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.

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.

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.

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.

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.

Motivational Models of Courtship in Male Threespine Sticklebacks (Gasterosteus Aculeatus)

Behaviour ◽  
1989 ◽  
Vol 109 (3-4) ◽  
pp. 285-302 ◽  
Author(s):  
Patrick W. Colgan ◽  
Stephen S. Crawford
Keyword(s):  
Temporal Variability ◽  
Gasterosteus Aculeatus ◽  
Threespine Stickleback ◽  
Random Model ◽  
Assessment Procedure ◽  
Time Budgets ◽  
Time Sharing ◽  
Threespine Sticklebacks ◽  
Behavioural Switching ◽  
Methodological Difficulties

AbstractThe objective of this study was to determine which of the Random, Competition, and Time-sharing models provides the best description of courtship in the male threespine stickleback (Gasterosteus aculeatus). A critical re-evaluation of experiments in this field revealed both theoretical and methodological difficulties. An attempt was made to correct these problems and provide a more quantitative and statistically valid approach to the motivational study of behavioural switching. Eighteen subjects were tested over four stimulus conditions in a modified double-interruption experiment, where they alternated between courtship and nest-related behaviour. The animals were visually presented with one or three females, with or without eggs in the nest. Assessments of motivational 'dominance' were made on the basis of incomplete visits and variation of visit durations. Data on time budgets, and temporal variability and associations were also analyzed. The results provided little support for the Competition model. In 33 of the 36 sessions, the Random model was accepted as a logical default when the various methods of assessment failed to support, or contradicted the Time-sharing model. The remaining assessments of Time-sharing (both female- and nest-dominant) may be considered as artefacts of the assessment procedure. Four possible explanations of these results were discussed with respect to experimental design and motivational theory.

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.

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.

Phenotypic Variation in Threespine Sticklebacks (Gasterosteus aculeatus) of the Chignik River System, Alaska

1969 ◽  
Vol 26 (2) ◽  
pp. 405-412 ◽  
Author(s):  
David W. Narver
Keyword(s):  
Life History ◽  
Phenotypic Variation ◽  
Gasterosteus Aculeatus ◽  
River System ◽  
Threespine Stickleback ◽  
Caudal Peduncle ◽  
Threespine Sticklebacks ◽  
History Of ◽  
Lateral Plates

Four phenotypes of the threespine stickleback, Gasterosteus aculeatus Linnaeus, were identified from the two Chignik lakes, Alaska: unplated (2–6 anterior plates); half-plated (7–15 anterior plates); fully plated (18–22 plates) lacustrine; and fully plated (18–22) estuarine. Distinctions lie in number and size of lateral plates and extent of lateral keel development on the caudal peduncle. Composition of the three lacustrine phenotypes in either lake population was similar among the years 1962–64 for both age I and age II in Black Lake but dissimilar in Chignik Lake. The Black Lake population contained a higher proportion of the unplated and half-plated phenotypes but fewer of the fully plated phenotypes than the Chignik Lake population. The life history of the estuarine phenotype is outlined. The mechanisms responsible for the maintenance of the four phenotypes in the Chignik River system have not been determined.

Parasites of the Threespine Stickleback (Gasterosteus aculeatus) in Newfoundland and Labrador

1970 ◽  
Vol 27 (5) ◽  
pp. 901-907 ◽  
Author(s):  
George Hanek ◽  
William Threlfall
Keyword(s):  
North America ◽  
Newfoundland And Labrador ◽  
Gasterosteus Aculeatus ◽  
New Records ◽  
Threespine Stickleback ◽  
New Host ◽  
Parasitic Copepods ◽  
Threespine Sticklebacks ◽  
New Host Records

Fifteen genera of helminths (19 species) and two genera of parasitic copepods (2 species) were recovered from 375 threespine sticklebacks (Gasterosteus aculeatus Linnaeus, 1758) taken in 10 sampling areas in Newfoundland and Labrador during 1968 and 1969. Two new host records and two new records for North America are included.

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