scholarly journals Wild and farmed burbot Lota lota: differences in energy consumption and behavior during the spawning season

2021 ◽  
Vol 13 ◽  
pp. 51-63
Author(s):  
O Slavík ◽  
P Horký
Keyword(s):  
Spatial Distribution ◽  
Energy Consumption ◽  
Egg Production ◽  
Spawning Season ◽  
Movement Activity ◽  
Farmed Fish ◽  
In The Wild ◽  
Spawning Behaviour ◽  
And Behavior ◽  
Wild Group

Farmed fish released in a native environment can display different spawning behaviour compared to their wild conspecifics. In our study, farmed and wild burbot, a species recently introduced for aquacultural production, were equipped with electromyogram (EMG) radio tags. EMG biotelemetry allows a description of the spatial distribution of fish together with simultaneous measurements of individual energy consumption. Farmed burbot were released into the wild to simulate stocking or hatchery escape and were observed over a nocturnal phase during November to January. The observational period was assumed to cover the whole spawning season, including an expected peak of spawning activity determined according to egg production by naturally spawning burbot in an experimental seminatural river channel. We detected increased energy consumption and lower movement activity at the time of expected peak spawning for wild burbot only. Across the whole spawning season, farmed females showed lower movement activity and energy consumption than wild females, whereas the opposite results were found for farmed males. Farmed and wild fish kept larger distances between each other than the individuals within a group (farmed and wild) across the whole spawning season. The closest positions occurred between males and females in the wild group, while for farmed fish, the closest position was found within the same sex. Sexually conditioned energy consumption and spatial distribution differed between wild and farmed fish.

Golden Shiner Egg Production during a Spawning Season

2010 ◽  
Vol 72 (3) ◽  
pp. 272-277 ◽  
Author(s):  
Troy Clemment ◽  
Nathan Stone
Keyword(s):  
Egg Production ◽  
Spawning Season ◽  
Golden Shiner

scholarly journals Features Of Hippocampal Astrocytic Domains And Their Spatial Relation To Excitatory And Inhibitory Neurons

2020 ◽  
Author(s):  
Ron Refaeli ◽  
Adi Doron ◽  
Aviya Benmelech-Chovav ◽  
Maya Groysman ◽  
Tirzah Kreisel ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Pyramidal Neurons ◽  
Spatial Relation ◽  
Design Principles ◽  
Inhibitory Neurons ◽  
Computational Tools ◽  
Close Proximity ◽  
Somatostatin Neurons ◽  
And Behavior ◽  
Elaborate Structure

SUMMARYThe mounting evidence for the involvement of astrocytes in neuronal circuits function and behavior stands in stark contrast to the lack of detailed anatomical description of these cells and the neurons in their domains. To fill this void, we imaged >30,000 astrocytes in cleared hippocampi, and employed converging genetic, histological and computational tools to determine the elaborate structure, distribution and neuronal content of astrocytic domains. First, we characterized the spatial distribution of >19,000 astrocytes across CA1 lamina, and analyzed the detailed morphology of thousands of reconstructed domains. We then determined the excitatory content of CA1 astrocytes, averaging above 13 pyramidal neurons per domain and increasing towards CA1 midline. Finally, we discovered that somatostatin neurons are found in close proximity to astrocytes, compared to parvalbumin and VIP inhibitory neurons. This resource expands our understanding of fundamental hippocampal design principles, and provides the first quantitative foundation for neuron-astrocyte interactions in this region.

scholarly journals Density-dependent changes in neophobia and stress-coping styles in the world's oldest farmed fish

2018 ◽  
Vol 5 (12) ◽  
pp. 181473 ◽  
Author(s):  
T. Champneys ◽  
G. Castaldo ◽  
S. Consuegra ◽  
C. Garcia de Leaniz
Keyword(s):  
Coping Style ◽  
Coping Styles ◽  
High Density ◽  
Low Density ◽  
Stress Coping ◽  
Farmed Fish ◽  
Test Arena ◽  
Novel Foods ◽  
In Captivity ◽  
In The Wild

Farmed fish are typically reared at densities much higher than those observed in the wild, but to what extent crowding results in abnormal behaviours that can impact welfare and stress coping styles is subject to debate. Neophobia (i.e. fear of the ‘new’) is thought to be adaptive under natural conditions by limiting risks, but it is potentially maladapted in captivity, where there are no predators or novel foods. We reared juvenile Nile tilapia ( Oreochromis niloticus ) for six weeks at either high (50 g l −1 ) or low density (14 g l −1 ), assessed the extent of skin and eye darkening (two proxies of chronic stress), and exposed them to a novel object in an open test arena, with and without cover, to assess the effects of density on neophobia and stress coping styles. Fish reared at high density were darker, more neophobic, less aggressive, less mobile and less likely to take risks than those reared at low density, and these effects were exacerbated when no cover was available. Thus, the reactive coping style shown by fish at high density was very different from the proactive coping style shown by fish at low density. Our findings provide novel insights into the plasticity of fish behaviour and the effects of aquaculture intensification on one of the world's oldest farmed and most invasive fish, and highlight the importance of considering context. Crowding could have a positive effect on the welfare of tilapia by reducing aggressive behaviour, but it can also make fish chronically stressed and more fearful, which could make them less invasive.

Multiple spawning and the dynamics of fish populations: inferences from an individual-based simulation model

1998 ◽  
Vol 55 (10) ◽  
pp. 2244-2254 ◽  
Author(s):  
Susan K Lowerre-Barbieri ◽  
James M Lowerre ◽  
Luiz R Barbieri
Keyword(s):  
Simulation Model ◽  
Egg Production ◽  
Adult Population ◽  
Individual Variability ◽  
Spawning Season ◽  
Average Life Span ◽  
Multiple Spawning ◽  
Individual Based Simulation ◽  
First Maturity ◽  
Size At Age

We used an individual-based Monte Carlo simulation model to assess how aspects associated with multiple spawning (within a spawning season) affected survivorship, lifetime fecundity, cohort egg production, and yield-per-recruit of a highly exploited species. To make our model more realistic, we included and tested the effects of individual variability in growth and a seasonal growth pattern. Birth months influenced when fish first matured and became vulnerable to the fishery. There was a sixfold increase in mature fish at the beginning of their first spawning season associated with having been born early versus late the previous season. Early born fish had a lower average life-span than later born fish. Although early born fish had lower survivorship they produced the most eggs because of an early size at first maturity, low fishing mortality in the first year, and their larger size at age. These results suggest multiple spawning can have important implications for recruitment and adult population dynamics.

Spawning Behaviour and Spatial Distribution of Atlantic Herring on Georges Bank Revealed by Ocean Acoustics Waveguide Remote Sensing

2008 ◽  
Vol 123 (5) ◽  
pp. 3103-3103 ◽  
Author(s):  
Purnima Ratilal ◽  
Zheng Gong ◽  
Daniel Cocuzzo ◽  
Mark Andrews ◽  
Srinivasan Jagannathan ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Spatial Distribution ◽  
Atlantic Herring ◽  
Georges Bank ◽  
Ocean Acoustics ◽  
Spawning Behaviour

scholarly journals A poor substitute for the real thing: captive-reared monarch butterflies are weaker, paler and have less elongated wings than wild migrants

2020 ◽  
Vol 16 (4) ◽  
pp. 20190922 ◽  
Author(s):  
Andrew K. Davis ◽  
Farran M. Smith ◽  
Ashley M. Ballew
Keyword(s):  
Danaus Plexippus ◽  
Late Summer ◽  
Population Declines ◽  
Average Strength ◽  
Long Distance ◽  
Monarch Butterflies ◽  
Real Thing ◽  
In The Wild ◽  
Wild Group ◽  
Migration Propensity

For many animals and insects that are experiencing dramatic population declines, the only recourse for conservationists is captive rearing. To ensure success, reared individuals should be biologically indistinct from those in the wild. We tested if this is true with monarch butterflies, Danaus plexippus , which are increasingly being reared for release by citizens and commercial breeders. Since late-summer monarchs should be as migration capable as possible for surviving the arduous long-distance migration, we evaluated four migration-relevant traits across two groups of captive-reared monarchs ( n = 41 and 42) and one group of wild-caught migrants ( n = 41). Monarchs (descendants of wild individuals) were reared from eggs to adulthood either in a warm indoor room next to a window, or in an incubator that mimicked late-summer conditions. Using an apparatus consisting of a perch mounted to an electronic force gauge, we assessed ‘grip strength' of all groups, then used image analysis to measure forewing size, pigmentation and elongation. In three of the four traits, reared monarchs underperformed compared to wild ones, even those reared under conditions that should have produced migration-ready individuals. The average strength of reared monarchs combined was 56% less than the wild group, even when accounting for size. Their orange wing colour was paler (an indicator of poor condition and flight ability) and their forewings were less elongated (elongation is associated with migration propensity) than wild monarchs. The reason(s) behind these effects is unknown but could stem from the frequent disturbance and/or handling of reared monarchs, or the fact that rearing removes the element of natural selection from all stages. Regardless, these results explain prior tagging studies that showed reared monarchs have lower migratory success compared to wild.

scholarly journals Sexual conflict drives male manipulation of female postmating responses inDrosophila melanogaster

2019 ◽  
Vol 116 (17) ◽  
pp. 8437-8444 ◽  
Author(s):  
Brian Hollis ◽  
Mareike Koppik ◽  
Kristina U. Wensing ◽  
Hanna Ruhmann ◽  
Eléonore Genzoni ◽  
...  
Keyword(s):  
Sexual Conflict ◽  
Egg Production ◽  
Seminal Fluid ◽  
Activity Levels ◽  
Feeding Rates ◽  
Single Male ◽  
Seminal Fluid Proteins ◽  
Expression Of Genes ◽  
Genes Encoding ◽  
And Behavior

In many animals, females respond to mating with changes in physiology and behavior that are triggered by molecules transferred by males during mating. InDrosophila melanogaster, proteins in the seminal fluid are responsible for important female postmating responses, including temporal changes in egg production, elevated feeding rates and activity levels, reduced sexual receptivity, and activation of the immune system. It is unclear to what extent these changes are mutually beneficial to females and males or instead represent male manipulation. Here we use an experimental evolution approach in which females are randomly paired with a single male each generation, eliminating any opportunity for competition for mates or mate choice and thereby aligning the evolutionary interests of the sexes. After >150 generations of evolution, males from monogamous populations elicited a weaker postmating stimulation of egg production and activity than males from control populations that evolved with a polygamous mating system. Males from monogamous populations did not differ from males from polygamous populations in their ability to induce refractoriness to remating in females, but they were inferior to polygamous males in sperm competition. Mating-responsive genes in both the female abdomen and head showed a dampened response to mating with males from monogamous populations. Males from monogamous populations also exhibited lower expression of genes encoding seminal fluid proteins, which mediate the female response to mating. Together, these results demonstrate that the female postmating response, and the male molecules involved in eliciting this response, are shaped by ongoing sexual conflict.

Secondary sexual characters, energy use, senescence, and the cost of reproduction in sockeye salmon

1999 ◽  
Vol 77 (11) ◽  
pp. 1663-1675 ◽  
Author(s):  
Andrew P Hendry ◽  
Ole K Berg
Keyword(s):  
Egg Production ◽  
Sockeye Salmon ◽  
Energy Use ◽  
Relative Size ◽  
Cost Of Reproduction ◽  
Bristol Bay ◽  
Secondary Sexual Characters ◽  
In The Wild ◽  
The Cost ◽  
Secondary Sexual

Reproductive development and energy stores were characterized for sockeye salmon (Oncorhynchus nerka) maturing in the wild (Pick Creek, Bristol Bay, Alaska). Between freshwater entry and the start of spawning, ovaries increased in mass by 87.1% and secondary sexual characters increased in linear dimension by 13.0-47.4%. Between the start of spawning and death, secondary sexual characters decreased in relative size by 3.3-12.7%. Mass-specific somatic energy declined from freshwater entry (6.7% fat, 20.6% protein, 6.6 kJ·g-1) to the start of spawning (1.6% fat, 18.0% protein, 4.5 kJ·g-1) and finally to death (0.1% fat, 14.4% protein, 2.9 kJ·g-1). Stored fat appeared to be used primarily for upriver migration and egg production, whereas stored protein appeared to be used primarily for the development of secondary sexual characters and metabolism during spawning. Most development of secondary sexual characters occurred late in maturation, perhaps to forestall deterioration of muscle tissue. Relative to populations with long freshwater migrations, Bristol Bay sockeye salmon stored less fat before entering fresh water and used less fat before death. The total energy cost of reproduction (freshwater entry until death, including gonad investment) was 74.1% for females and 66.1% for males, higher than levels typically reported for iteroparous salmonids.

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