The development of paired appendages was a key innovation during evolution and facilitated the aquatic to terrestrial transition of vertebrates. Largely derived from the lateral plate mesoderm (LPM), one hypothesis for the evolution of paired fins invokes derivation from unpaired median fins via a pair of lateral fin folds located between pectoral and pelvic fin territories1. Whilst unpaired and paired fins exhibit similar structural and molecular characteristics, no definitive evidence exists for paired lateral fin folds in larvae or adults of any extant or extinct species. As unpaired fin core components are regarded as exclusively derived from paraxial mesoderm, any transition presumes both co-option of a fin developmental programme to the LPM and bilateral duplication2. Here, we identify that the larval zebrafish unpaired pre-anal fin fold (PAFF) is derived from the LPM and thus may represent a developmental intermediate between median and paired fins. We trace the contribution of LPM to the PAFF in both cyclostomes and gnathostomes, supporting the notion that this is an ancient trait of vertebrates. Finally, we observe that the PAFF can be bifurcated by increasing bone morphogenetic protein signalling, generating LPM-derived paired fin folds. Our work provides evidence that lateral fin folds may have existed as embryonic anlage for elaboration to paired fins.

• MeSH
• biologická evoluce * MeSH
• dánio pruhované * anatomie a histologie   embryologie   růst a vývoj   MeSH
• kostní morfogenetické proteiny metabolismus   MeSH
• larva anatomie a histologie   růst a vývoj   MeSH
• mezoderm * anatomie a histologie   embryologie   růst a vývoj   MeSH
• ploutve zvířat * anatomie a histologie   embryologie   růst a vývoj   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• kostní morfogenetické proteiny MeSH

After its introduction for scientific investigation in the 1950s, the cypriniform zebrafish, Danio rerio, has become a valuable model for the study of regenerative processes and mechanisms. Zebrafish exhibit epimorphic regeneration, in which a nondifferentiated cell mass formed after amputation is able to fully regenerate lost tissue such as limbs, heart muscle, brain, retina, and spinal cord. The process of limb regeneration in zebrafish comprises several stages characterized by the activation of specific signaling pathways and gene expression. We review current research on key factors in limb regeneration using zebrafish as a model.

• Klíčová slova
• Danio rerio, biomedicine, model organism, regeneration, zebrafish,
• MeSH
• dánio pruhované genetika   fyziologie   MeSH
• exprese genu * MeSH
• modely u zvířat MeSH
• ploutve zvířat fyziologie   MeSH
• regenerace * MeSH
• signální transdukce * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

We evaluated the relationship of stocking density to survival, growth performance and fin condition of European perch Perca fluviatilis with hand feeding and self-feeders. Hand-fed perch (body weight 19.1 ± 5.1 g and total length 107 ± 9 mm) were reared at 0.5, 1.0, 1.5 and 2.0 fish/L. Self-feeding perch (body weight 25.4 ± 3.9 g and total length 128 ± 7 mm) were reared at stocking densities of 0.6, 1.0 and 1.4 fish/L. Pond-reared perch served as a comparison group for fin damage assessment. We found no differences in survival rate among stocking densities with either feeding method. Hand-fed fish displayed the highest weight gain and SGR at stocking density of 0.5 fish/L. The self-feeding fish showed a non-linear association of weight gain with stocking density with the highest growth at 1.0 fish/L. Fin length was noticeably greater in pond-reared fish compared with RAS-reared fish regardless of feeding method. In both experiments, fin length relative to standard length showed a negative relationship with stocking density, with pectoral fins showing the greatest effect. Fin condition deteriorated with increasing stocking density, and growth was highest at 0.5 and 1.0 fish/L in hand-fed and self-feeding fish, respectively.

• Klíčová slova
• Perca fluviatilis, fin erosion, intensive culture, self-feeders, stocking density, welfare,
• MeSH
• hustota populace MeSH
• metody výživy veterinární   MeSH
• okounovití růst a vývoj   zranění   fyziologie   MeSH
• ploutve zvířat zranění   patologie   MeSH
• rybářství * MeSH
• vodní hospodářství * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

We describe a new species, Gyrodactylus ginestrae n. sp., a parasite of the big-scale sand smelt (Atherina boyeri) from the Black Sea. This is the third monogenean species known from this fish host, found at 70% prevalence, but at relatively low abundance (1.9), on fish gills and fins. The new species is, both morphologically and genetically, most similar to G. salinae, which parasitizes the killifish Aphanius fasciatus (Cyprinodontidae) in the Mediterranean region. These species differ in the size of the haptoral hard parts and the number of small spines of the male copulatory organ. For molecular characterization, the internal transcribed spacer 1 (ITS1), 5.8S rRNA gene, and the internal transcribed spacer 2 (ITS2) were sequenced, completed by a fragment of the COII gene, thereby representing the first molecularly characterized gyrodactylid species from the Black Sea. Phylogenetic reconstruction based on the ITS1-5.8S-ITS2 sequence data indicated the position of G. ginestrae n. sp. in the marine "rugiensis" group of G. (Paranephrotus) and G. (Neonephrotus) subgenera which is part of the monophyletic "long ITS1" group. Taking into account the similarity of G. ginestrae n. sp. to several monogeneans from the Atlantic and Mediterranean regions, we suggest the Boreal-Atlantic origin of this species.

• Klíčová slova
• Brackish water, Gulf of Odessa, Gyrodactylidae, Molecular study, Phylogeny, Ponto-Caspian,
• MeSH
• DNA helmintů genetika   MeSH
• druhová specificita MeSH
• fylogeneze * MeSH
• Osmeriformes parazitologie   MeSH
• ploutve zvířat parazitologie   MeSH
• ribozomální DNA genetika   MeSH
• Trematoda anatomie a histologie   klasifikace   genetika   MeSH
• žábry parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Černé moře MeSH
• Názvy látek
• DNA helmintů MeSH
• ribozomální DNA MeSH

The parasitic copepod Neoergasilus japonicus (Harada, 1930) (Ergasilidae), native to east Asia, is widely distributed in Asia, Europe, and North and Central America. Recently, this species appeared in lentic water bodies of the River Dyje floodplain (Danube basin, Czech Republic). It was first recorded in 2015 and in 2 years it reached a 100% prevalence in recently expanding non-native fish host, Lepomis gibbosus (Linnaeus, 1758) (Centrarchidae, native to North America) at two borrow pits. Abundance of N. japonicus increased with fish length, with maximum intensity of infection reaching 99 parasites per fish. The parasite was most frequently found attached to the dorsal and anal fins of fish, while preference for the dorsal fin was more evident with lower infection intensities. Utilization of expanding fish hosts in water bodies that are regularly interconnected via natural or managed flooding may support the rapid dispersal of this non-native parasite.

• Klíčová slova
• 18S, 28S rDNA, Centrarchidae, Copepod, Lepomis, Neoergasilus, Species introductions,
• MeSH
• Copepoda fyziologie   MeSH
• infestace ektoparazity parazitologie   veterinární   MeSH
• nemoci ryb parazitologie   MeSH
• Perciformes parazitologie   MeSH
• ploutve zvířat parazitologie   MeSH
• řeky parazitologie   MeSH
• zavlečené druhy MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika epidemiologie   MeSH

• Klíčová slova
• abnormalities, fin damage, opercular deformity, radiography, spinal deformity, vertebrae,
• MeSH
• kosti a kostní tkáň abnormality   MeSH
• nemoci ryb vrozené   diagnostické zobrazování   MeSH
• ploutve zvířat abnormality   MeSH
• prevalence MeSH
• rybníky MeSH
• Salmonidae abnormality   anatomie a histologie   MeSH
• vodní hospodářství metody   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• Geografické názvy
• Česká republika MeSH

Muscle tissue and pectoral fins of two important indicator fish species, frequently used in biomonitoring programs, were sampled and analysed for total mercury content (THg) at six localities within the Czech Republic. The relationship between mercury concentration in muscle and in fin-clips was described. Mean values of THg fin-clip concentration correlate significantly (p < 0.01) with those measured in muscle of indicator fish. Concerning comparison among localities, a coefficient of determination (r(2)) of 0.85 and 0.91 was found between studied approaches in the case of chub (Squalius cephalus) and bream (Abramis brama), respectively. THg muscle concentrations (mean, n = 10) varied from 0.181 to 0.491 μg g(-1) wet, depending on indicator species and locality. A concentration-dependent relationship between muscle and fin-clip THg content was found in both species. Based on this finding, a novel method for the prediction of muscle THg concentration from fin-clips analysis was developed. The difference between measured and predicted muscle concentration was below 10% in both indicator species at most sampling sites. Use of fish fin-clips was found as an appropriate nonlethal approach for the evaluation of mercury contamination in aquatic environments as well as for human health risk assessment.

• Klíčová slova
• Bream, Chub, Health risk, Hg, Muscle, Prediction,
• MeSH
• chemické látky znečišťující vodu analýza   MeSH
• Cyprinidae MeSH
• hodnocení rizik metody   MeSH
• lidé MeSH
• monitorování životního prostředí metody   MeSH
• ploutve zvířat chemie   MeSH
• regresní analýza MeSH
• rtuť analýza   MeSH
• ryby * MeSH
• svaly chemie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH
• Názvy látek
• chemické látky znečišťující vodu MeSH
• rtuť MeSH

BACKGROUND: Understanding the genetic basis of novel traits is a central topic in evolutionary biology. Two novel pigmentation phenotypes, egg-spots and blotches, emerged during the rapid diversification of East African cichlid fishes. Egg-spots are circular pigmentation markings on the anal fins of hundreds of derived haplochromine cichlids species, whereas blotches are patches of conspicuous anal fin pigmentation with ill-defined boundaries that occur in few species that belong to basal cichlid lineages. Both traits play an important role in the breeding behavior of this group of fishes. Knowledge about the origin, homology and underlying genetics of these pigmentation traits is sparse. RESULTS: Here, we present a comparative transcriptomic and differential gene expression analysis of egg-spots and blotches. We first conducted an RNA sequencing experiment where we compared egg-spot tissue with the remaining portion of egg-spot-free fin tissue using six individuals of Astatotilapia burtoni. We identified 1229 differentially expressed genes between the two tissue types. We then showed that rates of evolution of these genes are higher than average estimated on whole transcriptome data. Using quantitative real-time PCR, we found that 29 out of a subset of 46 differentially expressed genes showed an analogous expression pattern in another haplochromine species' egg-spots, Cynotilapia pulpican, strongly suggesting that these genes are involved in the egg-spot phenotype. Among these are the previously identified egg-spot gene fhl2a, two known patterning genes (hoxC12a and bmp3) as well as other pigmentation related genes such as asip. Finally, we analyzed the expression patterns of the same gene subset in two species that feature blotches instead of egg-spots, one haplochromine species (Pseudocrenilabrus philander) and one ectodine species (Callochromis macrops), revealing that the expression patterns in blotches and egg-spots are rather distinct. CONCLUSIONS: We identified several candidate genes that will serve as an important and useful resource for future research on the emergence and diversification of cichlid fishes' egg-spots. Only a limited degree of conservation of gene expression patterns was detected between the egg-spots of the derived haplochromines and blotches from ancestral haplochromines, as well as between the two types of blotches, suggesting an independent origin of these traits.

• Klíčová slova
• Blotches, Diversity, East African cichlids, Egg-spot, Gene expression, Pigmentation,
• MeSH
• anální kanál fyziologie   MeSH
• cichlidy genetika   MeSH
• druhová specificita MeSH
• fylogeneze MeSH
• molekulární evoluce MeSH
• pigmentace kůže genetika   MeSH
• ploutve zvířat fyziologie   MeSH
• regulace genové exprese MeSH
• rybí proteiny genetika   MeSH
• sekvenční analýza RNA metody   MeSH
• stanovení celkové genové exprese metody   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• rybí proteiny MeSH

New findings on Gyrodactylus spp. parasitising African cichlids in southern Africa are presented, comprising data from Zimbabwe and South Africa. Morphometry of opisthaptoral hard parts in combination with nuclear ribosomal DNA sequences confirmed the presence of six species of Gyrodactylus von Nordmann, 1832. Three new species are described from fishes in Zimbabwe: Gyrodactylus chitandiri n. sp. from the gill arches of Coptodon rendalli (Boulenger) and Pseudocrenilabrus philander (Weber); Gyrodactylus occupatus n. sp. from the fins of Oreochromis niloticus (L.), Pharyngochromis acuticeps (Steindachner) and P. philander; and Gyrodactylus parisellei n. sp. from the fins of O. niloticus, P. philander and Tilapia sp. Gyrodactylus nyanzae Paperna, 1973 was also identified from the gills of O. niloticus and C. rendalli collected from two localities in Zimbabwe; these findings represent new host and locality records for this parasite. Gyrodactylus sturmbaueri Vanhove, Snoeks, Volckaert & Huyse, 2011 was identified from P. philander collected in South Africa and Zimbabwe thereby providing new host and locality records for this parasite. Finally, Gyrodactylus yacatli García-Vásquez, Hansen, Christison, Bron & Shinn, 2011 was collected from the fins of O. niloticus and P. philander studied in Zimbabwe; this represents the first record of this species from the continent of Africa. Notably, this study improves upon the knowledge of Gyrodactylus spp. parasitising cichlids from these southern African regions. All species studied were recorded from at least two different cichlid host species indicating trend for a wide range of Gyrodactylus hosts in Africa. Accordingly, this supports the idea of intensive host switching in the course of their evolution.

• MeSH
• biodiverzita MeSH
• cichlidy parazitologie   MeSH
• DNA helmintů genetika   MeSH
• druhová specificita MeSH
• fylogeneze MeSH
• hostitelská specificita MeSH
• ploutve zvířat parazitologie   MeSH
• řeky MeSH
• ribozomální DNA genetika   MeSH
• Trematoda anatomie a histologie   klasifikace   genetika   MeSH
• žábry parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Jihoafrická republika MeSH
• Zimbabwe MeSH
• Názvy látek
• DNA helmintů MeSH
• ribozomální DNA MeSH

A new nematode species, Philometroides acanthopagri sp. nov. (Philometridae), is described from gravid and subgravid specimens found in the musculature near pectoral fins and in nasal cavity of the yellowfin seabream Acanthopagrus latus (Houttuyn) (Sparidae, Perciformes) from marine waters off the coast of southern Iraq. Based on light and scanning electron microscopical examination, the new species differs from its congeners in a combination of morphological and biometrical features. It is the first species of Philometroides reported from a sparid fish and the first representative of this genus recorded from fishes in the Arabian Gulf. A key to Philometroides species parasitizing marine and brackish-water fishes is provided.

• MeSH
• biometrie MeSH
• Dracunculoidea anatomie a histologie   izolace a purifikace   MeSH
• mikroskopie MeSH
• mořská voda MeSH
• nematodózy parazitologie   veterinární   MeSH
• nemoci ryb parazitologie   MeSH
• nosní dutina parazitologie   MeSH
• Perciformes parazitologie   MeSH
• ploutve zvířat parazitologie   MeSH
• svaly parazitologie   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Irák MeSH