A global reptile assessment highlights shared conservation needs of tetrapods.

Comprehensive assessments of species' extinction risks have documented the extinction crisis1 and underpinned strategies for reducing those risks2. Global assessments reveal that, among tetrapods, 40.7% of amphibians, 25.4% of mammals and 13.6% of birds are threatened with extinction3. Because global assessments have been lacking, reptiles have been omitted from conservation-prioritization analyses that encompass other tetrapods4-7. Reptiles are unusually diverse in arid regions, suggesting that they may have different conservation needs6. Here we provide a comprehensive extinction-risk assessment of reptiles and show that at least 1,829 out of 10,196 species (21.1%) are threatened-confirming a previous extrapolation8 and representing 15.6 billion years of phylogenetic diversity. Reptiles are threatened by the same major factors that threaten other tetrapods-agriculture, logging, urban development and invasive species-although the threat posed by climate change remains uncertain. Reptiles inhabiting forests, where these threats are strongest, are more threatened than those in arid habitats, contrary to our prediction. Birds, mammals and amphibians are unexpectedly good surrogates for the conservation of reptiles, although threatened reptiles with the smallest ranges tend to be isolated from other threatened tetrapods. Although some reptiles-including most species of crocodiles and turtles-require urgent, targeted action to prevent extinctions, efforts to protect other tetrapods, such as habitat preservation and control of trade and invasive species, will probably also benefit many reptiles.

First molecular detection of Hemolivia and Hepatozoon parasites in reptile-associated ticks on Iriomote Island, Japan.

Hepatozoon and Hemolivia are members of the haemogregarines and are reported in reptiles and reptile-associated ticks. However, no studies have reported on Hepatozoon and Hemolivia in Japanese reptile-associated ticks. This study aimed to molecularly identify and to characterize Hepatozoon and Hemolivia in Japanese reptile-associated ticks, Amblyomma geoemydae (Cantor, 1847) and Amblyomma nitidum (Hirst & Hirst, 1910). A total of 41 and 75 DNA samples from A. geoemydae and A. nitidum ticks, respectively, were used for screening of Hepatozoon and Hemolivia with polymerase chain reaction targeting 18S rDNA. As a result, Hemolivia and Hepatozoon were detected in two A. geoemydae and one A. nitidum, respectively. The sequences of Hemolivia spp. showed a 99.5% (1,050/1,055 bp) identity with Hemolivia parvula (KR069083), and the Hemolivia spp. were located in the same clade as H. parvula in the phylogenetic tree. The sequences of Hepatozoon sp. showed a 98.4% (1,521/1,545 bp) identity with Hepatozoon colubri (MN723844), and the Hepatozoon sp. was distinct from validated Hepatozoon species in the tree. Our findings highlight the first molecular record of Hemolivia in Japan and present the first detection of Hepatozoon in A. nitidum. Further investigations on these tick-borne protozoa are required to understand their life cycle and pathogenicity.

Rickettsia spp. and Ehrlichia spp. in Amblyomma ticks parasitizing wild amphibious sea kraits and yellow-margined box turtles in Okinawa, Japan.

Recently, several tick-borne pathogens were detected in reptile-associated ticks. However, studies on the microorganisms in reptile-associated ticks in Japan are limited. This molecular survey thus aimed to identify and characterize tick-borne pathogens (Rickettsiaceae and Anaplasmataceae) in reptile-associated ticks in Japan. In total, 77 Amblyomma nitidum and 104 Amblyomma geoemydae were collected from wild amphibious sea kraits (Laticauda semifasciata, Laticauda colubrina, and Laticauda laticaudata) and from yellow-margined box turtles (Cuora flavomarginata evelynae), respectively. Conventional polymerase chain reaction was performed using the DNA extracted from the ticks to detect the selected pathogens. Sequencing analysis of four Rickettsia genes (gltA, ompA, ompB, and sca4) led to the identification of a putative novel Rickettsia sp. and Rickettsia aeschlimannii-like rickettsia in A. nitidum and A. geoemydae, respectively. Sequencing analysis of gltA and groEL of Anaplasmataceae revealed that the Ehrlichia spp. in these ticks were novel and related to Candidatus Ehrlichia occidentalis. This is the first study on the microorganisms in A. nitidium and the first record of Rickettsia and Ehrlichia in A. geoemydae. Further studies are required to understand their pathogenicity to humans and animals and their life cycle in the wild.

Comparison of freshwater discrimination ability in three species of sea kraits (Laticauda semifasciata, L. laticaudata and L. colubrina).

Three species of amphibious sea kraits (Laticauda spp.) require drinking freshwater to regulate water balance. The extent of terrestriality is known to differ among them. Species with higher extent of terrestriality would drink freshwater accumulated on land, whereas less terrestrial species would rely totally on freshwater that runs into the sea. Consequently, we predicted that the latter species might have a better ability to follow the flow of freshwater or lower salinity water in the sea than the former. We investigated the freshwater discrimination ability of three sea krait species, using a Y-maze apparatus. We found that Laticauda semifasciata and Laticauda laticaudata, less terrestrial species, followed freshwater significantly more frequently than seawater, whereas Laticauda colubrina, more terrestrial species, unbiasedly selected freshwater and seawater. This result supports our prediction and suggests that less terrestrial sea kraits more efficiently access freshwater sources in the sea than highly terrestrial sea kraits. It is likely that behavioral rehydration systems vary among sea kraits in relation to their terrestrial tendency.