Predictors of shell size in long‐lived lake gastropods

Abstract

Aim To investigate shell size variation among gastropod faunas of fossil and recent long-lived European lakes and discuss potential underlying processes.Location Twenty-three long-lived lakes of the Miocene to Recent of Europe.Methods Based on a dataset of 1412 species of both fossil and extant lacustrine gastropods, we assessed differences in shell size in terms of characteristics of the faunas (species richness, degree of endemism, differences in family composition) and the lakes (surface area, latitude and longitude of lake centroid, distance to closest neighbouring lake) using multiple and linear regression models. Because of a strong species-area relationship, we used resampling to determine whether any observed correlation is driven by that relationship.Results The regression models indicated size range expansion rather than unidirectional increase or decrease as the dominant pattern of size evolution. The multiple regression models for size range and maximum and minimum size were statistically significant, while the model with mean size was not. Individual contributions and linear regressions indicated species richness and lake surface area as best predictors for size changes. Resampling analysis revealed no significant effects of species richness on the observed patterns. The correlations are comparable across families of different size classes, suggesting a general pattern.Main conclusions Among the chosen variables, species richness and lake surface area are the most robust predictors of shell size in long-lived lake gastropods. Although the most outstanding and attractive examples for size evolution in lacustrine gastropods come from lakes with extensive durations, shell size appears to be independent of the duration of the lake as well as longevity of a species. The analogue of long-lived lakes as 'evolutionary islands' does not hold for developments of shell size because different sets of parameters predict size changes.

Description of a new species of Mediotipula from Albania, with consideration of the eastern Mediterranean as a diversity hotspot (Diptera, Tipulidae)

“…We hypothesised a restricted distribution of the species, most probably as a result of the presently isolated distribution of humid ecosystems in the Mediterranean area. Several aquatic and semi-aquatic organisms have similarly restricted or fragmented distributions in the Mediterranean area, which most probably followed the general decline of humid ecosystems during the late Cainozoic and simultaneous retreat in highly-fragmented local populations (sometimes highly-divergent evolutionary significant units, or in many cases distinct species) ( Fernandez-Mazuecos et al 2014 , Godunko et al 2017 , Neubauer et al 2016 ).…”

The fossil record of freshwater Gastropoda – a global review

“…Apart from the sometimes astounding levels of species diversity, the most extraordinary cases of shape and size evolution in freshwater gastropods derive from long-lived lakes. Notable examples include: (i) the huge, limpet-shaped lymnaeids of the subfamily Valencienniinae, which evolved in the Late Miocene in Lake Pannon from small ancestors of the genus Radix (Gorjanovi c- Kramberger, 1923;Taktakishvili, 1967;Neubauer et al, 2016a;Neubauer, 2023); (ii) the Middle Miocene Gyraulus species flock in the Steinheim Basin (Hilgendorf, 1867;Mensink, 1984;Rasser, 2013); (iii) the Plio-Pleistocene Viviparus species flock in Lake Slavonia (Neumayr & Paul, 1875); (iv) the middle Miocene to Pliocene 'Kosovia'-Popovicia lineage (Bulinidae) in Serbia and Kosovo, showing the step-wise evolution of sculptured sinistral Bulinus to pseudodextral, planorbiform morphologies (Atanackovi c, 1959;Popovi c, 1964;Miloševi c, 1970;Neubauer et al, 2017); and (v) the cochliopid radiation in the Miocene Pebas wetland in South America (Wesselingh, 2006a,b;Wesselingh & Renema, 2009).…”

From marginal outcrops to basin interior: a new perspective on the sedimentary evolution of the eastern Pannonian Basin

“…The brackish-water Lake Pannon, characterized by an endemic biota, covered the Pannonian Basin System from the Vienna Basin in the west to the Transylvanian Basin in the east, encompassing an area of ca. 230,000 km 2 (Neubauer et al 2016). During the first few million years of its geological history, the lake had a highly articulated shoreline with many islands and peninsulas.…”