Gills Of Freshwater Mussels Research Articles

Integrated Biomarker Response of Oxidative Stress Parameters in the Digestive Glands and Gills of Autochthonous and Invasive Freshwater Mussels from the Sava River, Serbia.

In this study, the activity of oxidative stress parameters superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GSH-Px), glutathione reductase (GR), and glutathione S-transferase (GST), as well as the concentrations of vitamin E (Vit E) and SH groups in the digestive glands and gills of freshwater mussels Unio pictorum and Sinanodonta woodiana from the Sava River in Serbia were investigated. These parameters were determined in native and invasive mussels under the same environmental conditions. The activities of GSH-Px and GR and the concentration of Vit E were significantly higher in the digestive glands of the autochthonous species U. pictorum than in the invasive species S. woodiana, while the CAT activity and the concentration of SH groups were lower. In the gills of U. pictorum, GSH-Px activity and Vit E concentration were significantly higher, while CAT, GST, and SH groups were lower. Principal component analysis (PCA) showed that oxidative stress parameters were strictly tissue- and species-specific. In addition, integrated biomarker response (IBR) showed a combined response of enzymatic and non-enzymatic oxidative stress parameters depending on the tissue or species studied, indicating different metabolic activities and behaviors of an autochthonous versus an introduced bivalve species.

Genotyping of two congeneric bitterling fish species by nuclear SNP markers and the detection of hybridization in a sympatric region

AbstractBitterling fish species (subfamily: Acheilognathinae) are endangered in Japan due to habitat loss. The decline of freshwater mussels also enhances the decrease of bitterlings because bitterlings lay eggs in the gills of freshwater mussels. Furthermore, loss of unionid mussels causes hybridization between bitterling species. This study aims to analyze the frequency of hybridization between congeneric species of bitterlings—Tanakia lanceolata and Tanakia limbata—at a well‐preserved site, where both species occur naturally and compare this with other regions more severely impacted by human intervention. One part of the irrigation streams of the Asahi River System, Okayama, is inhabited by a natural monument species of Japan, a benthic cobitid, Parabotia curtus, and therefore, the natural substratum and the structurally heterogeneous stream banks are maintained. We collected Tanakia individuals and surveyed mussel density at this well‐preserved site. We also developed six nuclear single‐nucleotide polymorphism (SNP) markers on different chromosomes to distinguish T. lanceolata and T. limbata. These SNP markers effectively determined individuals as being either one of these species or a hybrid. Based on genotyping, eight individuals were determined to be hybrids, whereas 90 and 173 individuals were determined as purebreds of T. lanceolata and T. limbata, respectively. The proportion of hybrid individuals was 3.0% and was relatively low compared to other regions. In addition, five species of unionids were densely distributed in this stream. Prezygotic isolation between sympatric T. lanceolata and T. limbata was established at this well‐preserved site, where unionid mussels are densely populated and provide enough breeding substrate for both species.

Characterization of ATPases in the gill of freshwater mussel (Unio tigridis) and effects of ionic and nanoparticle forms of aluminium and copper

Mussels are often used to monitor the aquatic systems for different ecological aims, as they are one of the best bioindicator animals. However, the characterization of biomarkers should be known before using them in environmental monitoring and toxicology studies. There is no study to our knowledge on the characterization of Na-ATPase and Ca-ATPase in tissues of freshwater mussel (Unio tigridis). Thus, this study was undertaken to characterize the optimum working conditions of Na-ATPase and Ca-ATPase in the gill of mussels, determining the highest levels of parameters (Na+, Mg2+, Ca2+, ATP, pH, temperature, enzyme amount, incubation time) to obtain maximum activity. The present study also aimed to investigate in vitro effects of ionic and nanoparticle (Al2O3, CuO) forms of aluminium and copper (0, 30, 90, 270 μg/L) on the activities of Na-ATPase and Ca-ATPase. Data showed that there was no ouabain-sensitive ATPase activity in the gill up to 10 mM ouabain concentrations. Na-ATPase and Ca-ATPase activities in the gill of control mussels were 5.124 ± 0.373 and 3.750 ± 0.211 μmol Pi/mg pro./h, respectively. Exposure to different concentrations of nanoparticles did not alter significantly (P > 0.05) the activities of Na-ATPase and Ca-ATPase in vitro, whereas the same concentrations of ionic aluminium and copper significantly decreased (P < 0.05) the enzyme activities. Data emphasized that there were different modes of action between ionic and nanoparticle forms of aluminium and copper. Data also suggested that in vivo studies should also be carried out to estimate better the effects of nanoparticle and ionic forms of metals on ATPases of U. tigridis.

Assesment of Na+/K+-ATPase, Mg2+-ATPase, Ca2+-ATPase, and Total-ATPase Activities in Gills of Freshwater Mussels Exposed to Penconazole

Triazol bir fungusit olan penkonazol, tarimsal uretimi arttirmak ve funguslari kontrol etmek icin dunya capinda yaygin olarak kullanilmaktadir. Cift kabuklu yumusakcalar, ozellikle midyeler, sucul ekosistemlerde kirliligin spesifik biyomonitor organizmalaridir. Bu calismada tatli su midyelerinin ( Unio mancus ) solungac Na + /K + -ATPaz, Mg 2+ -ATPaz, Ca 2+ -ATPaz ve Total-ATPaz aktiviteleri uzerine penkonazol maruziyetinin olasi toksik etkileri degerlendirilmistir. Bu amacla, 96 saatlik statik yenileme test sisteminde tatli su midyeleri farkli konsantrasyonlarda penkonazole (1, 10, 100 ve 1000 µg AI L -1 ) maruz birakilmistir. Toksisite testlerinde penkonazolun ticari formu (TOPAS ® 100 EC, Syngenta, Almanya) kullanilmistir. Maruziyet ortamindaki gercek penkonazol konsantrasyonlari LC-MS/MS analizi ile belirlenmistir. LC-MS/MS analizi sonuclarina gore, maruziyet ortamindaki gercek penkonazol konsantrasyonlarinin, nominal penkonazol konsantrasyonlarindan yaklasik % 25 oraninda daha dusuk oldugu belirlenmistir. 96 saatlik maruziyetten sonra, en yuksek penkonazol konsantrasyonu Mg 2+ -ATPaz haric diger ATPaz aktivitelerinin onemli duzeyde inhibisyonuna neden olmustur (P < 0.05). Elde edilen veriler, akut penconazol maruziyetinin tatli su midyeleri icin potansiyel bir risk olabilecegini ve ATPaz enzimlerinin akuatik toksikoloji calismalari icin onemli ve faydali biyokimyasal belirtecler oldugunu gostermistir.

Sperm is a sexual ornament in rose bitterling

In many taxa, odour cues mediate mating decisions. A key question is what these odours comprise, where they are produced, and what they signal. Using rose bitterling, fish that spawn in the gills of freshwater mussels, we investigated the role of sperm cues on female oviposition decisions using individuals of known MHC genotype. Male bitterling frequently released sperm prior to female oviposition and females responded with an increased probability of oviposition and released a greater number of eggs, particularly if males had a dissimilar MHC genotype. These mating preferences by females were shown to be adaptive, with MHC dissimilarity of males and females correlated positively with embryo survival. These results support a role for indirect benefits to rose bitterling mate choice, and we propose that sperm acts as a releaser pheromone in bitterling, functioning as a sexual ornament signalling male quality as a mate.

Monitoring DNA Damage in Gills of Freshwater Mussels (Anodonta anatina) Exposed to Heavy Metals

Monitoring DNA Damage in Gills of Freshwater Mussels (Anodonta anatina) Exposed to Heavy Metals

Monitoring DNA Damage in Gills of Freshwater Mussels (Anodonta anatina) Exposed to Heavy Metals

Monitoring DNA Damage in Gills of Freshwater Mussels (Anodonta anatina) Exposed to Heavy Metals

Bayesian inference supports the host selection hypothesis in explaining adaptive host specificity by European bitterling

Generalist parasites have the capacity to infect multiple hosts. The temporal pattern of host specificity by generalist parasites is rarely studied, but is critical to understanding what variables underpin infection and thereby the impact of parasites on host species and the way they impose selection on hosts. Here, the temporal dynamics of infection of four species of freshwater mussel by European bitterling fish (Rhodeus amarus) was investigated over three spawning seasons. Bitterling lay their eggs in the gills of freshwater mussels, which suffer reduced growth, oxygen stress, gill damage and elevated mortality as a result of parasitism. The temporal pattern of infection of mussels by European bitterling in multiple populations was examined. Using a Bernoulli Generalized Additive Mixed Model with Bayesian inference it was demonstrated that one mussel species, Unio pictorum, was exploited over the entire bitterling spawning season. As the season progressed, bitterling showed a preference for other mussel species, which were inferior hosts. Temporal changes in host use reflected elevated density-dependent mortality in preferred hosts that were already infected. Plasticity in host specificity by bitterling conformed with the predictions of the host selection hypothesis. The relationship between bitterling and their host mussels differs qualitatively from that of avian brood parasites.

Strategic sperm allocation and a Coolidge effect in an externally fertilizing species

Because sperm is costly and limiting, males are predicted to allocate sperm differentially across matings, according to the level of sperm competition, female reproductive quality, and female novelty. We investigated sperm allocation in the European bitterling (Rhodeus amarus), an externally fertilizing species of fish that spawns and incubates its eggs in the gills of freshwater mussels. We predicted that males would allocate sperm differentially according to the quality and novelty of mussels. Dominant males responded to rivals by increasing both sperm investment and aggression, whereas subordinates responded chiefly through sperm investment. Dominant males invested more sperm in novel mussels in accordance with predictions for a Coolidge effect, the mussel representing a new fertilization opportunity. However, subordinate males were not influenced by mussel novelty but were responsive to order of mating. Males did not allocate sperm according to mussel quality, suggesting that certainty of paternity is a more important variable than offspring survival in shaping bitterling sperm allocation strategies. This study demonstrates strategic ejaculate expenditure in an externally fertilizing species, analogous to that in internal fertilizers, but with sperm investment operating on the level of the site of fertilization rather than the female. Key wor ds: ejaculate, mate choice, mating system, mussel, oviposition, sexual selection, sperm depletion. [Behav Ecol]

The reproductive ecology of the southern red tabira bitterling Acheilognathus tabira jordani in Japan

The life history, population and reproductive variables of the southern red tabira bitterling Acheilognathus tabira jordani were investigated in a lowland reach of the River Ohara in Shimane Prefecture, western Honshu, Japan. Acheilognathus t. jordani, like all other species of bitterling, lays its eggs on the gills of freshwater mussels. It was the only species of bitterling present in the study reach, and three species of bivalve mussel were available to it for spawning: Anemina arcaeformis, Anodonta lauta and Corbicula leana. Spawning by A.t. jordani was recorded between early April and early July in 2003 and began at a size of 38. 0 mm standard length (L(S)) in the 1+ age class. Ovipositor length (L(OP)) during oviposition was positively correlated with female L(S), and showed significant seasonal variation, with a mean +/-s.d.L(OP) of 27. 5 +/- 5. 3 mm ranging from 16. 8 to 42. 0 mm during the spawning period, which was shorter than that of a previously studied A. t. tabira population. Eggs of this subspecies are relatively long and elliptic in shape, with a volume of c. 2. 4 mm(3). Egg number correlated positively with female L(S) and both egg shape and volume changed significantly with season. The population size of adults was estimated to be 850 individuals, and comprised age 0+ to 3+ individuals with L(S) ranging from 12. 0 to 72. 2 mm. The population sex ratio was significantly female biased, with seven females: three males. Egg shape and size and L(OP) during oviposition in the present A. tabira population may be the result of local adaptations to the mussel species utilized and no competition with other bitterling species for spawning sites.

Sperm depletion as a consequence of increased sperm competition risk in the European bitterling, Rhodeus amarus

Sperm depletion occurs when males are unable to maintain ejaculate size over successive ejaculations and appears to be widespread across multiple taxa. We used the European bitterling, a fish that lays its eggs in the gills of freshwater mussels, in experiments to investigate sperm depletion over different temporal scales at different levels of sperm competition risk. The spermatozoa density of territorial male ejaculates declined over five consecutive ejaculations, but mean ejaculate size was significantly larger if the male was exposed to a rival, suggesting males were sensitive to sperm competition risk and modulated ejaculate size in accordance with theoretical models. However, following successive matings over the course of a day, males exposed to rivals produced significantly smaller ejaculates than males with a low risk of sperm competition. Results are discussed with reference to a possible intersexual conflict over the size and distribution of ejaculates in the context of male sperm depletion and female sperm limitation.

Effects of Deltamethrin on Antioxidant Status and Oxidative Stress Biomarkers in Freshwater Mussel, Unio elongatulus eucirrus

In this study, the effects of deltamethrin on antioxidant status and oxidative stress biomarkers in digestive gland and gill of freshwater mussel, Unio elongatulus eucirrus, was examined. Deltamethrin was applied at concentrations of 25, 50, 100, 200, 400, 800 and 1,600 microg L(-1), for 1, 24, 48, 72 and 96 h. With increasing deltamethrin concentrations, the mussels exposed duration 1-96 h significantly increased lipid peroxidation, which might be associated to decreased levels of reduced glutathione and catalase activity in digestive gland and gill of freshwater mussel (p<0.05 for each cases). Negative correlations were observed between the lipid peroxidation and glutathione or catalase levels after deltamethrin exposure, indicating a protective role of glutathione and catalase against lipid peroxidation, suggesting the use of these antioxidants as a potential biomarker of toxicity associated with contaminant exposure in freshwater mussels.

Toxicological effects of primary-treated urban wastewaters, before and after ozone treatment, on freshwater mussels ( Elliptio complanata)

This study examined the toxic potential of a primary-treated municipal effluent, before and after ozonation, in freshwater mussels. Animals were exposed to various concentrations (0, 1, 3, 10 and 20% v/v) of a primary-treated effluent and also after a treatment with ozone at 10 mg/L in continuous flow-through mode for seven weeks. A suite of biomarkers was used to assess the potential toxic effects of various contaminants typically present in municipal wastewaters: heavy metal metabolism (metallothioneins and labile zinc), cytochrome P4501A1 and 3A4, glutathione S-transferase activities (biotransformation of organic compounds), lipid peroxidation and xanthine oxidoreductase (oxygen radical scavenging), DNA damage, mitochondrial electron transport activity at various temperatures and gonad lipid levels (cellular energy allocation) and aspartate transcarbamoylase and dihydrofolate reductase (gonad activity). On the one hand, some biomarkers, including metallothioneins, labile zinc, glutathione S-transferase, cytochrome P4503A4 activity, dehydrofolate reductase and aspartate transcarbamoylase, were readily decreased. In contrast, these biomarkers, cytochrome P4501A1, gill lipid peroxidation, DNA strand breaks in gills and digestive gland, mitochondrial electron transport at high and low temperatures (temperature-dependent activity) and total gonad lipids, were readily increased. In general, ozone treatment reduced adverse effects by either decreasing the intensity of the toxic responses or increasing the threshold concentration. For gill lipid peroxidation, however, intensity was greater at a higher threshold concentration. Ozone treatment eliminated the temperature sensitivity of the mitochondrial electron transport system, indicating a loss of interaction between temperature and urban pollution in terms of energy expenditure in mussels. Ozone treatment could significantly decrease either the toxic potency or intensity of urban pollutants at the expense of increased oxidative stress in gills of freshwater mussels.

The bitterling–mussel interaction as a test case for co‐evolution

The European bitterling Rhodeus sericeus(Cyprinidae) spawns in the gills of freshwater mussels (Unionidae) and shows some obvious adaptations to this type of spawning, such as the development of an ovipositor. Furthermore, recent studies have shown that the fish avoid species of mussels that have a high likelihood of ejecting their eggs prematurely. This leads to the question of whether the interaction between bitterling and mussels could represent a case of co‐evolution, involving evolutionary responses by both species to selection imposed by the other. The evidence for and against co‐evolution is reviewed, incorporating new results from two sets of experiments designed to test for adaptive choices by bitterling according to the mussels’ sex and reproductive state, as well as a preliminary study of potential benefits for mussels from exposure to bitterling. Host preferences by bitterling, both among and within mussel species, may indeed have evolved in response to differences in benefits for offspring survival. There is no evidence yet for any benefits to mussels from receiving eggs, whereas there are costs due to reduced ventilation rates when the gills contain bitterling eggs. While there are differences among mussel species and individuals in their tendency to reject bitterling embryos, these differences do not provide strong evidence for co‐evolution. For example, they may reflect differences in host physiology such as ventilation rate and generalized responses to expelling objects from their gills. Therefore, while bitterling are well adapted for their obligate spawning relationship with mussels, it has been much more difficult to find evidence for adaptations by mussels for dealing with bitterling. This suggests that any co‐evolutionary dynamics between bitterling and mussels may be asymmetric, with stronger responses to selection by the fish than by mussels.

The European bitterling: a model for oviposition decision

For oviparous species, oviposition decisions can have significant fitness consequences. The European bitterling (Rhodeus sericeus) is a cyprinid fish that lays its eggs on the gills of freshwater mussels. Because bitterling use a discrete spawning site that can be readily manipulated, they are unusually amenable to field and laboratory studies aimed at understanding the adaptiveness and consequences of oviposition decisions. Here I present data demonstrating the adaptiveness of oviposition decisions by female bitterling, and link these decisions, using game‐theory models, with bitterling population dynamics. I explain the proximate cues used by females in making oviposition choices, and how these respond to environmental variables. I also show how the oviposition decisions of males relate to the risk of sperm competition in mussels, and propose that oviposition choices may represent an inter‐sexual conflict in bitterling. Finally, I present behavioural and genetic data from mesocosm experiments to show the implications of global and local male densities for female oviposition opportunities, and consider the consequences for bitterling population dynamics.

Development of European bitterling in the gills of freshwater mussels

The development of bitterling embryos within the unique environment of a freshwater mussel's gills requires a departure from typical cyprinid embryological development. Eggs are large (2·6×1·7 mm), illustrating the low risk of predation, and elliptical; a response to unionid gill morphology and a way of increasing the transfer rates of respiratory and excretory products to and from the tissues. The yolk sac develops elongated lateral processes during early ontogeny; these secure the embryo into the host's interlamellar space. Once the larva is capable of movement (8·2 mm) the lateral processes are lost and the larva becomes less dependent of the host's gills for the provision of oxygen. Hatching (3·3 mm) and pigmentation of the blood (6·4 mm) occur relatively early; this may increase the rate of oxygen supply to the tissues. Pigmentation of the eyes and appearance of the melanophores occurs relatively late (7·4 mm and 7·9 mm, respectively); embryos are not required to detect or avoid predators. Bitterling larvae generally emerge from the host once the yolk sac has been consumed (10·5 mm); this may mark a change in respiratory and nutritional requirements.

Development of European bitterling in the gills of freshwater mussels

Development of European bitterling in the gills of freshwater mussels

Pressure effects on metabolism in tissues from mice (Mus muscalis) and freshwater mussel (Elliptio complanata)

Metabolic rates of tissue sections from freshwater mussel gills and mouse brain and lung tissue were measured by calorimetry in ampules pressurized with gas mixtures. Increasing partial pressure of oxygen or total pressure with constant partial pressure of O2 does not affect the respiratory quotient but increases rates of tissue metabolism. Changes in metabolic activity occur over pressure and Po2 ranges commonly encountered by humans engaged in SCUBA diving.

Long-Term Culture of Freshwater Mussel Gill Strips: Use of Serotonin to Affect Aseptic Conditions.

Serotonin relaxes the musculature and increases epithelial ciliary activity in freshwater mussel gills. This results in greater than normal water flow through the labyrinth of water canals and channels of the gill. These water spaces harbor significant microbial populations that make aseptic culture of freshwater mussel gills difficult. High concentrations of antibiotics can maintain short-term cultures, but are toxic to the tissue and reduce the lifespan of the culture. Moderate levels of antibiotics used in combination with 0.1 mM serotonin during a single, short pretreatment produces aseptic cultures. These cultures can now be established routinely and are viable for over a month as assayed by gill structural integrity, trypan blue exclusion, leucine incorporation into TCA precipitable protein, and normal physiological responsiveness to serotonin re-exposure.

Musculature Associated with the Water Canals in Freshwater Mussels and Response to Monoamines In Vitro.

The gills of freshwater mussels perform many functions that depend on water flow through the water canals and channels. Regulation of water flow depends in part on ciliary activity and in part on the contraction of musculature underlying the gill filament and water channel epithelium. Obliquely striated muscles control water canal openings (ostia) at the base of the filaments and also at the entry into the water channel (internal ostia, IO). The muscles adjacent to the ostia are oriented in an anterior-posterior direction (perpendicular to gill filaments), and those controlling the internal ostia are oriented in a dorso-ventral direction (parallel to gill filaments). Small bundles of fibers radiate from the major dorso-ventral IO muscle bands and appear to insert at the base of the water canal epithelial cells at the canal-channel junction. Both muscular bands are closely associated with the branchial nerves in the gill. When gills are exposed to 10-5 M serotonin in vitro, both ostial openings dilate and gill ciliary activity increases. The net result of serotonin treatment is an increase in ciliary activity, a maximal opening of the water canal ostia, and, presumably, an increase in water flow through the gill.