scholarly journals Molecular approaches reveal weak sibship aggregation and a high dispersal propensity in a non‐native fish parasite

2021 ◽  
Author(s):  
Jérôme G. Prunier ◽  
Keoni Saint‐Pé ◽  
Simon Blanchet ◽  
Géraldine Loot ◽  
Olivier Rey
Keyword(s):  
Native Fish ◽  
Fish Parasite ◽  
Molecular Approaches ◽  
High Dispersal ◽  
Dispersal Propensity

Habitat use, but not dispersal limitation, as the mechanism behind the aggregated population structure of the mygalomorph species Atypus affinis

2012 ◽  
Vol 62 (2) ◽  
pp. 181-192 ◽  
Author(s):  
Julien Pétillon ◽  
David Deruytter ◽  
Arthur Decae ◽  
David Renault ◽  
Dries Bonte
Keyword(s):  
Habitat Use ◽  
Calluna Vulgaris ◽  
Dispersal Limitation ◽  
High Dispersal ◽  
Negative Effect ◽  
Dispersal Abilities ◽  
Dispersal Propensity ◽  
Positive Effect ◽  
Very High ◽  
Habitat Variables

Dispersal and habitat selection are the main factors that affect the distribution of species in spatially structured habitat. Species typically occurring in an aggregated way are supposed to experience dispersal limitation or to be highly selective for specific habitat attributes in their environment. In order to understand the distribution pattern of a mygalomorph spider species, Atypus affinis, we conducted an intensive survey to detect correlations of spider densities with specific habitat variables and empirically tested the dispersal propensity of spiderlings. In the field, the spiders exhibited an aggregated distribution correlated with patches of heathlands (dominated by Calluna vulgaris). Contrary to our expectations, laboratory experiments revealed a very high dispersal propensity in juveniles (more than 80% of individuals dispersed at least once during two experiments). This dispersal was strongly context dependent with a pronounced negative effect of starvation and a positive effect of clutch size. Kin competition is hypothezised to be the driving force behind these high dispersal abilities. The aggregation of A. affinis is a likely result of habitat use rather than dispersal limitation.

scholarly journals Quantification of floating ephippia in lakes: a step to a better understanding of high dispersal propensity of freshwater plankters

Hydrobiologia ◽  
2015 ◽  
Vol 798 (1) ◽  
pp. 61-72 ◽  
Author(s):  
Mirosław Ślusarczyk ◽  
Tomasz Grabowski ◽  
Barbara Pietrzak
Keyword(s):  
High Dispersal ◽  
Dispersal Propensity

scholarly journals Experimental transmission of Caligus rogercresseyi between two different fish species

2020 ◽  
Vol 141 ◽  
pp. 127-138
Author(s):  
MP González-Gómez ◽  
L Ovalle ◽  
C Spinetto ◽  
C Oyarzo ◽  
R Oyarzún ◽  
...  
Keyword(s):  
Salmo Salar ◽  
Fish Species ◽  
Native Fish ◽  
Fish Parasite ◽  
Southern Chile ◽  
Experimental Transmission ◽  
Eleginops Maclovinus ◽  
Wide Range ◽  
Developmental Rates ◽  
Fish Hosts

Caligus rogercresseyi is the dominant sea louse parasite affecting the salmon and trout industry in southern Chile. This parasite has a wide range of native and endemic fish hosts. The Patagonian blenny Eleginops maclovinus, which is parasitized mostly by the caligid species Lepeophtheirus spp. and C. rogercresseyi, is presumably responsible for the transmission of C. rogercresseyi to salmonids. The aim of this study was to characterize the transmission of parasites between different fish species and parasite cohort development under laboratory conditions. Parasite abundances and intensities were quantified. Transmission of parasites from Patagonian blenny to Atlantic salmon Salmo salar was lower (~9%, mainly corresponding to C. rogercresseyi) than from salmon to Patagonian blenny (14.7-26.9%, where only C. rogercresseyi were observed). This suggests that the transmission of C. rogercresseyi from salmon individuals is higher than the transmission from a native fish. Parasite cohorts developed successfully on both fish species, but apparently under different developmental rates. Water temperature, oxygen, and juvenile abundances were the variables that better explained cohort development success and variation in C. rogercresseyi adult abundances over time.

scholarly journals Egg predation on native fish by invasive round goby revealed by species-specific gut content DNA analyses

2019 ◽  
Author(s):  
Elisabeth Lutz ◽  
Philipp Hirsch ◽  
Karen Bussmann ◽  
Joschka Wiegleb ◽  
Hans-Peter Jermann ◽  
...  
Keyword(s):  
Freshwater Fish ◽  
Round Goby ◽  
Neogobius Melanostomus ◽  
Native Fish ◽  
Gut Content ◽  
Egg Predation ◽  
Spawning Period ◽  
Molecular Approaches ◽  
Longitudinal Connectivity ◽  
Species Specific

1.Conservation of riverine fish typically aims at improving access to spawning grounds and the restoration of longitudinal connectivity requires substantial investments. However, the removal of migration barriers also enables the upstream invasion of non-native species into spawning areas, with potential negative effects on recruitment of threatened freshwater fish through egg or fry predation. 2.Detecting egg predation is often challenging. Visual gut inspections are thought to underestimate predation on soft material such as eggs and fry, which hampers the discovery of predators preying upon these life-stages. For soft materials, molecular approaches may therefore offer a more sensitive tool for detection. 3.Here, we uncover such a macroscopically invisible conservation issue caused by predation of invasive round goby (Neogobius melanostomus) predation on eggs or fry of threatened common nase (Chondrostoma nasus) in Switzerland.4.In addition, this manuscript presents species-specific molecular assays for five more valuable native fish, including endangered salmonid and cyprinid river spawners, and confirms the applicability of the assays in a series of laboratory and field feeding experiments involving eggs and fish tissue. The manuscript also provides a guiding tool for conservation managers regarding the use and applicability of different molecular approaches in gut-content analysis.5.Our results inspire recommendations for local conservation measures such as a temporary reduction of round goby densities at the spawning site prior to the spawning period, and demonstrate how the targeted application of species-specific molecular markers can inform freshwater fish management.

Exploring molecular approaches in Amyotrophic lateral sclerosis: Drug targets from clinical and pre-clinical findings

2020 ◽  
Vol 13 ◽  
Author(s):  
Mamtaj Alam ◽  
Rajeshwar Kumar Yadav ◽  
Elizabeth Minj ◽  
Aarti Tiwari ◽  
Sidharth Mehan
Keyword(s):  
Amyotrophic Lateral Sclerosis ◽  
Motor Neurons ◽  
Drug Targets ◽  
Therapeutic Index ◽  
Experimental Models ◽  
Clinical Findings ◽  
Adenyl Cyclase ◽  
Molecular Approaches ◽  
Pharmacologically Active ◽  
Lateral Sclerosis

: Amyotrophic lateral sclerosis (ALS) is a fatal motor neuron disease (MND) characterised by the death of upper and lower motor neurons (corticospinal tract) in the motor cortex, basal ganglia, brain stem, and spinal cord. The patient experiences the sign and symptoms between 55 to 75 years of age included impaired motor movement, difficulty in speaking and swallowing, grip loss, muscle atrophy, spasticity and sometimes associated with memory and cognitive impairments. Median survival is 3 to 5 years after diagnosis and 5 to 10% beyond 10 years of age. The limited intervention of pharmacologically active compounds that are used clinically is majorly associated with the narrow therapeutic index. Pre-clinically established experimental models where neurotoxin methyl mercury mimics the ALS like behavioural and neurochemical alterations in rodents associated with neuronal mitochondrial dysfunctions and downregulation of adenyl cyclase mediated cAMP/CREB is the main pathological hallmark for the progression of ALS in central as well in the peripheral nervous system. Despite the considerable investigation into neuroprotection, it still constrains treatment choices to strong care and organization of ALS complications. Therefore, current review specially targeted in the investigation of clinical and pre-clinical features available for ALS to understand the pathogenic mechanisms and to explore the pharmacological interventions associated with up-regulation of intracellular adenyl cyclase/cAMP/CREB and mitochondrial-ETC coenzyme-Q10 activation as a future drug target in the amelioration of ALS mediated motor neuronal dysfunctions.

Neuronal nitric oxide synthase and systemic vasodilation in rats with cirrhosis

2000 ◽  
Vol 279 (6) ◽  
pp. F1110-F1115 ◽  
Author(s):  
Lieming Xu ◽  
Ethan P. Carter ◽  
Mamiko Ohara ◽  
Pierre-Yves Martin ◽  
Boris Rogachev ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Liver Cirrhosis ◽  
Nitric Oxide Synthase ◽  
Control Treatment ◽  
Sodium Balance ◽  
Hyperdynamic Circulation ◽  
Molecular Approaches ◽  
Advanced Liver Cirrhosis ◽  
Oxide Synthase

Cirrhosis is typically associated with a hyperdynamic circulation consisting of low blood pressure, low systemic vascular resistance (SVR), and high cardiac output. We have recently reported that nonspecific inhibition of nitric oxide synthase (NOS) with nitro-l-arginine methyl ester reverses the hyperdynamic circulation in rats with advanced liver cirrhosis induced by carbon tetrachloride (CCl4). Although an important role for endothelial NOS (eNOS) is documented in cirrhosis, the role of neuronal NOS (nNOS) has not been investigated. The present study was carried out to specifically investigate the role of nNOS during liver cirrhosis. Specifically, physiological, biochemical, and molecular approaches were employed to evaluate the contribution of nNOS to the cirrhosis-related hyperdynamic circulation in CCl4-induced cirrhotic rats with ascites. Cirrhotic animals had a significant increase in water and sodium retention. In the aorta from cirrhotic animals, both nNOS protein expression and cGMP concentration were significantly elevated compared with control. Treatment of cirrhotic rats for 7 days with the specific nNOS inhibitor 7-nitroindazole (7-NI) normalized the low SVR and mean arterial pressure, elevated cardiac index, and reversed the positive sodium balance. Increased plasma arginine vasopressin concentrations in the cirrhotic animals were also repressed with 7-NI in association with diminished water retention. The circulatory changes were associated with a reduction in aortic nNOS expression and cGMP. However, 7-NI treatment did not restore renal function in cirrhotic rats (creatinine clearance: 0.76 ± 0.03 ml · min−1· 100 g body wt−1in cirrhotic rats vs. 0.79 ± 0.05 ml · min−1· 100 g body wt−1in cirrhotic rats+7-NI; P NS.). Taken together, these results indicate that nNOS-derived NO contributes to the development of the hyperdynamic circulation and fluid retention in cirrhosis.

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