Genetic structure of Barbus spp. populations in the Marches Region of central Italy and its relevance to conservation actions

Abstract

A genetic survey of Barbus spp. populations in the Marches Region (Adriatic River basins), central Italy, was carried out using mitochondrial and nuclear markers (partial D-loop, cyt b sequences and microsatellite loci) in order to ascertain their systematic position and to address their genetic structure which is key to conservation action planning. Analyses were conducted on sequences obtained from 91 individuals collected from eight sampling sites in five different rivers, from two specimens provided by the Ichthyological Centre of Rome and mitochondrial sequences of Barbus spp. retrieved from GenBank. Presumptive classification based on external morphological characters was not confirmed by genetic analysis, by means of which all specimens collected in the Marches Region were ascribed to Barbus plebejus. Genetic diversity values (h and π) of sampling groups were all different from 0 except the one sample collected from the upper reaches of the River Tenna, above a hydroelectric dam. Population connectivity and colonization patterns of the studied area were inferred from an analysis of molecular variance distribution and evolutionary relationships among haplotypes. The results point to different levels of isolation among sampling groups due to ecological and anthropogenic factors and the effect of an artificial barrier on genetic variability and conservation status of the population. Finally, this study confirms the uncertainty associated with systematic classification of Barbus spp. based on morphological characters due to the phenotypic plasticity of the species.

Combining geometric morphometrics with molecular genetics to investigate a putative hybrid complex: a case study with barbels Barbus spp. (Teleostei: Cyprinidae)

“…Results from the molecular comparison are consistent with Buonerba's () finding of a monophyletic B. caninus group, and unclear relationships between B. plebejus and B. tyberinus , as also documented elsewhere (Tsigenopoulos et al ., ; Livi et al ., ; Buonerba et al ., ). In order to illustrate the complex situation in Italian barbels, one example is presented in detail.…”

Genetic and morphological analyses reveal a complex biogeographic pattern in the endemic barbel populations of the southern Italian peninsula

“…Regarding the congruence of the genetic and morphological data, these Italian fluvio‐lacustrine barbels, representing a complex of cryptic species, were only partially identifiable by morphology, with their morphological and molecular divergence not always well correlated across the species (Bianco, ; Kottelat & Freyhof, ; Livi et al, ; Lorenzoni et al, ; Zaccara et al, ). Despite this lack of congruence between the genetic and morphological approaches, there was nevertheless some significant correlation between evolutionary lineages and body shape.…”

“…Total genomic DNA was extracted from all individuals using a proteinase K digestion, followed by sodium chloride extraction and ethanol precipitation (Aljanabi & Martinez, ). Two sets of primers were used to amplify mitochondrial control region (D‐loop) and cytochrome b (cyt b ) gene (Livi et al, ). D‐loop sequences were obtained from the 197 individuals and used for all genetic analyses, while cyt b sequences were analyzed for a subsample of 26 fish, selected as a representative pool of the fish with specific D‐loop haplotypes.…”

“…To date, fish biogeographic studies in the Italian peninsula have generally focused on the northern and central regions (e.g., Buonerba et al, 2015;Carosi, Ghetti, Forconi, & Lorenzoni, 2015;Livi et al, 2013;Marchetto, Zaccara, Muenzel, & Salzburger, 2010;Meraner et al, 2013;Stefani, Galli, Zaccara, & Crosa, 2004;Zaccara et al, 2019;Zaccara, Stefani, & Delmastro, 2007). These studies have centered on the Padano-Venetian (PV) district of the Italian northeast region, including basins flowing into the upper and middle Adriatic Sea (north of the Vomano River in Abruzzo Region and the Krka River in Croatia), and on the Tuscano-Latium (TL) district of central western region, including all basins draining into the middle Tyrrhenian Sea (Bianco, 1990(Bianco, , 1995a.…”

“…Conversely, the Apulo-Campano (AC) district of the southern region of Italy, which includes all basins flowing into southern Adriatic, southern Tyrrhenian, and Ionian seas (Bianco, 1990(Bianco, , 1995a; Figure 1), has received little research attention. For studies that have been completed, evidence suggests the AC district has long been isolated, and so might have been less influenced by lowered sea levels that occurred during Pleistocene period than basins further north (e.g., Bianco, 2014;Ketmaier et al, 2004), such as the paleo-Po drainage (Bianco, 2014;Buonerba et al, 2015;Livi et al, 2013;Stefani et al, 2004;Zaccara et al, 2019).…”