scholarly journals First record of the stone crayfish in the Romanian lowlands

Author(s):  
Marius-Ioan Groza ◽  
Diana Cupșa ◽  
Leona Lovrenčić ◽  
Ivana Maguire

The stone crayfish is a native European freshwater species with significant population declines caused by anthropogenic pressure onto its habitats, climate change and spreading of non-indigenous invasive crayfish and their pathogens (e.g., Aphanomyces astaci). We present the first record of an Austropotamobius torrentium population in a small stream from the southern lowlands of Romania, in an area without limestone or karst, known as a typical stone crayfish habitat in this country. No additional populations were found in the neighbouring streams. The mtDNA analysis based on sequencing a short fragment of the cytochrome c oxidase subunit I (COI) gene revealed that specimens from this newly discovered population belongs to the most widespread phylogroup of A. torrentium (CSE) and share the same haplotype as the specimens found in Croatia. Unfortunately, this crayfish population has disappeared most likely because of the crayfish plague since pathogen A. astaci was isolated from moribund crayfish. Our study highlights the vulnerability of isolated relic populations in the face of outside stressors.

2021 ◽  
Vol 4 ◽  
Author(s):  
Leona Lovrenčić ◽  
Lena Bonassin ◽  
Frederic Grandjean ◽  
Chris Austin ◽  
Ivana Maguire

The stone crayfish Austropotamobius torrentium is a native European freshwater species with significant population declines caused by anthropogenic pressure onto its habitats, climate change and spreading of non-native invasive crayfish and their pathogens. Large-scale DNA barcoding based on sequencing a short fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene revealed this species represents a highly divergent taxon whose evolutionary heritage is preserved in genetically divergent mtDNA phylogroups, with majority of them having restricted distribution ranges. Guarding in mind vanishing populations trends and potential loss of genetic diversity, effective conservation planning and monitoring are needed for ensuring the persistence and long-term survival of this endangered species. Since genetic data are often critical for defining populations for conservation and management purposes, along with DNA barcoding, we employed microsatellites to examine samples of more than 400 individuals from 17 populations across its entire distribution range in Croatia, known as the stone crayfish diversity hot spot. Microsatellite analyses revealed high level of genetic diversity and differentiation among studied populations that grouped according to their geographical position and mtDNA phylogroup. Almost all sampled populations represent a distinct genetic cluster, showing high level of differentiation and reflecting long periods of isolation. Results of genetic characterisation enabled selection of suitable donor populations for future restocking and reintroduction programs. Combination of DNA barcoding and microsatellites provided good insight into genetic diversity and population structure as well as enabled sound conservation programs for this threatened species in Croatia.


2020 ◽  
Vol 7 (2) ◽  
pp. 88-97
Author(s):  
Aouadj Sid Ahmed ◽  
Nasrallah Yahia ◽  
Hasnaoui Okkacha ◽  
Khatir Hadj

AbstractThe forest of Doui Thabet is one of the forests of the Mounts of Saida (Western Algeria) which is experiencing a dynamic regressive. Located in the semi-arid bioclimatic stage, it is located at the edge of two phytogeographic sub-sectors: atlas Tellien Oranais (O3) and high plateau subsector (H1). Among the factors that threaten to curb this fragile and weakened ecosystem, in addition to drought and climate aridity and which has become a structural ecological phenomenon; the overgrazing is also a major limiting factor. This current study provides a qualitative and quantitative assessment of anthropogenic pressure exerted in this area zone. The methodology adopted in this study is that of Le Houerou (1969) and Montoya (1983), which it is based on the calculation of the annual needs of the herd in forage units, the estimate of the feed potential of production, the coefficient of overgrazing and in addition to the anthropogenic pressure index. The result of the forage balance in the forest rangelands of the studied area has a forage deficit (overload) of (96.64%) (a sylvopastoral imbalance), in addition to that, the coefficient of overgrazing is (92.3%) and the anthropogenic pressure index is very high (28). The conservation and the restoration of this area is a major concern in the face of global changes, taking into account their mode of reproduction and their dynamics, for the development of restoration strategies and more effective ways of protection.


2021 ◽  
Vol 9 ◽  
Author(s):  
Laura Martín-Torrijos ◽  
Angel Jose Correa-Villalona ◽  
Juan Carlos Azofeifa-Solano ◽  
Fresia Villalobos-Rojas ◽  
Ingo S. Wehrtmann ◽  
...  

The crayfish plague pathogen Aphanomyces astaci is one of the main factors responsible for the decline in European and Asian native crayfish species. This pathogen was transported to these regions through its natural carriers, North American crayfish species, which were introduced during the last century. Since then, the carrier species and the pathogen have spread worldwide due to globalization and the highly invasive nature of these species. In Europe, five carrier species have been categorized as high-risk as they are responsible for the loss of provisioning services, which endangers freshwater ecosystems. The red swamp crayfish Procambarus clarkii, in particular, is currently one of the most concerning species as its spread threatens crayfish biodiversity and freshwater ecosystems worldwide. In this study, we describe the first detection of A. astaci in an introduced population of P. clarkii in Central America, specifically in Costa Rica. Using molecular approaches, we analyzed 48 crayfish samples collected from Reservoir Cachí and detected the presence of A. astaci in four of these samples. The introduction of P. clarkii and the incorrect management of the species (related to its fishery and the commercialization of live specimens) over the past decades in Europe are mistakes that should not be repeated elsewhere. The detection of the pathogen is a warning sign about the dangerous impact that the introduction of this invasive crayfish may have, not only as a carrier of an emerging disease but also as a direct risk to the invaded ecosystems. Our results may serve to (1) assess current and future consequences, and (2) direct future research activities, such as determining the potential impacts of A. astaci on native decapod species, or on other introduced crayfish species that are used for aquaculture purposes, such as Cherax quadricarinatus.


2019 ◽  
Vol 19 (3) ◽  
Author(s):  
Gabriel Raposo Silva de Souza ◽  
José Sabino ◽  
Domingos Garrone-Neto

Abstract: A new foraging tactic for the pearl cichlid, Geophagus brasiliensis, is described from underwater observations performed in a coastal stream of the Atlantic Forest, Southeastern Brazil. Named "shift picking", the foraging tactic involved the manoeuvering of leaves, wood twigs and tree bark present in the substrate, with fish using its mouth to turn objects and uncover macroinvertebrates adhered to the underside of the object being picked ("B-side"). The object-shifting behaviour is rarely reported for fish and the present description seems to be the first record for a freshwater species of South America.


2015 ◽  
Vol 282 (1805) ◽  
pp. 20142881 ◽  
Author(s):  
Matthew H. Becker ◽  
Jenifer B. Walke ◽  
Shawna Cikanek ◽  
Anna E. Savage ◽  
Nichole Mattheus ◽  
...  

Symbiotic microbes can dramatically impact host health and fitness, and recent research in a diversity of systems suggests that different symbiont community structures may result in distinct outcomes for the host. In amphibians, some symbiotic skin bacteria produce metabolites that inhibit the growth of Batrachochytrium dendrobatidis (Bd), a cutaneous fungal pathogen that has caused many amphibian population declines and extinctions. Treatment with beneficial bacteria (probiotics) prevents Bd infection in some amphibian species and creates optimism for conservation of species that are highly susceptible to chytridiomycosis, the disease caused by Bd. In a laboratory experiment, we used Bd-inhibitory bacteria from Bd-tolerant Panamanian amphibians in a probiotic development trial with Panamanian golden frogs, Atelopus zeteki , a species currently surviving only in captive assurance colonies. Approximately 30% of infected golden frogs survived Bd exposure by either clearing infection or maintaining low Bd loads, but this was not associated with probiotic treatment. Survival was instead related to initial composition of the skin bacterial community and metabolites present on the skin. These results suggest a strong link between the structure of these symbiotic microbial communities and amphibian host health in the face of Bd exposure and also suggest a new approach for developing amphibian probiotics.


Author(s):  
T.A. Schram ◽  
L. Iversen ◽  
P.A. Heuch ◽  
E. Sterud

Six specimens of an unknown Argulus species were found on a cod caught off the coast of Finnmark in northern Norway. All six were found to be sixth stage male larvae, ∼2·6 mm long and 1·6 mm wide. Argulus has not previously been recorded from cod and this is also the first record of a marine Argulus from Norwegian waters. The Argulus sp. from cod can be easily distinguished from other marine species found in northern European waters, and also from Norwegian freshwater species of Argulus. It is believed that it represents a new species, but a complete species description must await the finding of adult stages.


2017 ◽  
Vol 149 ◽  
pp. 15-20 ◽  
Author(s):  
Japo Jussila ◽  
Al Vrezec ◽  
Tina Jaklič ◽  
Hobo Kukkonen ◽  
Jenny Makkonen ◽  
...  

2020 ◽  
Vol 25 (1) ◽  
pp. 31-37
Author(s):  
Kensuke Kamimura ◽  
Tadashi Kawai

Abstract Crayfish plague is a severe disease of crayfish that is caused by the oomycete Aphanomyces astaci. Two crayfish hosts of this parasite, Procambarus clarkii and Pacifastacus leniusculus, were imported from North America into Japan and were found to be infected with this parasite. Since the endemic Japanese crayfish, Cambaroides japonicus, has a low resistance to the crayfish plague, infection with this parasite will likely lead to crayfish death. Specimens of both invasive crayfish species were collected across Japan and their infection status was examined using a PCR technique. Aphanomyces astaci was detected in all localities and the average infection prevalence was 67%. Additionally, when the signs of melanization were compared with the results from PCR analyses, it suggested that the DNA detection procedure is more reliable than observation of tissue melanization. Moreover, the relationship between prevalence and water temperature in the field was analyzed, indicated that water temperature influenced the prevalence of A. astaci infection.


Author(s):  
Cláudia Regina da Silva Leite ◽  
Valter José Cobo

 This report provides the new record of the sponge Radiospongilla inesi and the slug Omalonyx matheroni for the Vale do Paraiba, State of São Paulo, southeastern Brazil, besides the symbiosis among R. inesi and individuals of some benthic macroinvertebrates. Monthly collections were carried out in the Ribeirão dos Mottas, with a 0.5 cm sieve in the edge vegetation, as well as collections by hand. Three specimens of R. inesi were found, from a lotic environment under pebbles. In addition, individuals of four insect families, Sisyridae, Hydropsychidae, Chironomidae e Simuliidae, were found on the sponge aquiferous system. Six individuals of the semi-aquatic slug O. matheroni were also caught under rocks and cans. Despite the sponges are commonly found in the most of the environments, the freshwater species represents one of the most unknown animal groups of the world.  R. inesi was report at first time in Brazil in Pernambuco State, northeastern Brazil region, and this report represents just the second record of this species in Brazil, and the first time to the southeastern region. The presence of individuals of four insect families pointing out the importance of R. inesi on the life history of these animals. Despite some records of Omalonix sp. to the São Paulo State, this report seems to be the first record of the O. matheroni to the Vale do Paraíba, northern of the São Paulo State.


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