Over the past 150 years, the waters of the Czech Republic were experimentally stocked or invaded by a total of 41 alien (non-native) fish species. The following species have become fully naturalized and produced self-sustained populations: Carassius gibelio, Pseudorasbora parva, Ameiurus nebulosus and Gasterosteus aculeatus, which produced stable populations in several spatially limited localities. In some cases Oncorhynchus mykiss, Salvelinus fontinalis and Coregonus maraena will produce instable temporary populations based on released material obtained from fish farms and ponds. The occurrence of the remaining acclimatized alien species (Coregonus peled, Ctenopharyngodon idella, Hypophthalmichthys molitrix, Aristichthys nobilis) in natural ecosystems and fishponds depends on stocking fish obtained from artificial spawning and cultures. The documented annual average production of alien species fit for human consumption amounts to around 2 000 tonnes, i.e. 8.2 % of the annual average production of marketable fish cultures in the Czech Republic. A significant negative impact of the introduced species on native ichthyofauna has been ascertained as regards its ecological, biological properties, biodiversity and health. Considered a typical invasive alien species, Carassius gibelio heavily depressed the occurrence and numbers of indigenous Carassius carassius populations and also contributed to the decreased numbers of Tinca tinca, Leucaspius delineatus and other native cyprinid fish. P. parva and A. nebulosus show a much weaker and limited impact. The introduction of C. idella was accompanied by the introduction of the tapeworm species, Bothriocephalus gowkongensis, which subsequently caused heavy losses in cultures of Cyprinus carpio. In 2008, Neogobius melanostomus was recorded for the first time in this country at the confluence of the Morava and Dyje rivers.
Kněz velký (Acanthosoma haemorrhoidale) je největším fytofágním dendrofilním druhem z čel. knězovitých (Acanthosomatidae) v České republice. Žije roztroušeně na různých druzích opadavých stromů a keřů. Podle našich pozorování a údajů z literatury klade tato ploštice vajíčka pouze na listy jeřábu obecného, trnce obecné a hlohu. Rodičovská péče o potomstvo nebyla pozorována. V článku jsou poprvé zveřejněny fotografie dokumentující vývojová stadia kněze velkého a parazitické vosičky vejcomara rodu Trissolcus, která někdy jeho vajíčka napadá. and The Hawthorn Shield Bug (Acanthosoma haemorrhoidale) is the largest phytophagous dendrophilous species of the family Acanthosomatidae in the Czech Republic. According to authors’ observations and literary sources, the eggs are laid only on leaves of the Rowan Tree, Hawthorn or Blackthorn. Parental (maternal) care does not exist in the species. In the article, the developmental stages of the Hawthorn Shield Bug and parasitic wasps of the genus Trissolcus sometimes invading their eggs, are documented by photos for the first time.
V živočišné říši nalezneme rozličné způsoby chování, které zajišťují a zvyšují šanci potomků na přežití, což zaručuje přenos a působnost genotypu rodičů v dalších generacích. Nejčastější formou je přímá péče o vajíčka a mláďata. Rodičovská péče je zajímavý evoluční fenomén, jehož různé projevy můžeme pozorovat u mnoha skupin bezobratlých živočichů i obratlovců. V tomto článku si přiblížíme naše zástupce ploštic rodu Elasmucha, které patří mezi běžné druhy a vyznačují se zajímavou mateřskou péčí. Uvedené výsledky vycházejí z publikovaných literárních pramenů a našich vlastních víceletých pozorování v přírodě i v insektáriích. and This article describes the maternal care of the Parent Bug Elasmucha grisea, Blueberry Shield Bug Elasmucha ferrugata and the Spotted Breeding Bug Elasmucha fieberi. Females straddle their eggs and young nymphs whilst showing specific defensive behaviour against various invertebrate predators. Defensive behaviour of the female includes body movements such as rotation, tilting, wing fanning and attacking, which may be physiologically costly.
Four lamprey species and 55 fish species are considered autochthonous taxa in the Czech Republic. In recent years, as a result of spontaneous migrations, the native ichthyofauna has been increased by three species Sander volgensis, Gymnocephalus baloni, Proterorhinus marmoratus) which, in view of their autochthonous occurrence in the Central European region, are evaluated as native. At present, according to the criteria of the IUCN (2001) version 3.1, two lamprey species and 6 fish species are evaluated as “regionally extinct”. Most of these taxons are denoted as anadromous. One species has been classified in the category “Extinct in the wild”. Two lamprey species and 25 fish species are considered to be endangered to various extent: one lamprey species and 10 fish species are classified as “Critically endangered”; one lamprey species and 5 fish species as “Endangered”; ten fish species as “Vulnerable”. In the course of the past two centuries, attempts have been made at introducing about 30 fish species (see Lusk et al. 1998, Hanel 2003); of these, the introduction of 11 species can be evaluated as successful. Only four non-native species have established stable and naturally reproducing populations in natural conditions (Pseudorasbora parva, Carassius auratus, Ameiurus nebulosus, Gasterosteus aculeatus).
The species richness of free-living vertebrates was analysed using mapping of occurrence within individual grid squares (12 x 11.1 km) over the territory of the Czech Republic. The data on species distribution were derived from recent distributional atlases published in the last 15 years, and the records originated mostly in the last 20 years. Altogether, 384 species of cyclostomes, bony fishes, amphibians, reptiles, birds and mammals were included in this study and their presence or absence was recorded in 678 grid squares. The species numbers ascertained in the 523 grid squares situated completely within the Czech Republic varied from 92 to 259 species, with a median of 182 species. The first two principal components explained 44.9 % of the total variance and separated two main habitat gradients based on values of different environmental, topographic, and demographic variables in particular squares. The PC1 represents a gradient from urban habitats at lower altitudes to more homogenous habitats with dominant coniferous forests and meadows situated at higher altitudes. The importance of natural habitats (represented by broad-leaved and mixed forests, as well as by protected areas) and landscape heterogeneity increases along the PC2. Generalized Linear Modelling for each group of vertebrates was fitted using the number of species of individual vertebrate groups as a response variable and the first two principal components as explanatory variables. The species richness of all vertebrate groups except for reptiles is highly dependent on the PC1. The number of fish, amphibian, and bird species in squares decreases with increasing value of the PC1, i.e. it is higher in urban areas at lower altitudes. By contrast, the number of mammal species is higher in uninhabited areas at higher altitudes. The gradient represented by the PC2 is highly significant for species richness of reptiles and mammals, and the number of species of both groups increases with increasing importance of natural habitats.