Sexual selection can be a major driving force that favours morphological evolution at the intraspecific level. According to the sexual selection theory, morphological variation may accompany non-random mating or fertilization. Here both variation of linear measurements and variation in the shape of certain structures can significantly influence mate choice in different organisms. In the present work, we quantified sexual behaviour of the millipede Megaphyllum bosniense (Verhoeff, 1897) as characterized by several sequences. These are: mating latency, duration of copulation, contact to copulation time, duration of contact without copulation, time from entrance (time-point when individuals were placed in boxes in which tests occurred) to contact with copulation, and time from entrance to contact without copulation. Further, we analysed the influence of morphological variation (both variation of linear measurements and variation in the shape of several structures) on mating success. Variation of body length, antennal length, length of the walking legs, trunk width, and trunk height was analysed by traditional morphometrics, while variation in size and shape of the antennae, walking legs, head, and gonopods (promeres, opisthomeres) was analysed using geometric morphometrics. More than half of all physical contacts detected among the millipedes resulted in copulation. Based on the value of sexual selection coefficients, preferences toward the previous partner were found to be prevalent in both female and male choice tests. Individuals with different mating status significantly differed in some morphological traits (body mass, head centroid size, head shape, and promere shape). Our study yielded new information about the sexual behaviour of millipedes and variation of morphological traits as a potential basis for mate preferences.
During the past decade, golden jackal populations have substantially increased, yet little is known of their potential for transmitting parasites within animal and human hosts. In the present study, between 2005 and 2010, 447 jackals from six localities in Serbia were examined for intestinal parasites. Two species of trematodes (Alaria alata, Pseudamphistomum truncatum), three nematodes (Toxocara canis, Ancylostoma caninum, Gongylonema sp.), and seven cestodes (Taenia pisiformis, Taenia hydatigena, Multiceps multiceps, Multiceps serialis, Mesocestoides lineatus, Mesocestoides litteratus, Dipylidium caninum) were identified. Pseudamphistomum truncatum and M. serialis species were recorded for the first time. The overall prevalence of parasitic infection was 10.3%. No significant differences were found in the prevalence of infection between males and females (P>0.817), between localities (P>0.502), or with regard to annual cycles (P>0.502). In the infected jackal population, 65% harboured multiple infections and one individual was a host to five different types of parasite species, the highest number of parasites we recorded in a single host. These findings indicate that although the prevalence of gastrointestinal helminths in the jackal population in Serbia is significantly lower than expected from earlier studies, further monitoring is required given the jackal's rapid population increase.
Plants are exposed to increasing levels of diverse human activities that have profound effects on their overall morphology and, specifically, on leaf morphology. Anthropogenic disturbances in urban and suburban forest recreational sites are attracting growing research interest. To explore the persisting recreational impact on leaf shape and size, we conducted a field study on the dioecious forb Mercurialis perennis L. (Euphorbiaceae), typical for undisturbed understory communities. We selected adjacent sites in a suburban forest, which experience contrasting regimes of disturbance by human trampling under otherwise concordant natural conditions. Patterns of leaf shape and size variation and putative sex-specific response to disturbance were analyzed using a geometric morphometric approach. In addition to leaf-level data, plant height, internode and leaf number were analyzed to explore the same response at the whole-plant level. The results show significant variations associated with disturbance at both levels: plants growing under a heavy disturbance regime had shorter stems with a greater number of wider and shorter leaves. Significant differences between sites were also found for leaf size, with larger leaves observed in an undisturbed site. The effects of sex and sex x site interaction on leaf size and shape were nonsignificant, pointing to the absence of sexual dimorphism and sex-specific response to disturbance. Contrary to leaf shape and size, all three analyzed shoot traits showed highly significant sexual dimorphism, with male plants being higher and having higher leaf and internode count.
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