Parasitic organisms inhabiting the alimentary canal should permanently resist the destructive action of host digestive enzymes. The intestinal parasites were shown to produce specific protease inhibitors protecting them from proteolysis. However, little is known about this adaptive mechanism in cestodes so far, especially for the tapeworms dwelling inside the fish intestines. Here, we explored the ability to inactivate proteolytic enzymes in the fish tapeworm Eubothrium rugosum (Batsch, 1786) (Bothriocephalidea) parasitising the intestine of wild burbot, Lota lota (Linnaeus). The assays were conducted with different concentrations of commercial trypsin and homogenate of intestinal mucosa both being the sources of proteinases. The incubation of live E. rugosum in trypsin solutions of two different concentrations caused a significant decrease in the enzyme activity. The extent of activity reduction was dependent on trypsin concentration. At the same time, the inhibitory effect of the worm incubation medium turned out to be statistically insignificant. These findings suggest partial adsorption of the enzyme to the tegument surface, with its further inactivation. In contrast to the incubation medium, the worm extract suppressed over 80% of trypsin activity and nearly half of the proteolytic activity in the mucosa homogenate. Notably, the inhibitory activity of the tapeworms hardly depended on their size characteristics. Finally, the research has demonstrated secretion of proteinase inhibitor in E. rugosum, which appears to be essential for its survival in enzymatically hostile environment., Galina I. Izvekova, Tatyana V. Frolova, Evgeny I. Izvekov., and Obsahuje bibliografii
Příspěvek se věnuje způsobu života čichavce líbajícího (Helostoma temminkii), jednoho ze zajímavých druhů labyrintních ryb. Popisuje způsob jejich života a také jejich využití. Jde o sladkovodní konzumní ryby, jejichž domovinou je jihovýchodní Asie. Své místo zaujaly také v akvaristice. Málo známý je i zajímavý způsob rozmnožování čichavce líbajícího chovaného v zajetí, který zachycují fotografické záběry při nočním tření., This article describes lifestyle and the use of the Kissing Gourami (Helostoma temminkii), one of the labyrinth fish. These edible freshwater fish native to south-east Asia are occasionally seen in aquaristics. The interesting way in which the Kissing Gourami breeds in captivity has only rarely been documented by photos because of its night time spawning., and Jaroslav Eliáš.
Výskyt mihule ukrajinské (Eudontomyzon mariae) byl znám na území České republiky po více než 40 let pouze z Račího potoka (povodí řeky Moravy) na severní Moravě. Od roku 1994 až do současnosti byla tamější populace dlouhodobě monitorována odlovy elektrickým agregátem. Počet evidovaných larev se ve sledovaném období pohyboval mezi 16 (1988) a 325 (2006) jedinci v přepočtu na jeden hektar. Synergické působení několika faktorů (přítomnost neprostupných migračních bariér, nestabilita naplavených jemných sedimentů, výskyt četných větších pstruhů) vedlo ke snížení její početnosti. Revitalizační opatření v toku během letech 2003-06 se ukázala být nedostatečná a nevedla k očekávanému zvýšení početnosti populace. Poslední průzkum v roce 2013 již nepotvrdil žádné exempláře mihule ukrajinské ve zkoumaném úseku potoka, v současné době je zde tedy pod hranicí zjistitelnost., The only population of Eudontomyzon mariae in the Czech Republic is known (for over 40 years) from the Račí potok brook in Northern Moravia. Since 1994, this population has been monitored. Numbers of larvae captured using electrofishing constantly indicated that the population is at the verge of extinction. The synergic influence of impermeable migration barriers, instability of sediments and numerous bigger trouts (Salmo trutta) has led to a reduction in the number of specimens. The revitalisation measures (2003-06) appeared to be insufficient for the anticipated population development. In 2013 no specimens were confirmed in the examined section of brook. The species can be classified as missing (i. e. below the detection threshold)., and Lubomír Hanel, Stanislav Lusk.
Článek se zabývá taxonomií, reprodukční biologií, fylogenetikou, fylogeografií a introdukční historií ryb rodu karas (Carassius). Článek poskytuje souhrn poznatků, které jsou značně komplikované a spojené s jedinečným způsobem rozmnožování, definicí druhu a nepřesným chápáním biologie a systematiky těchto ryb v minulosti. Celá problematika je ještě daleko od svého kompletního vyřešení, ale současný pohled nám může pomoci v lepší péči o vodní prostředí., This article deals with the taxonomy, reproductive biology, phylogenetics, phylogeography and introduction history of the fishes of the genus Carassius. It summarizes findings associated with their unique mode of reproduction, challenging species delimitation and insufficient understanding of the biology and systematics of these fishes in the past. Deeper insight into the biology of Prussian Carp (Carassius gibelio) will require more research, but the available results can improve our understanding and management of the aquatic environment., Lukáš Kalous., and Obsahuje seznam literatury
K lalokoploutvým rybám lze vysledovat původ nejstarších čtvernožců (tetrapodů). Přestože dnes přežívají jen dva druhy rodu latimerie (Latimeria), v minulosti tyto ryby představovaly poměrně úspěšnou skupinu vodních obratlovců. Článek popisuje hlavní znaky jednotlivých skupin a jejich minulost., Fossil lobe-finned fishes can be traced as direct ancestors of the first terrestrial tetrapods. Although two species of one genus (coelacanths Latimeria chalumnae and L. menadoensis) have survived to these days, the lobe-finned fishes formed a successful group of aquatic vertebrates in the past. The main features and history of their subgroups are described., and Tomáš Přikryl.
This paper summarises the results of parasitological examinations of the European eel Anguilla anguilla (Linnaeus) in the Czech Republic, carried out at the Institute of Parasitology, Czech Academy of Sciences (previously the Czechoslovak Academy of Sciences) within the period of 50 years (1958-2008). Even though this survey is limited to the Czech Republic, it provides extensive data probably incomparable with any other study anywhere regarding the number of eels examined and parasites found. A total of 723 eels was examined from 42 localities that belong to all of the three main river drainage systems in the country, i.e. the Elbe, Danube and Oder river basins. Of the 31 species of adult and larval macroparasites including Monogenea (4 species), Trematoda (3), Cestoda (3), Nematoda (11), Acanthocephala (5), Hirudinea (1), Bivalvia (1), Copepoda (1), Branchiura (1) and Acariformes (1), most of them (30) were recorded from the Elbe River basin. These parasites can be divided into three main groups regarding their host specificity: parasites specific for eels (26%), non-specific adult parasites occurring also in other fishes (61%) and non-specific larvae (13%). The highest number (19) of parasite species was recorded in the Mácha Lake fishpond system in northern Bohemia. The parasite communities in eels from the individual localities exhibited large differences in their species composition and diversity depending on local ecological conditions. The parasite fauna of A. anguilla in the Czech Republic is compared with that in other European countries. The nematode Cucullanus egyptae Abdel-Ghaffar, Bashtar, Abdel-Gaber, Morsy, Mehlhorn, Al Quraishy et Mohammed, 2014 is designated as a species inquirenda., František Moravec, Tomáš Scholz., and Obsahuje bibliografii
Chovu malých jihoamerických cichlid rodů Laetacara a Nannacara se mohou věnovat i akvaristé, kteří své zálibě nemohou vyčlenit ve svém domově příliš velký prostor. Velkoryse pojaté akvaristické zázemí není v tomto případu nezbytné. Tyto rybky se starají o své potomstvo velmi starostlivě, takže lze při rozmnožování pozorovat různé projevy rodičovské péče., South American cichlids of the genera Laetacara and Nannacara can be bred also by aquarists without an elaborate aquarium equipment. These little fish look after their offspring very carefully, so various displays of parent care can be observed., and Jaroslav Eliáš.
The paper presents a survey of the metacercariae of trematodes found in 581 fishes of 15 species from 39 cenotes (sinkholes) of the Yucatan Peninsula, southeastern Mexico. The following 21 species were found: Echinochasmus sp. 1, Echino-chasmus sp. 2, Echinostomatinae gen. sp. (family Echinostomatidae), Stunkardiella minima (Stunkard, 1938), Alrophecaecum (?) astorquii (Watson, 1976), Peiaezia loossi (Pérez Vigueras, 1957) (Acanthostomidae); Ascocotyle (Ascocotyle) tenuicollis Price, 1935, Ascocotyle (Ascolotyle) sp. 1, Ascocotyle (Phagicola) diminuta (Stunkard et Haviland, 1924), Ascocotyle (Phagicola) sp. 2 (= Phagicola angrense Travassos, 1916 of Salgado-Maldonado and Aguirre-Macedo, 1991), Ascocotyle (Phagicola) sp. 3 (Heterophyidae); Cladocystis trifolium (Braun, 1901) (Opisthorchiidae); Oligogonotylus manieri Watson, 1976 (Cryptogonimidae); Clinostomum cf. complanatum (Rudolphi, 1814) (Clinostomidae); Diplostomum (Auslrodiplostomum) com-paclum (Lutz, 1928), Posthodiplostomum minimum (MacCallum, 1921), Posthodiplostomum sp. (Diplostomidae); Neodiplos-tomidae gen. sp. 1 ; Neodiplostomidae gen. sp. 2 (Neodiplostomidae); and Apharyngostrigea sp. (Strigeidae). All species found are described and figured, and their life cycles are briefly discussed.
This paper comprises a systematic survey of larval nematodes collected from fishes from cenotes (= sinkholes) of the Peninsula of Yucatan, southern Mexico, in 1993-1994. Larvae of the following nine species were recorded: Physocephalus sexa-lalus, Acuariidae gen. sp., Spiroxys sp., Falcausira sp., Hysterothylacium cenotae, Contracaecum sp. Type 1, Contracaecum sp. Type 2, Goezia sp., and Eustrongylides sp. Larvae of P. sexalatus are recorded from fishes (Rhamdia guatemalensis) for the first time. The larvae are briefly described and illustrated and problems concerning their morphology, taxonomy, hosts and geographical distribution are discussed. Adults of these larvae are parasitic in piscivorous fishes, reptiles, birds and mammals (definitive hosts). Fishes harbouring the larvae of these parasites serve as paratenic hosts, being mostly an important source of infection for the definitive hosts.