Discovery of cryptic species using molecular tools has become common in many animal groups but it is rarely accompanied by morphological revision, creating ongoing problems in taxonomy and conservation. In copepods, cryptic species have been discovered in most groups where fast-evolving molecular markers were employed. In this study at Yeelirrie in Western Australia we investigate a subterranean species complex belonging to the harpacticoid genus Schizopera Sars, 1905, using both the barcoding mitochondrial COI gene and landmark-based two-dimensional geometric morphometrics. Integumental organs (sensilla and pores) are used as landmarks for the first time in any crustacean group. Complete congruence between DNA-based species delimitation and relative position of integumental organs in two independent morphological structures suggests the existence of three distinct evolutionary units. We describe two of them as new species, employing a condensed taxonomic format appropriate for cryptic species. We argue that many supposedly cryptic species might not be cryptic if researchers focus on analyzing morphological structures with multivariate tools that explicitly take into account geometry of the phenotype. A perceived supremacy of molecular methods in detecting cryptic species is in our view a consequence of disparity of investment and unexploited recent advancements in morphometrics among taxonomists. Our study shows that morphometric data alone could be used to find diagnostic morphological traits and gives hope to anyone studying small animals with a hard integument or shell, especially opening the door to assessing fossil diversity and rich museum collections. We expect that simultaneous use of molecular tools with geometry-oriented morphometrics may yield faster formal description of species. Decrypted species in this study are a good example for urgency of formal descriptions, as they display short-range endemism in small groundwater calcrete aquifers in a paleochannel, where their conservation may be threatened by proposed mining.
Because of its importance as a pollinator and its potential economic usefulness for the biodegradation of organic animal waste, the genetic and phenotypic diversity of the drone fly, Eristalis tenax L. (Diptera: Syrphidae), was studied in both wild and captive populations from southeastern Europe. Wild specimens from a natural protected habitat (with low human impact), field crop habitat (semisynanthropic condition), and intensive pig farming habitat (synanthropic condition) were compared with a laboratory colony reared on artificial media An integrative approach was applied based on allozyme loci, cytochrome c oxidase I mitochondrial DNA, wing traits (size and shape), and abdominal color patterns. Our results indicate that the fourth and eighth generations of the laboratory colony show a severe lack of genetic diversity compared with natural populations. Reduced genetic diversity in subsequent generations (F4 and F8) of the laboratory colony was found to be linked with phenotypic divergence. Loss of genetic variability associated with phenotypic differentiation in laboratory samples suggests a founder effect, followed by stochastic genetic processes and inbreeding. Hence, our results have implications for captive bred Eristalis flies, which have been used in crop pollination and biodegradation of organic waste under synanthropic conditions.
A study of population connectivity of the migratory insect species, such as dronefly Eristalis tenax (Diptera, Syrphidae), has an essential importance in understanding the relative influence of the evolutionary forces and environmental features that interact in the spatial distribution of molecular and morphological diversity. However, specific study aiming to understand spatial genetic structure of dronefly populations and its migratory potential is lacking. Hence, we studied a spatial pattern of genetic and phenotypic variation of seven European populations of E. tenax incorporating landscape genetic methods using allozyme data, wing size and shape and abdominal colour pattern. Based on the observed lack of genotypic structuring, we suggested that there has been sufficient long‐distance gene flow to effectively homogenize population structuring at a broader geographical scale. Wing shape similarity among populations and an overlap of abdominal colour variation showed no clear clustering related to geography, which is in congruence with genetic data. However, genetic (FST values) and phenotypic (wing size) data and landscape genetics indicated subdivision between the Balkan populations (four Serbian samples) and populations from Central (Germany and Switzerland) and Northern (Finland) Europe. These findings indicated a potential connection between the Central and Northern Europe supporting the Central European origin of the flies caught in Finland. Thus, by performing spatial analysis and combining genetic–morphological approach, we shed light on the movement pattern in complex landscapes and thus provided the necessary guidelines to a broad‐scale analysis of this widespread generalist pollinator.
In terrestrial animals with rigid protective structures, the ability to upright after being overturned can make the difference between life and death, especially in suboptimal thermal conditions or in the presence of predators. This trait is assumed to be under strong selection. Different factors can influence righting ability, body dimensions and body mass for instance. As these morphological traits diverge among populations, inter‐population variability in righting ability is expected. Previous studies on tortoises were performed within single populations and they usually focused on juveniles raised in captivity, precluding an assessment of the inter‐population variability in a natural (realistic) context. In the current study, we quantified the righting performance in four populations of free‐ranging adult tortoises. We found strong differences in righting success among populations and between genders, suggesting possible adaptations to local conditions. For instance, the topography (e.g. slopes) of each study site varied markedly. On average, males were more successful in righting themselves than females. Body size did not influence righting performances in males, but larger females were less successful compared to smaller ones. The success in righting was positively correlated with carapace domedness (height) and short bridges.
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