Mobility of individual roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> (L.) in three weir-fragmented Belgian rivers

Adult roach Rutilus rutilus (L.) (N = 24; 19.9–36.1 cm FL) from three highly fragmented Belgian rivers were tagged with surgically implanted radio transmitters. Their seasonal movements were observed from March to August 2004 (circum reproduction period) in river stretches delimited by two physical barriers. In the three rivers, roach displayed similar patterns of movements which were mainly influenced by the date of observation (movements increased in late April–May) and water temperature (travel distances were more important when water temperature ranged between 10°C and 14°C). Roach sometimes cleared physical obstacles. The mean distances travelled in each river were relatively short (max. 2.5 km) and mainly influenced by the length of the study reach, which was delimited by physical barriers.     

Behavioral and morphological asymmetries in roach <Emphasis Type="Italic">Rutilus rutilus</Emphasis> (Cyprinidae: Cypriniformes) underyearlings

The underyearlings of roach, Rutilus rutilus, displayed a bilateral asymmetry of C-bend—the initial stage of escape behavior. Most individuals exhibited a significant bias to turn leftward or rightward after being stimulated by electrical current. This individual asymmetry was consistent when the same fish were retested ten days later. A significant correlation was revealed between the behavioral asymmetry and the bilateral asymmetry of surface area of frontal (positive correlation) and parietal (negative correlation) cranial bones. No significant correlation was found with the bilateral asymmetry of other morphological characteristics: numbers of pores of the seismosensory canals (praeopercular-mandibular, supraorbital, and supratemporal) in flat cranial bones (dental, praeopercular, frontal, and parietal numbers of lateral line pores, and numbers of rays in pectoral and ventral fins.     

Effects of an induced magnetic storm on the early ontogenesis of roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> (L.)

The influence that an induced magnetic storm (IMS) modeled in a confined volume has on the early ontogenesis of Rutilus rutilus was studied. The significant effects of the IMS were observed for the hatching rate of roach embryos, the size-weight and morphometric parameters of the fry, the variability of the vertebral column, and ontogeny stability in the roach offspring.     

Mating patterns of first-generation hybrids of the roach, <Emphasis Type=Italic>Rutilus rutilus</Emphasis> (L.), and the silver bream, <Emphasis Type=Italic>Blicca bjoerkna</Emphasis> (L.)

Mating patterns among first-generation hybrids of the roach, Rutilus rutilus, and the silver bream, Blicca bjoerkna, between hybrids or with parent-species males, have been investigated under experimental reproduction conditions. The results reveal that the level of sexual activity of these hybrids is high. Hybrid females mated simultaneously and successively with all types of male, resulting in fertilised eggs. Individual participation of roach males in mating was never observed, however.     

The viability of the first generation roach (<Emphasis Type=Italic>Rutilus rutilus</Emphasis> L.), bream (<Emphasis Type=Italic>Abramis brama</Emphasis> L.), and blue bream (<Emphasis Type=Italic>Abramis ballerus</Emphasis> L.) hybrids at early stages of development

The viability of bream, roach, and blue bream F ₁hybrids at early stages of their development is analyzed. Viability is controlled according to parameters of the survival rate at stages from fertilized eggs to yearlings. During embryogenesis, significant stages (blastula—gastrula and hatching) are revealed by the amount of losses. The viability of hybrids of the first generation (compared to pure species) from the hatching stage and in the subsequent development constantly increases. At the stage of fingerlings, the viability of F ₁hybrids significantly exceeds that of pure species, which points to the heterozygous effect according to the parameters of hybrid survival for the first generation, which is absent in embryogenesis.     

Dependence that the community structure of the roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> (L.) parasites has on the host age

The changes that take place in the structure of the parasite communities of two roach populations as the hosts grow older have been studied in the Chivyrkuiskii Bay of Lake Baikal and the estuary of the Selenga River. The parasite communities are analyzed at the levels of host individuals (infracommunities), host age groups (sets of infracommunities), and host population (component community). The number of parasite species regularly increases as the roaches age in both aquatic bodies, whereas the evenness of the parasite communities decreases. The Berger-Parker dominance index of the parasite communities changes with the roach age in different directions, increasing in the Chivyrkuiskii Bay and decreasing in the estuary of the Selenga River. The changes in the Shannon diversity index for sets of infracommunities of roach parasites are the opposite of those in the Berger-Parker index.     

Effect of thyroid hormones on activity dynamics of enzymes of intestinal mucosa of juvenile roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis>

The effect of thyroid hormones on activity dynamics of enzymes (proteinases and glycosidases) of intestinal mucosa of juvenile roach Rutilius rutilus was investigated. Application of substances increasing and decreasing the level of thyroid hormones in blood plasma significantly influences the growth rate and the activity of proteinases and glycosidases functioning in the intestinal mucosa. In most cases, the activity level of trypsin-like proteinases and the activity of glycosidases in the fish exposed to triiodothyronine were significantly higher than in the control. The activity level of chymotrypsin-like proteinases in fish form the group with exposure of exogenous triiodothyronine only in the end of the experiment surpassed the values of this parameter in the control fish. In the fish developing at deficiency of thyroid hormones, the growth rate and proteinases activity were significantly lower in comparison with the control.     

Exploratory behavior of juvenile roach <Emphasis Type="Italic">Rutilus rutilus</Emphasis> (L.) (Teleostei: Cyprinidae) in a maze after different magnetic impacts on embryos

We have investigated a sequence of visits to arms in a cross maze in juvenile (1-year-old) roach Rutilus rutilus (L.). Fish embryos of one group are raised under a natural geomagnetic field. The embryos of another group are exposed to the main phase of a simulated geomagnetic storm (changes in geomagnetic field up to 100 nT for each component). It turns out that the sequence of visits does not differ from random in both groups. Thus, the exploratory behavior in juvenile roach differs from other animal taxa investigated earlier. In the latter taxa a spontaneous alternation was observed: a tendency to visit the arm which was visited least recently.     

Comparative analysis of generative parameters of the roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> (L., 1758) in the Volga reach of the Rybinsk Reservoir

An analysis of the reproductive potential of roach in the Volga reach of the Rybinsk Reservoir is made on the basis of published data and our own data obtained from 1953 to 2012. Values of fecundity obtained in the 2000s are the most similar to the results of 1976. Parameters of the intensity of the generative exchange of females (absolute and relative fecundity and size and mass of eggs) were high in 2007 and 2012, which indicates a sufficient food supply, especially of medium and large roach.     

<Emphasis Type=Italic>Paraliparis adustus</Emphasis> and <Emphasis Type=Italic>Paraliparis bullacephalus</Emphasis>: two new snailfish species (Teleostei: Liparidae) from Alaska

Paraliparis adustus sp. nov., a snailfish species from the Bering Sea near the Aleutian Island Archipelago, Alaska, is described based on a single mesopelagic specimen. This new species is clearly distinguished by a combination of several morphological features and meristic counts, including long pointed gill rakers with 0–3 spinules at or near the tip, anus positioned forward near the pectoral symphysis, and color uniform brown. Paraliparis bullacephalus sp. nov. from Shelikof Strait, Gulf of Alaska, is also described. This new species is very similar in meristic characters and general body shape and size to P. holomelas Gilbert, but differs primarily in morphological features of the head, particularly in the shape of the dorsal contour of the head, snout, and opercular flap, mouth size, and eye position.     

The effect of raising conditions on behavior of juvenile roach <Emphasis Type="Italic">Rutilus rutilus</Emphasis> (L.) (Cyprinidae)

The behavior of juvenile 4.5-month-old roach Rutilus rutilus (L.) raised (starting on the 12th day after hatching) at different levels of habitat informational diversity (feeding with live and immobilized zooplankton and benthos, the presence of a predator, and a constant water flow in the nursery aquarium) was studied. The fish’s exploratory behavior and locomotor activity were tested in a circular chamber; swimming activity was tested in a hydrodynamic conduit. It was experimentally shown that juvenile roach raised in the presence of a predator differed significantly (p < 0.05) in regards to behavioral characteristics from the fries raised in a water current and in conditions of a high level of environmental deprivation.     

Molecular and morphological analysis of endangered species <Emphasis Type=Italic>Gymnodiptychus integrigymnatus</Emphasis> (Teleostei: Cyprinidae)

Gymnodiptychus integrigymnatus is a critically endangered species endemic to the Gaoligongshan Mountains. It was thought to be only distributed in several headwater-streams of the Longchuanjiang River (west slope of the Gaoligongshan Mountains, belonging to the Irrawaddy River drainage). In recent years, dozens of G. integrigymnatus specimens have been collected in some streams on the east slope of the Gaoligongshan Mountains (the Salween drainage). We performed a morphological and genetic analyses (based on cytochrome b and D-loop) of the newly discovered populations of G. integrigymnatus to determine whether the degree of separation of these populations warrants species status. Our analysis from the cytochrome b gene revealed that nine individuals from the Irrawaddy drainage area and seven individuals from the Salween drainage area each have only one unique haplotype. The genetic distance between the two haplotypes is 1.97%. Our phylogenetic analysis revealed that G. integrigymnatus is closely related to highly specialized schizothoracine fishes. Analysis from the mitochondrial control region revealed that G. integrigymnatus has relatively high genetic diversity (π was 0.00891 and h was 0.8714), and individuals from different river drainages do not share the same haplotypes. The AMOVA results indicated 87.27% genetic variability between the Salween and Irrawaddy populations. Phylogenetic trees show two major geographic groups corresponding to the river systems. We recommend that G. integrigymnatus should be considered as a high priority for protected species status in the Gaoligongshan Mountains National Nature Reserve, and that the area of the Gaoligongshan Mountains National Nature Reserve should be expanded to cover the entire distribution of G. integrigymnatus. Populations of G. integrigymnatus from different river systems should be treated as evolutionarily significant units.     

Effect of thyroid hormones on the development of pharyngeal dentition in roach <Emphasis Type="Italic">Rutilus rutilus</Emphasis> (Cyprinidae,Cypriniformes)

Development of teeth on the pharyngeal bones of roach Rutilus rutilus and the effect of thyroid hormones on this development are investigated. The addition of exogenous triiodothyronine leads to accelerated development of the teeth, but the deficit of triiodothyronine (provoked by the addition of thiourea in the media) stimulates the retardation of this development. Change of developmental rate of the organism leads to change in the definitive state of the pharyngeal teeth formula. Owing to accelerated development, the number of teeth significantly decreases, and the formulas 5–5, 5–4, and 4–4 appear instead of the typical formula 6–5 in the control group and in the fish from natural populations. Retarded development of the organism leads to increased frequency of occurrence of the formula 6–6. The directed asymmetry in the numbers of pharyngeal teeth with the formula (6–5), most likely, is connected with different types of teeth development on the left and right pharyngeal bones.     

The effect of an alternating electromagnetic field upon early development in roach (<Emphasis Type="Italic">Rutilus rutilus</Emphasis>: Cyprinidae,cypriniformes)

The effect of an alternating electromagnetic field (EMF) upon three stages of roach’s (Rutilus rutilus) early development was studied. The studies covered the periods before gastrulation; from gastrulation until hatching; and from hatching until yolk sac resorption. It has been shown that the EMF effect is as stronger as earlier in the embryogenesis the roach was subjected to an impact. The following responses to EMF were registered: earlier hatching of prelarvae, increase in the morphological diversity of juvenile fish, decrease in body lengths and weights, and changes in the number of vertebrae in yearlings.     

Morphological Variability of Roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> (L.) from the Volga Reach of Rybinsk Reservoir

A comparative analysis of literature data and our own results on the morphology of roach from the Volga Reach (Rybinsk Reservoir) in different years is conducted. Recently, (from 2007 to 2010), the morphological characteristics of the roach have been similar to those observed between 1976 and 1978. The roach is characterized by an intermediate position between the herbivorous and malacophagous morphs, but it is more similar to the herbivorous morph.     

Life cycle of <Emphasis Type=Italic>Aylax hypecoi</Emphasis> (<Emphasis Type=Italic>Insecta: Hymenoptera: Cynipidae</Emphasis>), a gall inducer on <Emphasis Type=Italic>Hypecoum</Emphasis> ssp. (<Emphasis Type=Italic>Papaveraceae</Emphasis>)

The life cycle and developmental stages of Aylax hypecoi (Trotter, 1913, Hymenoptera: Cynipidae: Aylacini) were studied in detail. Aylax hypecoi is known to induce galls in fruits of two Hypecoum species — H. imberbe and H. geslini (Papaveraceae) and the larva develops in host plant fruits. The morphology and development of egg, larva and pupa were investigated, which has previously not been done. The shape and size of terminal-instar larvae and associated galls are sex-specific. Overwintering stage, adult emergence and flying periods, and egg productivity were studied also.     

The role of thyroid hormones in the formation of behavioral responses in juvenile roach (<Emphasis Type="Italic">Rutilus rutilus</Emphasis> (L.) (Cyprinidae)

The effect of thyroid hormones (THs) on the formation of behavioral responses in juvenile roach was studied. Eggs taken from one pair of spawners were split into three groups and kept in different environments: a clean water control, with the addition of a hormone, and with the addition of a substance blocking thyroid-gland synthetic activity. It was revealed that control fish and those with an enhanced hormonal status manifest more mature behavior than the fish with a lowered hormonal status.     

Indicators of innate immunity and oxidizing processes in the blood serum and liver in roach <Emphasis Type=Italic>Rutilus rutilus</Emphasis> L. from the Kuban River

Antimicrobial properties of the blood serum and the content of immune complexes, lipid peroxidation products, and antioxidants in the blood serum and liver have been analyzed in roach living in areas of the Kuban River with different levels of anthropogenic pollution. The relationship between the studied parameters and fish habitats is shown.     

Probiotic <Emphasis Type=Italic>Lactobacillus</Emphasis> strains: <Emphasis Type=Italic>in vitro</Emphasis> and <Emphasis Type=Italic>in vivo</Emphasis> studies

Three Lactobacillus strains (LOCK 0900, LOCK 0908, LOCK 0919) out of twenty-four isolates were selected according to their antagonistic activity against pathogenic bacteria, resistance to low pH and milieu of bile salts. Intragastric administration of a mixture of these strains to Balb/c mice affected cytokine T_H1-T_H2 balance toward nonallergic T_H1 response. Spleen cells, isolated from lactobacilli-treated mice and re-stimulated in vitro with the mixture of heat-inactivated tested strains, produced significantly higher amounts of anti-allergic tumor necrosis factor- and interferon-γ than control animals whereas the level of pro-allergic interleukin-5 was significantly lower. Lactobacillus cells did not translocate through the intestinal barrier into blood, liver and spleen; a few Lactobacillus cells found in mesenteric lymph nodes could create antigenic reservoir activating the immune system. The mixture of Lactobacillus LOCK 0900, LOCK 0908 and LOCK 0919 strains represents a probiotic bacterial preparation with possible use in prophylaxis and/or therapy of allergic diseases.