Ecomorphological Variation in Three Species of Cybotoid Anoles

© 2018 by The Herpetologists' League, Inc. Caribbean Anolis lizards exhibit a complex suite of ecological, morphological, and behavioral traits that allow their specialization to particular microhabitats. These microhabitat specialists, called ecomorphs, have independently evolved on the four islands of the Greater Antilles, and diversification among anole ecomorphs has been the focus of many studies. Yet, habitat specialization has also occurred among species within the same ecomorph group. Here, we examined ecological, morphological, and behavioral divergence in three Hispaniolan trunk-ground species, the cybotoid anoles: Anolis cybotes, A. marcanoi, and A. longitibialis. We found differences in limb morphology, locomotor behavior, and perch use among the three cybotoid species that mirror differences across the ecomorphs. Among these species of cybotoids, those that have longer limbs tend to move less frequently, occupy broader perches, and have smaller fourth toes with fewer lamellae. We also observed that the species with greater male-biased size dimorphism had larger heads, smaller dewlaps, and smaller testes. These results are consistent with the predictions of sexual selection theory, in that species with large male body size may have larger heads because of increased male-male combat, and smaller testes potentially attributable to a trade-off between pre- and postcopulatory selection. Overall, our study suggests that a combination of local adaptation to different structural habitats and sexual selection might produce ecomorphological diversification within cybotoid anoles of the same ecomorph group

Data from: Does adaptive radiation of a host lineage promote ecological diversity of its bacterial communities? A test using gut microbiota of Anolis lizards

Adaptive radiations provide unique opportunities to test whether and how recent ecological and evolutionary diversification of host species structures the composition of entire bacterial communities. We used 16S rRNA gene sequencing of faecal samples to test for differences in the gut microbiota of six species of Puerto Rican Anolis lizards characterized by the evolution of distinct ‘ecomorphs’ related to differences in habitat use. We found substantial variation in the composition of the microbiota within each species and ecomorph (trunk-crown, trunk-ground, grass-bush), but no differences in bacterial alpha diversity among species or ecomorphs. Beta diversity analyses revealed subtle but significant differences in bacterial composition related to host phylogeny and species, but these differences were not consistently associated with Anolis ecomorph. Comparison of a trunk-ground species from this clade (A. cristatellus) with a distantly related member of the same ecomorph class (A. sagrei) where the two species have been introduced and are now sympatric in Florida revealed pronounced differences in the alpha diversity and beta diversity of their microbiota despite their ecological similarity. Comparisons of these populations with allopatric conspecifics also revealed geographic differences in bacterial alpha diversity and beta diversity within each species. Finally, we observed high intraindividual variation over time and strong effects of a simplified laboratory diet on the microbiota of A. sagrei. Collectively, our results indicate that bacterial communities are only weakly shaped by the diversification of their lizard hosts due to the strikingly high levels of bacterial diversity and variation observed within Anolis species

Sperm Sizer: a program to semi-automate the measurement of sperm length

Research on sperm is incorporated into many areas of ecology and evolution including sexual selection, reproductive physiology and ecotoxicology, as well as comparative studies in evolution and phylogenetics. Currently, producing data on sperm morphology involves several time-consuming steps, particularly photographing sperm and measuring their length (e.g. head, midpiece, tail and total sperm length). Here, we present Sperm Sizer, a freely available Java program that semi-automates the process of measuring sperm length along the centre of the sperm (including head, midpiece, tail and total length). We compare sperm measurements made with Sperm Sizer to those made with the widely used non-automated software ImageJ, for sperm from a single bird species (the long-tailed finch Poephila acuticauda), eight species of passerine bird and eight species of lizard, and provide examples demonstrating that the program can measure at least some mammalian, fish and mollusc sperm. Sperm length measurements from Sperm Sizer are highly correlated to those made using ImageJ, demonstrating that Sperm Sizer produces high quality sperm length data while taking drastically less time. Our data suggests that Sperm Sizer measurements could possibly be incorporated into existing large datasets with a small correction, although this will need to be assessed on a case-by-case basis. We suggest that generally, sperm image quality (high contrast, minimal overlap of sperm, etc.) will be more important than the shape of the sperm for whether or not Sperm Sizer can be employed for a given project

all_lizard_partB.fasta

Fasta file containing the sequences for lizard fecal 16S rRNA V1-V3 region. Sequencing was performed on MiSeq platform, and fasta files are generated after QC. Sequence ID contains sampleID (see metadata file for details) followed by sequence number. This file needs to be combined with partA

lizard_metadata.xlsx

This is the metadata file contains information concerning the lizard samples used in analyses

all_lizard_partA.fasta

Fasta file containing the sequences for lizard fecal 16S rRNA V1-V3 region. Sequencing was performed on MiSeq platform, and fasta files are generated after QC. Sequence ID contains sampleID (see metadata file for details) followed by sequence number. This file needs to be combined with partB

Selection on Sperm Count, but Not on Sperm Morphology or Velocity, in a Wild Population of Anolis Lizards

Sperm competition is a widespread phenomenon that shapes male reproductive success. Ejaculates present many potential targets for postcopulatory selection (e.g., sperm morphology, count, and velocity), which are often highly correlated and potentially subject to complex multivariate selection. Although multivariate selection on ejaculate traits has been observed in laboratory experiments, it is unclear whether selection is similarly complex in wild populations, where individuals mate frequently over longer periods of time. We measured univariate and multivariate selection on sperm morphology, sperm count, and sperm velocity in a wild population of brown anole lizards (Anolis sagrei). We conducted a mark-recapture study with genetic parentage assignment to estimate individual reproductive success. We found significant negative directional selection and negative quadratic selection on sperm count, but we did not detect directional or quadratic selection on any other sperm traits, nor did we detect correlational selection on any trait combinations. Our results may reflect pressure on males to produce many small ejaculates and mate frequently over a six-month reproductive season. This study is the first to measure multivariate selection on sperm traits in a wild population and provides an interesting contrast to experimental studies of external fertilizers, which have found complex multivariate selection on sperm phenotypes