Seasonal changes in the gonadotropic cells of the male threespine stickleback, Gasterosteus aculeatus L.

1988 ◽  
Vol 66 (9) ◽  
pp. 1961-1967 ◽  
Author(s):  
Bertil Borg ◽  
Jan Peute ◽  
Göran Paulson
Keyword(s):  
Breeding Season ◽  
Seasonal Changes ◽  
Gasterosteus Aculeatus ◽  
Light And Electron Microscopy ◽  
Threespine Stickleback ◽  
Synthetic Activity ◽  
Cell Nuclei ◽  
Gonadotropic Cells ◽  
Different Seasons ◽  
Threespine Sticklebacks

Pituitaries from threespine sticklebacks (Gasterosteus aculeatus) sampled in the field in different seasons were studied using light and electron microscopy. At the start of breeding in May the gonadotropic cells demonstrated an increase in the amount of dilated granular endoplasmic reticulum cisternae and in the size of Golgi complexes, indicating increased synthetic activity. When the breeding season ended in August these features declined. In the period April to August there was a continuous decrease in the amount and size of granules stored in the gonadotropic cells. The size of the gonadotropic cell nuclei was larger in April than in the breeding season and at the end of breeding it declined further.

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.

Flexibility of nuptial colouration in a unique ecotype of Threespine Stickleback (Gasterosteus aculeatus)

2021 ◽  
Author(s):  
Rachel Corney ◽  
Anne Haley ◽  
Laura Weir
Keyword(s):  
Breeding Season ◽  
Gasterosteus Aculeatus ◽  
Colour Change ◽  
Threespine Stickleback ◽  
Relative Role ◽  
Mate Quality ◽  
Breeding Seasons ◽  
Potential Signal ◽  
Intersexual Competition

Nuptial colouration in animals may serve as a signal of competitor and/or mate quality during breeding. In many temperate fishes, nuptial colouration develops during discrete breeding seasons and is a target of sexual selection. We examine nuptial colouration and behaviour of a unique ecotype of Threespine Stickleback (Gasterosteus aculeatus Linnaeus, 1758), wherein males turn from dull brown-grey to pearlescent white during the breeding season. The main goal of this work was to determine the relative role of white colouration in intersexual competition and mate choice. In a combination of a field and laboratory work, we found that males are brightest white when engaging in courtship activities in the presence of a female; this indicates that white colouration may be primarily related to enhancing signalling during mate attraction. White colouration intensity increased as the breeding season progressed and may be related to an influx of conspecifics. Colour change from cryptic grey to bright white occurred rapidly (< 90 seconds) and may be deployed to enhance behavioural signals. We conclude that bright white colouration in the white ecotype is a potential signal of mate quality and may have evolved from a previously existing capacity for colour plasticity in common Threespine Stickleback.

scholarly journals Genome Characterization, Prevalence, and Transmission Mode of a Novel Picornavirus Associated with the Threespine Stickleback Fish (Gasterosteus aculeatus)

2019 ◽  
Vol 93 (9) ◽  
Author(s):  
Megan A. Hahn ◽  
Nolwenn M. Dheilly
Keyword(s):  
Gasterosteus Aculeatus ◽  
Rna Virus ◽  
Wide Distribution ◽  
Model System ◽  
Threespine Stickleback ◽  
Tissue Samples ◽  
Content Type ◽  
Threespine Sticklebacks ◽  
The Impact

ABSTRACT The complete genome sequence of an RNA virus was assembled from RNA sequencing of virus particles purified from threespine stickleback intestine tissue samples. This new virus is most closely related to the Eel picornavirus and can be assigned to the genus Potamipivirus in the family Picornaviridae. Its unique genetic properties are enough to establish a new species, dubbed the Threespine Stickleback picornavirus (TSPV). Due to their broad geographic distribution throughout the Northern Hemisphere and parallel adaptation to freshwater, threespine sticklebacks have become a model in evolutionary ecology. Further analysis using diagnostic PCRs revealed that TSPV is highly prevalent in both anadromous and freshwater populations of threespine sticklebacks, infects almost all fish tissues, and is transmitted vertically to offspring obtained from in vitro fertilization in laboratory settings. Finally, TSPV was found in Sequence Reads Archives of transcriptome of Gasterosteus aculeatus, further demonstrating its wide distribution and unsought prevalence in samples. It is thus necessary to test the impact of TSPV on the biology of threespine sticklebacks, as this widespread virus could interfere with the behavioral, physiological, or immunological studies that employ this fish as a model system. IMPORTANCE The threespine stickleback species complex is an important model system in ecological and evolutionary studies because of the large number of isolated divergent populations that are experimentally tractable. For similar reasons, its coevolution with the cestode parasite Schistocephalus solidus, its interaction with gut microbes, and the evolution of its immune system are of growing interest. Herein we describe the discovery of an RNA virus that infects both freshwater and anadromous populations of sticklebacks. We show that the virus is transmitted vertically in laboratory settings and found it in Sequence Reads Archives, suggesting that experiments using sticklebacks were conducted in the presence of the virus. This discovery can serve as a reminder that the presence of viruses in wild-caught animals is possible, even when animals appear healthy. Regarding threespine sticklebacks, the impact of Threespine Stickleback picornavirus (TSPV) on the fish biology should be investigated further to ensure that it does not interfere with experimental results.

Raiding shoal size and a distraction display in male sticklebacks (Gasterosteus)

1988 ◽  
Vol 66 (1) ◽  
pp. 201-205 ◽  
Author(s):  
Mark S. Ridgway ◽  
J. D. McPhail
Keyword(s):  
Nest Predation ◽  
Species Complex ◽  
Food Source ◽  
Gasterosteus Aculeatus ◽  
Nest Site ◽  
Sympatric Species ◽  
Threespine Stickleback ◽  
Species Pairs ◽  
Threespine Sticklebacks

In threespine sticklebacks (Gasterosteus aculeatus), shoals of foraging conspecifics attack the nests of parental males and consume the offspring. This type of nest predation also occurs in lakes with sympatric species pairs of sticklebacks (Gasterosteus sp.) in which benthic stickleback shoals attack the nests of parental limnetic males. We manipulated shoal size of benthic sticklebacks in Paxton and Enos lakes to determine if there is a minimum shoal size necessary before parental limnetic males will perform the spasmodic swim display, a behaviour used by parental males to lure foraging shoals away from their nest and offspring. Males showed a significant increase in display frequency beginning with shoals of eight fish. The display occurred only when there were offspring in the nest and not when the nest was empty. We interpret the display to be a foraging deception in which parental males manipulate raiding shoals into giving up their search for a food source, causing them to leave the area of the male's nest site. This distraction display appears to be widespread within the threespine stickleback species complex.

Effect of pituitary homotransplants on peripheral target organs in intact threespine sticklebacks, Gasterosteus aculeatus L. form trachurus

1970 ◽  
Vol 48 (6) ◽  
pp. 1341-1344 ◽  
Author(s):  
John F. Leatherland
Keyword(s):  
Thyroid Gland ◽  
Gasterosteus Aculeatus ◽  
Threespine Stickleback ◽  
Peripheral Target ◽  
Partial Regression ◽  
Target Organs ◽  
Threespine Sticklebacks ◽  
Anadromous Form

The activity of pituitary homotransplants in the anadromous form (trachurus) of the threespine stickleback, Gasterosteus aculeatus L. was investigated by examining the structure of the thyroid, interrenal, gonad, and in situ pituitary; the melanophore index was also measured.The thyroid gland was markedly more active and the in situ thyrotrophs more granulated in the recipient fish when compared with the sham-operated animals. Similarly, the interrenal nuclear index was slightly (but significantly) larger in the recipient fish and there was a concomitant partial regression of the in situ pituitary corticotrophs.There was no difference between the structure of the gonads in the two groups although the in situ gonadotrophs were apparently smaller and less well granulated in the recipient fish.The melanophore index was significantly lower in recipient sticklebacks.In situ prolactin-secreting cells, somatotrophs, and neurointermediate lobes were similar in recipient and sham-operated animals.

Some effects of the cestode (Schistocephalus solidus) on reproduction in the threespine stickleback (Gasterosteus aculeatus): evolutionary aspects of a host–parasite interaction

1983 ◽  
Vol 61 (4) ◽  
pp. 901-908 ◽  
Author(s):  
J. D. McPhail ◽  
S. D. Peacock
Keyword(s):  
Adverse Effects ◽  
Breeding Season ◽  
Gasterosteus Aculeatus ◽  
Threespine Stickleback ◽  
Schistocephalus Solidus ◽  
Egg Number ◽  
Gravid Females ◽  
Host Parasite ◽  
Evolutionary Aspects ◽  
Sexually Mature

Monthly samples of threespine stickleback (Gasterosteus aculeatus) were collected from May through September 1975 from Fuller Lake, Vancouver Island. A total of 2175 adult sticklebacks were collected from 10 trap sites located at depths ranging from 0.25 to 5 m. These samples were assayed for length, weight, sex, state of maturity, and egg number (when applicable). In addition, we recorded the number and weight of the plerocercoids of a cestode tapeworm (Schistocephalus solidus) often found in the abdominal cavities of sticklebacks. The purpose of the study was to document the effects of Schistocephalus on reproduction in Gasterosteus. Stickleback spawning reached a peak in June and declined sharply through July and August. Over the entire breeding season, less than 5% of the gravid females were infected with Schistocephalus, whereas over 40% of the sexually mature but nongravid females were infected. There was no difference between breeding and nonbreeding males in the prevalence of Schistocephalus. In both sexes, the prevalence and severity of Schistocephalus infection were low in May, June, and July but increased sharply through August and September. Since the majority of Fuller Lake sticklebacks live for 1 year, the major adverse effects of Schistocephalus were confined to postreproductive adults. We hypothesize that Schistocephalus plerocercoids have been selected to delay adverse effects on their host until after the host has reproduced.

Mate selection in threespine sticklebacks (Gasterosteus)

1975 ◽  
Vol 53 (4) ◽  
pp. 441-450 ◽  
Author(s):  
D. E. Hay ◽  
J. D. McPhail
Keyword(s):  
Assortative Mating ◽  
Mate Selection ◽  
Gasterosteus Aculeatus ◽  
Threespine Stickleback ◽  
Threespine Sticklebacks ◽  
Anadromous Form ◽  
Isolating Mechanism

Earlier studies suggest that the freshwater form of the threespine stickleback (Gasterosteus aculeatus) may be reproductively isolated from the anadromous form. In this study, assortative mating is examined as a possible isolating mechanism between the two forms. Mate selection tests were conducted in which (1) courting males were simultaneously exposed to receptive females of both forms, and (2) receptive females were simultaneously exposed to both forms of courting males. The results demonstrate clearly that in choice situations matings between similar phenotypes are more likely than matings between dissimilar phenotypes.

Catch-up growth and swimming performance in threespine sticklebacks (Gasterosteus aculeatus): seasonal changes in the cost of compensation

2005 ◽  
Vol 62 (9) ◽  
pp. 2169-2176 ◽  
Author(s):  
D Álvarez ◽  
N B Metcalfe
Keyword(s):  
Breeding Season ◽  
Rapid Growth ◽  
Compensatory Growth ◽  
Gasterosteus Aculeatus ◽  
Swimming Performance ◽  
Growth Depression ◽  
Poor Growth ◽  
Threespine Sticklebacks ◽  
Catch Up ◽  
Time Of Year

Compensatory growth is a phase of unusually rapid growth following a period of growth depression. This response allows animals to achieve the same size-for-age as continuously fed contemporaries. We tested the hypothesis that a period of poor growth followed by compensation reduces the swimming abilities of threespine sticklebacks (Gasterosteus aculeatus), even after the period of rapid growth had ceased; we also investigated how the time of year in which the rapid growth occurred affected the possible costs in swimming performance. The threespine sticklebacks showed a compensatory growth response after a period of food shortage, both in winter and in spring. This change in growth trajectory subsequently caused a reduction in ability to withstand high flows, but only when the period of rapid growth occurred just prior to the breeding season. We suggest that threespine sticklebacks may be willing to incur the swimming costs of catch-up growth just prior to the breeding season to maximize their expected reproductive success.

Meristic Variation in the Threespine Stickleback, Gasterosteus aculeatus, in the Matamek River System, Quebec

1974 ◽  
Vol 31 (6) ◽  
pp. 1155-1157 ◽  
Author(s):  
Brian W. Coad ◽  
G. Power
Keyword(s):  
Gasterosteus Aculeatus ◽  
Low Frequency ◽  
River System ◽  
Threespine Stickleback ◽  
Meristic Characters ◽  
Fin Ray ◽  
Threespine Sticklebacks ◽  
River Sample ◽  
Meristic Variation ◽  
Gill Raker

Samples of threespine sticklebacks, Gasterosteus aculeatus, from two lakes and a river in the Matamek River system, Québec were analyzed for five meristic characters. Mean vertebral number differed for each area (range 32.00–32.85) but mean soft fin ray number showed little variation (dorsal rays 11.52–11.79, anal rays 8.68–8.76). Gill raker number was higher in the lake samples (21.25 and 21.80) than in the river sample (20.76). In Matamek Lake only semiarmatus plate morphs were found; in Bill Lake, semiarmatus and trachurus morphs in a ratio of 4:1 with about 10% intermediate; and in the lower Matamek River, semiarmatus and, at a low frequency, leiurus morphs.

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