Two cases of bites by a South African psammophiid snake, Psammophylax rhombeatus, are described and analyzed. These are the first detailed reports of local envenoming by a Psammophylax spp. While ...handling a wild-collected 1 m P. rhombeatus, the snake inflicted a protracted bite proximal to the metacarpophalangeal joint of digit #5, left hand of a 24−year-old male amateur herpetologist. Local edema persisted for three days, but no pain or other signs or symptoms including non-specific autonomic effects (e.g. headache, nausea) occurred. In a second case, a 28−year-old male herpetologist-photographer was repositioning a 0.58 m female P. rhombeatus in order to photograph the snake and her egg clutch, when the snake bit the metacarpophalangeal joint of digit #5, left hand, and briefly advanced its jaws. The bite caused mild local pain, progressive edema of the left hand, and arthralgia; resolution required almost 1 week. Bites from non-front-fanged snakes such as these by P. rhombeatus are uncommonly reported in comparison with those described for front-fanged snakes (e.g. Viperidae, Elapidae). Therefore, documentation of bites even with minimal effects provides information essential for the construction of an accurate medical risk profile for these less-known species.
•Historical review of anecdotal reported bites caused by Psammophylax spp.•Brief inventory of the genus Psammophylax (Psammophiidae).•Description of two cases of local envenoming by the spotted grass snake or Skaapsteker, Psammophylax rhombeatus.•Victims reported similar progressive local edema, functional limitation of manual dexterity, and resolution within 1 week.
The article considers the comparative analysis of the functional activity of mitochondria isolated from the liver of grass snakes,
Natrix natrix
(Linnaeus, 1758) that were kept at different ...temperatures (23–26 °C and 4-5 °C). It was found that liver mitochondria of hypothermia-exposed grass snakes are characterized by weak coupling of oxidative phosphorylation as compared to mitochondria of active animals which is caused by inhibition of succinate-fuelled respiration in ADP-stimulated state, as well as by activation of basal non-phosphorylating rate. Inhibition of mitochondrial respiration in hibernating animals is associated with a decrease in the activity of the respiratory chain complexes of organelles. A significant decrease in the rate of K
+
transport in the liver mitochondria of hibernating animals has been established. Under these conditions, a decrease in the calcium capacity of the organelles was also revealed, which indicates a decrease in the resistance of the mitochondria of hibernating animals to the induction of the Ca
2+
-dependent mitochondrial pore. All these changes in the functional activity of mitochondria are observed on the background of increasing H
2
O
2
production as well as increasing the proportion of polyunsaturated fatty acids in phospholipid composition of mitochondrial membranes, which are the targets of reactive oxygen species. It can lead to increased formation of lipid peroxides and activation of destructive processes associated with the induction of Ca
2+
-dependent mitochondrial pore.
Most embryos of squamates use their egg tooth to facilitate hatching when their development is completed. After they are out of the shell, this tooth is shed and, in the case, of the grass snake ...(Natrix natrix), not replaced by a successor teeth. The structure of this transient tooth resembles the development and histology of the regular teeth of vertebrates. Morphological, histological and scanning electron microscopic observations indicated that the egg tooth of the grass snake has four developmental phases. Like the teeth of other vertebrate species, it undergoes oral epithelium thickening as well as the bud, cap and bell phases. However, due to the specialised function it performs, the egg tooth differs significantly from the other teeth both in its morphology and development. The egg tooth of Natrix natrix embryos is an unpaired true tooth, as in most squamates. Our study indicated that the egg tooth started its development in the rostral part of the snout by the thickening of the oral epithelium and there was a condensation of mesenchyme underneath it. It formed very early, around developmental stage III, at approximately the same time as the null-generation teeth. After the thickening of the oral epithelium, only one tooth germ is formed, in contrast to lizards in which two germs can be observed during their embryonic life; however, in the course of development, one regressed and the other shifted into the midline position and developed into the functional egg tooth. The next step in the egg tooth development was the differentiation of the enamel organ and the dental papilla. Three layers of the enamel organ developed – the inner enamel epithelium, the stellate reticulum and the outer enamel epithelium, while a superficial layer of the dental papilla differentiated into the odontoblasts. The egg tooth was ready to erupt when its development ended at developmental stage XII, after the hard tissues developed.
The aim of the article is to identify and explain the mythical images used in Saulius Tomas Kondrotas’ novel “The Look of a Grass-Snake”. By transforming pagan and Christian mythical systems, the ...writer contrasts them with rational thinking. In “New Age“ there is no place for myths and the meanings of figurative language. The mythical dimension in the work is understood as a way of perceiving the world that contradicts the modern idea of progress. S. T. Kondrotas also transforms the meanings of archetypal figures such as fire, sun or grass-snake in his novel. The concepts of life, death, or rebirth gain the different perspectives from archaic and modern world. New mythical dimension allows us to reconsider existential phenomena of human existence in a new light. In this way, the Baltic worldview extends its life in works of art, and the literature, which contains mythical elements, becomes a modern version of the myth.
Psammophylax (Fitzinger 1843) is a widespread yet poorly studied genus of African grass snakes. A genetic phylogeny of six of the seven species was estimated using multiple phylogenetic and ...distance‐based methods. To support the genetic analyses, we conducted morphological analyses on the body (traditional morphology) and head (geometric morphometrics) separately. Phylogenetic analyses recovered a similar topology to past studies, but with better resolution and node support. We found substantial genetic structuring within the genus, supported by significantly different head shapes between P. a. acutus and other Psammophylax. Psammophylax a. acutus was recovered as sister to its congeners, and sequence divergence values and morphometrics supported its recognition as a new genus. Increased sampling in East Africa (Tanzania, Kenya, and Ethiopia) revealed that Psammophylax multisquamis is polyphyletic, necessitating the description of a new, morphologically cryptic species from northern Tanzania. The distribution of P. multisquamis sensu stricto is likely restricted to Kenya and Ethiopia. The study has further resolved multiple aspects of Psammophylax systematics, including the taxonomic validity of two central African subspecies, P. variabilis vanoyei (Laurent 1956) and P. tritaeniatus subniger (Laurent 1956). Inclusion of specimens from the more remote parts of Africa, in future analyses, may result in the recovery of additional diversity within Psammophylax.
Psammophylax (Fitzinger 1843) is a widespread grass snake endemic to Africa. A genetic phylogeny of six of the seven species was estimated using multiple phylogenetic and distance‐based methods. Psammophylax a. acutus (A) was recovered as sister to its congeners, and sequence divergence values and morphological analysis (2D morphometrics) supported its recognition as a new genus. Increased sampling in East Africa revealed that Psammophylax multisquamis is polyphyletic, necessitating the description of a new, morphologically cryptic species from northern Tanzania (B).
Reptiles are declining in many parts of the world, mainly due to habitat loss and environmental change. A major factor in this is availability of suitable food. For many animals, dietary requirements ...shift during developmental stages and a habitat will only be suitable for conserving a species if it supports all stages. Conventional methods for establishing diet often rely on visual recognition of morphologically identifiable features of prey in faeces, regurgitation or stomach contents, which suffer from biases and poor resolution of taxa. DNA‐based techniques facilitate noninvasive analysis of diet from faeces without these constraints. We tested the hypothesis that diet changes during growth stages of smooth snakes (Coronella austriaca), which have a highly restricted distribution in the UK but are widespread in continental Europe. Small numbers of the sympatric grass snake (Natrix natrix) were analysed for comparison. Faecal samples were collected from snakes and prey DNA analysed using PCR, targeting amphibians, reptiles, mammals and invertebrates. Over 85% of smooth snakes were found to have eaten reptiles and 28% had eaten mammals. Predation on mammals increased with age and was entirely absent among juveniles and subadults. Predation on reptiles did not change ontogenetically. Smooth snakes may, therefore, be restricted to areas of sufficiently high reptile densities to support young snakes.
Aggregations (e.g. group basking) by snakes are usually limited to specific life cycle phases (e.g. mating) or are a consequence of drastic environmental changes (e.g. habitat destruction), high prey ...densities or highly limited resources within an environment (e.g. basking sites, wintering dens). Here, we report intra- and interspecific observations of four reptile species (primarily
Natrix natrix
and
Vipera berus
) sharing basking sites at the confluence of the rivers Dunajec and Poprad near the town of Stary Sącz in southern Poland. From a total of 84 records in the field between 2020–2022, there were 11 interactions from 24 July 2020 to 1 May 2022. Previous studies have indicated direct competition or interference in many species, which we did not observe. There is a noticeable lack of such observations of microhabitat sharing for basking between squamate species in scientific literature. Hence, the accumulation of such observations has the potential to reveal new insights into the behaviour and ecology of
N. natrix
and
V. berus
.
The critically endangered Cyprus grass snake (
) has been studied for the past 25 years. Although the need for a complete survey on the distribution of its population, outside the strict boundaries ...of the known mountainous localities, had been stressed, such an effort has not been conducted to date. In this study, we used a rapid survey approach to investigate possible sightings of the species upstream of the known distribution in the Troodos Mountains. We are presenting evidence from 13 sightings of the species that expand the previously known distribution in Cyprus by nearly 70%. This is the first time that new localities for the critically endangered
have been reported since the rediscovery of the species in 1992 and the extensive work that followed. Almost all new localities were discovered outside of the currently known species distribution, while individuals were found, for the first time, within the Natura 2000 site of Dasos Machaira (CY2000004) with indications of healthy populations in the area. New localities were recorded within watersheds of the Pediaios and Gialias Rivers, the first sightings outside of Serrachis watershed, indicating an even broader distribution of the species in the Troodos region. The importance of sparse springs within systems of ephemeral streams is highlighted as an exceptional niche for the population in the region. We are discussing the importance of our findings for the conservation of the species and propose targeted conservation actions that will highly improve connectivity of the populations in the region. We underline the necessity of expanding the research on this critically endangered subspecies, based on current findings, so as to fully comprehend its ecology and distribution range in the region.
We analyzed the development of the pancreatic ducts in grass snake Natrix natrix L. embryos with special focus on the three-dimensional (3D)-structure of the duct network, ultrastructural ...differentiation of ducts with attention to cell types and lumen formation. Our results indicated that the system of ducts in the embryonic pancreas of the grass snake can be divided into extralobular, intralobular, and intercalated ducts, similarly as in other vertebrate species. However, the pattern of branching was different from that in other vertebrates, which was related to the specific topography of the snake's internal organs. The process of duct remodeling in Natrix embryos began when the duct walls started to change from multilayered to single-layered and ended together with tube formation. It began in the dorsal pancreatic bud and proceeded toward the caudal direction. The lumen of pancreatic ducts differentiated by cavitation because a population of centrally located cells was cleared through cell death resembling anoikis. During embryonic development in the pancreatic duct walls of the grass snake four types of cells were present, that is, principal, endocrine, goblet, and basal cells, which is different from other vertebrate species. The principal cells were electron-dense, contained indented nuclei with abundant heterochromatin, microvilli and cilia, and were connected by interdigitations of lateral membranes and junctional complexes. The endocrine cells were electron-translucent and some of them included endocrine granules. The goblet cells were filled with large granules with nonhomogeneous, moderately electron-dense material. The basal cells were small, electron-dense, and did not reach the duct lumen.
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