143 to 0.857 (x̄ = 0.562), and the expected heterozygosity (He) from 0.201 to 0.755 (x̄ = 0.550). The polymorphism information content (PIC) varied from 0.188 to 0.705 (x̄ = 0.500). The results indicated a moderate level of genetic diversity among the red goral population in Shanghai Zoo.

The gut microbiota of seabirds can undergo shifts during the moulting period due to fasting. Understanding the characteristics of gut microbiota in African penguins (Spheniscus demersus) throughout moulting is meaningful for the conservation and management of this critically endangered seabird species. A total of 12 captive African penguins reared in Shanghai Zoo were divided into three sampling stages: (1) pre-moulting (Pre); (2) mid-moulting (Mid); and (3) post-moulting (Post). The 16S rDNA gene sequencing of faecal samples was performed to evaluate differences in diversity, composition, and predicted function of the gut microbiota across the moulting period. The results showed that Firmicutes, Proteobacteria, and Actinobacteria were the predominant bacterial phyla in African penguins throughout moulting. Moulting significantly altered the diversity and composition of gut microbiota in captive African penguins. Pre-moulting penguins exhibited higher abundances of Bacilli and Lactobacillales compared with mid- and post-moulting groups, whereas mid- and post-moulting penguins had increased abundances of several potentially harmful bacteria. In addition, the functional prediction analysis indicated that pre-moulting penguins had a higher abundance of protein N-glycosylation pathway compared with both mid- and post-moulting penguins. The pre-moulting group also exhibited a decreased abundance of the vitamin E biosynthesis pathway compared with the mid-moulting group. The present study has revealed that the gut environment of African penguins is more vulnerable during the mid- and post-moulting periods. The findings provide reference information for improving the management of endangered seabird species during moult.

This study aimed to determine whether the fetuses experienced hypoxic distress or intra-partum death due to compromised oxygen supply by quantitatively analyzing the lung structures of deceased captive South China Tiger (Panthera tigris amoyensis, SCT) cubs. Furthermore, it investigated the etiology and mechanisms of asphyxia in the deceased cubs and explored potential factors contributing to the high mortality rate of SCT cubs. The research focused on three deceased SCT cubs, using three deceased neonatal Amur Tigers (P. t. altaica, AT) with no inbreeding background as controls. Histological analysis of the cubs’ lungs was conducted using hematoxylin–eosin (H&E) and special staining techniques. The possible causes of death in SCT cubs were evaluated by comparing pulmonary pathological changes and morphological parameters, including alveolar space (P(ASP)) values, mean alveolar linear intercept (L_m), and mean thickness of alveolar septa (Tas). Our research reveals that hypoxia is one of the most significant factors contributing to the mortality of tiger cubs. Additionally, we hypothesize that inbreeding depression may lead to abnormal lung development (e.g., thickening of lung tissue) in SCT cubs. This study lays the foundation for comprehensive investigations into the mortality of highly inbred SCT cubs.