Karel Halačka

Morphometric and genetic analysis of Carassius auratus complex from an artificial wetland in Morava River floodplain, Czech Republic

A Carassius auratus complex from an artificial wetland in the Morava River basin is composed of triploid females. Based on body depth, sampled females could be divided into two groups: (i) high-dorsal (42.5% of standard length); and (ii) low-dorsal (36.1% of standard length). Both groups differed also in number of gill rakers (50.2 versus 45.4, respectively). In concordance with morphological differences, genetic analysis proved the existence of two haplotypes in examined individuals. The first haplotype is bound to the high-dorsal form with higher number of gill rakers. This is the most frequent haplotype in populations of the C. a gibelio form in the Czech Republic. The second haplotype is characteristic of the low-dorsal form with a lower number of gill rakers. This haplotype is close to haplotypes described in the C. a. langsdorfii form, which is known from Japan. and its occurrence within haplotypes specified in European territory is sporadic.

Permanent Genetic Resources added to Molecular Ecology Resources Database 1 April 2012 - 31 May 2012: PERMANENT GENETIC RESOURCES NOTE

This article documents the addition of 123 microsatellite marker loci to the Molecular Ecology Resources Database. Loci were developed for the following species: Brenthis ino, Cichla orinocensis, Cichla temensis, Epinephelus striatus, Gobio gobio, Liocarcinus depurator, Macrolophus pygmaeus, Monilinia vaccinii‐corymbosi, Pelochelys cantorii, Philotrypesis josephi, Romanogobio vladykovi, Takydromus luyeanus and Takydromus viridipunctatus. These loci were cross‐tested on the following species: Cichla intermedia, Cichla ocellaris, Cichla pinima, Epinephelus acanthistius, Gobio carpathicus, Gobio obtusirostris, Gobio sp. 1, Gobio volgensis, Macrolophus costalis, Macrolophus melanotoma, Macrolophus pygmaeus, Romanogobio albipinnatus, Romanogobio banaticus, Romanogobio belingi, Romanogobio kesslerii, Romanogobio parvus, Romanogobio pentatrichus, Romanogobio uranoscopus, Takydromus formosanus, Takydromus hsuehshanesis and Takydromus stejnegeri.

A multilocus assessment of nuclear and mitochondrial sequence data elucidates phylogenetic relationships among European spirlins (Alburnoides, Cyprinidae).

The phylogenetic relationships and taxonomy of the spirlins in the genus Alburnoides are examined by comparative sequencing analysis of mitochondrial and nuclear markers. Molecular analyses revealed 17 Eurasian lineages divided into two main clades, termed the Ponto-Caspian and European in accordance with the lineage distribution. The indel diagnostics of β-actin and S7 markers and translation of cyt b to the amino acid chain were evaluated as a reliable identifying tool for most of the recognised lineages. Lineage richness is closely connected with the existence of known glacial refugia in most cases. The underestimation of species richness in the genus Alburnoides is confirmed: the genetic analyses support the validity of 11 morphologically accepted species; apart from them, four phylogenetic lineages requiring descriptions as separate species were revealed. The distribution area of the nominotypical species A. bipunctatus s. stricto is newly defined. Two diverging phylogenetic lineages, A. ohridanus, and A. prespensis complex, were observed in the Southeast Adriatic Freshwater Ecoregion, confirmed as a hotspot of endemic biodiversity. A. ohridanus demonstrates high divergence from the A. prespensis complex, represented by three similar mitochondrial lineages with the same nuclear haplotypes and sympatric occurrence. The range restricted endemism was confirmed for at least seven species. The Albanian river systems, as well as the wider Ponto-Caspian basin exhibit complications among definite species delineations and gaps in understanding of microevolutionary processes; these areas require further investigations.

The epidermal structure of Carassius gibelio: a link with ploidy status in spawning and postspawning periods.

A reduction of epidermal club cells and an increase of goblet cells were found in Carassius gibelio during spawning when compared to postspawning. A significantly lower proportion of club cells at spawning was found in diploid males and triploid females than in diploid females. It could be linked to male efforts to avoid a fright reaction and the potential adoption of this strategy by gynogenetic females, or alternatively to a higher parasite infection or immunosuppression during spawning.

The effect of ploidy and temporal changes in the biochemical profile of gibel carp (Carassius gibelio): a cyprinid fish species with dual reproductive strategies

The basic biochemical profile of gibel carp (Carassius gibelio), diploid–triploid cyprinid species complex with dual reproduction modes, was investigated. The aim of the study was to test for the effect of fish group (which combines the effects of ploidy and sex) and temporal changes on indicators of the biochemical profile of blood in gibel carp. We showed that the basic biochemical profile of blood is significantly influenced by season and fish group. Triploid gynogenetic females had a better condition measured by total protein concentration than sexual diploids. The higher concentrations of triacylglycerols and cholesterol in triploid females when compared to diploids indicate a higher metabolic rate and higher energy intake during the whole year, which may represent a disadvantage for triploids. Differences in the concentrations of blood biochemical analytes between triploid females and diploids suggest a potential difference in the regulation of a wide range of physiological and biochemical processes in which these analytes participate. The biochemical profiles of two forms of C. gibelio could at least partially explain the changes of character of its naturally occurring populations.

Epidermis structure and blood parameter differences between sculpin Cottus gobio and Siberian sculpin Cottus poecilopus from the Morava watershed

Abstract. The epidermis structure of the studied specimens of Cottus gobio and C. poecilopus from the Morava watershed showed important differences. We noted a lower number of sacciform secretory cells in C. gobio, and also differences in relation to reproductive activity (the decrease in the number of secretory cells during the spawning period in both species). Significant differences were found in the erythrocyte count (1.90 ± 0.15 T.l-1 in C. gobio and 1.57 ± 0.07 T.l-1 in C. poecilopus), whereas the leucocyte count did not differ. A three-day-long exposure in higher temperature and lower oxygen saturated water conditions caused a marked increase in both blood parameters. These differences can be related to the distant physiological and ethological requirements of the species.

Physiological and condition-related traits in the gynogenetic-sexual Carassius auratus complex: different investments promoting the coexistence of two reproductive forms?

BackgroundCarassius auratus complex is an extraordinary species complex including the diploid and polyploid forms exhibiting asexual and sexual reproduction modes. The coexistence of both forms in the same habitats is currently reported. The stable coexistence of asexual and sexual forms assumes some disadvantages for asexuals that balance the costs of sex. In our study, we hypothesized and tested the differences in physiological (including heamatological and immunological), growth-related, condition-related, and fitness-related traits between gynogenetic females and sexuals.ResultsOur results revealed similar growth performance in gynogenetic females and sexuals measured by body size and weight, or expressed by condition factor. The energy allocation in reproduction measured by the relative size of gonads revealed no difference between gynogenetic and sexual females; in addition, both females in spawning expressed the same estradiol levels in blood plasma. We found a gender specific trade-off between investment in reproduction and immunocompetence (measured by the spleen-somatic index). Higher aerobic performance expressed by the heart index and higher oxygen-carrying capacity were found in sexual males, with increasing values before and during spawning. Our study evidenced significantly lower aerobic performance but higher oxygen-carrying capacity per erythrocyte in gynogenetic females when compared to sexuals. IgM production differed between gynogens and sexuals of C. auratus complex.ConclusionsOur study indicates that a similar amount of energy is invested by both gynogenetic and sexual females of C. auratus complex in reproductive behaviour. We suggest that lower aerobic performance in gynogens may represent their physiological disadvantage balancing the cost of sexual reproduction. A trade-off between the number of erythrocytes and the oxygen-carrying capacity per erythrocyte in sexual males and gynogenetic females may contribute to the coexistence of gynogenetic and sexual forms. In addition, the differences in specific immunity between gynogens and sexuals may also reduce the evolutionary disadvantage of sexual reproduction. In conclusion, we propose that several mechanisms contribute to the coexistence of the gynogenetic-sexual C. auratus complex.

The first record of a natural hybrid of the roach Rutilus rutilus and nase Chondrostoma nasus in the Danube River Basin, Czech Republic: morphological, karyological and molecular characteristics

Morphological (meristic and morphometric traits), karyological and molecular (microsatellites, cytochrome b) analyses were performed to characterize a hybrid of the roach Rutilus rutilus and nase Chondrostoma nasus. Meristic and morphometric traits were different between hybrid and both parental species. The number of chromosomes found in hybrid specimen indicated that this individual represents the post-F(1) generation of hybrids and the microsatellite analysis of the hybrid showed the presence of variants typical for R. rutilus and C. nasus.

The X1X1X2X2/X1X2Y multiple sex chromosome system in the Zingel zingel (Pisces: Perciformes) from the Morava River (Czech Republic)

Abstract The karyotype of Zingel zingel from the Morava River (Czech Republic) was analyzed. The diploid chromosome number was 2n=48 in females and 2n=47 in males, however, one large unpaired metacentric chromosome was present in males. This proves to be the X1X1X2X2/X1X2Y multiple sex chromosome system developed from the fusion of two sub- or acrocentric chromosomes where a sex chromosome Y was present as one of them.

Growth differences in different biotypes of the hybrid complex of Cobitis elongatoides × Cobitis tanaitica (Actinopterygii: Cypriniformes: Cobitidae) in the Okna River (Danube River basin), Slovakia

Background. Many of Cobitis subpopulations exist as diploid–polyploid hybrid complexes where polyploid gynogenetic females act as “sperm parasites” of diploid individuals. In addition to sexual strategy, the life history of such individuals is also affected by their growth performance. In order to elucidate unknown aspects of the Cobitis hybrid complexes we decided to identify differences in the annual size increments between individuals representing different ploidy and sex, and to compare the condition factor expressed by length–weight (L–W) relation within the same ploidy and sex groups. Material and methods. In total, 158 specimens representing Cobitis elongatoides (Băcescu et Mayer, 1969) × Cobitis tanaitica (Băcescu et Mayer, 1969) hybrid complex were caught in August and September 2014, of which 132 were analysed. The fish were caught in the Okna River (Danube River basin), Slovakia. Sex was determined based on externally visible morphological features or based on microscopic observation of the gonads. Ploidy level was determined by means of flow cytometry on fin clips taken from each specimen. Age was estimated based on the total number of annuli visible on vertebrae. All statistical models were performed in the R statistical environment. Results. Sex ratio varied within age classes, with 3+ fish primarily composed of females and, 4+ fish mostly triploid. Maximum back-calculated lengths for diploid females were obtained up to 3+, and for the 4+ age group for triploid. L–W relations for adult males and females also differed significantly, but did not vary between diploid and triploid females. There were differences in at specific body lengths for Cobitis with different ploidy level. Diploid males were characterised by short annual age and length increments during the first two years of life. Annual increments in diploid females were highest overall though their frequency decreased after the reaching the fourth year of life (3+). On the contrary, annual increments in triploid females were the lowest within all groups until their fourth year, thought their frequency in the oldest age group (4+). Conclusion. In our study, we first confirmed that yearly increments and maximal age of Cobitis individuals are affected by different ploidy. Contrary, the L–W relations of gutted diploid and triploid females did not differ and they were affected only by sex. We suggest that the intensity of growth is more affected by ploidy, while the L–W of Cobitis is determined by intensity of feeding and stage of gonad development at the local conditions during season. Therefore, in the future studies of Cobitis growth and condition parameters the ploidy level of individuals should also be considered.