Species History Masks the Effects of Human-Induced Range Loss – Unexpected Genetic Diversity in the Endangered Giant Mayfly Palingenia longicauda

Abstract

Freshwater biodiversity has declined dramatically in Europe in recent decades. Because of massive habitat pollution and morphological degradation of water bodies, many once widespread species persist in small fractions of their original range. These range contractions are generally believed to be accompanied by loss of intraspecific genetic diversity, due to the reduction of effective population sizes and the extinction of regional genetic lineages. We aimed to assess the loss of genetic diversity and its significance for future potential reintroduction of the long-tailed mayfly Palingenia longicauda (Olivier), which experienced approximately 98% range loss during the past century. Analysis of 936 bp of mitochondrial DNA of 245 extant specimens across the current range revealed a surprisingly large number of haplotypes (87), and a high level of haplotype diversity (). In contrast, historic specimens (6) from the lost range (Rhine catchment) were not differentiated from the extant Rába population (, ), despite considerable geographic distance separating the two rivers. These observations can be explained by an overlap of the current with the historic (Pleistocene) refugia of the species. Most likely, the massive recent range loss mainly affected the range which was occupied by rapid post-glacial dispersal. We conclude that massive range losses do not necessarily coincide with genetic impoverishment and that a species' history must be considered when estimating loss of genetic diversity. The assessment of spatial genetic structures and prior phylogeographic information seems essential to conserve once widespread species.

Differences in oviposition strategies between two ecotypes of the endangered myrmecophilous butterfly Maculinea alcon (Lepidoptera: Lycaenidae) under unique syntopic conditions

“…Maintaining intra‐specific diversity in the case of threatened taxa is an important issue for nature conservation. Within‐species variations among ecotypes may be important for preserving endangered species, due to the ecotypes’ differential response to environmental changes (Bálint et al ., ; Sielezniew et al ., ). Although egg‐laying behaviour has already been studied in the case of both forms of M. alcon (see Dolek et al ., ; Árnyas et al ., , for M .…”

“…Maintaining intra-specific diversity in the case of threatened taxa is an important issue for nature conservation. Within-species variations among ecotypes may be important for preserving endangered species, due to the ecotypes' differential response to environmental changes (B alint et al, 2012;Sielezniew et al, 2012). Although egglaying behaviour has already been studied in the case of both forms of M. alcon (see Dolek et al, 1998;Arnyas et al, 2006Arnyas et al, , 2009Van Dyck et al, 2000;Nowicki et al, 2005;F€ urst & Nash, 2010;Van Dyck & Regniers, 2010 for M. alcon; for both), it has never been analysed in syntopic conditions and a comparison between the egg-laying behaviour of the two ecotypes has not been made.…”

Integrating molecular tools into freshwater ecology: developments and opportunities

“…Freshwater ecology has a long history of describing spatial patterns of biological diversity (Allan & Castillo, ), and molecular tools have provided a great deal of information on genetic diversity (Gustafson et al ., ; Bálint et al ., , ) and population structure of freshwater species (Bunn & Hughes, ; Monaghan et al ., ; Wilcock, Nichols & Hildrew, ). The study of genetic and species diversity in fresh waters has often been carried out separately, despite several conceptual and methodological similarities (Etienne & Olff, ; Hu, He & Hubbell, ).…”

Reintroduction of freshwater macroinvertebrates: challenges and opportunities

“…for different species of crayfish see Fratini et al, , Dawkins & Burnham, and Schrimpf et al, ]. Generally, the founder population(s) selected for a reintroduction should be the genetically closest to the original wild population, and museum samples or environmental samples stored in laboratories may provide a wealth of information if a given taxon is extinct on a larger scale (Wandeler, Hoeck & Keller, ; Bálint et al, ). If no genetic information is available from the extinct population, the founder population should preferably stem from the same catchment or at least the closest geographic neighbour population, ideally considering the phylogeographic structure observed in related taxa if such information is available.…”

“…We identified 16 studies on reintroductions of aquatic insects that provided monitoring for more than one generation, of which only half were assessed as at least partially successful (Table ). For instance, the mayfly Palingenia longicauda (Palingeniidae; Ephemeroptera) was formerly widely distributed in Europe, but now occurs in only 2% of its former range (Tittizer et al, ; Bálint et al, ). Reintroductions of P. longicauda were attempted twice in the River Lippe (a tributary of the River Rhine in Germany), where this species still occurred by the end of the 19th century (Tittizer et al, ).…”