1. The topography of the organic components (conchiolin) has been investigated on positive, postshadow-cast, formvar, and carbon replicas of mother-of-pearl from shells of a Cephalopod, of two Gastropods, and of six Pelecypods. All these shells are characterized by a true nacreous inner shell layer. 2. The material included normal shell surfaces, fragments of cleavage obtained by fracture, and ...

We describe the epidemiology of the protostrongylid parasites Parelaphostrongylus odocoilei and Protostrongylus stilesi in Dall's sheep (Ovis dalli dalli) from the Mackenzie Mountains, Northwest Territories, Canada (65 degrees N; 128 degrees W). Peak numbers of 1st-stage larvae of both parasites were shed by Dall's sheep on their winter range from March until May. In larval development experime...

BACKGROUND Developmental instability of shelled gastropods is measured as deviations from a perfect equiangular (logarithmic) spiral. We studied six species of gastropods at 'Evolution Canyons I and II' in Carmel and the Galilee Mountains, Israel, respectively. The xeric, south-facing, 'African' slopes and the mesic, north-facing, 'European' slopes have dramatically different microclimates and ...

Tributyltin pollution from antifouling paint is well known to disrupt the endocrine system in female marine gastropods. The masculinization of females, including the aberrant growth of a penis and vas deferens and occlusion of the capsule gland, has been reported primarily in neogastropods and is particularly well documented in muricids. Compared to temperate areas, few studies of imposex have ...

Changes in nutrient loading and invasive species are among the strongest human-driven disturbances in freshwater ecosystems, but our knowledge on how they affect the biodiversity of lakes is still limited. We conducted a detailed historical analysis of the mollusc community of Oneida Lake based on our comprehensive lakewide study in 2012 and previous surveys dating back to 1915. In the early 20...

INTRODUCTION A small group of Gastropods possessing giant neurons have long been used to study a wide variety of fundamental neurophysiological phenomena. However, the majority of gastropods do not have large neurons but instead have large numbers of small neurons and remain largely unstudied. We explored neuron size and rate of increase in neuron numbers in the Chinese mud snail, Cipangopaludi...

Endozoochory plays a prominent role for the dispersal of seed plants. However, for most other plant taxa it is not known whether this mode of dispersal occurs at all. Among those other taxa, lichens as symbiotic associations of algae and fungi are peculiar as their successful dispersal requires movement of propagules that leaves the symbiosis functional. However, the potential for endozoochorou...

We aimed to determine the effects of water level and habitat heterogeneity on gastropod fauna in littoral zone, differentiation functional feeding guilds (FFG) gastropods. Two periods were analyzed: 2012 (low level, LWL) 2013 (high HWL) zone two shallow waterbodies (Sutla backwater, NW Croatia). Waterbody S1, covered with Ceratophyllum demersum, was sampled macrophyte stands, benthal area, whil...