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Charlotta Kvarnemo - One of the best experts on this subject based on the ideXlab platform.
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Viability rawdata
2019Co-Authors: Leon Green, Charlotta KvarnemoAbstract:Sperm viability raw data from Pomatoschistus minutus sperm tested with and without associated sperm duct gland substances
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CASA rawdata
2019Co-Authors: Leon Green, Charlotta KvarnemoAbstract:Computer assisted sperm analysis from Pomatoschistus minutus sperm tested with and without associated sperm duct gland substances
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Effects of salinity on nest-building behaviour in a marine fish.
BMC ecology, 2016Co-Authors: Topi K Lehtonen, Bob B. M. Wong, Charlotta KvarnemoAbstract:Background Parental allocation and reproductive success are often strongly influenced by environmental factors. In this respect, salinity is a key factor influencing species distributions and community structure in aquatic animals. Nevertheless, the effects of salinity on reproductive behaviours are not well known. Here, we used the sand goby (Pomatoschistus minutus), a small fish inhabiting a range of different salinities, to experimentally assess the effects of changes in salinity on nesting behaviour, a key component of reproduction in sand gobies and many other taxa.
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Investment in testes, sperm-duct glands and lipid reserves differs between male morphs but not between early and late breeding season in Pomatoschistus minutus.
Journal of fish biology, 2010Co-Authors: Charlotta Kvarnemo, Ola Svensson, W. MansonAbstract:This study of the sand goby Pomatoschistus minutus, a nest-holding fish with paternal care, focused on gonadal investment among males of different sizes collected early and late in the breeding season. All males caught at the nest had breeding colour, whereas trawl-caught fish consisted of males both with and without colour. The absence or presence of breeding colour was a good predictor of testes investment. Compared to males with breeding colour, males without colour were smaller in body size but had extraordinarily large testes. In absolute terms, testes mass of males without breeding colour was on average 3.4 times greater than those of males with breeding colour. Since small colourless males are known to reproduce as sneaker males, this heavy investment in testes probably reflects that they are forced to spawn under sperm competition. Contrary to testes size, sperm-duct glands were largest among males with breeding colour. These glands produce mucins used for making sperm-containing mucous trails that males place in the nest before and during spawning. Since both sneakers and nest-holders potentially could benefit from having large glands, this result is intriguing. Yet, high mucus production may be more important for nest-holders, because it also protects developing embryos from infections. There was no significant effect of season on body size, testes or sperm-duct glands size, but colourless males tended to be less common late in the season. Possibly this may indicate that individual small colourless males develop into their more colourful counterparts within the breeding season.
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Genetic mating patterns studied in pools with manipulated nest site availability in two populations of Pomatoschistus minutus.
Journal of evolutionary biology, 2006Co-Authors: A. Singer, Kai Lindstrom, Charlotta Kvarnemo, Ola SvenssonAbstract:Pomatoschistus minutus show paternal care in a resource defence mating system. We investigated the effect of nest-site availability on parasitic spawning. Each experimental pool contained four potentially nest-building males, four females and nests-sites in shortage (2) or excess (6). Both treatments were conducted in two populations; one with natural nest-sites in excess, one with a nest-site shortage. Microsatellite-DNA revealed that all nest-holders had fertilized most of the eggs they tended. Yet, 35% of the nests contained eggs fertilized by another male and 14.4% of the males had performed parasitic spawning. There was no site or treatment effect. Several females spawned in two nests, which coincided with parasitic spawnings, suggesting a cost to the nest-holder in terms of lost mating success. Nest-holders with and without eggs and non-nesting males all spawned parasitically, generating a significantly lower opportunity for sexual selection compared to if there had been no parasitic spawning.
Ola Svensson - One of the best experts on this subject based on the ideXlab platform.
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Investment in testes, sperm-duct glands and lipid reserves differs between male morphs but not between early and late breeding season in Pomatoschistus minutus.
Journal of fish biology, 2010Co-Authors: Charlotta Kvarnemo, Ola Svensson, W. MansonAbstract:This study of the sand goby Pomatoschistus minutus, a nest-holding fish with paternal care, focused on gonadal investment among males of different sizes collected early and late in the breeding season. All males caught at the nest had breeding colour, whereas trawl-caught fish consisted of males both with and without colour. The absence or presence of breeding colour was a good predictor of testes investment. Compared to males with breeding colour, males without colour were smaller in body size but had extraordinarily large testes. In absolute terms, testes mass of males without breeding colour was on average 3.4 times greater than those of males with breeding colour. Since small colourless males are known to reproduce as sneaker males, this heavy investment in testes probably reflects that they are forced to spawn under sperm competition. Contrary to testes size, sperm-duct glands were largest among males with breeding colour. These glands produce mucins used for making sperm-containing mucous trails that males place in the nest before and during spawning. Since both sneakers and nest-holders potentially could benefit from having large glands, this result is intriguing. Yet, high mucus production may be more important for nest-holders, because it also protects developing embryos from infections. There was no significant effect of season on body size, testes or sperm-duct glands size, but colourless males tended to be less common late in the season. Possibly this may indicate that individual small colourless males develop into their more colourful counterparts within the breeding season.
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Offspring recognition and the influence of clutch size on nest fostering among male sand gobies, Pomatoschistus minutus
Behavioral Ecology and Sociobiology, 2010Co-Authors: Ola Svensson, Maria Lissåker, Kenyon B. MobleyAbstract:When parental care is costly, parents should avoid caring for unrelated young. Therefore, it is an advantage to discriminate between related and unrelated offspring so that parents can make informed decisions about parental care. In the present study, we test the hypothesis that male sand gobies (Pomatoschistus minutus) recognize and differentially care for their own offspring when given a choice between a nest with sired eggs and a second nest with eggs sired by an unrelated male. The sand goby is a species with exclusive and costly paternal care. Male parasitic spawnings (e.g., sneaking) as well as nest takeovers by other males are common. Our results show that nests containing sired eggs were preferred and received significantly more care, as measured by nest building and nest occupancy, than nests with foreign eggs even when males cared for both nests. These findings suggest that males respond to paternity cues and recognize their own clutches. Relative clutch size also had a significant effect on male parental care. When sired clutches were larger than foreign clutches, males preferred to care for their own nest. In the few cases where males chose to take care of foreign nests, the foreign clutch was larger than their own clutch. Taken together, our results provide evidence that both paternity cues and clutch size influence parenting decisions among male sand gobies.
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Cannibalize or care? The role of perceived paternity in the sand goby, Pomatoschistus minutus
Behavioral Ecology and Sociobiology, 2008Co-Authors: Maria Lissåker, Ola SvenssonAbstract:Parental care is a costly part of reproduction. Hence, natural selection should favor males which avoid caring for unrelated young. However, the decision to abandon or reduce care requires cues which are evaluated to give information on potential reproductive value of the offspring. The prediction that male sand gobies, Pomatoschistus minutus, care for foreign eggs as long as they were spawned in their own nest and at least some of such cues are fulfilled was tested. Egg-guarding males that had recently taken part in a spawning event were given a clutch of eggs that was sired either by themselves or another male, in either their own or another male’s aquarium. Males that had not taken part in a spawning event were used as controls and were given eggs sired by another male. We measured the amount of filial cannibalism and nest building. Control group males did not care for eggs and ate them all before rebuilding the nest. In the other treatments, there were no significant effects of paternity, though males moved to another male’s aquarium increased their clutch area threshold and completely consumed larger clutches than males that were not moved. There was no intermediate response in any treatment in the form of increased partial filial cannibalism or less well-constructed nests. Our results suggest that egg-guarding males cannot distinguish between eggs sired by themselves and those sired by other males but are able to react to cues indicating paternity state. Males do not adopt eggs to attract females in P. minutus.
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Genetic mating patterns studied in pools with manipulated nest site availability in two populations of Pomatoschistus minutus.
Journal of evolutionary biology, 2006Co-Authors: A. Singer, Kai Lindstrom, Charlotta Kvarnemo, Ola SvenssonAbstract:Pomatoschistus minutus show paternal care in a resource defence mating system. We investigated the effect of nest-site availability on parasitic spawning. Each experimental pool contained four potentially nest-building males, four females and nests-sites in shortage (2) or excess (6). Both treatments were conducted in two populations; one with natural nest-sites in excess, one with a nest-site shortage. Microsatellite-DNA revealed that all nest-holders had fertilized most of the eggs they tended. Yet, 35% of the nests contained eggs fertilized by another male and 14.4% of the males had performed parasitic spawning. There was no site or treatment effect. Several females spawned in two nests, which coincided with parasitic spawnings, suggesting a cost to the nest-holder in terms of lost mating success. Nest-holders with and without eggs and non-nesting males all spawned parasitically, generating a significantly lower opportunity for sexual selection compared to if there had been no parasitic spawning.
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The importance of sperm competition risk and nest appearance for male behavior and female choice in the sand goby, Pomatoschistus minutus
Behavioral Ecology, 2005Co-Authors: Ola Svensson, Charlotta KvarnemoAbstract:To test if an increased sperm competition risk affects male behavior and mating decisions of both sexes, we performed two experiments using the sand goby, Pomatoschistus minutus, a nest-building fish with exclusive paternal care. In our first experiment, a nest-holding male, with a confined female, was sequentially exposed to a vial with a sneaker male or an empty vial. While male courtship, nest building, displacement fanning, and time outside the nest were unaffected, individual males showed a higher mucus preparation effort inside the nest in the presence of a sneaker male than when alone. We found such mucus to contain sperm, thus clearly suggesting an importance in sperm competition. In our second experiment, a female was free to spawn with two different males, one of which was exposed to a confined sneaker male. Male mating success was not affected by the presence of a sneaker male. However, the volume of sand the male had put on his nest was positively associated with female spawning decision, while nest-opening width was not. In a partial correlation of five traits thought to attract females (nest-opening width, sand volume, male courtship display, displacement fanning, and male size), males that fanned well were found to also build large nests or display intensely, but not both. This indicates that rather than being jacks-of-all-trades, individual males focus on a subset of traits for attracting females. Key words: alternative reproductive tactics, courtship, mating decisions, signal honesty, sperm competition, sperm trail. [Behav Ecol]
Kai Lindstrom - One of the best experts on this subject based on the ideXlab platform.
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Effects of 17α-ethinyl estradiol exposure on estrogen receptors α and β and vitellogenins A, B and C mRNA expression in the liver of sand goby (Pomatoschistus minutus)
Marine environmental research, 2014Co-Authors: Joseph L Humble, Kai Lindstrom, Minna Saaristo, Kari K Lehtonen, John A. CraftAbstract:This study aims to characterize the estrogen receptor (er) in sand goby (Pomatoschistus minutus) and determine the temporal effects of 17α-ethinyl estradiol (EE2) on erα and vitellogenin (vtg) gene expression in males. Two partial cDNA sequences (erα and erβ1) are presented showing conserved structural features with ers of other species. Transcript levels for both ers were low in control fish but EE2 exposure (11 ng/L, for 29 days) increased both to a pattern similar to vitellogenic females. The relative expression of three vtg genes (vtga, vtgb and vtgc) along with erα was determined in control and male fish exposed to EE2 (11 ng/L) at multiple time-points over 29 days. All four transcripts were significantly induced due to exposure and expression rose during the time course with distinct temporal patterns and vtga reached a substantially higher level at the end of the time course coinciding with rapid elevation in erα expression.
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Characterisation of genes transcriptionally upregulated in the liver of sand goby (Pomatoschistus minutus) by 17α-ethinyloestradiol: identification of distinct vitellogenin and zona radiata protein transcripts.
Chemosphere, 2012Co-Authors: Joseph L Humble, Kai Lindstrom, Minna Saaristo, Kari K Lehtonen, Elaine Hands, Oihane Diaz De Cerio, Ibon Cancio, Gemma Wilson, John A. CraftAbstract:Abstract The sand goby ( Pomatoschistus minutus ), is a marine and estuarine teleost that is used in environmental, reproductive and behavioural studies of oestrogenic endocrine disruption. The xeno-oestrogen, 17α-ethinyloestradiol (EE2), induces expression of egg proteins vitellogenin (VTG) and zona radiata protein (ZRP) in male fish and impairs reproduction. Multiple forms of VTG and ZRP genes are found in other teleost species, yet the characteristics of VTG and ZRP in the sand goby are unknown. In this investigation, Suppressive Subtractive Hybridization was used to isolate cDNA fragments from liver, identified as belonging to 11 distinct sand goby genes, suggesting that these genes are transcriptionally upregulated by EE2. Assembly of these fragments revealed three VTG genes which shared homology with VTG classes A, B and C in other fish and two ZRP genes sharing homology with ZRP classes Ba and Bb. RTqPCR of RNA from the sand goby liver was used to show that these VTGs and ZRPs were present in low levels in control males and high levels in mature females. Exposure of males to a concentration of 11 ng L −1 EE2 caused a significant increase in all VTG and ZRP transcript levels. The identification of these egg protein transcripts and the development of validated assays for their quantification will facilitate future work with this useful model species.
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Exposure to 17α-ethinyl estradiol impairs courtship and aggressive behaviour of male sand gobies (Pomatoschistus minutus)
Chemosphere, 2010Co-Authors: Minna Saaristo, John A. Craft, Kari K Lehtonen, Kai LindstromAbstract:Endocrine disrupting chemicals (EDCs), natural or manmade, are known to interfere with the endocrinology of organisms and also cause behavioural changes. The aim of this study was to test how 1-4weeks exposure to 17alpha-ethinyl estradiol (EE2, 11ngL(-1)) affects nest building, courtship and aggressive behaviour of male fish. Our study species, the sand goby (Pomatoschistus minutus) exhibits a polygynous mating system, in which males compete for females and defend their nest against intruders. Nest takeovers are common in their nest-constrained habitat. In our experiment, control and EE2-exposed males were first allowed to build a nest and mate with non-exposed females. When the males had received eggs in their nest, three rival males were introduced into the test aquarium, and the males were left to compete for the nest site overnight. Courtship and aggressive defence behaviour were recorded using a video camera. In addition to behavioural endpoints we measured the expression of hepatic vitellogenin (Vtg) and zona radiata protein (Zrp) mRNA, and several common somatic indices. Our study showed that exposure to EE2 delays nest building and decreases male courtship and leading behaviour. Additionally, EE2-exposed males were significantly less aggressive than control males. Nest takeover rate was not affected by EE2 exposure: an equal percent of males in both treatments lost their nest to competitors. EE2 exposure also induced Vtg and Zrp mRNA expression in males and decreased the hepatosomatic index. The observed changes in nest building, courtship and aggressive behaviour of EE2-exposed males are likely to have negative implications for male reproductive success.
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Sand goby (Pomatoschistus minutus) males exposed to an endocrine disrupting chemical fail in nest and mate competition.
Hormones and behavior, 2009Co-Authors: Minna Saaristo, John A. Craft, Kari K Lehtonen, Kai LindstromAbstract:Abstract Endocrine disrupting chemicals (EDCs) are a widely studied group of chemicals that interfere with the endocrinology of organisms. So far, few studies have demonstrated the effect of EDCs on the reproductive behavior of aquatic wildlife. Here we show that sand goby males' ( Pomatoschistus minutus ) success in mating competition greatly decreases after an exposure for 7 to 24 days to 17α-ethinyl estradiol (EE2, measured concentration 4 ng L − 1 ). The sand goby exhibits a polygynous mating system with male parental care, in which males compete for nest sites and females. The aim of this study was to test how EE2 exposure affects the ability of males to compete for breeding resources, i.e. nest sites and mates. First, EE2 exposed males competed over a nest site against a non-exposed, control male of the same size. Secondly, we examined male courtship behavior and female mate preferences for EE2 exposed males and similar-sized non-exposed, control males. In addition to the behavioral experiments we determined the zona radiata protein (Zrp) mRNA gene expression and measured morphometric indicators of sexual maturation. Our study revealed that EE2 treated males were not able to acquire or defend a nest site. Additionally, EE2 treated males spent significantly less time in active courtship and nest leading behavior than control males. As a result, females clearly preferred to mate with control males. However, we found no significant differences in Zrp mRNA expression or the morphometric indicators between treatments. Our study illustrates that exposure to this EDC can greatly reduce the chances of an individual reproducing successfully. Moreover, it demonstrates that severe behavioral effects can be seen before any effects are detectable at the molecular or morphometric level.
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disruption of sexual selection in sand gobies Pomatoschistus minutus by 17α ethinyl estradiol an endocrine disruptor
Hormones and Behavior, 2009Co-Authors: Minna Saaristo, John A. Craft, Kari K Lehtonen, Heikki Bjork, Kai LindstromAbstract:Abstract In aquatic environments, endocrine disrupting chemicals (EDCs) that interfere with the reproductive physiology of males form a threat to the reproduction of populations. This is often manifested as decreased sexual performance or sterility among males. We show that exposure to EDCs can directly affect the mating system of a marine fish, the sand goby ( Pomatoschistus minutus ). We exposed males for 1 to 4 weeks to two different concentrations (5 ng L − 1 and 24 ng L − 1 ) of 17α-ethinyl estradiol (EE2); a synthetic compound mimicking estrogen and a water control. The sand goby exhibits a polygynous mating system, in which male mating success is typically skewed towards the largest males, resulting in strong sexual selection for increased male size. Our experiment shows that when males have been exposed to EE2, male size has a smaller effect on mating success, resulting in weaker sexual selection on male size as compared to the control. There was an interaction between treatment and exposure time on the expression of vitellogenin and zona radiata protein mRNAs. Males exposed to high EE2 reached much higher expression levels than males exposed to low EE2. Of the somatic markers, the hepatosomatic index was lower in males exposed to high EE2 than in the low EE2 and control males. Our results suggest that exposure to EDCs can have effects on the mating system before physiological changes are observable. These effects can be of profound nature as they interfere with sexual selection, and may in the long run lead to the loss of traits maintained through sexual selection.
Miguel M. Santos - One of the best experts on this subject based on the ideXlab platform.
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Urogenital papilla feminization in male Pomatoschistus minutus from two estuaries in northwestern Iberian Peninsula.
Marine environmental research, 2006Co-Authors: P Rodrigues, Maria Armanda Reis-henriques, J. Campos, Miguel M. SantosAbstract:Recently, male urogenital papilla feminization (UGPF) in the sand goby Pomatoschistus minutus was reported in several UK estuaries with high levels of estrogenic compounds. The fact that this species is also common in southern European estuaries, together with its life-cycle characteristics, prompted us to investigate P. minutus UGPF in the northwestern of Iberian Peninsula. Specimens of P. minutus were periodically sampled during 2004 at several locations in two estuaries (Minho and Lima). Evidence for UGPF was recorded in both estuaries, the highest incidence being observed in the Lima estuary (50%). Estrogen levels (17beta-estradiol and estrone) above 100 pg/l were observed in both estuaries, the higher concentrations being found in the Lima estuary. Overall, the results suggest a relationship between the feminization of male P. minutus urogenital papilla and the presence of estrogenic compounds. In the future, more in-depth studies are required in order to use P. minutus as a sentinel species for estrogenic compound monitoring in estuaries.
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Urogenital papilla feminization in male Pomatoschistus minutus from two estuaries in northwestern Iberian Peninsula.
Marine Environmental Research, 2006Co-Authors: Pedro Nuno R. Rodrigues, Maria Armanda Reis-henriques, J. Campos, Miguel M. SantosAbstract:Recently, male urogenital papilla feminization (UGPF) in the sand goby Pomatoschistus minutus was reported in several UK estuaries with high levels of estrogenic compounds. The fact that this species is also common in southern European estuaries, together with its life-cycle characteristics, prompted us to investigate P. minutus UGPF in the northwestern of Iberian Peninsula. Specimens of P. minutus were periodically sampled during 2004 at several locations in two estuaries (Minho and Lima). Evidence for UGPF was recorded in both estuaries, the highest incidence being observed in the Lima estuary (50%). Estrogen levels (17β-estradiol and estrone) above 100 pg/l were observed in both estuaries, the higher concentrations being found in the Lima estuary. Overall, the results suggest a relationship between the feminization of male P. minutus urogenital papilla and the presence of estrogenic compounds. In the future, more in-depth studies are required in order to use P. minutus as a sentinel species for estrogenic compound monitoring in estuaries.
C. Dieter Zander - One of the best experts on this subject based on the ideXlab platform.
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Four-year monitoring of parasite communities in gobiid fishes of the south-western Baltic
Parasitology Research, 2004Co-Authors: C. Dieter ZanderAbstract:The parasite infracommunity of five goby species ( Pomatoschistus minutus, P. pictus, P.microps, Gobiusculus flavescens, Gobius niger ) from the south-western Baltic was investigated during spring, summer and autumn of the years 1997–2000. The mean parasite species number in single hosts was high, ranging between 1.1 ( P. minutus ), 2.1 ( P. pictus ) to even 3.3 ( P. microps ). Gobius niger is the only host which lives longer than a year and is infested by almost identical parasites for longer times, i.e. the parasite species composition has greater homogeneity. Most intensity of infestation values peaked in summer and were lowest in autumn; only a few exceptions were found in spring or autumn. Only the Digenea Podocotyle atomon and Cryptocotyle concavum were abundant enough to show a clear seasonal fluctuation in Pomatoschistus minutus, P. pictus and Gobiusculus flavescens . Aphalloides timmi and Apatemon gracilis (Digenea) also attained high intensities in P. microps . These four parasite species and, additionally, Cryptocotyle lingua (Digenea), and Hysterothylacium sp. (Nematoda) can be strongly accumulated from either prey or free-swimming larvae and, thus, decisively influence the structure of the infracommunities. Due to selection by filter mechanisms, rare parasites settle rather by chance after competition with other species. The number of parasite species usually increased significantly with host growth. As many as four parasite species were found at the same time in the intestinal tract microhabitat of Gobius niger and P. minutus ; at most three parasite species were present on the skin and fins or in the body cavity. The level of infection is due to the respective life history patterns and the kinds of prey, which harbour different parasites as intermediate hosts. Additionally, it depends on the time of appearance of goby offspring in the course of the year.
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Four-year monitoring of parasite communities in gobiid fishes of the south-western BalticII. Infracommunity.
Parasitology research, 2004Co-Authors: C. Dieter ZanderAbstract:The parasite infracommunity of five goby species (Pomatoschistus minutus, P. pictus, P. microps, Gobiusculus flavescens, Gobius niger) from the south-western Baltic was investigated during spring, summer and autumn of the years 1997-2000. The mean parasite species number in single hosts was high, ranging between 1.1 (P. minutus), 2.1 (P. pictus) to even 3.3 (P. microps). Gobius niger is the only host which lives longer than a year and is infested by almost identical parasites for longer times, i.e. the parasite species composition has greater homogeneity. Most intensity of infestation values peaked in summer and were lowest in autumn; only a few exceptions were found in spring or autumn. Only the Digenea Podocotyle atomon and Cryptocotyle concavum were abundant enough to show a clear seasonal fluctuation in Pomatoschistus minutus, P. pictus and Gobiusculus flavescens. Aphalloides timmi and Apatemon gracilis (Digenea) also attained high intensities in P. microps. These four parasite species and, additionally, Cryptocotyle lingua (Digenea), and Hysterothylacium sp. (Nematoda) can be strongly accumulated from either prey or free-swimming larvae and, thus, decisively influence the structure of the infracommunities. Due to selection by filter mechanisms, rare parasites settle rather by chance after competition with other species. The number of parasite species usually increased significantly with host growth. As many as four parasite species were found at the same time in the intestinal tract microhabitat of Gobius niger and P. minutus; at most three parasite species were present on the skin and fins or in the body cavity. The level of infection is due to the respective life history patterns and the kinds of prey, which harbour different parasites as intermediate hosts. Additionally, it depends on the time of appearance of goby offspring in the course of the year.