Allochthonous Species Research Articles

Reproductive features of the invasive crab Cronius ruber (Brachyura, Portunidae) on the Canary Islands (central eastern Atlantic), Spain

The main features of the life cycle and ecology of the invasive species Cronius ruber in both its native range and invaded areas are unknown. Therefore, the reproductive traits of this invasive allochthonous species were studied in the Canary Islands, including sex structure, maturity, fecundity, and egg development. Females were more abundant than males, mainly in the size range between 25 and 80 mm CW. Only males were observed in size classes above 80 mm CW. Reproduction of C. ruber is continuous throughout the year, with a new oviposition immediately after the end of the egg incubation period. This process can be repeated in females up to six times, without re-mating, due to the sperm stored by females in the spermathecae. Sexual maturity was estimated at a similar size in both sexes, corresponding to 57–59 % of their maximum observed size. Egg development appeared to be completely synchronous, with a development period lasting slightly less than 1 month. The mean fecundity was 657,282 eggs, with a maximum observed fecundity of 988,509 eggs. This species shows a high reproductive potential, characteristic of invasive species.

Recent findings of alien insect in citrus and olive groves in the Mediterranean basin: new risks for integrated pest management (IPM)

Recently, the number of alien arthropods found in the Mediterranean basin has increased considerably. This phenomenon occurred especially in the milder climate areas of the southern sector. In this context, citrus and olive groves see their productions and even their existence at risk. In the last three decades, the increased number of allochthonous species introduced to Italy and potentially harmful to Citrus and Olea genera has alerted and worried farmers, especially for those species capable of transmitting diseases for which no phytosanitary remedies are yet known. The adoption of an integrated supra-regional surveillance and monitoring system is therefore essential. Here the focus is on some invasive alien insect species (phytophagous and predators) recently reported on the Italian territory on Citrus and Olea plant species.

Small-scale fishery catch composition in Rhodes (Eastern Mediterranean Sea)

Trammel net and boat-seine experimental fishing samplings were carried out seasonally, over a rocky-sandy and a Posidonia oceanica habitat respectively, in the coastal waters of Rhodes, south-eastern Aegean Sea, Greece, between 2019 and 2020. Fish catch composition, abundance and biomass were investigated as a contribution to the qualitative and quantitative monitoring of the fish assemblages in the artisanal fishery in this Greek marine region most affected by biological invasion. A total of 56 native and 11 alien fish species were captured. Five invasive species Fistularia commersonii, Pterois miles, Siganus rivulatus, Siganus luridus and Lagocephalus sceleratus were recorded using both fishing gear. In trammel nets, the alien to native fish species ratio was 1:2.87 with eight allochthonous species composing 43% of the total abundance and greatly exceeding native species biomass with the most dominant being F. commersonii, P. miles, S. rivulatus and S. luridus. Boat seine samples were dominated by Spicara smaris and Boops boops, which accounted for 84% and 56% of total abundance and biomass, respectively, while the alien to native fish species ratio was 1:5.1. The 10 Lessepsian fish, i.e., fish that have entered the Mediterranean Sea via the Suez Canal, identified on a Posidonia seabed represented a small proportion of the total abundance (3.4%), while their biomass reached 17% of the total catch, with a prevalence of F. commersonii. Among alien fish on P. oceanica, S. rivulatus exhibited the greatest abundance, followed by F. commersonii, Parupeneus forsskali and S. luridus, with small but not negligible densities of Pteragogus trispilus and Torquigener flavimaculosus. The abundance of Pterois miles over the rocky-sandy habitat was remarkable. Results indicate a transitional shift in fish catch composition with introduced species competing with natives for food and space (i.e. between introduced siganids and Sparisoma cretense, Sarpa salpa, between the recently introduced P. forsskali and mullids, and between introduced P. miles and scorpaenids), further influenced synergistically by environmental and anthropogenic factors. The Total-Standard length and Total weight-Total length relationships and their applications in fisheries data for the allochthonous fish are briefly discussed.

Veronica cymbalaria (Plantaginaceae): A new species for the exotic flora of Chile.

Background and aims: Botanic gardens play a fundamental role in conservation due to the maintenance of seed and live plant collections. However, the exchange of ornamental plant seeds between botanic gardens can facilitate the entry of seeds of alien species with invasive potential. In 2018, during a visit to the collections of the National Botanical Garden (Chile), we discovered populations of an herb of the genus Veronica (Plantaginaceae). The aim of this paper is to report for the first time the presence of Veronica cymbalaria as a new exotic feral species for the flora of Chile. M&M: Live material was studied and compared with the original description of the species. The collected material was deposited in the herbarium of the National Botanical Garden (JBN). Results: Veronica cymbalaria, which grows abundantly in and around the biological collections of the National Botanical Garden, is described. Images of the species, a map of the site of occurrence and a key to distinguish Veronica species growing in Chile are included. Conclusions: Veronica cymbalaria is reported for the first time for the flora of Chile. The distribution range of this alien species is extended to southern America. The genus Veronica is represented by ten allochthonous species in Chile.

First Record of the Alien and Invasive Polychaete Laonome triangularis Hutchings & Murray, 1984 (Annelida, Sabellidae) in Italian Waters

In recent years, the introduction of alien and invasive marine species in the Mediterranean Sea has rapidly increased. Laonome triangularis is a sabellid worm, native to the Australian coasts. Its first record in the Mediterranean Sea dates back to 2009 and, in this area, it is currently labeled as an allochthonous species. In the present work, we report the fìrst record of this polycheate in Italian waters and we provide some diagnostic features that are useful to identify the species.

Spontaneous vascular flora of the historical monumental cemetery of Modena (N-Italy)

The first floristic study of the historical monumental cemetery of San Cataldo in Modena (N-Italy) is presented. The research was performed in the period 2019–2022, considering only spontaneous individuals growing within the historical area (4.8 ha). A total of 266 taxa (species and subspecies) was found, of which 1 new for the flora of Italy (Malus × robusta ‘John Downie’), 2 new for the administrative region of Emilia-Romagna (Calocedrus decurrens and Salvia haematodes) and 1 new for the province of Modena (Epilobium ciliatum). Therophytes prevail (37.6%), followed by hemicryptophytes (31.6%), phanerophytes (16.2%) and geophytes (11.7%). The chorological spectrum is dominated by Eurasian species (32.0%), followed by Mediterranean (26.3%), Cosmopolitan (24.8%), Boreal (6%) and N-American (4.5%) ones. Allochthonous species are 16.5% of the list, with neophytes always prevailing over archaeophytes (28 vs. 9 species). Invasive species are 67.8% of the neophytes; on a regional scale they are 1.5% of the list. Protected species are 2.6% of the total; 3 of them are internationally protected and 2 are included in the red list of Italian flora. This study confirms the great biological richness of urban environments and the potential of historical cemeteries as a refugium for the conservation of species that have become rare, endangered or infrequent at a regional or national level, because of the heavy human impact on the territory.

Time pattern variation of alien plant introductions in an insular biodiversity hotspot: the Balearic Islands as a case study for the Mediterranean region

Allochthonous plant species are considered among the main environmental issues worldwide, being especially accused in the Mediterranean basin. The present study aims to update Balearic Alien Flora and discuss its time and spatial variation and invasiveness. Information regarding allochthonous plant records of the Balearic Islands were gathered and analysed based on published checklists and online databases. For each species several general traits were assigned based on previous references to characterise the alien Balearic Flora. Records of allochthonous species between 1827 and 2023 indicate that Alien Balearic Flora is composed of 624 taxa recorded unevenly among islands, with lower records in smaller islands. Alien flora is mainly composed of therophytes and phanerophytes being held mainly in human related habitats. Introduction pathway is mainly ornamental, with over 50% of taxa entering through gardening and horticultural practices. Main biogeographical origins are American, Mediterranean, Euroasiatic and Cape origins. Invasive status of Balearic alien flora shows that 44% of all taxa can be regarded as casual, while 35% are naturalised, and 17% can be considered invasive, being the latter increased in smaller islands. Time variations trends starting mainly in the 70 s and predictive models show that alien species increase exponentially, being the most represented taxa from synanthropic habitats, introduced as ornamentals, lianas, phanerophytes and therophytes from Cactaceae, Asteraceae and Leguminosae families. The results of the present study can serve as a model to facilitate the scientifically informed decision making and management of plant invasions both in the Balearic Islands and other continental insular systems and Mediterranean regions.

Bombus terrestris terrestris (Linnaeus, 1758) and hybrids with the endemic Bombus xanthopus spotted on Capraia Island (Tuscan Archipelago, Italy): some conservation management implications

Expansion of wild and managed allochthonous species leads to potential negative consequences for the endemic wildlife, such as resource competition, pathogens spread, hybridization and native species replacements. On Capraia Island, the last sighting of Bombus terrestris terrestris dates back to 1917. All subsequent surveys carried out on the island only reported the presence of B. xanthopus and B. pascuorum melleofacies with B. t. terrestris apparently no longer existing in the area. In 2021 B. t. terrestris was again detected on the island raising two main hypotheses: (i) B. t. terrestris has always been present with a low population density, such as not to be detected in previous investigations, or (ii) its presence is the result of a more recent recolonization. The recolonization event may be promoted by either intentional or unintentional introduction or it may be the result of a natural migration from the mainland or surrounding islands. Hybridization between B. t. terrestris × B. xanthopus on Capraia Island has been also ascertained by the detection of hybrid queens, workers and males. These new finding provides insight on the distribution range of B. t. terrestris in the Tuscan Archipelago and raise concern on the conservation of the endemic B. xanthopus population.

Landscape factors and allochthonous congeneric species influence Callithrix aurita occurrence in Brazilian Atlantic Forest remnants.

The buffy-tufted-ear marmoset (Callithrix aurita) is a small primate endemic to the Brazilian Atlantic Forest biome, and one of the 25 most endangered primates in the world, due to fragmentation, loss of habitat, and invasion by allochthonous Callithrix species. Using occurrence data for C. aurita from published data papers, we employed model selection using Akaike Information Criterion corrected for small samples and cumulative AICc weight (w +) to evaluate whether fragment size, distance to fragments with allochthonous species, altitude, connectivity, and surrounding matrices influence the occurrence of C. aurita within its distributional range. Distance to fragments with C. jacchus (w + = 0.94) and nonvegetated areas (w + = 0.59) correlated negatively with C. aurita occurrence. Conversely, the percentage of agriculture and pasture mosaic (w + = 0.61) and the percentage of savanna formation (w + = 0.59) in the surrounding matrix correlated positively with C. aurita occurrence. The findings indicate that C. aurita is isolated in forest fragments surrounded by potentially inhospitable matrices, along with proximity of a more generalist and invasive species, thereby increasing the possibility of introgressive hybridization. The findings also highlighted the importance of landscape elements and allochthonous congeneric species for C. aurita conservation, besides indicating urgency for allochthonous species management. Finally, the approach used here can be applied to improve conservation studies of other endangered species, such as C. flaviceps, which is also endemic to the Brazilian Atlantic Forest and faces the same challenges.

Non-native freshwater fish from drainages of Rio Grande do Sul State, Brazil

The present study catalogues exotic and allochthonous fish species found in the three main freshwater river drainages of Rio Grande do Sul State using records of scientific collections and literature, and discusses the main impacts caused by their introduction in natural environments. Ten exotic species are found in the area, i.e., Clarias gariepinus, Coptodon rendalli, Ctenopharyngodon idella, Cyprinus carpio, Hypophthalmichthys molitrix, Hypophthalmichthys nobilis, Ictalurus punctatus, Micropterus salmoides, Oncorhynchus mykiss and Oreochromis niloticus, belonging to five orders, nine genera and seven families. These fishes are native from African, Asian, European and North American countries. The eight allochthonous species, i.e., Acestrorhynchus pantaneiro, Hoplerythrinus unitaeniatus, Hoplias lacerdae, Megaleporinus macrocephalus, Piaractus mesopotamicus, Pachyurus bonariensis, Serrasalmus maculatus, and Trachelyopterus lucenai, belong to three orders, eight genera, and six families, are native from the Río La Plata basin, that includes the Río Uruguay, and have been all registered in the Laguna dos Patos. Two of these species are further recorded in the Rio Tramandaí system (A. pantaneiro and T. lucenai). The study also presentes a brief history of the first records of exotic species in the state and in the country, and their main vectors of introduction. According to the records of exotic species in scientific collections, the two exotic species with the highest number of records in the country are tilapias Coptodon rendalii (508 records) and Oreochromis niloticus (376 records), and most records occurred in the last two decades. The two carps Cyprinus carpio and Ctenopharyngodon idella are the only exotic species recorded in the three main drainage basins of the state. In addition, we warn about the importance of studies about the biology and negative impacts of exotic species over native species on the understanding of management in wild environments.

Stanje stabala crvenog hrasta u gradskoj sredini Beograda (Srbija)

Forty-two trees of northern red oak (Quercus rubra L.) were examined in the area of the municipality of Savski Venac, Belgrade, to assess the condition of this allochthonous species in Serbia and its adaptability to urban environments. Physical measurements were taken and ratings of vitality and decorativeness were given. The analyzed trees are in very good condition based on their health status (80.95% of trees without visible indication of disease) and the mean values of ratings for vitality (4.45) and decorativeness (3.88). The obtained values of vitality and some physical measurements were greater than those stated in the literature, suggesting that the species has adapted well to the urban environment of Belgrade and it should be considered a suitable landscape tree species for planting in urban areas of Serbia.

Acid-tolerant Lactiplantibacillus plantarum ZDY2013 shows a colonization niche preference and interacts with enterotoxigenic Bacillus cereus in specific-pathogen-free mice.

Probiotics have long been utilized as functional food and modulate gut microbial homeostasis, but their colonization niche is mostly unclear and transient, which restrains the development of microbiome-targeted strategies. Lactiplantibacillus (L.) plantarum ZDY2013 is an allochthonous species of the human gastrointestinal tract with acid-tolerant properties. It serves as an antagonistic agent against the food-borne pathogen Bacillus (B.) cereus and a potent regulator of the gut microbiota. However, there is a knowledge gap regarding the colonization dynamics of L. plantarum ZDY2013 in the host intestine and the colonization niche of its interaction with pathogens. Here, we designed a pair of specific primers targeting L. plantarum ZDY2013 based on its whole genome sequence. We evaluated their accuracy and sensitivity with other host-derived strains and confirmed their availability with artificially spiked fecal samples from different mouse models. Additionally, the content of L. plantarum ZDY2013 was quantified by qPCR in fecal samples from BALB/c mice, followed by the analysis of its colonization niche preference. Moreover, the interactions between L. plantarum ZDY2013 and enterotoxigenic B. cereus HN001 were also elucidated. The results revealed that the newly designed primers could identify L. plantarum ZDY2013 with high specificity and were resistant to the influence of the complex fecal matrix and gut microbes from different hosts. Interestingly, the content of mixed L. plantarum ZDY2013 and B. cereus HN001 when orally administered remained higher when compared with the single strain group in BALB/c mice upon discontinuation of intragastric administration. In addition, L. plantarum ZDY2013 was mainly enriched in the large intestine during the ingestion period and maintained the highest content in the stomach after discontinuing supplementation on day 7. Moreover, L. plantarum ZDY2013 colonization neither damaged the intestine nor ameliorated the damage triggered by B. cereus in BALB/c mice. Overall, our study constructed two efficient specific primers targeting L. plantarum ZDY2013 and provided the potential to explore the underlying mechanism of competition between L. plantarum ZDY2013 and pathogens in host species.

First record of Anatololacerta pelasgiana (Mertens, 1959) in mainland Greece: another new species in Athens

Urban habitats receive an increasing number of species due to anthropogenic activities, mainly transportations. Here, we report a new addition to the herpetofauna of Athens (Greece): a small population of the Pelasgian wall lizard (Anatololacerta pelasgiana) was found in a suburb of the Athenian metropolitan area. The species normally occurs in southwestern Anatolia and southeastern Aegean islands and this is the first record in the Greek mainland. Allochthonous species that successfully colonize cities raise new challenges to urban ecology.

Cereal Aphid Parasitoids in Europe (Hymenoptera: Braconidae: Aphidiinae): Taxonomy, Biodiversity, and Ecology.

Cereals are very common and widespread crops in Europe. Aphids are a diverse group of herbivorous pests on cereals and one of the most important limiting factors of cereal production. Here, we present an overview of knowledge about the taxonomy, biodiversity, and ecology of cereal aphid parasitoids in Europe, an important group of natural enemies contributing to cereal aphid control. We review the knowledge obtained from the integrative taxonomy of 26 cereal aphid primary parasitoid species, including two allochthonous species (Lysiphlebus testaceipes and Trioxys sunnysidensis) and two recently described species (Lipolexis labialis and Paralipsis brachycaudi). We further review 28 hyperparasitoid species belonging to three hymenopteran superfamilies and four families (Ceraphronoidea: Megaspillidae; Chalcidoidea: Pteromalidae, Encyrtidae; Cynipoidea: Figitidae). We also compile knowledge on the presence of secondary endosymbionts in cereal aphids, as these are expected to influence the community composition and biocontrol efficiency of cereal aphid parasitoids. To study aphid-parasitoid-hyperparasitoid food webs more effectively, we present two kinds of DNA-based approach: (i) diagnostic PCR (mainly multiplex PCR), and (ii) DNA sequence-based methods. Finally, we also review the effects of landscape complexity on the different trophic levels in the food webs of cereal aphids and their associated parasitoids, as well as the impacts of agricultural practices and environmental variation.

Weather Influence on Native and Alien Mantis Dynamics and Their Abundance in the Current Climate Change Conditions

Humans have traded and transported alien species for millennia, both with and without intention to spread them to new areas. Consistent knowledge of their ecology will allow decision makers to take suitable conservation actions, with the aim of avoiding threatening native species. Praying mantids (Mantodea) are predatory insects with a high impact on local invertebrates’ fauna. An alien mantis species (Hierodula tenuidentata) could create a disequilibrium in both the local ecosystem and in autochthonous mantid species (Mantis religiosa) if it can adapt to the local ecological conditions. Through this study, we reveal that the number of Hierodula tenuidentata individuals from an Eastern European Natura 2000 site was 7.6 times higher than the number of Mantis religiosa suggesting a higher density of the allochthonous species in the study area. According to a GLM analysis, the population of Mantis religiosa, measured from August to the end of October, declines more rapidly and is negatively influenced by the number of days from the first day of the year, while the population of Hierodula tenuidentata is influenced by local weather factors. This is the first study which analyzes the influence of local weather factors (namely air temperature, precipitation, daily atmospheric pressure, daily wind direction and speed, daily cloud cover, sunshine duration and number of days from the first day of the year) on the abundance dynamic of mantises in order to understand their ecology in the current climate change influence.

Environmental DNA metabarcoding reveals spatial and seasonal patterns in the fish community in the Venice Lagoon

Environmental DNA (eDNA) is an emerging tool for assessing biodiversity and understanding spatial and temporal community patterns and processes, directly from DNA sequencing of environmental samples such as air, water, and sediments. We applied eDNA methods to monitor bony fish communities, detecting as well locally allochthonous species, and to reveal seasonal patterns at two sites in the Venice Lagoon. We analyzed 17 water samples collected over 12 months at two ecologically distinct sites by using available primers for teleosts and High Throughput Illumina sequencing. We identified 1,289 amplicon sequence variants (ASVs) assigned to 62 fish taxa. Most of the species known to inhabit or to enter the Venice Lagoon were detected, with eDNA data reflecting differences in fish communities between the internal (freshwater associated) and the external (sea associated) part of the lagoon. Moreover, seasonal trends of migration have been portrayed, highlighting the most involved species and disclosing possible clashes between migration events and the temporary interruption of sea-lagoon connectivity due to MOSE (MOdulo Sperimentale Elettromeccanico). Of interest, the first-time detection of Oceanic puffer (Lagocephalus lagocephalus) DNA in the Venice Lagoon provides evidence of the further northward expansion of this species in the high Adriatic Sea. eDNA successfully profiled fish communities by season and habitat in the Venice Lagoon. Our results support routine application of eDNA to monitor potential ecological consequences of MOSE closures in this World Heritage site.

New species of fish and crustaceans in Montenegrin waters (South Adriatic Sea)

The structure and composition of Mediterranean biodiversity has changed significantly. So far, in Montenegrin coastal waters, nine new non-native species have been recorded: Tylosurus acus imperialis, Caranx crysos, Siganus luridus, Fistularia commersonii, Stephanolepis diaspros, Sphoeroides pachygaster, Lagocephalus sceleratus, Callinectes sapidus and Farfantepanaeus aztecus. Allochthonous species are starting to compete for food and space and leading to habitat degradation, socio-economic impacts and can hybridise with the native species. Natural factors and human activities have enabled the arrival of non-native species into the Adriatic Sea. Four of the species are Lessepsian immigrants, which arrived via the Suez Canal, but five others were introduced from the Atlantic Ocean, through the Strait of Gibraltar. Analysis using the Marine Fish Invasiveness Screening Kit (MFISK), Aquatic Invasiveness Screening Kit (AS-ISK) and Receiver operating characteristic (ROC) showed a calibration threshold of 22.5 for MFISK, a BRA (Basic Risk Assessment) score of 34 and a CCA (Climate Change Assessment) score of 46. A measure of the accuracy of the calibration analysis is the area under the ROC curve (AUC). Two species were characterised as non-invasive: Tylosurus acus imperialis and Caranx crysos, but five others were characterised as invasive and covered by the categories from moderate to high-risk.

Assessment and potential of ecosystem services of ornamental dendroflora in public green areas.

The green infrastructure of the city of Novi Sad is characterized by a significant presence of ornamental invasive alien species, which might lead to their uncontrolled spread and suppression of autochthonous dendroflora. This study aimed to determine the ecosystem services and disservices of ornamental dendroflora in Novi Sad, as well as how they can affect urban green areas. Of the total ornamental dendroflora in Novi Sad, 88.33% of species with a good adaptation were determined, while 10% had a medium and 1.67% had a very good adaptation. Thirty-four allochthonous species showed very high (38.24%), moderate (47.06%), and low (14.71%) invasive potential according to the conducted invasiveness risk assessment. These species are also characterized by high (2.94%), moderate (67.65%), and low (29.41%) allergenic potential. On the contrary, 26 ornamental autochthonous species are characterized by moderate (38.46%) and low (61.54%) rates of spread on public green areas, while also characterized by high (26.92%), moderate (50%), and weak (23.08%) allergenic potential. Ornamental dendroflora provides many more positive ecosystem services, such as urban afforestation, climate regulation, decorative-aesthetic value, air and water purification, ecotourism and recreation, and other services that are of great benefit to the residents of that city. The highest calculated values of ecosystem services in allochthonous and autochthonous species were 27 and 26.5 (out of possible maximal value 40), while ecosystem disservices accounted down to the value of - 13.5 (out of possible minimal value - 22). Therefore, intrinsic disservices such as the production of large amounts of green waste of ornamental dendroflora can be shifted into a novel ecosystem service-green solutions based on nature, to avoid unsuitable deposition of seeds in the soil and creation of suitable vegetation on public green areas.

Microalgae-Based PUFAs for Food and Feed: Current Applications, Future Possibilities, and Constraints

Microalgae are currently considered an attractive source of highly valuable compounds for human and animal consumption, including polyunsaturated fatty acids (PUFAs). Several microalgae-derived compounds, such as ω-3 fatty acids, pigments, and whole dried biomasses are available on the market and are mainly produced by culturing microalgae in open ponds, which can be achieved with low setup and maintenance costs with respect to enclosed systems. However, open tanks are more susceptible to bacterial and other environmental contamination, do not guarantee a high reproducibility of algal biochemical profiles and productivities, and constrain massive cultivation to a limited number of species. Genetic engineering techniques have substantially improved over the last decade, and several model microalgae have been successfully modified to promote the accumulation of specific value-added compounds. However, transgenic strains should be cultured in closed photobioreactors (PBRs) to minimize risks of contamination of aquatic environments with allochthonous species; in addition, faster growth rates and higher yields of compounds of interest can be achieved in PBRs compared to open ponds. In this review, we present information collected about the major microalgae-derived commodities (with a special focus on PUFAs) produced at industrial scale, as well genetically-engineered microalgae to increase PUFA production. We also critically analyzed the main bottlenecks that make large-scale production of algal commodities difficult, as well as possible solutions to overcome the main problems and render the processes economically and environmentally safe.

An updated dichotomous key to the snakes of Europe

This work presents an updated dichotomous key to all snake species of Europe, based on morphological, morphometric and distributional characters. It gathers data from both the last dichotomous keys concerning European snake species and every following paper giving updates on taxonomic classification or the occurrence of new allochthonous species. The key includes 58 snake taxa, including 57species and one still unnamed taxon, distributed on the European territory, and photographic material for each species. The aim of this paper is to make the identification of all European snake species through a single manuscript more accessible, not only for researchers, but also for citizen science, thus enhancing data collection and assist species conservation.