Marko Maričić

Freshwater turtles, although predominantly aquatic, use the terrestrial part of their habitat for migration and egg‐laying. On land, turtles are at risk of being overturned onto their carapace, which can lead to issues such as breathing difficulties, overheating, dehydration, starvation or predation. Thus, the ability to return to an upright position is essential for their survival. So far, the relationship between antipredator behaviour and self‐righting has received limited investigation, and the potential effects of body condition and muscular strength have not yet been assessed in natural populations of turtles. In this study, we investigated the factors influencing locomotor performance and antipredator behaviour in the European pond turtle ( Emys orbicularis ) by testing 436 adult individuals in five remote populations using a self‐righting test after a simulated predator attack. Smaller adults were more successful at self‐righting than larger ones, and individuals with relatively greater muscle strength and better body condition self‐righted more quickly. Our results reveal local adaptation in locomotor performance and antipredator behaviour. For example, turtles from heavily fished areas reacted significantly faster to a simulated predator attack than turtles from areas with little or no fishing. In addition, our results showed that females waited longer to react after a simulated predator attack and were slower to self‐right successfully compared to males. These findings reveal the intricate relationship among morphology, self‐righting performance and antipredator behaviour.

Kotschy’s gecko, Mediodactylus kotschyi, is native to the Eastern part of the Mediterranean Basin and a successful colonizer, with an extensive distribution across the Balkans and outside its native range. In Serbia, it was presumed native in Prizren (Kosovo and Metohija province) and introduced across the remaining territory. To explore the origin of Serbian Kotschy’s gecko, we collected specimens from most of the Serbian populations where the species was recorded and assessed their phylogenetic relationships based on three mtDNA markers (COI, cytb, 16S rRNA) under Maximum Likelihood (ML) and Bayesian Inference (BI) approaches. First, our results support that the specimens found in Serbia belong to M. kotschyi. Second, all populations except Prizren belong to the subspecies M. kotschyi skopjensis. Furthermore, the Italian populations are sister to the specimens from Prizren, suggesting a Balkan origin for these populations, which settled in Apulia likely through ancient human-mediated dispersion. The small genetic differentiation found suggests that Kotschy’s gecko rapidly colonized the Central Balkans, originating from Northern Greece and North Macedonia. The results also suggest a story of multiple, complex (most likely) human-mediated introductions. However, further studies should be conducted to properly elucidate the colonization pathways, and to truly disentangle the potential fast natural range expansion from an anthropogenic dispersion of this gecko species.

Haemogregarines (Apicomplexa: Adeleorina) are the most common and widespread reptilian blood parasites. Haemogregarina stepanowi was the first haemogregarine described from a reptile, the European pond turtle Emys orbicularis, and initial assessments indicated it was widespread across different pond turtle host species across much of Europe, the Middle East and North Africa. However, recent molecular assessments have indicated the presence of multiple genetically distinct forms in North Africa and the Iberian Peninsula, and extensive mixed infections which may be associated with a negative impact on the hosts. Here, we screened two native species, E. orbicularis and Mauremys rivulata, and the introduced Trachemys scripta from Serbia and North Macedonia for haemogregarines by amplifying and sequencing part of the 18S rRNA gene of these parasites, and used a standard DNA barcoding approach to identify leeches, the final host, attached to pond turtles. Our results again demonstrate the occurrence of considerable diversity of parasites in the analysed pond turtle species, and that T. scripta are likely infected by local haemogregarine parasites, and not those that are found in its native range. Leeches were identified as Placobdella costata, part of a lineage from Northern Europe. Mixed infections within pond turtles were again common. Current haemogregarine taxonomy does not reflect the genetic diversity identified, and a full taxonomic reassessment is needed.

The ring-legged earwig Euborellia annulipes (Lucas, 1847) is recorded for the first time on the territory of Serbia. The species was found in the greenhouse of Jevremovac Botanical Garden in Belgrade and represents the second allochthonous invertebrate species registered in this greenhouse, after an exotic millipede. In total, 10 specimens of ring-legged earwig were found in the sections of the greenhouse where tropical and subtropical plants are cultivated. The first checklist of earwigs of Serbia was compiled and notes on autochthonous species are given.

According to international and national legislation European pond turtle and its habitats have been highlighted as priority regarding protection. Due to such status, this species is the subject of population research and active protection throughout its native range, however, systematic research was started only recently on the territory of the Republic of Serbia. Population studies of pond turtles have lasted the longest in our country at Lake Ludaš, where the twelfth research season was marked in August 2022. This paper presents the population parameters processed so far, including: population density, survival rate, gender ratio of adult individuals, as well as gender dimorphism in shell size and body mass. In addition, the threatening factors that were recorded on the terrain, as well as active protection measures that were undertaken or proposed have been described.

Studies of body condition in snakes are generally lacking and were only done on a few species and with limited sample sizes. Additionally, almost no studies considered how different factors affect body condition. We used a large dataset amassed over a 15 year-long ecological study to make a preliminary screening of body condition index (BCI) variation in a metapopulation of dice snakes (Natrix tessellata) in the region of Lake Prespa. We considered how factors such as sex, food, colour morph, locality and time affect BCI. We demonstrate a positive effect of food (relatively less in males), and lower BCI in females. Importantly, there is a strong seasonal effect, summer months having a positive effect as opposed to spring. The results of our study raise important considerations for future studies on snake BCI, but also conservation of freshwater ecosystems.

U ovom radu, prikazujemo ažurirane podatke o distribuciji kompleksa vrsta slepića (Anguis fragilis complex) u Srbiji. Podaci se sastoje iz nalaza objavljenih u literaturi ili na Internetu, zajedno sa prethodno neobjavljenim distribucionim podacima sakupljenim na terenu. Od dve vrste kompleksa prisutne u Srbiji, Anguis fragilis je rasprostranjen u zapadnim i južnim krajevima naše zemlje dok je Anguis colchica prisutan u severoistočnim i istočnim krajevima. U najsevernijim delovima naše zemlje konstatovano je odsustvo obe vrste, zbog nedostatka odgovarajućeg staništa. Nalazi su brojniji u planinsko-kotlinskom regionu i ređi i raštrkaniji u peripanonskom i panonskom regionu, što se delimično može objasniti nesistematskim uzorkovanjem. Lokacija i širina kontaktne zone dve vrste slepića u Srbiji je još uvek nedovoljno poznata. Pretpostavlja se da se pruža duž doline Velike Morave ka jugu a zatim prati granicu između Rodopskog i Karpatsko-Balkanskog planinskog masiva ka jugo-istoku, ali postoje indicije da se hibridna zona nalazi i zapadnije. Postoji izvesno neslaganje, u literaturi, između kontaktne zone predložene na osnovu morfoloških analiza i one predložene na osnovu molekularnih analiza. Ovo ukazuje na potrebu za opsežnijim uzorkovanjem i daljim analizama. Konačno, pošto razdvajanje dve kriptičke vrste slepića do sada nije prepoznato u našoj nomenklaturi, u ovom radu predlažemo zvanične srpske nazive za navedene vrste. Vrsta Anguis fragilis će zadržati standardno srpsko ime "Slepić", dok za vrstu Anguis colchica predlažemo ime "Istočni slepić".