Fine-scale geographic difference of the endangered Big-headed Turtle (Platysternon megacephalum) fecal microbiota, and comparison with the syntopic Beale's Eyed Turtle (Sacalia bealei).

BACKGROUND: Studies have elucidated the importance of gut microbiota for an organism, but we are still learning about the important influencing factors. Several factors have been identified in helping shape the microbiome of a host, and in this study we focus on two factors-geography and host. We characterize the fecal microbiota of the Big-headed Turtle (Platysternon megacephalum) and compare across a relatively fine geographic scale (three populations within an 8-km radius) and between two syntopic hosts (P. megacephalum and Sacalia bealei). Both species are endangered, which limits the number of samples we include in the study. Despite this limitation, these data serve as baseline data for healthy, wild fecal microbiotas of two endangered turtle species to aid in conservation management. RESULTS: For geography, the beta diversity of fecal microbiota differed between the most distant sites. The genus Citrobacter significantly differs between sites, which may indicate a difference in food availability, environmental microbiota, or both. Also, we identify the common core microbiome for Platysternon across Hong Kong as the shared taxa across the three sites. Additionally, beta diversity differs between host species. Since the two species are from the same site and encounter the same environmental microbiota, we infer that there is a host effect on the fecal microbiota, such as diet or the recruitment of host-adapted bacteria. Lastly, functional analyses found metabolism pathways (KEGG level 1) to be the most common, and pathways (KEGG level 3) to be statistically significant between sites, but statistically indistinguishable between species at the same site. CONCLUSIONS: We find that fecal microbiota can significantly differ at a fine geographic scale and between syntopic hosts. Also, the function of fecal microbiota seems to be strongly affected by geographic site, rather than species. This study characterizes the identity and function of the fecal microbiota of two endangered turtle species, from what is likely their last remaining wild populations. These data of healthy, wild fecal microbiota will serve as a baseline for comparison and contribute to the conservation of these two endangered species.

Home and hub: pet trade and traditional medicine impact reptile populations in source locations and destinations.

The pet trade and Traditional Chinese Medicine (TCM) consumption are major drivers of global biodiversity loss. Tokay geckos (Gekko gecko) are among the most traded reptile species worldwide. In Hong Kong, pet and TCM markets sell tokay geckos while wild populations also persist. To clarify connections between trade sources and destinations, we compared genetics and stable isotopes of wild tokays in local and non-local populations to dried individuals from TCM markets across Hong Kong. We found that TCM tokays are likely not of local origin. Most wild tokays were related to individuals in South China, indicating a probable natural origin. However, two populations contained individuals more similar to distant populations, indicating pet trade origins. Our results highlight the complexity of wildlife trade impacts within trade hubs. Such trade dynamics complicate local legal regulation when endangered species are protected, but the same species might also be non-native and possibly damaging to the environment.

Demographic evidence of illegal harvesting of an endangered asian turtle.

Harvesting pressure on Asian freshwater turtles is severe, and dramatic population declines of these turtles are being driven by unsustainable collection for food markets, pet trade, and traditional Chinese medicine. Populations of big-headed turtle (Platysternon megacephalum) have declined substantially across its distribution, particularly in China, because of overcollection. To understand the effects of chronic harvesting pressure on big-headed turtle populations, we examined the effects of illegal harvesting on the demography of populations in Hong Kong, where some populations still exist. We used mark-recapture methods to compare demographic characteristics between sites with harvesting histories and one site in a fully protected area. Sites with a history of illegal turtle harvesting were characterized by the absence of large adults and skewed ratios of juveniles to adults, which may have negative implications for the long-term viability of populations. These sites also had lower densities of adults and smaller adult body sizes than the protected site. Given that populations throughout most of the species' range are heavily harvested and individuals are increasingly difficult to find in mainland China, the illegal collection of turtles from populations in Hong Kong may increase over time. Long-term monitoring of populations is essential to track effects of illegal collection, and increased patrolling is needed to help control illegal harvesting of populations, particularly in national parks. Because few, if any, other completely protected populations remain in the region, our data on an unharvested population of big-headed turtles serve as an important reference for assessing the negative consequences of harvesting on populations of stream turtles. Evidencia Demográfica de la Captura Ilegal de una Tortuga Asiática en Peligro.

A new species of the genus Opisthotropis Gunther, 1872 (Squamata: Colubridae: Natricinae) from Guangdong Province, China.

A new natricid snake of the genus Opisthotropis Gunther, 1872, Opisthotropis laui sp. nov., is described from Mt. Gudou, Jiangmen City, Guangdong Province, China. The new species can be distinguished from other congeners by the combination of the following characters: dorsal scales weakly keeled throughout, in 25:23:23 rows; 10 supralabials; 11 infralabials; two internasals, longer than wide, not touching the loreal; one loreal, not touching the eye; one preocular; two postoculars; one anterior temporal scale; 152 ventrals; 53 subcaudals; body and tail dark olive above, with light yellow crossbars.

OCCURRENCE OF PATHOGENIC CHYTRID FUNGI BATRACHOCHYTRIUM SALAMANDRIVORANS AND BATRACHOCHYTRIUM DENDROBATIDIS IN THE HONG KONG NEWT (PARAMESOTRITON HONGKONGENSIS) AND OTHER WILD AND IMPORTED AMPHIBIANS IN A SUBTROPICAL ASIAN REGION.

One of the major threats for the massive loss in global amphibian diversity is chytridiomycosis, caused by chytrid fungi Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). Following its discovery in 2013, Bsal has emerged as a severe threat to the global survival of urodelans. In 2018, a study reported a high prevalence of Bsal (65.6%) in the Hong Kong newts (Paramesotriton hongkongensis, Near Threatened) of a southern China population adjacent to Hong Kong (HK). Uncertainty regarding the Bsal infection status of P. hongkongensis inhabiting HK raised deep concern over the risk of introducing Bsal from that population. We screened the skin swabs from wild individuals of P. hongkongensis, 15 sympatric amphibian species, and 16 imported amphibian species in HK for chytrids. We found that both Bsal and Bd occur in low prevalences in P. hongkongensis (Bsal 1.7%, 5/293; Bd 0.34%, 1/293), Hong Kong cascade frog, Amolops hongkongensis, family Ranidae (Bsal only, 5.26%, 1/19), and Asian common toad, Duttaphrynus melanostictus, family Bufonidae (Bsal only, 5.88%, 1/17), populations of HK, with infected individuals being asymptomatic, suggesting a potential role of these species as reservoirs of Bsal. Conversely, Bd, but not Bsal, was present on 13.2% (9/68) of imported amphibians, indicating a high chytrid introduction risk posed by international amphibian trade. Long-term surveillance of the presence of Bd and Bsal in wild and captive amphibians would be advisable, and we recommend that import and export of nonnative chytrid carriers should be prevented, especially to those regions with amphibian populations naïve to Bd and Bsal.

Using eDNA techniques to find the endangered big-headed turtle (Platysternon megacephalum).

We evaluate the efficacy of environmental DNA (eDNA) techniques to locate wild populations and estimate the population size of the endangered big-headed turtle (Platysternon megacephalum) in Hong Kong. The results from this study are important for identifying priority sites for protection and further research. Additionally, we assess the impact of two environmental variables (temperature and pH) on eDNA quantity. We surveyed 34 streams for three years, sampling four times each year. Four new populations were first identified with eDNA analysis, and then verified by field surveys. Our multi-year survey highlights that eDNA detection can be inconsistent over time, even in streams with known populations. There was no significant relationship between eDNA quantity and the environmental variables tested. Lastly, our results suggest that eDNA methods remain promising to estimate population size, since number of positive detections were positively correlated with population size in streams with known populations. We conclude that eDNA methods are powerful, but care must be taken when interpreting field results as they are affected by species ecology and environmental conditions.

Recovery of tropical marine benthos after a trawl ban demonstrates linkage between abiotic and biotic changes.

Bottom trawling, which is highly detrimental to seabed habitats, has been banned in some jurisdictions to mitigate the problems of habitat destruction and overfishing. However, most reports of ecosystem responses to trawling impacts originate from temperate latitudes, focusing on commercial species, and recovery of invertebrate macrobenthos from trawl ban has hardly ever been studied in the tropics. In Hong Kong (lat. 22.4°N), a history of intensive trawling with various types of gears has long degraded coastal ecosystems. To facilitate the recovery of fisheries resources and associated benthic ecosystems, the Government of the Hong Kong Special Administrative Region implemented a territory-wide trawl ban on December 31, 2012. Comparison of surveys conducted in June 2012 (before the trawl ban) and June 2015 (2.5 years after the ban) revealed higher organic contents in sediment and lower suspended-solid loads in water column, as well as a significant increase in site-based abundance, species richness, functional diversity and among-site similarity of macrobenthos after the trawl ban. Our results suggest that the imposition of a trawl ban can be an effective measure for biodiversity conservation in tropical coastal waters.

DNA metabarcoding reveals the dietary composition in the endangered black-faced spoonbill.

Extensive loss of natural wetlands caused by changes in land use largely diminishes the food resources essential for the survival of migratory waterbirds. Globally, the decline in waterbird populations in East Asia is the most serious, with 64% of these populations showing a decreasing trend. In this study, we applied DNA metabarcoding to examine the spatiotemporal variations and diversities in the dietary compositions of migratory waterbirds in a natural/artificial wetland complex in Asia. By investigating 110 fecal samples from the endangered black-faced spoonbill (Platalea minor) wintering in the wetland, our results show that P. minor had a broad dietary spectrum. The birds fed on at least 26 species in the classes Actinopterygii and Malacostraca, with Mugiliformes, Cichliformes, and Gobiiformes being the main taxa in their diets. Our results also demonstrated clear patterns of the spatiotemporal variations between the roosting groups and intraspecific variations between the individuals, which potentially reflect some of their feeding habits, and the probable usage of different habitat types in the wetland complex. Using high-throughput sequencing, we were able to elucidate the food resources that are critical to P. minor non-invasively, this method can also be used to provide invaluable information for the conservation of many other waterbird species.

International socioeconomic inequality drives trade patterns in the global wildlife market.

The wildlife trade is a major cause of species loss and a pathway for disease transmission. Socioeconomic drivers of the wildlife trade are influential at the local scale yet rarely accounted for in multinational agreements aimed at curtailing international trade in threatened species. In recent decades (1998-2018), approximately 421,000,000 threatened (i.e., CITES-listed) wild animals were traded between 226 nations/territories. The global trade network was more highly connected under conditions of greater international wealth inequality, when rich importers may have a larger economic advantage over poorer exporting nations/territories. Bilateral trade was driven primarily by socioeconomic factors at the supply end, with wealthier exporters likely to supply more animals to the global market. Our findings suggest that international policies for reducing the global wildlife trade should address inequalities between signatory states, possibly using incentive/compensation-driven programs modeled after other transnational environmental initiatives (e.g., REDD+).

Comparative Analysis of the Fecal Microbiota of Wild and Captive Beal's Eyed Turtle (Sacalia bealei) by 16S rRNA Gene Sequencing.

The Beal's eyed turtle (Sacalia bealei) is threatened with extinction due to hunting for large-scale trade. In Hong Kong, there are some of the world's remaining wild populations of S. bealei, as well as a breeding colony. This breeding colony is at the core of conservation efforts (captive breeding, reintroduction programs). Therefore, we would like to know how captivity, in particular diet, affects the gut microbiota. Using high-throughput 16S rRNA gene sequencing, we comparatively analyzed the fecal microbiota of wild and captive S. bealei. We found that wild S. bealei have higher alpha diversity than captive S. bealei, but the difference was not significant. Significant differences were found in ß-diversity; at the phylum level, wild S. bealei have higher relative abundances of Proteobacteria and captive S. bealei have higher relative abundances of Firmicutes. At the genus level, Cetobacterium and Citrobacter are more abundant in wild S. bealei, while Clostridium spp. are significantly more abundant in captive S. bealei. These results suggest conditions in captivity, with diet being a major factor, influence the gut microbiota of S. bealei. The connection between diet and health has always been considered for captive animals, and in this study we use the gut microbiota as an another tool to assess health.

Spatial ecology of little egret (Egretta garzetta) in Hong Kong uncovers preference for commercial fishponds.

Many natural wetlands have been converted to human-influenced wetlands. In some instances, human-influenced wetlands could provide complementary habitats for waterbirds, compensating for the loss of natural wetlands. Inner Deep Bay in Hong Kong is composed of both natural and human-influenced wetlands and is under immense development pressure. From an ecology perspective, we need to understand if different wetland types play the same ecological role. To achieve this, we tracked nine little egrets (Egretta garzetta) using GPS loggers for 14 months to study their spatial ecology, home range, movement and habitat use. We found that over 88% of the home range of all individuals comprised of wetlands (commercial fishponds, mangrove, gei wai, channel, and intertidal mudflat). Among these wetland types, nearly all (seven of nine) individuals preferred commercial fishponds over other habitats in all seasons. Little egrets exhibited seasonal movement and habitat use among seasons, with largest home range, greatest movement, and most frequent visits to commercial fishponds in winter compared to spring and autumn. Our results highlight the significant role of commercial fishponds, providing a feeding ground for little egrets. However, other wetland types cannot be ignored, as they were also used considerably. These findings underscore the importance of maintaining a diversity of wetland types as alternative foraging and breeding habitats.

A new species of the genus Achalinus from southwestern Guangdong Province, China (Squamata: Xenodermatidae).

A new species of xenodermatid snake, Achalinus yunkaiensis J. Wang, Y. Li Y.Y. Wang, sp. nov. was described based on a series of specimens collected from Dawuling Forestry Station located in the Yunkai Mountains of western Guangdong Province. It can be distinguished from known congeners by a significant genetic divergence at the mitochondrial CO1 gene fragment examined (p-distance ≥ 12.0%) and the following combination of characters: (1) dorsal scales strongly keeled, in 23 rows throughout the body, the most outer row on each side smooth and significantly enlarged; (2) tail relatively shorter, TaL/TL ratio 18.5-20.0%; (3) maxillary teeth 20-22; (4) length of suture between internasals subequal to that between the prefrontals; (5) nasal divided into two sections by nasal cleft, posterior one half as long as anterior; (6) loreal elongated, nearly twice as wide as high; (7) supralabials six; (8) infralabials six; (9) temporals 2+2+3 (rarely 2+2+4), the two anterior temporals in contact with eye; (10) ventrals 151-162, subcaudals 49-56 arranged in single row, not paired; (11) cloacal entire; (12) uniform brown (in adults) or black (in juveniles) above, tinged weakly iridescent, with a longitudinal dark-colored vertebral line; (13) light brown (in adults) or greyish white (in juveniles) beneath; and (14) dorsum with a longitudinal dark brown vertebral stripe from posterior margin of parietals to tail tip. Currently, 13 species are known in the genus Achalinus, with seven from mainland China.

A new species of Hemiphyllodactylus (Squamata: Gekkonidae) from Hong Kong.

A new species of gekkonid, Hemiphyllodactylus hongkongensis sp. nov., is described based on a series of specimens collected from Hong Kong SAR, China. The new species can be distinguished from other known congeners by molecular divergence in the mitochondrial ND2 gene and morphological characters including 5-6 chin scales; a manual lamellar formula of 3-3(4)-4-4; a pedal lamellar formula of 3(4)-4(5)-4(5)-4; 24-25 continuous femoral and precloacal pores; 12-15 dorsal scales and 9-10 ventral scales contained in diameter of eye. At present, the genus Hemiphyllodactylus comprises 22 described species.

A new species of Amolops (Anura: Ranidae) from southwestern Guangdong, China.

A new species, Amolops yunkaiensis sp. nov. is described based on a series of specimens from Ehuangzhang Nature Reserve and Yunkaishan Nature Reserve, southwestern Guangdong Province, China. The new species can be distinguished from all known congeners by molecular divergence in the mitochondrial 16S rRNA, 12S rRNA and CO1 genes, and a combination of the following characters: relatively small body size, SVL 31.8-34.1 mm in adult males, 35.2-39.0 mm in adult females; numerous raised large warts on dorsum and flanks; dorsal body olive-brown or light brown with dark brown blotches; absence of vomerine teeth; absence of tarsal glands; presence of a pair of subgular vocal sacs, nuptial spines on the first finger, and sparse translucent tubercles on the lower jaw, forechest, posterior belly and ventral thigh in male. Hence, the genus Amolops contains 52 species, 29 of which occur in China.

Diet of the endangered big-headed turtle Platysternon megacephalum.

Populations of the big-headed turtle Platysternon megacephalum are declining at unprecedented rates across most of its distribution in Southeast Asia owing to unsustainable harvest for pet, food, and Chinese medicine markets. Research on Asian freshwater turtles becomes more challenging as populations decline and basic ecological information is needed to inform conservation efforts. We examined fecal samples collected from P. megacephalum in five streams in Hong Kong to quantify the diet, and we compared the germination success of ingested and uningested seeds. Fruits, primarily of Machilus spp., were most frequently consumed, followed by insects, plant matter, crabs and mollusks. The niche breadth of adults was wider than that of juveniles. Diet composition differed between sites, which may be attributable to the history of illegal trapping at some sites, which reduced the proportion of larger and older individuals. Digestion of Machilus spp. fruits by P. megacephalum enhanced germination success of seeds by about 30%. However, most digested seeds are likely defecated in water in this highly aquatic species, which limits the potential benefit to dispersal. The results of our study can be used by conservation-related captive breeding programs to ensure a more optimal diet is provided to captive P. megacephalum.

A new species of Amolops (Anura: Ranidae) from southern China.

A new species, Amolops albispinus sp. nov. is described based on a series of specimens collected from Mt. Wutong, Shenzhen, Guangdong Province, China. The new species can be distinguished from other known congeners by molecular divergence in the mitochondrial COI and 16S rRNA gene and morphological characters including presence of white conical spines on the lips, loreal and temporal regions, excluding the tympanum; small body, SVL 36.7-42.4 mm in adult males and 43.1-51.9 mm in adult females; very rough dorsal skin of body with numerous raised large warts; olive-brown dorsum with dark brown blotches; strongly developed vomerine teeth; absence of vocal sacs; absence of tarsal glands; absence of dorsolateral folds; presence of circummarginals groove on the disk of first finger; and absence of outer metatarsal tubercles. At present, the genus Amolops contains 51 species, of which 23 occur in China.

[Influence of surface water availability on mammal distributions in Nonggang National Nature Reserve, Guangxi, China].

Surface water is a major limiting factor affecting animal activities in karst ecosystems. From March, 2006 to June, 2007 and from October, 2010 to May, 2011, infra-red camera traps were installed along animal trails and temporary rain pools in Nonggang National Nature Reserve, Guangxi, China, to monitor mammal diversity and relative abundance. In total, 19 species from 17 genera, 12 families, and 5 orders were recorded, including two State Key Protection Class I species, the François' langur (Trachypithecus francoisi) and Assam macaque (Macaca assamensis). Although 42% of species only occurred in one of the microhabitats, differences in species assemblages between trails and pools were not significant. The results of our observation indicated that camera trapping was effective in monitoring medium to large sized mammals, and for recording illegal hunting. In addition, our results suggest that authorities should reinforce patrolling, especially at water pools during the dry season, and eradicate unsustainable extraction of underground water. Moreover, based on the advantages of large inhibited environments to animal species, especially to large predators, we also recommend connecting the three isolated sections of the reserve to promote species recovery and dispersal.