An elongated COI fragment to discriminate botryllid species and as an improved ascidian DNA barcode

Botryllids are colonial ascidians widely studied for their potential invasiveness and as model organisms, however the morphological description and discrimination of these species is very problematic, leading to frequent specimen misidentifications. To facilitate species discrimination and detection of cryptic/new species, we developed new barcoding primers for the amplification of a COI fragment of about 860 bp (860-COI), which is an extension of the common Folmer's barcode region. Our 860-COI was successfully amplified in 177 worldwide-sampled botryllid colonies. Combined with morphological analyses, 860-COI allowed not only discriminating known species, but also identifying undescribed and cryptic species, resurrecting old species currently in synonymy, and proposing the assignment of clade D of the model organism Botryllus schlosseri to Botryllus renierii. Importantly, within clade A of B. schlosseri, 860-COI recognized at least two candidate species against only one recognized by the Folmer's fragment, underlining the need of further genetic investigations on this clade. This result also suggests that the 860-COI could have a greater ability to diagnose cryptic/new species than the Folmer's fragment at very short evolutionary distances, such as those observed within clade A. Finally, our new primers simplify the amplification of 860-COI even in non-botryllid ascidians, suggesting their wider usefulness in ascidians

Genetic and behavioural factors affecting interpopulation colour pattern variation in two congeneric chameleon species

We conducted a study on interpopulation variation of colour patterns in two congeneric chameleon species, which have an analogous life history. Both species are able to rapidly change colour pattern, and their context-dependent colour patterns often vary across a wide geographical range. Specifically, we tested four hypotheses that can explain the observed interpopulation variation of colour patterns by a series of behavioural field trials where the colour patterns of individuals were recorded and later analysed by a deep neural network algorithm. We used redundancy analysis to relate genetic, spectral and behavioural predictors to interpopulation colour pattern distance. Our results showed that both isolation by distance (IBD) and alternative mating tactics were significant predictors for interpopulation colour pattern variation in Chamaeleo chamaeleon males. By contrast, in Chamaeleo dilepis, the interpopulation colour pattern variation was largely explained by IBD, and evidence for alternative mating tactics was absent. In both chameleon species, the environmental colours showed no evidence of influencing chameleon interpopulation colour pattern variation, regardless of sex or behavioural context. This contrasting finding suggests that interpopulation context-dependent colour pattern variations in each species are maintained under a different set of selective pressures or circumstances

Fig. S1;Fig. S2 from Genetic and behavioural factors affecting interpopulation colour pattern variation in two congeneric chameleon species

a) The experiment set-up is a straight wooden stick placed horizontally. The color board was our standard for adjusting the chameleon colors patterns to different light conditions. b) Record of color patterns on the lateral side and snout-vent size by photography (C. dilepis, South Africa). c) Record of color pattern changes during a social interaction (C. dilepis, South Africa).;Discriminant function analysis (DFA) for the vegetation and ground color at individual capture locations for Chamaeleo chamaeleon (a, b) and Chamaeleo dilepis (d, e), and violin plot for female and male SVL by site for Chamaeleo chamaeleon (c) and Chamaeleo dilepis (f). Sites are denoted by letters and color (Israel: CC - Carmel coast and WN - western Negev; Spain: CB - La Herradura and JE - Sanlúcar; South Africa: DN - Simbithi, MB - Maduma Boma, and ZF - Zulu Falls). Misclassification rate and sample size are presented above each DFA plot. Site centroids (crosses) and 95% CI ellipsoids are denoted by color