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

The Italian peninsula is a biodiversity hotspot, with its freshwater fish fauna characterized by high levels of local endemism. Two endemic fluvio-lacustrine fishes of the genus Barbus (barbel, family Cyprinidae) have allopatric distributions in the Tyrrhenian and Adriatic basins of Italy. Barbus plebejus inhabits the mid- to northern Adriatic basins, while B. tyberinus is widespread in all central-northern basins draining into the Tyrrhenian Sea. For basins in Southern Italy draining into the southern parts of these seas, there remains a knowledge gap on their barbel populations due to no previous genetic and morphological studies, despite their apparent biogeographic isolation. Correspondingly, this study quantified the presence and distribution of barbels in the Adriatic and Tyrrhenian basins of Southern Italy through genetic and morphological analyses of 197 fish sampled across eight populations. Testing of how local isolation has influenced the evolution and persistence of these populations was completed by examining sequence variation at two mitochondrial loci (cytochrome b and D-loop) and performing geometric morphometric analyses of body shape, plus measuring 11 morphometric and meristic characters. Phylogenetic and morphological analyses revealed the presence of two genetically distinct lineages that differed significantly from adjacent B. tyberinus and B. plebejus populations. These two new taxa, here described as SI1 and SI2 Barbus lineages, are highly structured and reflect a complex mosaic biogeographic pattern that is strongly associated with the underlying hydrographical scenarios of the basins. The geographic isolation of these basins thus has high evolutionary importance that has to be considered for maintaining endemism

Evolutionary history and population genetics of a cyprinid fish (Iberochondrostoma olisiponensis) endangered by introgression from a more abundant relative

The use of molecular techniques has shown that hybridization and introgression have significant impacts in evolution, by means of transfer of genetic variation and formation of hybrid species. In this paper we use mitochondrial and nuclear sequence data to investigate the evolutionary history, levels of genetic diversity and population differentiation of a rare and endangered fish species. Our results suggest that a hybrid origin scenario of Chondrostoma olisiponensis is a likely explanation for the shared genetic and morphological traits with Iberochondrostoma and Achondrostoma ? Pseudochondrostoma. The basal positioning of C. olisiponensis alleles in all loci analyzed indicates that hybridization events occurred before differentiation within each of these groups, most likely during Middle–Late Miocene. Originally described as C. olisiponensis, we suggest that this species should be placed in the genus Iberochondrostoma to avoid confusion with ‘real’ central European Chondrostoma and to (partially) reflect its evolutionary history. Analyses of levels of genetic diversity and patterns of population subdivision show that populations of the rare Iberochondrostoma olisiponensis are differentiated (high and significant uST and FST) and genetically depauperate (very low S, p, and h). I. olisiponensis is simultaneously imperiled by small population sizes and contemporary bidirectional hybridization with another critically endangered sympatric species (Iberochondrostoma lusitanicum). Urgent ex-situ conservation measures involving supportive breeding of I. olisiponensis are needed to preserve present genetic variation and eventually increase in situ population sizes, along with further studies focused on different life history and behavioral characteristics of this highly endangered species.FCT - Pluriannual Program UI&D 331/94 and 329/201

Guia dos peixes de água doce e migradores de Portugal Continental

Num total de cerca de 35 500 espécies de peixes conhecidas em todo o mundo, aproxima- damente 18 000 espécies habitam ecossistemas de água doce. Apesar de representarem menos de 1% da superfície terrestre, os ecossistemas de água doce possuem uma enorme diversidade de condições tipicamente instáveis que, associadas ao isolamento geográfico das bacias hidrográficas, favorecem a formação de novas espécie

Evaluating the range expansion of recreational non-native fishes in Portuguese freshwaters using scientific and citizen science data

Updating information on the distribution of recently introduced and other poorly known non-natives is essential to prevent and control their spread and better address biological invasions. Here, we combine scientific and citizen science data to update the distribution of five recently arrived (i.e., < 25 years), non-native fish species (Alburnus alburnus, Ameiurus melas, Rutilus rutilus, Sander lucioperca and Silurus glanis) and one rare, longer established (i.e., > 50 years), non-native (Esox lucius) in Portugal. These species have been increasingly targeted by recreational fishermen, thus likely expanding their distribution. Specifically, we obtained distribution maps for each species, based on data gathered through a comprehensive search for records in 1) scientific literature, 2) unpublished reports of research projects, and 3) citizen science databases. We gathered 443 valid records, of which 64% were from citizen science data, mainly provided by recreational fishermen. Data highlighted that all species have expanded their distribution in the last 20 years, with high numbers of new records for A. alburnus, S. lucioperca and S. glanis, mostly located in the Tagus, Guadiana and Douro river basins. Changes in species distributions reflected dispersal within invaded basins and colonisation of previously unoccupied drainages. Integrating citizen science with scientific data provides an effective framework to understand non-native species introduction and spread, stressing the need for increasingly encourage and engage recreational fishermen in information sharing.FCT; Mohamed Bin Zayed Species Conservation Fund, FCT/UE, Foundation for Science and Technology through the strategic plan of the Marine and Environmental Sciences Centre (MARE) , LIFE INVASAQUAinfo:eu-repo/semantics/publishedVersio