The temporal-spatial pattern of vertical migration by the freshwater copepod Skistodiaptomus oregonensis relative to predation risk

1998 ◽  
Vol 55 (6) ◽  
pp. 1350-1363 ◽  
Author(s):  
David Ghan ◽  
J D McPhail ◽  
K D Hyatt
Keyword(s):  
Predation Risk ◽  
Surface Waters ◽  
Vertical Migration ◽  
Feeding Behaviour ◽  
Sockeye Salmon ◽  
Laboratory Experiments ◽  
Gasterosteus Aculeatus ◽  
Feeding Rate ◽  
Predation Rate ◽  
Threespine Stickleback

Skistodiaptomus oregonensis vertical migration in Kennedy Lake and Paxton Lake may be an adaptation to avoid predation by threespine stickleback (Gasterosteus aculeatus). In Kennedy Lake, juvenile sockeye salmon (Oncorhynchus nerka) and the mysid Neomysis mercedis are also predators that potentially drive the vertical migration. A corollary of the hypothesis that predation selects for vertical migration is that the extent and timing of the vertical migration decreases predation risk. This corollary is tested for each of the potential predators. Laboratory experiments indicate that stickleback feeding rate decreases below 1.6 µE ·s-1 ·m-2. In Kennedy and Paxton lakes, S. oregonensis occupied depths below this light intensity during the day. Furthermore, as S. oregonensis ascended at dusk and descended at dawn, they remained within light intensities that reduced stickleback predation rate. In Kennedy Lake, hydroacoustic data coupled with information in the literature on feeding behaviour of juvenile sockeye indicate that this species move to surface waters to feed before sunrise and after sunset. Vertically migrating S. oregonensis are near the surface during the twilight feeding periods of juvenile sockeye. The timing of S. oregonensis vertical migration also does not reduce the time it is in contact with the predator N. mercedis.

scholarly journals Divergent Response to the SSRI Citalopram in Male and Female Three-Spine Sticklebacks (Gasterosteus aculeatus)

2020 ◽  
Vol 79 (4) ◽  
pp. 478-487
Author(s):  
Martin Kellner ◽  
K. Håkan Olsén
Keyword(s):  
Surface Waters ◽  
Aggressive Behaviour ◽  
Feeding Behaviour ◽  
Selective Serotonin Reuptake Inhibitors ◽  
Gasterosteus Aculeatus ◽  
Male And Female ◽  
Behavioural Effects ◽  
Before And After ◽  
Over Time ◽  
Divergent Response

AbstractSelective serotonin reuptake inhibitors (SSRIs) are psychotropic pharmaceuticals used as antidepressants. SSRIs are commonly found in surface waters in populated areas across the globe. They exert their effect by blocking the serotonin re-uptake transporter in the presynaptic nerve ending. The present study examined whether behavioural effects to exposure to SSRI citalopram depend on personality and sex in the stickleback (Gasterosteus aculeatus). Three aspects of stickleback behaviour are examined: feeding behaviour, aggression, and boldness. We exposed sticklebacks to 350–380 ng/l citalopram for 3 weeks. Feeding and aggressive behaviour were recorded before and after exposure, whereas scototaxis behaviour was tested after exposure. The results show treatment effects in feeding and aggressive behaviour. Feeding is suppressed only in the male group (χ2 = 20.4, P < 0.001) but not in the females (χ2 = 0.91, P = 0.339). Aggressive behaviour was significantly affected by treatment (χ2 = 161.9, P < 0.001), sex (χ2 = 86.3, P < 0.001), and baseline value (χ2 = 58.8, P < 0.001). Aggressiveness was suppressed by citalopram treatment. In addition, the fish showed no change in aggression and feeding behaviour over time regardless of sex and treatment, which indicate personality traits. Only females are affected by treatment in the scototaxis test. The exposed females spent significantly (χ2 = 5.02, P = 0.050) less time in the white zone than the female controls.

scholarly journals Density-Dependent Habitat Selection in a Growing Threespine Stickleback Population

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Ulrika Candolin ◽  
Marita Selin
Keyword(s):  
Population Growth ◽  
Predation Risk ◽  
Gasterosteus Aculeatus ◽  
Structural Complexity ◽  
Perca Fluviatilis ◽  
Threespine Stickleback ◽  
Density Dependent ◽  
Offspring Production ◽  
Foraging Rate ◽  
Complex Habitat

Human-induced eutrophication has increased offspring production in a population of threespine sticklebackGasterosteus aculeatusin the Baltic Sea. Here, we experimentally investigated the effects of an increased density of juveniles on behaviours that influence survival and dispersal, and, hence, population growth—habitat choice, risk taking, and foraging rate. Juveniles were allowed to choose between two habitats that differed in structural complexity, in the absence and presence of predators and conspecific juveniles. In the absence of predators or conspecifics, juveniles preferred the more complex habitat. The preference was further enhanced in the presence of a natural predator, a perchPerca fluviatilis(behind a transparent Plexiglas wall). However, an increased density of conspecifics relaxed the predator-enhanced preference for the complex habitat and increased the use of the open, more predator-exposed habitat. Foraging rate was reduced under increased perceived predation risk. These results suggest that density-dependent behaviours can cause individuals to choose suboptimal habitats where predation risk is high and foraging rate low. This could contribute to the regulation of population growth in eutrophicated areas where offspring production is high.

Effects of Predation Risk and Parasitism on the Feeding Ecology, Habitat Use, and Abondance of Lacustrine Threespine Stickleback (Gasterosteus aculeatus)

1988 ◽  
Vol 45 (3) ◽  
pp. 426-431 ◽  
Author(s):  
Per Johan Jakobsen ◽  
Geir Helge Johnsen ◽  
Petter Larsson
Keyword(s):  
Predation Risk ◽  
Salmo Salar ◽  
Littoral Zone ◽  
Gasterosteus Aculeatus ◽  
Population Decline ◽  
Length Distribution ◽  
Threespine Stickleback ◽  
Selective Predation ◽  
Restricted Area ◽  
High Predation

From 1980 to 1985, we investigated a lacustrine population of threespine stickleback (Gasterosteus aculeatus) with respect to densities, individual length, distribution, diet, frequency of parasitism by Schistocepbalus solidus, and selective predation by Atlantic salmon (Salmo salar). From these investigations we concluded the following. (1) When stickleback are forced into the littoral zone by salmon, competition in this restricted area increases, or alternatively, stickleback distribute themselves in an area with less profitable prey. This, combined with predation from salmon, results in a population decline and reduced growth of the stickleback. (2) At least in autumn, parasitized stickleback distribute themselves in areas with high predation risk from salmon; when exposed to salmon predation, parasitized stickleback are preyed upon at a higher rate than healthy ones. Hence, parasitized individuals have almost disappeared from the stickleback population in Lake Kvernavann, Norway.

Benefits and costs of vertical migration by the freshwater copepod Skistodiaptomus oregonensis: testing hypotheses through population comparison

1998 ◽  
Vol 55 (6) ◽  
pp. 1338-1349 ◽  
Author(s):  
David Ghan ◽  
K D Hyatt ◽  
J D McPhail
Keyword(s):  
Vertical Migration ◽  
Sockeye Salmon ◽  
Gasterosteus Aculeatus ◽  
Food Distribution ◽  
Foraging Efficiency ◽  
Migration Behaviour ◽  
Population Comparison ◽  
Deep Habitat ◽  
Benefits And Costs ◽  
Efficiency Hypothesis

The benefits and costs of vertical migration behaviour of the freshwater lacustrine copepod, Skistodiaptomus oregonensis, is explored through the study of two migrating and two nonmigrating populations. The association of vertical migration with the presence of pelagic threespine stickleback (Gasterosteus aculeatus) is consistent with the hypothesis that the adaptive benefit of vertical migration by S. oregonensis is avoidance of predatory stickleback. The hypothesis of avoidance of juvenile sockeye salmon (Oncorhynchus nerka) predation is not supported. Skistodiaptomus oregonensis do not migrate in the lake with the highest juvenile sockeye abundance but do migrate in the lake where juvenile sockeye are absent. A foraging efficiency hypothesis does not explain migration behaviour; neither food abundance nor food distribution distinguish lakes where S. oregonensis migrate from lakes where they do not migrate. Neither a bioenergetic efficiency hypothesis nor a thermal advantage hypothesis explain migration behaviour; temperature structures are similar in all four lakes examined. Vertical migration appears to be the result of a trade-off between predator avoidance and resource acquisition. Phytoplankton food is less concentrated in the deep habitat where S. oregonensis reside during the day. Furthermore, migrators contain less phytoplankton food in their guts than nonmigrators.

Threespine stickleback aggregations create a potential predation refuge for sockeye salmon fry

1992 ◽  
Vol 70 (5) ◽  
pp. 1052-1056 ◽  
Author(s):  
Gregory T. Ruggerone
Keyword(s):  
Sockeye Salmon ◽  
Gasterosteus Aculeatus ◽  
Coho Salmon ◽  
Prey Size ◽  
Threespine Stickleback ◽  
Salmon Fry ◽  
Threespine Sticklebacks ◽  
Series Of Experiments ◽  
Predation Rates ◽  
Predation Refuge

Coho salmon (Oncorhynchus kisutch) frequently consume sockeye salmon (Oncorhynchus nerka) fry in Chignik Lake, Alaska, but have never been observed to consume threespine sticklebacks (Gasterosteus aculeatus), which are often closely associated with sockeye fry. Because coho salmon are visual predators and appear to avoid sticklebacks, a series of experiments was conducted in net pens to determine whether juvenile sockeye associated with threespine sticklebacks experienced less prédation than sockeye without sticklebacks and whether prey size affected prédation rates. Significantly fewer sockeye fry by coho were consumed in the pen containing 60 sticklebacks [Formula: see text] than in the 30-stickleback (4.7 fry/day) and 0-stickleback (4.4 fry/day) pens. An identical experiment with large, yearling sockeye (rather than sticklebacks) did not reveal a significant effect (p = 0.28), although there was a tendency for fewer large fry to be consumed when yearlings were abundant. A third experiment demonstrated predation rates on fry that were 45% lower in the presence of sticklebacks (1.2 fry/day) than in the presence of yearling sockeye (2.2 fry/day). Large sockeye fry (37–44 mm) consumed by coho declined steadily from about 36 to 29 to 22% of the total number of fry eaten as the number of sticklebacks or yearling sockeye increased from 0 to 30 to 60, respectively. These data suggest that the presence of threespine sticklebacks may reduce predation by coho on juvenile sockeye, especially those sockeye similar in size to sticklebacks.

Human-induced eutrophication maintains high parasite prevalence in breeding threespine stickleback populations

Parasitology ◽  
2014 ◽  
Vol 142 (5) ◽  
pp. 719-727 ◽  
Author(s):  
ALEXANDRE BUDRIA ◽  
ULRIKA CANDOLIN
Keyword(s):  
Species Interactions ◽  
Gasterosteus Aculeatus ◽  
Anthropogenic Activities ◽  
Parasite Prevalence ◽  
Predation Rate ◽  
Infected Fish ◽  
Threespine Stickleback ◽  
Schistocephalus Solidus ◽  
Host Parasite ◽  
High Parasite

SUMMARYAnthropogenic activities are having profound impacts on species interactions, with further consequences for populations and communities. We investigated the influence that anthropogenic eutrophication has on the prevalence of the parasitic tapeworm Schistocephalus solidus in threespine stickleback Gasterosteus aculeatus populations. We caught stickleback from four areas along the coast of Finland, and within each area from one undisturbed and one eutrophied habitat. We found the prevalence of the parasite to be lower in the eutrophied habitats at the start of the breeding season, probably because of fewer piscivorous birds that transmit the parasite. However, while the prevalence of the parasite declined across the season in the undisturbed habitat, it did less so in eutrophied habitats. We discuss different processes that could be behind the differences, such as lower predation rate on infected fish, higher food availability and less dispersal in eutrophied habitats. We found no effect of eutrophication on the proportion of infected stickleback that entered reproductive condition. Together with earlier findings, this suggests that eutrophication increases the proportion of infected stickleback that reproduce. This could promote the evolution of less parasite resistant populations, with potential consequences for the viability of the interacting parties of the host–parasite system.

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