scholarly journals Ancestral Sperm Ecotypes Reveal Multiple Invasions of a Non-Native Fish in Northern Europe

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1743
Author(s):  
Leon Green ◽  
Apostolos Apostolou ◽  
Ellika Faust ◽  
Kajsa Palmqvist ◽  
Jane W. Behrens ◽  
...  

For externally fertilising organisms in the aquatic environment, the abiotic fertilisation medium can be a strong selecting force. Among bony fishes, sperm are adapted to function in a narrow salinity range. A notable exception is the family Gobiidae, where several species reproduce across a wide salinity range. The family also contains several wide-spread invasive species. To better understand how these fishes tolerate such varying conditions, we measured sperm performance in relation to salinity from a freshwater and a brackish population within their ancestral Ponto-Caspian region of the round goby, Neogobius melanostomus. These two ancestral populations were then compared to nine additional invaded sites across northern Europe, both in terms of their sperm traits and by using genomic SNP markers. Our results show clear patterns of ancestral adaptations to freshwater and brackish salinities in their sperm performance. Population genomic analyses show that the ancestral ecotypes have generally established themselves in environments that fit their sperm adaptations. Sites close to ports with intense shipping show that both outbreeding and admixture can affect the sperm performance of a population in a given salinity. Rapid adaptation to local conditions is also supported at some sites. Historical and contemporary evolution in the traits of the round goby sperm cells is tightly linked to the population and seascape genomics as well as biogeographic processes in these invasive fishes. Since the risk of a population establishing in an area is related to the genotype by environment match, port connectivity and the ancestry of the round goby population can likely be useful for predicting the species spread.

2018 ◽  
Author(s):  
J. M. Dickson ◽  
J. A. Janssen

ABSTRACTMembers of the family Gobiidae have an unusual lateral line morphology in which some of the lateral line canal segments do not develop or enclose. This loss of lateral line canal segments is frequently accompanied by proliferation of superficial neuromasts. Although the proliferation of superficial neuromasts forms intricate patterns that have been used as a taxonomic tool to identify individual gobiid species, there has never been a detailed study that has documented the development of the lateral line system in gobies. The Round Goby, Neogobius melanostomus, is the focus of this study because the absence of the lateral line canal segments below the eye are accompanied by numerous transverse rows of superficial neuromasts. Our results suggest that the origin of some of these superficial neuromast lines could be the result of single presumptive canal neuromasts that have proliferated after canal enclosure is arrested. Many of the intricate patterns of neuromasts observed in gobiids develop from a simplified pattern of neuromast that is very similar among different species of gobies. The proliferation of superficial neuromasts has evolved several times in fish families such as the tetras, gobies, and sculpins, and may provide an adaptive advantage to ‘tune’ the lateral line system for different environments and prey types.SIGNIFICANCE STATEMENTUnderstanding the development of different lateral line morphologies can provide insights into how these morphologies have convergently evolved in many fish taxa. This is the first study to document the progression of the development of the reduced lateral line morphology. This study shows evidence that the developmental origins of orthogonal lines of superficial neuromasts posterior to the eye are not neomorphic lines, but in fact arise from precursor neuromasts that seem to be analogous to presumptive canal neuromasts.


2017 ◽  
Vol 26 (2) ◽  
pp. 392-405 ◽  
Author(s):  
O.A. Diripasko ◽  
T.A. Zabroda

A total of 38 morphometric characters of the round goby Neogobius melanostomus melanostomus (Pallas, 1814) were studied in its native range in the Sea of Azov. The aim was to assess joint effect of sexual dimorphism and size variability on overall variability within groups of samples (populations) using appropriate methods of traditional statistical analysis (one-dimensional and multivariate statistics). Sex and size-dependent variability was studied based on model samples of males and females of different size. Most of the studied morphometric characters of round goby from the Sea of Azov demonstrated statistically significant sex- and size-dependent in-group variability. The pattern of the variability suggests that, for a comparison of round goby from different sea regions and between populations, separate samples of males and females within the range 9–13 cm SL should be examined in order to minimise the effect of the size and sex factors. The approach of searching for the most informative size range could be useful not only for further studies of infraspecific variation but for comparisons between morphologically close gobiin species.


Author(s):  
Artūras Skabeikis ◽  
Jūratė Lesutienė

AbstractFeeding activity and diet composition of round goby were investigated in the south-eastern Baltic Sea, the Lithuanian coastal waters during May-October 2012 in order to determine main feeding objects and seasonal periods when native fauna could be most affected by predation of this highly invasive species. In total, prey represented by 18 taxa was found in the gut contents of dissected fish. Feeding activity of round goby varied depending on the body size, sex and stage of the reproduction period. The gut contents of < 50 mm specimens were dominated by zooplanktonic and meiobenthic organisms, whereas larger individuals (50–99 mm) shifted to amphipods and mollusks. Individuals of the intermediate 100-200 mm length had a variable diet, changing depending on the season; in spring they mostly preyed on Macoma balthica, in summer − on polychaetes, while in autumn the contribution of Mytilus trossulus and fish considerably increased in their diet. Diet composition of individuals ≥ 200 mm was relatively constant in the course of the study with substantial preference to M. balthica. These findings imply that benthic fauna, particularly a newly settled generation of epibenthic mollusks in autumn is under strong predatory pressure of the round goby.


2021 ◽  
Vol 55 (3) ◽  
pp. 236-247
Author(s):  
S. I. Tarasjuk ◽  
V. V. Zamorov ◽  
O. V. Zaloilo ◽  
O. Iu. Bielikova ◽  
D. B. Radionov

2017 ◽  
Vol 128 ◽  
pp. 484-490 ◽  
Author(s):  
Maira Melvere ◽  
Kaspars Ivanovs ◽  
Jelena Pubule ◽  
Dagnija Blumberga

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