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opencc-zeroDec 2013View details →

Data from: Body size and allometric shape variation in the molly Poecilia vivipara along a gradient of salinity and predation

Background: Phenotypic diversity among populations may result from divergent natural selection acting directly on traits or via correlated responses to changes in other traits. One of the most frequent patterns of correlated response is the proportional change in the dimensions of anatomical traits associated with changes in growth or absolute size, known as allometry. Livebearing fishes subject to predation gradients have been shown to repeatedly evolve larger caudal peduncles and smaller cranial regions under high predation regimes. Poecilia vivipara is a livebearing fish commonly found in coastal lagoons in the north of the state of Rio de Janeiro, Brazil. Similar to what is observed in other predation gradients, lagoons inhabited by P. vivipara vary in the presence of piscivorous fishes; contrary to other poeciliid systems, populations of P. vivipara vary greatly in body size, which opens the possibility of strong allometric effects on shape variation. Here we investigated body shape diversification among six populations of P. vivipara along a predation gradient and its relationship with allometric trajectories within and among populations.ResultsWe found substantial body size variation and correlated shape changes among populations. Multivariate regression analysis showed that size variation among populations accounted for 66% of shape variation in females and 38% in males, suggesting that size is the most important dimension underlying shape variation among populations of P. vivipara in this system. Changes in the relative sizes of the caudal peduncle and cranial regions were only partly in line with predictions from divergent natural selection associated with predation regime.ConclusionsOur results suggest the possibility that adaptive shape variation among populations has been partly constrained by allometry in P. vivipara. Processes governing body size changes are therefore important in the diversification of this species. We conclude that in species characterized by substantial among-population differences in body size, ignoring allometric effects when investigating divergent natural selection?s role in phenotypic diversification might not be warranted.

opencc-zeroDec 2015View details →

Data from: Constrained body shape among highly genetically divergent allopatric lineages of the supralittoral isopod Ligia occidentalis (Oniscidea)

Multiple highly divergent lineages have been identified within Ligia occidentalis sensu lato, a rocky supralittoral isopod distributed along a ~3000 km latitudinal gradient that encompasses several proposed marine biogeographic provinces and ecoregions in the eastern Pacific. Highly divergent lineages have nonoverlapping geographic distributions, with distributional limits that generally correspond with sharp environmental changes. Crossbreeding experiments suggest postmating reproductive barriers exist among some of them, and surveys of mitochondrial and nuclear gene markers do not show evidence of hybridization. Populations are highly isolated, some of which appear to be very small; thus, the effects of drift are expected to reduce the efficiency of selection. Large genetic divergences among lineages, marked environmental differences in their ranges, reproductive isolation, and/or high isolation of populations may have resulted in morphological differences in L. occidentalis, not detected yet by traditional taxonomy. We used landmark-based geometric morphometric analyses to test for differences in body shape among highly divergent lineages of L. occidentalis, and among populations within these lineages. We analyzed a total of 492 individuals from 53 coastal localities from the southern California Bight to Central Mexico, including the Gulf of California. We conducted discriminant function analyses (DFAs) on body shape morphometrics to assess morphological variation among genetically differentiated lineages and their populations. We also tested for associations between phylogeny and morphological variation, and whether genetic divergence is correlated to multivariate morphological divergence. We detected significant differences in body shape among highly divergent lineages, and among populations within these lineages. Nonetheless, neither lineages nor populations can be discriminated on the basis of body shape, because correct classification rates of cross-validated DFAs were low. Genetic distance and phylogeny had weak to no effect on body shape variation. The supralittoral environment appears to exert strong stabilizing selection and/or strong functional constraints on body shape in L. occidentalis, thereby leading to morphological stasis in this isopod.

opencc-zeroDec 2017View details →

Data from: Body shape diversity in Triassic‒Early Cretaceous neopterygian fishes: sustained holostean disparity and predominantly gradual increases in teleost phenotypic variety

Comprising Holostei and Teleostei, the ~32,000 species of neopterygian fishes are anatomically disparate and represent the dominant group of aquatic vertebrates today. However, the pattern by which teleosts rose to represent almost all of this diversity, while their holostean sister group dwindled to 8 extant species and two broad morphologies, is poorly constrained. A geometric morphometric approach was taken to generate a morphospace from over 400 fossil taxa, representing almost all articulated neopterygian taxa known from the first 150 million years—roughly 60%—of history (Triassic‒Early Cretaceous). Patterns of morphospace occupancy and disparity are examined in order to: assess evidence for a phenotypically 'dominant' holostean phase; evaluate whether expansions in teleost phenotypic variety are predominantly abrupt or gradual, including assessment of whether apomorphy-defined teleosts are as morphologically conservative as typically assumed; compare diversification in crown and stem teleosts. The systematic affinities of dapediiforms and pycnodontiforms, two extinct neopterygian clades of uncertain phylogenetic placement, significantly impact patterns of morphological diversification. For instance, alternative placements dictate whether or not holosteans possessed statistically higher disparity than teleosts in the Late Triassic and Jurassic. Despite this ambiguity, all scenarios agree that holosteans do not exhibit a decline in disparity during the Early Triassic‒Early Cretaceous interval, but instead maintain their Toarcian‒Callovian variety until the end of the Early Cretaceous without substantial further expansions. After a conservative Induan‒Carnian phase, teleosts colonize (and persistently occupy) novel regions of morphospace in a predominantly gradual manner until the Hauterivian, after which expansions are rare. Furthermore, apomorphy-defined teleosts possess greater phenotypic variety than typically assumed. Comparison of crown and stem teleost partial disparity indicates that, despite substantial expansion in crown teleosts between the Late Jurassic and earliest Cretaceous, stem teleosts remained important long-term contributors to overall teleost disparity during this time.

opencc-zeroJun 2021View details →

Invasion history shapes host transcriptomic response to a body-snatching parasite

By shuffling biogeographic distributions, biological invasions can both disrupt long-standing associations between hosts and parasites and establish new ones. This creates natural experiments with which to study the ecology and evolution of host-parasite interactions. In estuaries of the Gulf of Mexico, the white-fingered mud crab (Rhithropanopeus harrisii) is infected by a native parasitic barnacle Loxothylacus panopaei (Rhizocephala), which manipulates host physiology and behavior. In the 1960s, L. panopaei was introduced to the Chesapeake Bay and has since expanded along the southeastern Atlantic coast, while host populations in the northeast have so far been spared. We use this system to test the host's transcriptomic response to parasitic infection and investigate how this response varies with the parasite's invasion history, comparing populations representing (1) long-term sympatry between host and parasite, (2) new associations where the parasite has invaded during the last sixty years, and (3) naïve hosts without prior exposure. A comparison of parasitized and control crabs revealed a core response, with widespread downregulation of transcripts involved in immunity and molting. The transcriptional response differed between hosts from the parasite's native range and where it is absent, consistent with previous observations of increased susceptibility in populations lacking exposure to the parasite. Crabs from the parasite's introduced range, where prevalence is highest, displayed the most dissimilar response, possibly reflecting immune priming. These results provide molecular evidence for parasitic manipulation of host phenotype and the role of gene regulation in mediating host-parasite interactions.

FIGURE 4 in A new Amphisbaena with chevron-shaped anterior body annuli from state of Pernambuco: Brazil (Squamata: Amphisbaenidae)

FIGURE 4. Type locality of Amphisbaena supernumeraria (MZUSP 98101) in the state of Pernambuco, northeastern Brazil.

FIGURE 1 in A new Amphisbaena with chevron-shaped anterior body annuli from state of Pernambuco: Brazil (Squamata: Amphisbaenidae)

FIGURE 1. Lateral, ventral, and dorsal views of the head of the holotype of Amphisbaena supernumeraria (MZUSP 98101).

FIGURE 3 in A new Amphisbaena with chevron-shaped anterior body annuli from state of Pernambuco: Brazil (Squamata: Amphisbaenidae)

FIGURE 3. Photo of lateral (A) and ventral (B) view of the tail of the holotype of Amphisbaena supernumeraria (MZUSP 98101).

FIGURE 2 in A new Amphisbaena with chevron-shaped anterior body annuli from state of Pernambuco: Brazil (Squamata: Amphisbaenidae)

FIGURE 2. Ventral view of the cloacal region of the holotype of Amphisbaena supernumeraria (MZUSP 98101).

opennotspecifiedDec 2016View details →

FIGURES 10–16. Body shape and proportions. Fig. 10 in The Afrotropical genus Rhinolaetia Schouteden, 1965 and its systematic position within Scutelleridae (Hemiptera: Heteroptera)

FIGURES 10–16. Body shape and proportions. Fig. 10, Xerobia sculpturata (Stål, 1858); Fig. 11, Hotea subfasciata (Westwood, 1837); Fig. 12, Irochrotus montandoni Schouteden, 1903; Fig. 13, Odontoscelis dorsalis (Fabricius, 1798); Fig. 14, Alphocoris lixoides Germar, 1839; Fig. 15, Urothyreus horvathianus Schouteden, 1908; Fig. 16 Cryptacrus comes (Fabricius, 1803).

opencc-zeroNov 2023View details →

The role of abiotic and biotic factors in the unequal body shape diversification of a Gondwanan fish radiation (Otophysi:Characiformes)

Understanding why some clades diversify greatly, while others do not, is a major goal of evolutionary biology. Both abiotic and biotic factors are important in driving unequal morphological diversity across the tree of life. However, few studies have quantified how differences in abiotic habitat and community composition influence unequal morphological diversification in spatiotemporally diffuse radiations. Here we use geometric morphometrics, abiotic habitat data generated by Geographic Information Systems (GIS) analyses, evolutionary simulations, and phylogenetic comparative methods to determine whether random evolution, habitat variation, competition for niches or a combination of factors influenced the unequal body shape diversity of a Gondwanan freshwater fish radiation. We find that neotropical characiform lineages, which exhibit substantially more body shape diversity than their African counterparts, occupy significantly more slope and elevation habitats than African lineages. Differences in habitat occupation between the continental radiations occur by a combination of competition with cypriniform fishes in Africa restricting access to higher slope and elevation habitats and significantly more low elevation and slope habitat available in the neotropics. Our findings suggest that spatiotemporally widespread radiations, like the Characiformes, do not diversify across homogenized habitats and biotic assemblages, with differences in community structure and physical habitat important in driving unequal morphological diversification.

opencc-zeroNov 2023View details →

Predation affects body shape in the knife livebearer Alfaro cultratus (Cyprinodontiformes: Poeciliidae)

Livebearing fishes are a common model for studying the effect of predation on prey biology. Numerous studies have found differences in life history, sexual selection, behavior, and morphology between populations of the same species that co-occur with predators and those that do not. Alfaro cultratus is a livebearing fish with populations in different predation environments, but unlike other livebearers, this species also has an extreme body shape that is laterally compressed. Given this unusual morphology, we asked if predation environment would still predict overall body shape, as has been documented in other species. We collected specimens from both predator and no-predator sites in Costa Rica and used a geometric morphometrics analysis to determine if body shape is affected by predation environment while controlling for size and river gradient. Body shape does indeed differ between predation environments; however, the observed differences contrast with the patterns found in other livebearer systems. Alfaro cultratus in predation environments had deeper and shorter bodies and deeper caudal peduncles than those found in environments without dominant fish predators.

Fig. 6. Canonical variate analysis between A in Quantifying elevational effect on the geometric body shape of Russian beetle Carabus exaratus (Coleoptera: Carabidae)

Fig. 6. Canonical variate analysis between A: dorsal and B: ventral views of Carabus exaratus populations. The colors represent the different levels of altitude: Lower elevation (plain): grey, middle elevation (foothill): green, and higher elevation (mountain): brown. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 4 in Quantifying elevational effect on the geometric body shape of Russian beetle Carabus exaratus (Coleoptera: Carabidae)

Fig. 4. Violin graph of centroid size representing the geometric body size for A: Dorsal and B: Ventral view of C. exaratus. The colors represent the different levels of altitude: Lower elevation (plain): grey, middle elevation (foothill): green, and higher elevation (mountain): brown. Graphical representation of the negative and positive shape contribution of the principal component 1. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 5 in Quantifying elevational effect on the geometric body shape of Russian beetle Carabus exaratus (Coleoptera: Carabidae)

Fig. 5. Multivariate regression of shape on centroid size (independent variable) in Carabus exaratus. The colors represent the different levels of altitude: Lower elevation (plain): grey, middle elevation (foothill): green, and higher elevation (mountain): brown. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 3 in Quantifying elevational effect on the geometric body shape of Russian beetle Carabus exaratus (Coleoptera: Carabidae)

Fig. 3. Principal Component analysis of the ventral view of Carabus exaratus. The colors represent the different levels of altitude: Lower elevation (plain): grey, middle elevation (foothill): green, and higher elevation (mountain): brown. Graphical representation of the negative and positive shape contribution of the principal component 1. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 2 in Quantifying elevational effect on the geometric body shape of Russian beetle Carabus exaratus (Coleoptera: Carabidae)

Fig. 2. Principal Component analysis of the dorsal view of Carabus exaratus. The colors represent the different levels of altitude: Lower elevation (plain): grey, middle elevation (foothill): green, and higher elevation (mountain): brown. (For interpretation of the references to color in this figure legend, the reader is referred to the Web version of this article.)

Fig. 1 in Quantifying elevational effect on the geometric body shape of Russian beetle Carabus exaratus (Coleoptera: Carabidae)

Fig. 1. Representation of dorsal and ventral landmarks of Carabus exaratus. A: dorsal (elytral) view with 19 landmarks, B: ventral view with 18 landmarks.

opencc-by-4.0Apr 2024View details →

Data for: Interplay of abiotic conditions, density, and body size in shaping demography in a high-elevation toad population

This dataset is used to estimate vital rates of a common toad (Bufo bufo) alpine population, and how they are associated with either abiotic (environmental conditions), biotic (in our case population size), and individual factors (body size). We have individual capture histories for the period 1993-2020 for 1615 males and 933 females, as well as body size measurements taken during capture events. For more info about the study system see: https://peercommunityjournal.org/articles/10.24072/pcjournal.240/ We run a capture-mark-recapture model coupled with a growth model, the latter to obtain information on body size for the years when the individuals were not captured. Aside from sex-specific survival, we estimate female breeding probability, since they show intermittent breeding. We include as covariates for these vital rates the length of the active season, the temperature at emergence from hibernation, population size, and body size.  We obtained climatic data for the period 1980–2020 from the DaymetCH dataset (data obtained from Bioclimatic maps of Switzerland © WSL, based on station data from the Federal Office of Meteorology and Climatology MeteoSwiss, and elaborated by the Land Change Science group, WSL). The README file further describes each uploaded file

opencc-zeroOct 2021View details →

Data from: Species interactions, environmental gradients and body size shape population niche width

Competition for shared resources is commonly assumed to restrict population-level niche width of coexisting species. However, the identity and abundance of coexisting species, the prevailing environmental conditions, and the individual body size may shape the effects of interspecific interactions on species' niche width. Here we study the effects of inter- and intraspecific interactions, lake area and altitude, and fish body size on the trophic niche width and resource use of a generalist predator, the littoral-dwelling large, sparsely-rakered morph of European whitefish (Coregonus lavaretus; hereafter LSR whitefish). We use stable isotope, diet and survey fishing data from 14 subarctic lakes along an environmental gradient in northern Norway. The isotopic niche width of LSR whitefish showed a humped-shaped relationship with increasing relative abundance of sympatric competitors, suggesting widest population niche at intermediate intensity of interspecific interactions. The isotopic niche width of LSR whitefish tended to decrease with increasing altitude, suggesting reduced niche in colder, less productive lakes. LSR whitefish typically shifted to a higher trophic position and increased reliance on littoral food resources with increasing body size, although between-lake differences in ontogenetic niche shifts were evident. In most lakes, LSR whitefish relied less on littoral food resources than coexisting fishes and the niche overlap between sympatric competitors was most evident among relatively large individuals (>250 mm). Individual niche variation was highest among >200 mm long LSR whitefish, which likely have escaped the predation window of sympatric predators. We demonstrate that intermediate intensity of interspecific interactions may broaden species' niche width, whereas strong competition for limited resources and high predation risk may suppress niche width in less productive environments. Acknowledging potential humped-shaped relationships between population niche width and interspecific interactions can help us understand species' responses to environmental disturbance (e.g., climate change and species invasions) as well as the driving forces of niche specialization.