Krystyna Szybiak

Anatomical and histological structure of the spermoviduct in the ovoviviparous snail Ruthenica filograna (Pulmonata, Clausiliidae)

The spermoviduct is a multifunctional part of the hermaphroditic reproductive system of stylommatophoran pulmonates. In this study, the anatomical and histological features of the spermoviduct in the ovoviviparous Ruthenica filograna are described for the first time. The spermoviduct is composed of three grooves that are not fully separated: the oviductal channel, autospermiduct, and allospermiduct. The wall of each groove is composed of specific subepithelial glandular cells and non-secretory epithelial cells. The prostatic gland is well developed in the proximal part of the spermoviduct and connected to the autospermiduct. In the distal part, the autospermiduct diverges, forming a free vas deferens, while the rest of the spermoviduct becomes a free oviduct. Initially, the free oviduct still contains the allospermiduct and the oviductal channel. Along the spermoviduct is a small diverticulum, that in the proximal section adheres to the allospermiduct, remaining an independent duct, opening into the bursa copulatrix stalk. The reproductive system of R. filograna is similar to those of semitriaulic Stylommatophora, but the allospermiduct, unlike in Helix species, continues in the distal part of the spermoviduct and in the proximal part of the free oviduct.

Effect of urbanization on centipede (Chilopoda) diversity in the Wielkopolska-Kujawy Lowlands of western Poland

Over fifty years of research data from various sources were compiled and analyzed in order to determine the effect of urbanization on centipede diversity in the Wielkopolska-Kujawy Lowlands of western Poland. Urbanization has had a significant effect on species composition and community structures. However, it has not reduced overall species richness and diversity in the centipede fauna. The centipede fauna from built-up areas was found to be rich and varied. The habitats with the highest levels of species richness were the city of Poznań and the beech forests in the surrounding region.

Reproduction and shell growth in two clausillids with different reproductive strategies

Abstract Reproduction and shell growth in two snail species from the family Clausiliidae differing in reproductive strategies were examined under laboratory conditions. The specimens of the oviparous species Clausilia bidentata and the ovoviviparous species Ruthenica filograna were collected in natural populations coexisting in the same area. The total time of shell growth in the specimens of C. bidentata ranged from 77 to 178 days and in R. filograna specimens ranged between 108 and 194 days. Under breeding conditions the species differed in the timing of reproduction and mortality. However the proportion of the number of surviving specimens to the number of eggs laid by C. bidentata or juveniles born by R. filograna proved to be similar.