Life-cycle
Dotaz
Zobrazit nápovědu
The taxonomic classification of some parasitic isopods of the family Gnathiidae has been revised in the last years. However, their biological cycles have been described only partially or incompletely. Gnathia maxillaris (Montagu, 1804) is one of the most studied species, but certain aspects of its life cycle are still poorly known. A detailed study on the life cycle of G. maxillaris was carried out over several years by sampling larvae from an infestation of large volume aquaria at the Aquarium of Barcelona. At the same time, a system of in vitro cultivation of G. maxillaris was developed, which provided new data to complete the description of its life cycle. Periods of incubation, fertilization, planktonic stages, the attachment site on the fish host and biometric characteristics of larval forms were detailed. The new information may help better control health state of marine fish in aquaculture.
- MeSH
- infestace ektoparazity parazitologie veterinární MeSH
- Isopoda fyziologie MeSH
- nemoci ryb parazitologie MeSH
- ryby MeSH
- stadia vývoje fyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- experimenty na zvířatech MeSH
- klíšťata růst a vývoj MeSH
- myši MeSH
- savci parazitologie MeSH
- Check Tag
- myši MeSH
- MeSH
- Anguilliformes parazitologie MeSH
- Cestoda růst a vývoj MeSH
- stadia vývoje MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
Ichthyophthirius multifiliis Fouquet, 1876, a ciliate parasite, is a cosmopolitan and problematic parasite of cultured freshwater fish. Each geographical isolate of I. multifiliis has variations in life cycle timing under different abiotic water conditions, such as temperature and salinity. We assessed the effects of salinity and temperature on the development and the preferred settlement site of a temperate Australian isolate of I. multifiliis. The time until theront release was significantly different between each temperature; development time was longest at 5 °C with a mean time of 189 h and decreased to a mean time of 11.7 h at 30 °C. At 5 °C our isolate produced a mean of 267 theronts per tomont, which increased to a mean of 493 theronts at 25 °C and reduced to a mean of 288 theronts at 30 °C. Theront length showed an inverse relationship to temperature; mean length was 62 μm at 5 °C and 41 μm at 30 °C. Our isolate reproduced faster at all temperatures and a greater sensitivity to salinity than all reported profiles for temperate isolates. Parasite abundance was highest on the dorsal region of the fish. An accurate understanding of temperature-life cycle information and optimal region to sample for surveillance will aid in the development of specific management plans for the Australian isolate of I. multifiliis, facilitating the strategic timing of treatments.
Blastocrithidia papi sp. n. is a cyst-forming trypanosomatid parasitizing firebugs (Pyrrhocoris apterus). It is a member of the Blastocrithidia clade and a very close relative of B. largi, to which it is almost identical through its SSU rRNA gene sequence. However, considering the SL RNA gene these two species represent quite distinct, not even related typing units. Morphological analysis of the new species revealed peculiar or even unique features, which may be useful for future taxonomic revision of the genus Blastocrithidia. These include a breach in the microtubular corset of rostrum at the site of contact with the flagellum, absence of desmosomes between flagellum and rostrum, large transparent vacuole near the flagellar pocket, and multiple vacuoles with fibrous content in the posterior portion of the cell. The study of the flagellates' behavior in the host intestine revealed that they may attach both to microvilli of enterocytes using swollen flagellar tip and to extracellular membranes layers using hemidesmosomes of flagellum. Laboratory experiments on B. papi transmission in P. apterus demonstrated that the parasite may be transmitted vertically (via contaminated surface of eggs) and horizontally (via contaminated substrate and/or necrophagy). We argue that the parasite exploits transmission mechanisms intended for obligate bacterial symbionts of P. apterus.
- MeSH
- Heteroptera mikrobiologie parazitologie MeSH
- stadia vývoje * MeSH
- střeva parazitologie MeSH
- Trypanosomatina klasifikace cytologie fyziologie MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
