scholarly journals Does juvenile Baltic sturgeon (Acipenser oxyrinchus) smell the enemy?

2018 ◽  
Author(s):  
Maria Cámara Ruiz ◽  
Carlos Espírito Santo ◽  
Alfons Mai ◽  
Jorn Gessner ◽  
Sven Wuertz

SUMMARYAtlantic sturgeon (Acipenser oxyrinchus), also known as Baltic sturgeon, is considered extinct in German waters. Fish-rearing for conservation purposes still relies on classical hatchery technology producing fish not well suited for facing life in the wild, lacking behavioural skills such as foraging or anti-predation. Predation is hence a major source of mortality in newly stocked individuals. The aim of this study was to evaluate if naïve Baltic sturgeon juveniles were able to smell and recognize a common predator, sander (Sander lucioperca). Over a period of 30 days, three tanks from each group of Baltic sturgeon were attached to a rearing tank with sander (sander unit) and, as a control, carp (carp unit). Morphology of the dorsal scutes, distribution within the tank, stress (glucose, lactate and cortisol) and gene expression of brain plasticity and cognition were studied in comparison to the control group (carp unit). No significant differences were observed in any of the parameters measured. Thus, we conclude that naïve Baltic sturgeon is not able to innately recognize potential predators and future studies should focus on implementing predator odour together with chemical alarm substances.

2018 ◽  
Author(s):  
Maria Cámara-Ruiz ◽  
Carlos Espirito Santo ◽  
Joern Gessner ◽  
Sven Wuertz

ABSTRACTAtlantic sturgeon (Acipenser oxyrinchus), also known as Baltic sturgeon, is considered missing or extinct in German waters. Current conservation efforts focus on re-stocking activities, but classical hatchery rearing may reduce the fitness of the respective juveniles. In this study, we evaluated if foraging efficiency can be improved by short term training. Over a period of 14 d, we kept individuals of the training group in a raceway and fed them chironomids buried in a small sand spot to stimulate benthic feeding behavior while fish of the control group were fed in tanks without substrate. Thereafter, each fish was transferred to a raceway entirely covered with sand. For feeding, chironomids were randomly buried in the sand. During the first 7 days, trained fish recovered the feed significantly faster than untrained fish of the control group. Gene expression revealed an up-regulation in neurod1 in all brain regions after 14 d of training. Thus, this study suggests that foraging efficiency can be improved through short-time training thus improve fitness upon restocking into the wild.


2021 ◽  
pp. 174749302110069
Author(s):  
Heidi Janssen ◽  
Louise Ada ◽  
Sandy Middleton ◽  
Michael Pollack ◽  
Michael Nilsson ◽  
...  

Background: Environmental enrichment involves organisation of the environment and provision of equipment to facilitate engagement in physical, cognitive and social activity. In animals with stroke, it promotes brain plasticity and recovery. Aims: To assess the feasibility and safety of a patient-driven model of environmental enrichment incorporating access to communal and individual environmental enrichment. Methods: A non-randomised cluster trial with blinded measurement involving people with stroke (n=193) in 4 rehabilitation units was carried out. Feasibility was operationalised as activity 10 days after admission to rehabilitation and availability of environmental enrichment. Safety was measured as falls and serious adverse events. Benefit was measured as clinical outcomes at 3 months, by an assessor blinded to group. Results: The experimental group (n=91) spent 7% (95% CI -14 to 0) less time inactive, 9% (95% CI 0 to 19) more time physically, and 6% (95% CI 2 to 10) more time socially active than the control group (n=102). Communal environmental enrichment was available 100% of the time, but individual environmental enrichment was rarely within reach (24%) or sight (39%). There were no between-group differences in serious adverse events or falls at discharge or 3 months nor in clinical outcomes at 3 months. Conclusions: This patient-driven model of environmental enrichment was feasible and safe. However, the very modest increase in activity by people with stroke, and the lack of benefit in clinical outcomes 3 months after stroke do not provide justification for an efficacy trial. Clinical Trial Registration: ANZCTR 12613000796785 Words: 245


2010 ◽  
Vol 115 (3) ◽  
pp. 193-206 ◽  
Author(s):  
Cheryl Frenck-Mestre ◽  
Nathalie Zardan ◽  
Annie Colas ◽  
Alain Ghio

Abstract Eye movements were examined to determine how readers with Down syndrome process sentences online. Participants were 9 individuals with Down syndrome ranging in reading level from Grades 1 to 3 and a reading-level-matched control group. For syntactically simple sentences, the pattern of reading times was similar for the two groups, with longer reading times found at sentence end. This “wrap-up” effect was also found in the first reading of more complex sentences for the control group, whereas it only emerged later for the readers with Down syndrome. Our results provide evidence that eye movements can be used to investigate reading in individuals with Down syndrome and underline the need for future studies.


2021 ◽  
pp. 089198872110064
Author(s):  
Kevin Duff ◽  
Jian Ying ◽  
Kayla R. Suhrie ◽  
Bonnie C.A. Dalley ◽  
Taylor J. Atkinson ◽  
...  

Objective: Computerized cognitive training has been successful in healthy older adults, but its efficacy has been mixed in patients with amnestic Mild Cognitive Impairment (MCI). Methods: In a randomized, placebo-controlled, double-blind, parallel clinical trial, we examined the short- and long-term efficacy of a brain-plasticity computerized cognitive training in 113 participants with amnestic MCI. Results: Immediately after 40-hours of training, participants in the active control group who played computer games performed better than those in the experimental group on the primary cognitive outcome (p = 0.02), which was an auditory memory/attention composite score. There were no group differences on 2 secondary outcomes (global cognitive composite and rating of daily functioning). After 1 year, there was no difference between the 2 groups on primary or secondary outcomes. No adverse events were noted. Conclusions: Although the experimental cognitive training program did not improve outcomes in those with MCI, the short-term effects of the control group should not be dismissed, which may alter treatment recommendations for these patients.


2021 ◽  
Author(s):  
Yang Cao ◽  
fei song ◽  
Xingtang Zhao ◽  
Liming He ◽  
Yaguang Zhan

Abstract Background: In this study, sodium nitrate (SNP, a donor of nitric oxide) and methyl jasmonate (MJ) were used as exogenous hormones. The experiment was conducted with the offspring (interspecific hybrid) D110 of ash and ash, and their respective parents (non-interspecific hybrid) D113 and 4-3 as experimental materials. The experiment set up three experimental groups of drought stress, exogenous hormone SNP and MJ, and a control group under normal growth (non-drought stress), to study the physiological indicators and gene expression of manchurian ash. Result: The results showed that under drought stress and exogenous application of hormone SNP or MJ, there were significant differences between hybrids and parents in plant growth, photosynthesis, defense enzyme activity, hormone content and gene expression.Conclusions: This experiment provides a new theoretical support for the existing hormone breeding methods of manchurian ash, which can improve the drought resistance of manchurian ash and increase its survival rate in the wild. Increasing the growth rate and breeding efficiency of manchurian ash brings new ideas.


2018 ◽  
Vol 20 (2) ◽  
pp. 167-184 ◽  
Author(s):  
John Waldman ◽  
S. Elizabeth Alter ◽  
Douglas Peterson ◽  
Lorraine Maceda ◽  
Nirmal Roy ◽  
...  

2021 ◽  
Author(s):  
Matthew Balazik ◽  
Safra Altman ◽  
Kevin Reine ◽  
Alan Katzenmeyer

This technical note describes a field study investigating the movements of federally endangered Atlantic sturgeon, Acipenser oxyrinchus oxyrinchus (ATS), during the summer and fall of 2017 near a cutterhead dredge working in the James River, Virginia, to provide data addressing the concern about the potential impacts of dredging activities (for example, excavation, transit, disposal, sounds, reduced water quality) on the ATS.


2018 ◽  
Vol 92 (4) ◽  
pp. 929-943
Author(s):  
L. M. Logan-Chesney ◽  
M. J. Dadswell ◽  
R. H. Karsten ◽  
I. Wirgin ◽  
M. J. W. Stokesbury

<em>Abstract</em>.—The anadromous Atlantic sturgeon <em>Acipenser oxyrinchus</em> once supported an important commercial fishery throughout its range (northern Florida, USA, to Labrador, Canada). All surviving populations are apparently depleted, presumably due to overfishing, pollution, and dam construction. A complete moratorium on the fishery has been established in U.S. waters. Unfortunately, population status is unknown for nearly all systems. Several 1994–2001 data sets from South Carolina rivers were examined for their potential in development of recruitment (year-class abundance) indices. Because Atlantic sturgeon often begin leaving their natal systems at age 2, after which they occupy other systems and then presumably return to natal areas at sexual maturity several years later, a valid river-specific abundance index must be based on either age0–1 or adult fish. Working with three former commercial Atlantic sturgeon fishermen to collect adults in two rivers during the spring and fall of 1998 resulted in collection of only 39 fish in 13 nominal age-classes. In another river, 2 years of monthly sampling with multipanel, anchored gill nets and otter trawls at eight stations throughout the estuary produced only 31 juvenile Atlantic sturgeon. Neither of these study designs provided adequate sample sizes. However, sampling in a clean-bottom section at the freshwater–brackish water interface of the Edisto River with a modified drift gill net produced large numbers of small Atlantic sturgeon. More than 3,000 juveniles have been collected and tagged since 1994. The 1,331 nominal age-1 Atlantic sturgeon that were captured displayed a distinct bimodal length frequency distribution, supporting the hypothesis that there are both spring and fall spawning events. A period of record drought impeded sampling efforts during a portion of this study. However, when flows and bottom configurations allow nets to be fished at the freshwater–brackish water interface, the gears and methods employed in the Edisto River can produce an age-1 Atlantic sturgeon catch per unit effort that is high enough to be used in estimating relative year-class strength.


<em>Abstract.</em>—Large-scale commercial fisheries for Atlantic sturgeon <em>Acipenser oxyrinchus</em> in the late 1880s eventually led to substantial reductions in the population size. The coastwide Atlantic sturgeon population of the United States has not recovered to the levels seen prior to the 1900s. A number of factors have contributed to the slow recovery or continued decline of Atlantic sturgeon populations, including continued commercial fishing and the targeting of females for caviar, bycatch in other fisheries, and changes in habitat due to dam construction and water quality degradation. The Atlantic States Marine Fisheries Commission (ASMFC) developed the first coastwide management plan for Atlantic sturgeon in 1990. In response to the shortcomings of that plan, the ASMFC applied new standards and the authority granted to it by the U.S. Congress to adopt a coastwide moratorium on all harvesting in 1998. A federal status review conducted in 1998 concluded that the continued existence of Atlantic sturgeon was not threatened given the situation at the time. Since then, monitoring programs have indicated varying levels of relative abundance in several water bodies along the Atlantic coast. The U.S. government is responsible for undertaking a status review to document any changes since the last review and determining whether those findings warrant a threatened or endangered listing for the species. The government’s findings may have far-reaching effects on many other Atlantic coastal fisheries.


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