Intraspecific Phenotypic Variation and Morphological Divergence of Strains of Folsomia candida (Willem) (Collembola: Isotomidae), the "Standard" Test Springtaill

Abstract

We describe and compare the external morphology of eleven clonal strains and one sexual lineage of the globally distributed Folsomia candida, known as “standard” test Collembola. Of the 18 morphological characters studied, we measured 14 to have significant between-strains genetic variations, 9 of these had high heritabilities (>78%). The quantified morphological polymorphism was used to analyse the within-species relationships between strains by using both a parsimony analysis and a distance tree. These two detailed morphological phylogenies have revealed that the parthenogenetic strains grouped themselves into two major clades. However the exact position of the sexual strain remains unclear and further analysis is needed to confirm its exact relationship with the parthenogenetic ones. The two morphologically based clades were found to be the same as the ones previously described using molecular analysis. This shows that despite large within-strain variations, morphological characters can be used to differentiate some strains that have diverged within a single morphospecies. We discuss the potential evolutionary interpretations and consequences of these different levels of phenotypic variability.

Distribution and hypoxia‐regulation of haemocyanin in springtails (Collembola)

“…To evaluate the response of F. candida to hypoxia, we measured the mRNA levels of Hc2 (Pick et al, 2009;Xie & Luan, 2014) and other selected putatively stressor oxygen-sensitive genes by quantitative real-time reverse transcription PCR (qRT-PCR). Hc1 (Pick et al, 2009) could not be identified in our culture, which might reflect the considerable differences in F. candida populations (Tully & Potapov, 2015). Pools of 200 adult specimens were exposed to four different hypoxia regimes (see Experimental procedures) along with the appropriate normoxia controls.…”

Within‐species variation in long‐term trajectories of growth, fecundity and mortality in the Collembola Folsomia candida

“…All experimental populations were kept in incubators at 16 °C, with constant humidity (~100%) and in darkness. We raised two genetically distinct clonal strains – labelled TO and HA (Tully et al ., ) – that are known to have different biodemographic strategies under both harsh and good conditions (Tully et al ., ; Tully & Ferrière, ; Tully & Lambert, ) and slight morphological differentiation (Tully & Potapov, ). First, we collected eggs from small cohorts of the two lineages (Fig.…”

The cold-adapted population ofFolsomia manolachei(Hexapoda, Collembola) from a glaciated karst doline of Central Europe: evidence for a cryptic species?

“…'Cryptic diversity' in F. manolachei Some measure of intraspecific variability was observed in the chaetotaxy of several Folsomia species (e.g. Grow and Christiansen 1976;Wetton 1987;Potapov 2001;Tully and Potapov 2015), F. manolachei included (Deharveng 1982). Thus, a 'manolachei species complex' may potentially involve a larger number of different taxa.…”

“…; Tully et al. ; Tully and Ferrière ; Tully and Potapov ). In contrast to large, epedaphic Collembola, genetic and phenotypic plasticity studies have only rarely been conducted in soil‐dwelling species (hemi‐ and euedaphic species).…”

“…Phenotypic differences are considered to be a variation in morphological, physiological or life history traits in animals living in different environmental conditions (Willmer et al 2005). For instance, a considerable level of genetic differentiation was shown in populations of F. candida in addition to some plasticity in morphology and life histories (Stam et al 1996;Tully et al 2006;Tully and Ferri ere 2008;Tully and Potapov 2015). In contrast to large, epedaphic Collembola, genetic and phenotypic plasticity studies have only rarely been conducted in soil-dwelling species (hemi-and euedaphic species).…”