A lateral plate dine, sexual dimorphism, and phenotypic variation in the black-spotted stickleback, Gasterosteus wheatlandi

1984 ◽  
Vol 62 (3) ◽  
pp. 368-376 ◽  
Author(s):  
R. Craig Sargent ◽  
Michael A. Bell ◽  
William H. Krueger ◽  
Jeffrey V. Baumgartner
Keyword(s):  
New York ◽  
Sexual Dimorphism ◽  
Geographical Variation ◽  
Gasterosteus Aculeatus ◽  
Morphological Characters ◽  
Cape Cod ◽  
Lateral Plate ◽  
Plate Number ◽  
Coastal Marine ◽  
Lateral Plates

We examined samples of Gasterosteus wheatlandi collected in coastal marine waters from northern Maine to southern New York. Gasterosteus wheatlandi exhibited remarkable variation in lateral plate number, including phenotypes similar to the low, partial, and complete morphs described in Gasterosteus aculeatus. Partials and completes, however, seemed to represent a continuum, thus we could only recognize two discreet phenotypes, low and partial–complete. The low phenotype predominated strongly north of Cape Cod and was rare or absent south of it. Within both phenotypes mean plate number increased toward the southern end of the range; thus, both lateral plate number and lateral plate phenotype exhibited a pronounced step-cline. We found significant sexual dimorphism among localities for total lateral plates and for a suite of other morphological characters. Both sexes had higher mean vertebral counts north of Cape Cod, a trend which ran counter to the cline in lateral plates. The pervasive sexual dimorphism in G. wheatlandi, and the fact that latitudinal variation in lateral plates ran counter to the trend in G. aculeatus, suggest that different processes may be responsible for maintaining the geographical variation in these two species.

Offshore Distribution, Size, Age, and Lateral Plate Variation of Late Larval/Early Juvenile Sticklebacks (Gasterosteus) off the Atlantic Coast of New Jersey and New York

1991 ◽  
Vol 48 (9) ◽  
pp. 1679-1684 ◽  
Author(s):  
Robert K. Cowen ◽  
Louis A. Chiarella ◽  
Candice J. Gomez ◽  
Michael A. Bell
Keyword(s):  
New York ◽  
New Jersey ◽  
Gasterosteus Aculeatus ◽  
Atlantic Coast ◽  
Cape Cod ◽  
Lateral Plate ◽  
Early Juvenile ◽  
New York Bight ◽  
York Bight

Late larval and early juvenile sticklebacks, Gasterosteus aculeatus (14–28 mm SL) and G. wheatlandi (11–19 mm SL), were collected over shelf waters in the New York Bight during May, June, and July 1988. Gasterosteus aculeatus occurred up to 110 km offshore, with peak abundances found from 3 to 75 km. Gasterosteus wheatlandi was most prevalent within 10 km of shore, but some individuals were collected up to 55 km offshore. The further offshore distribution of G. aculeatus should increase its potential for dispersal, perhaps explaining their capacity to found freshwater populations in recently deglaciated habitats. The relatively nearshore distribution of G. wheatlandi should minimize dispersal (especially around Cape Cod) and may maintain a distinct, morphological step cline by the relative isolation of two subpopulations above and below Cape Cod.

Do asymmetric sticklebacks make better fathers?

1996 ◽  
Vol 263 (1370) ◽  
pp. 535-539 ◽  
Keyword(s):  
Genetic Control ◽  
Natural Population ◽  
Fluctuating Asymmetry ◽  
Gasterosteus Aculeatus ◽  
Threespine Stickleback ◽  
Lateral Plate ◽  
Plate Number

Lateral plate number phenotypes in the low morph of the threespine stickleback, Gasterosteus aculeatus , are under strong genetic control and display fluctuating asymmetry. Results of a survey of a natural population show the nests of asymmetric males were more likely to contain fry than nests of symmetric males. This suggests asymmetric males were more reproductively successful than symmetric males. There is little or no possibility that plate number symmetry can be directly assessed by either potential mates or rival males which compete for mates and attack clutches. Asymmetric males may be slightly larger than symmetric males.

Spatial variation of morphology in a freshwater population of the threespine stickleback, Gasterosteus aculeatus

1992 ◽  
Vol 70 (6) ◽  
pp. 1140-1148 ◽  
Author(s):  
Jeffrey V. Baumgartner
Keyword(s):  
Gasterosteus Aculeatus ◽  
Lateral Plate ◽  
Coastal System ◽  
Body Form ◽  
Evolutionary Forces ◽  
Freshwater Population ◽  
Threespine Sticklebacks ◽  
Functional Components ◽  
Significant Size ◽  
Lateral Plates

Differentiation with respect to two functional components of morphology, the defensive complex and overall body form, was studied in a population of threespine sticklebacks (Gasterosteus aculeatus) from the Brush Creek drainage, a small coastal system in northern California with high- and low-gradient habitats. The vast majority of body-shape differences among localities was accounted for by size-related allometric variation, the differences being closely related to overall growth trends. Relative to general body size, small individuals had long spines and fins whereas larger individuals tended to be deep bodied and have shorter fins and shorter spines. Significant size-independent differentiation with respect to the defensive complex and overall body form was also observed. The spatial pattern of differentiation in the components of the defensive complex changed dramatically over the period of study, possibly in response to natural selection. Stable stepped clines for overall body form and lateral-plate morph ratio were observed. Both clines were centered on the ecotone between high- and low-gradient habitats, and were apparently maintained by differential selection in alternative stream-gradient habitats despite gene flow across the ecotone. Sticklebacks from the high-gradient habitat had a continuous row of lateral plates, were elongate, and had long fins, whereas those from the low-gradient or standing-water habitat tended to have only abdominal plates, were more robust through the midbody, and had shorter fins. The results of this study and previous work suggest that various aspects of stickleback morphology may respond independently and rapidly to different evolutionary forces and be functionally related to hydrodynamics.

scholarly journals FUNCTIONAL IMPLICATIONS OF FLUCTUATING ASYMMETRY AMONG ENDEMIC POPULATIONS OF GASTEROSTEUS ACULEATUS

Behaviour ◽  
2000 ◽  
Vol 137 (7-8) ◽  
pp. 1097-1112 ◽  
Author(s):  
◽  
Keyword(s):  
Fluctuating Asymmetry ◽  
Gasterosteus Aculeatus ◽  
Structural Integrity ◽  
Lateral Plate ◽  
Queen Charlotte Islands ◽  
Extreme Variation ◽  
Functional Implications ◽  
Measure Of Asymmetry ◽  
Selection For ◽  
Lateral Plates

AbstractFluctuating asymmetry (FA) has been used as a measure of developmental stability across many taxa, with asymmetric individuals presumed to have reduced fitness. FA has also been suggested for use in conservation biology as a measure of the health of populations. Here we assess the suitability of these uses of FA by using a novel measure of asymmetry in the bony lateral plates of threespine stickleback (Gasterosteus aculeatus) from 60 insular and endemic freshwater populations from the Queen Charlotte Islands. The frequency of asymmetric G. aculeatus individuals among populations varied from 1% to 76% with a mean of 42%. Extreme variation in the frequency of asymmetries among lateral plate positions within samples was also observed. Plates important to the structural integrity of predator defences were least asymmetric, either due to selection against asymmetry at these positions or to variation in the temporal development of the plates. These results emphasize the need for caution when interpreting differential levels of FA among traits in individuals and populations, as the differences may be due to variation in the strength or direction of selection for symmetry, and not exclusively to differences in fitness.

Fast-start swimming performance and reduction in lateral plate number in threespine stickleback

2002 ◽  
Vol 80 (2) ◽  
pp. 207-213 ◽  
Author(s):  
C A Bergstrom
Keyword(s):  
Large Scale ◽  
Gasterosteus Aculeatus ◽  
Swimming Performance ◽  
Maximum Velocity ◽  
Threespine Stickleback ◽  
Predatory Fish ◽  
Lateral Plate ◽  
Maximum Acceleration ◽  
Plate Number ◽  
Fast Start

Threespine stickleback (Gasterosteus aculeatus) have colonized freshwater habitats in circumboreal coastal regions, resulting in populations with variable but generally reduced lateral plate numbers compared with marine ancestors. Several abiotic and ecological factors associated with variation in lateral plate number among freshwater populations of G. aculeatus have been found, including large-scale climatic effects, variation in water-flow rates and levels of dissolved calcium, and the presence or absence of predatory fish. In addition, it has been proposed that plate reduction might be an adaptation for evading predator pursuit that enhances fast-start performance. If this hypothesis is correct, one would predict that fast-start performance would improve as lateral plate numbers decrease. I tested this prediction by comparing fast-start performance among stickleback with different numbers of lateral plates within two freshwater populations. Fast-starts of individual stickleback were video-recorded at 60 Hz and maximum velocity, maximum acceleration, displacement, and body curvature were calculated for each fish. Lateral plate number was significantly negatively correlated with velocity and displacement but not with acceleration or curvature. These results suggest that reduction in lateral plate number has the potential to be advantageous in some predation regimes because of its association with enhanced fast-start performance.

LATERAL PLATE VARIATION IN GALICIAN STICKLEBACK POPULATIONS IN THE RIVERS MIÑO AND LIMIA, NW SPAIN

Behaviour ◽  
2000 ◽  
Vol 137 (7-8) ◽  
pp. 965-979 ◽  
Author(s):  
◽  
E. San Miguel ◽  
◽  
Keyword(s):  
Cluster Analysis ◽  
Gasterosteus Aculeatus ◽  
Age Groups ◽  
Variation Analysis ◽  
Nw Spain ◽  
Lateral Plate ◽  
Males And Females ◽  
Time Of Year ◽  
Two Age Groups ◽  
Lateral Plates

AbstractWe examined lateral plate variation in populations of stickleback, Gasterosteus aculeatus, from the rivers Miño and Limia in Galicia (Northwest Spain), by analysing morphs, number of lateral plates, and position of the plates. In order to test for sexual dimorphism, the means and variances of plates were compared in males and females of some populations. No significant differences were found between sexes, therefore all remaining populations were analysed without controlling for sex. As stickleback populations in Galicia have an annual life span, the populations from the river Miño were divided in two age groups to compare lateral plate number. Analysis of each group revealed significant differences among populations, in accordance with the large amount of variation found in populations from other regions. Analysis of samples collected from the same place and at the same time of year, but in different years, indicated that there was little year to year variation. This suggests that populations are well adapted to their habitat, or that environmental conditions did not change significantly during the period of sampling. Finally, we propose a new method for the evaluation of scute variation analysis of the position of lateral plates. Cluster analysis of our data clearly differentiated populations from the rivers Miño and Limia.

The evolution of freshwater diversity in the threespine stickleback (Gasterosteus aculeatus): site-specific differentiation of trophic morphology

1985 ◽  
Vol 63 (11) ◽  
pp. 2632-2638 ◽  
Author(s):  
P. A. Lavin ◽  
J. D. Mcphail
Keyword(s):  
Gasterosteus Aculeatus ◽  
Morphological Variability ◽  
River System ◽  
Predatory Fish ◽  
Lateral Plate ◽  
Piscivorous Fish ◽  
Trophic Morphology ◽  
Interpopulation Variability ◽  
Gill Raker ◽  
Lateral Plates

To assess interpopulation levels of morphological variability populations of Gasterosteus aculeatus were sampled from lakes within the upper Cowichan River system (Vancouver Island, British Columbia). Phenotypic divergence between populations is assumed to be a postglacial event. Nine characters were scored; eight were related to feeding and the ninth character was lateral plate number. All populations were the low plate morph; however, populations of Gasterosteus in lakes lacking piscivorous fish had significantly fewer lateral plates than populations in lakes with predatory fish species. Two distinct trophic "morphotypes" were identified, each one associated with a specific lake environment. Populations inhabiting benthic-dominated environments were found to possess reduced gill raker number and reduced gill raker length but increased upper jaw length relative to populations from limnetic environments. We propose that the interpopulation variability in trophic morphology is a response to trophic resource differences between lakes.

scholarly journals Diversity and sexual dimorphism in the head lateral line system in North Sea populations of threespine sticklebacks, Gasterosteus aculeatus (Teleostei: Gasterosteidae)

Zoomorphology ◽  
2020 ◽  
Author(s):  
Harald Ahnelt ◽  
David Ramler ◽  
Maria Ø. Madsen ◽  
Lasse F. Jensen ◽  
Sonja Windhager
Keyword(s):  
Sexual Dimorphism ◽  
North Sea ◽  
Lateral Line ◽  
Gasterosteus Aculeatus ◽  
Sensory System ◽  
Threespine Stickleback ◽  
Lateral Line System ◽  
Line System ◽  
Marine Population ◽  
Threespine Sticklebacks

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.

Morphogenetic features of garnets from Dyukunakh placer (Yakutian diamondiferous province)

2021 ◽  
pp. 106-112
Author(s):  
Elvira Vlasova ◽  
Aleksandr Khmelkov
Keyword(s):  
Morphological Characters ◽  
Morphological Features ◽  
Primary Sources ◽  
Residual Soil ◽  
Coastal Marine ◽  
Upper Paleozoic ◽  
Morphogenetic Analysis

Morphological features of garnets from the Upper Paleozoic Dyukunakh placer were studied and the conditions of their morphogenesis were interpreted. As a result of the morphogenetic analysis, it was found that garnets have evolved in exogenous conditions, including extreme wear in coastal marine conditions and repeated redeposition. In addition, garnets underwent significant hypergene corrosion in the residual soil and subsequent dissolution under metasomatic conditions. As a result of such exogenous evolution, no trace of their primary morphological characters associated with the deep stage of morphogenesis remained on garnets. For this reason, it is impossible to quantify the degree of primary sources removal.

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