Blood cells and hematological parameters of Chiala Mountain Salamander, Batrachuperus karlschmidti (Urodela, Hynobiidae)

Hematological parameters are essential indices for assessing the function of blood and reflecting not only the health status of animal but also their physiological adaptation to the environment. Herein, the composition of blood cells and the hematological parameters of wild Batrachuperus karlschmidti were examined for the first time, and the effects of sex, body size, body mass, and age on the hematological parameters were explored. The morphology and morphometric data of the blood cells, as well as the hematological parameters, of B. karlschmidti were slightly differ from those of its congener. However, hematological differences between sexes were only found in erythrocyte and leukocyte count, and mean cell volume (MCV), which possibly reflecting the need for better oxygen distribution and stronger immune protection for reproduction. Hematocrit (Hct) and mean cell hemoglobin (MCH) were strongly dependent on body mass. These also might have been attributed to higher oxygen requirements with larger body masses. This is a pilot project exploring the hematology of this species that may help establish hematological parameters in future for supporting species protection and monitoring studies, as well as help understanding the physiological adaptation of this species.

Intraspecific variation in hematological parameters and erythrocyte size among three populations of Batrachuperus tibetanus (Caudata: Hynobiidae)

Intraspecific variation is a common phenomenon in nature, but to date, research on such variation in hematological traits of urodeles remains scarce. To compare intraspecific variation in hematological traits among populations, and explore whether snout–vent length (SVL) and body mass influence hematological traits, hematological parameters and erythrocyte size in 58 mature Batrachuperus tibetanus specimens belonging to three populations (Xihe, Meixian and Taibai) in northwestern China were analyzed. There were no sexual differences in any hematological trait for all populations. No hematological traits differed significantly between the Meixian and Taibai populations, but significantly lower values of erythrocyte count (RBC), hemoglobin (Hb), hematocrit (Hct), erythrocyte length (L), and erythrocyte area (A), as well as a significantly higher leukocyte count (WBC) were observed in the Xihe population compared with the other two. Linear regression analyses showed that significant relationships were present between SVL and Hb, RBC, Hct, and L; and body mass and Hb, RBC, Hct, and L. However, SVL and WBC were negatively correlated. Only L differed significantly among populations when accounting for the effects of SVL and body mass. Hb, RBC, WBC, and Hct variations among populations possibly contribute to differences in SVL or body mass, and erythrocyte size (L and A) variations are perhaps attributable to differences in lower Hb, RBC, and Hct; these variations are not the result of differences in habitat variables. Our results provide a foundation for understanding physiological intraspecific variation.

Blood cells and hematological parameters of the mountain dragon, Diploderma micangshanensis (Squamata: Lacertilia: Agamidae)

Hematological characteristics reflect the health status of animals and their physiological adaptation to the environment. However, few studies focused on the species of Diploderma. In this study, the blood cells and the hematological parameters of Diploderma micangshanensis, a species endemic to China, were examined based on 48 healthy adult (32 males and 16 females). The blood cells and hematological parameters of D. micangshanensis were similar to those of other lizard species. Although the values of erythrocyte morphometric characters and hematological parameters varied between males and females, the differences were only significant in the case of the hematocrit and erythrocyte size, which may allow for higher oxygen availability in males. Hemoglobin, mean corpuscular hemoglobin concentration, and mean corpuscle volume were strongly affected by the snout-vent length and/or body mass, which reflect the physiological adaptation to the oxygen requirement of different individuals. This is the first report of hematological data from a species of Diploderma, and the results will provide data for research on the adaptive evolution and health assessment in this species and other congeners.

The First Transcriptome Assembly of Yenyuan Stream Salamander (Batrachuperus yenyuanensis) Provides Novel Insights into Its Molecular Evolution

The Yenyuan stream salamander (Batrachuperus yenyuanensis) has been previously evaluated with regards to phylogeny, population genetics, and hematology, but genomic information is sparse due to the giant genome size of salamanders which contain highly repetitive sequences, thus resulting in the lack of a complete reference genome. This study evaluates the encoding genetic sequences and provides the first transcriptome assembly of Yenyuan stream salamander based on mixed samples from the liver, spermary, muscle and spleen tissues. Using this transcriptome assembly and available encoding sequences from other vertebrates, the gene families, phylogenetic status, and species divergence time were compared or estimated. A total of 13,750 encoding sequences were successfully obtained from the transcriptome assembly of Yenyuan stream salamander, estimated to contain 40.1% of the unigenes represented in tetrapod databases. A total of 88.79% of these genes could be annotated to a biological function by current databases. Through gene family clustering, we found multiple possible isoforms of the Scribble gene-whose function is related to regeneration-based on sequence similarity. Meanwhile, we constructed a robust phylogenetic tree based on 56 single-copy orthologues, which indicates that based on phylogenetic position, the Yenyuan stream salamander presents the closest relationship with the Chinese giant salamander (Andrias davidianus) of the investigated vertebrates. Based on the fossil-calibrated phylogeny, we estimated that the lineage divergence between the ancestral Yenyuan stream salamander and the Chinese giant salamander may have occurred during the Cretaceous period (~78.4 million years ago). In conclusion, this study not only provides a candidate gene that is valuable for exploring the remarkable capacity of regeneration in the future, but also gives an interesting insight into the understanding of Yenyuan stream salamander by this first transcriptome assembly.