Egg cannibalism and the reproductive strategies of threespine sticklebacks (Gasterosteus aculeatus) in a coastal British Columbia lake

1989 ◽  
Vol 67 (8) ◽  
pp. 2036-2046 ◽  
Author(s):  
K. D. Hyatt ◽  
N. H. Ringler

Patterns of egg eating and their association with differences in sex, size, abundance, and reproductive status of free-ranging sticklebacks from Kennedy Lake, British Columbia, were examined as a means of identifying the relative importance of filial cannibalism or heterocannibalism as the source of eggs in the diet. Egg cannibalism was a common event: 23.0 and 11.2% of the sticklebacks examined in 1982 and 1985, respectively, had engaged in egg eating. Eggs were a substantial part of the overall diet of the stickleback population during two breeding seasons: 27.4% of the diet of all fish by weight in 1982, 32.8% of the diet by volume in 1985. Our results do not support Rohwer's contention that filial cannibalism is the source of most eggs in stickleback diets. Ten out of 11 predictions based on the filial cannibalism hypothesis were rejected, whereas the 11th was compatible with either the filial cannibalism hypothesis or the alternative heterocannibalism hypothesis. We conclude that heterocannibalism, not filial cannibalism, is the major source of eggs in the diet of Kennedy Lake sticklebacks. We suggest that nest raiding and egg cannibalism may minimize time spent foraging and maximize time spent on activities that increase the probability of initiating and successfully completing one or more reproductive cycles. Although the benefits of nest raiding and cannibalism are most obvious for populations breeding under conditions where food supplies clearly limit their potential reproductive output, the benefits may still apply even under conditions where alternative prey sources appear to be abundant.

1989 ◽  
Vol 46 (3) ◽  
pp. 372-383 ◽  
Author(s):  
Kim D. Hyatt ◽  
Neil H. Ringler

The consequences of nest raiding and egg predation for population regulation of sticklebacks (Gasterosteus aculeatus) were studied in a British Columbia coastal lake. Stickleback eggs were present in the stomachs of 23 and 11% of all sticklebacks sampled from the field in 1982 and 1985 respectively. On average, males consumed more eggs than did females. Seasonal egg consumption increased with increases in stickleback density in breeding colonies. In experimental enclosure studies, nest densities varied between 0 and 3∙m−2 as stickleback numbers were manipulated from 1.5 to 12∙m−2. Peak nest densities occurred at 5.8 fish∙m−2. Stickleback density explained 70–86% of the variation in nest numbers in an application of a Ricker stock–recruit model and weekly rates of nest survival exhibited strong density dependence. Our evidence indicates that both nest raiding and egg cannibalism are important in limiting the production of stickleback fry as population density increases in scattered, lakeshore, breeding colonies of Kennedy Lake.


1999 ◽  
Vol 77 (8) ◽  
pp. 1314-1321 ◽  
Author(s):  
Toshihiko Saito ◽  
Shigeru Nakano

Relationships between reproductive timing of spawners and timing of hatch and age at maturity of their offspring were examined in fluvial threespine sticklebacks, Gasterosteus aculeatus. Some age 2 and all age 3 females matured in this age-structured population, with only a few females reproducing over two successive breeding seasons. Age 2 females spawned over the relatively long breeding season (March-August), whereas age 3 females spawned mainly early in the season (March-June). Although the standard length of mature age 3 females was greater than that of age 2 females, the back-calculated standard lengths of the former were always shorter than those of the latter at an equivalent age, the most distinct differences being apparent in young of the year. Analysis of daily otolith increments showed that the earlier the young of the year were born, the larger they were at the end of the growing season. As a result of these findings, age 3 females can be expected to produce offspring that will mature at age 2, whereas the offspring of late-spawning age 2 females are more likely to mature at age 3. Therefore, a partial alternation of life histories between generations is thought to occur.


1995 ◽  
Vol 73 (11) ◽  
pp. 2154-2158 ◽  
Author(s):  
Rees Kassen ◽  
Dolph Schluter ◽  
John Donald McPhail

Geologic and allozyme evidence suggests that threespine sticklebacks (Gasterosteus aculeatus complex) in low-lying southwestern British Columbia lakes were founded during two incursions of marine sticklebacks after the retreat of the Pleistocene glaciers (the double-invasion hypothesis). We used the salinity tolerance of embryos, measured as hatchability in salt water, to establish the relative order of freshwater invasion by marine sticklebacks and to test the double-invasion hypothesis. Limnetics and an anadromous population hatched nearly equivalent numbers of young in salt water as in fresh water, whereas benthics and one solitary freshwater population had low hatchability in salt water. We also found that eggs from freshwater populations were larger than those from marine populations and limnetics had smaller eggs than benthics and the solitary population. These results support the double-invasion hypothesis and suggest a trend of increasing egg size with increasing time spent in fresh water.


1985 ◽  
Vol 63 (3) ◽  
pp. 528-533 ◽  
Author(s):  
R. E. Withler ◽  
J. D. McPhail

Electrophoretic variation at eight loci was compared between anadromous and freshwater populations of threespine sticklebacks (Gasterosteus aculeatus) collected from 56 sites in southwestern British Columbia and northwestern Washington. Allelic frequencies at five polymorphic loci were heterogeneous among populations and the average allelic frequencies at four loci differed between anadromous and freshwater sticklebacks. The average number of polymorphic loci was greater in anadromous (4.6) than in freshwater (3.2) populations. The average heterozygosity was 0.113 ± 0.001 in anadromous and 0.117 ± 0.003 in freshwater stickleback populations. Anadromous populations were more polymorphic but less heterogeneous than freshwater populations. The standardized genetic variance indicated only moderate differentiation among anadromous populations from marine habitats, but considerable differentiation among populations from freshwater habitats. Our data are consistent with the hypothesis of postglacial polyphyletic origins for freshwater populations of Gasterosteus, but also indicate that selection favours different alleles in marine and freshwater environments, at least at the Mdh-1 locus.


Zoomorphology ◽  
2020 ◽  
Author(s):  
Harald Ahnelt ◽  
David Ramler ◽  
Maria Ø. Madsen ◽  
Lasse F. Jensen ◽  
Sonja Windhager

AbstractThe mechanosensory lateral line of fishes is a flow sensing system and supports a number of behaviors, e.g. prey detection, schooling or position holding in water currents. Differences in the neuromast pattern of this sensory system reflect adaptation to divergent ecological constraints. The threespine stickleback, Gasterosteus aculeatus, is known for its ecological plasticity resulting in three major ecotypes, a marine type, a migrating anadromous type and a resident freshwater type. We provide the first comparative study of the pattern of the head lateral line system of North Sea populations representing these three ecotypes including a brackish spawning population. We found no distinct difference in the pattern of the head lateral line system between the three ecotypes but significant differences in neuromast numbers. The anadromous and the brackish populations had distinctly less neuromasts than their freshwater and marine conspecifics. This difference in neuromast number between marine and anadromous threespine stickleback points to differences in swimming behavior. We also found sexual dimorphism in neuromast number with males having more neuromasts than females in the anadromous, brackish and the freshwater populations. But no such dimorphism occurred in the marine population. Our results suggest that the head lateral line of the three ecotypes is under divergent hydrodynamic constraints. Additionally, sexual dimorphism points to divergent niche partitioning of males and females in the anadromous and freshwater but not in the marine populations. Our findings imply careful sampling as an important prerequisite to discern especially between anadromous and marine threespine sticklebacks.


1996 ◽  
Vol 76 (2) ◽  
pp. 153-164 ◽  
Author(s):  
B. J. Zebarth ◽  
J. W. Paul ◽  
O. Schmidt ◽  
R. McDougall

Manure-N availability must be known in order to design application practices that maximize the nutrient value of the manure while minimizing adverse environmental impacts. This study determined the effect of time and rate of liquid manure application on silage corn yield and N utilization, and residual soil nitrate at harvest, in south coastal British Columbia. Liquid dairy or liquid hog manure was applied at target rates of 0, 175, 350 or 525 kg N ha−1, with or without addition of 100 kg N ha−1 as inorganic fertilizer, at two sites in each of 2 yr. Time of liquid-dairy-manure application was also tested at two sites in each of 2 yr with N-application treatments of: 600 kg N ha−1 as manure applied in spring; 600 kg N ha−1 as manure applied in fall; 300 kg N ha−1 as manure applied in each of spring and fall; 200 kg N ha−1 applied as inorganic fertilizer in spring; 300 kg N ha−1 as manure plus 100 kg N ha−1 as inorganic fertilizer applied in spring; and a control that received no applied N. Fall-applied manure did not increase corn yield or N uptake in the following growing season. At all sites, maximum yield was attained using manure only. Selection of proper spring application rates for manure and inorganic fertilizer were found to be equally important in minimizing residual soil nitrate at harvest. Apparent recovery of applied N in the crop ranged from 0 to 33% for manure and from 18 to 93% for inorganic fertilizer. Key words: N recovery, manure management


1965 ◽  
Vol 2 (5) ◽  
pp. 442-484 ◽  
Author(s):  
Donald Carlisle ◽  
Takeo Susuki

The highly deformed section at Open Bay is one of the few good exposures of a thick sedimentary unit within the prebatholithic rocks along coastal British Columbia. It provides new structural information relating to emplacement of a part of the Coast Range batholith and it contains an important Upper Triassic fauna unusually well represented. Structural and paleontological analyses are mutually supporting and are purposely combined in one paper.Thirteen ammonite genera from 14 localities clearly substantiate McLearn's tentative assignment to the Tropites subbullatus zone (Upper Karnian) and suggest a restriction to the T. dilleri subzone as defined in northern California.Contrary to an earlier view, the beds are lithologically similar across the whole bay except for variations in the intensity of deformation and thermal alteration. Their contact with slightly older relatively undeformed flows is apparently a zone of dislocation. Stratigraphic thicknesses cannot be measured with confidence, and subdivision into "Marble Bay Formation" and "Open Bay Group" cannot be accepted. Open Bay Formation is redefined to include all the folded marble and interbedded pillow lava at Open Bay. Lithologic and biostratigraphic correlation is suggested with the lower middle part of the Quatsino Formation on Iron River, 24 miles to the southwest. Basalt flows and pillowed volcanics west of Open Bay are correlated with the Texada Formation within the Karmutsen Group.The predominant folding is shown to precede, accompany, and follow intrusion of numerous andesitic pods and to precede emplacement of quartz diorite of the batholith. Structural asymmetry is shown to have originated through gentle cross-folding and emplacement of minor intrusives during deformation.


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