Figure 1.
Long-tailed mayfly – Palingenia longicauda.
A – freshly emerged Long-tailed mayfly (photo: A. Móra); B – males surrounding a female in a characteristic flower-like structure (“tiszavirág”) (photo: A. Orosz); C – the synchronized sunset swarming of millions of imagines (photo: L. Polyák).
Figure 2.
Former (light) and present (dark) distribution of P. longicauda.
Approximate collecting locality of the historic Rhine specimens is marked with a star. Subset: collection sites of extant specimens, numbered according to Table S1. The former distribution range of the species was reconstructed after [19], [20].
Figure 3.
Relationships of P. longicauda haplotypes.
A – median-joining networks of combined mtCOI and 16S haplotypes of successfully amplified extant specimens. B – median-joining networks of short mtCOI haplotypes of all extant and 24 historic specimens (Körös, Tisza, Maros and Bodrog marked as belonging to the Tisza catchment). Each circle represents a haloptype. The size of the circle indicates the frequency of the haplotype. Connecting lines represent single nucleotide substitutions.
Figure 4.
Demographic changes of P. longicauda populations.
The black line shows the mean population size, estimated by Bayesian skyline plot. Grey lines show population sizes within the highest and lowest 95% probability density intervals.
Figure 5.
Likelihood of ongoing migrations and the timing of the disjunction between the Tisza and Rába catchments.
A – The likelihood of ongoing migration to any directions is 0 (orange: migration from the Tisza to the Rába; blue: migration from the Rába to the Tisza). B – The complete separation of the Tisza and Rába populations most probably happened in the past. An extant connection between the two populations is unlikely.