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Rozhodovací proces u raků: problematika chování a reprodukce
KUBEC, Jan
This thesis provides an overview of case studies investigating the behaviour of freshwater crayfish, including social and reproductive interactions, decision making, and channels for recognition or processing of environmental stimuli. We described relationships between the environment and the organism and relationships among conspecifics and heterospecifics. These aspects are important, given that every decision and interaction has consequences for crayfish survival and reproduction, i.e. individual and even species success. For ethological studies in aquatic ecosystems, crustaceans, and especially crayfish, represent practical model organisms. Crayfish are advantageous over other invertebrates given their high level of social interaction in both the field and the laboratory. They exhibit unique eco- ethological behaviour in variety of feeding habits, activity cycles, habitat selection, and resource utilization at the level of species, sex, and age. Similar to vertebrates, crayfish demonstrate unique behaviours throughout their life. Subsequently, pollution impacts on native crayfish stock can result in ecosystem instability. The different reproductive strategies of females and males demonstrate that females rely on some familiarity of sexual partners as a reliable guarantee for successful mating. Crayfish females are choosier than males because of their higher energy costs for reproduction (oogenesis, incubation, parental care). While male reproduction prioritises securing their genetic information by searching for as many mates as possible. Crayfish mate preferences was analysed by facing the choosing crayfish with two equal sized mature counterparts from the same or different origin. Our conclusions could be applied in conservation research, captive breeding, and recovery programs as well as in aquaculture. The success of biological invaders has been described as the outcome from intra- and interspecific interactions. The marbled crayfish, known as parthenogenetic species with high adaptability, fast growth, early maturation, and high fecundity, established dominant status in more cases by interspecific combat victories. Fight intensity and aggressiveness decreased after dominance was established in particular pairs. Marbled crayfish seem to have an ability to conserve energy by increasing activity only at times of danger. Based on known species-specific abilities, the marbled crayfish is capable of outcompeting aggressive species, such as the red swamp crayfish. This parthenogenetic species poses a substantial threat to native ecosystems and biodiversity of aquatic environments, since it can establish not only in crayfish free habitats, but is also capable of outcompeting resident species. Recently, dilute concentrations of contaminants such as pharmaceuticals, daily-care products and pesticides have been reported to indirectly affect aquatic organisms. We found that selected pharmaceuticals can alter the behavioural patterns of crayfish, event at the very low concentration. The risks associated with surface water pollutants stresses the importance of research investigating their ecological impacts and their different/specific mechanisms of action. Prolonged exposure to the low concentrations of two pesticides exhibited changes in crayfish behavioural patterns. Various alterations in locomotion were observed after treatment in pesticide-free water. In the wild, decreased movement and activity can be a challenge for crayfish survival because of predation, even foraging to compensate for energy loss could be very difficult for less active individuals. This study suggests that crayfish behaviour assessment is a practical approach not only for investigating basic biology, or intra- and inter-specific interactions, but also for assessing the risks associated with micro-pollutants.
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Neonikotinoidy ve vodních ekosystémech a jejich vliv na necílové organismy
STROUHOVÁ, Alžběta
Neonicotinoids are one of the newesst class of pesticides, used in agriculture like insecticides. The first neonicotinoids has been used since the early 1990s, they become very popular and widely used worldwile for their low toxicity for vertebrates. Neonicotinoids were considered to be less toxic to aquatic organisms due to their low toxicity to standard test organisms Daphnia magna and Rainbow trout (Onchorhynchus mykiss), but recent studies have shown the opposite of this assumption. Partial aim of this study was, among summary of existing knowledges of the neonicotinoids in aquatic ecosystem and their impact on non-target organisms, also evidence toxicity of neonicotinoid preparation CALYPSO 480 SC, which contains 48 % of thiacloprid. Three species of crayfish were used to provide the toxicity Red swamp crayfish (Procambarus clarkii), Marbled crayfish (Procambarus fallax) and Yabby (Cherax destructor). To asses the toxiciy of Calypso, the acute toxicity tests on crayfish and acute immobilisation test on daphnia were used. The exposure time of tests were 96 and 48 hours. Juvenile crayfish were the most sensitive, their 96hLC50 ranged between 0.52 and 1.6 mg/l, 96hLC50 for older crayfish were between 1.94 and 27.3 mg/l. The 48hEC50 value for daphnia was 32.7 mg/l. During the acute toxicity test on crayfish, out of the mortality, changes in behavior of orgaisms were observed, the most frequent changes were the reduction of aggressiveness, slowing of motion of limbs, gills and breathing. Crayfish turned on their back, individuals were apathetic and died.
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Interaction of non-native species of crustaceans in Czech waters: Predator or prey?
ŠVAGROVÁ, Kateřina
This diploma thesis deals with non-native species of crustaceans, which are already present not only in Europe but also successfully inhabit the territory of the Czech Republic. The species that this work deals with is the signal crayfish (Pacifastacus leniusculus), marbled crayfish (Procambarus fallax f. virginalis) and the killer shrimp (Dikerogammarus villosus). The main goal of this study was to demonstrate the ability of killer shrimp to attack and prey on the crayfish eggs and hatchlings of above mentioned species, which were used not only for theuir presencein Czech Republic but also as model representatives of families Astacidae and Cambaridae. It was therefore the confirmation of high aggressiveness of killer shrimp and point out, that this species is capable of negatively influencing even the bigger invertebrates by direct predation on their early developmental stages. Another aim was to assess whether the killer shrimp can be a suitable prey for a crayfish. As the experiments have shown, killer shrimp is able to predate on crayfish eggs and hatchlings even directly on females abdomens wehre they are incubated and protected. The results confirmed the theory of killer shrimp hazards to aquatic ecosystems and its potential to directly influence the populations of larger organisms. At the same time, it has been found that killer shrimp may be a suitable prey for adult and subadult individuals of signal crayfish and adults of marbled crayfish.
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Některé reprodukční a fyziologické aspekty invasivních raků
YAZICIOGLU, Buket
Several studies have been carried out to understand reproductive biology of invasive crayfish. Many researchers have described how invasive species establish their population in new habitats, interactions between native and invasive species, their fast spreading, changing of behavior and biology especially reproductive behavior and even genetics. But it seems that there are still lots of questions and gaps which need to be addressed in case of invasive crayfish species. This thesis tried to focus on different aspects of reproduction biology of invasive crayfish. Generally, the normal crayfish reproduction mode is gonochorism. But, it has been showed in the literature that a few species such as Cherax quadricarinatus, Samastacus spinifrons, Parastacus virilastacus and Pacifastacus leniusculus may have different reproduction modes such as hermaphroditism or intersex. Parthenogenesis has been found in Procambarus fallax f. virginalis. Also, apomictic parthenogenesis has been reported in Orconectes limosus. Moreover, there have been several manipulations which directly affect reproduction biology of crayfish under lab conditions. Additionally, hybridization can be expected between Astacus astacus and Astacus leptodactylus, Orconectes rusticus and Orconectes propinquus under natural conditions. Some studies supposed that chemical factors also one of the reasons which could lead to some changes in reproductive system of crayfish. The objective of the Chapter 2 was to report first evidence of intersex in the signal crayfish, Pacifastacus leniusculus (Dana, 1852). That specimen appeared morphologically male but with both male and female genital openings, as well. Spermophores were obtained from vas defertia of this speciemen. Histological study was carried out and it has shown that both spermatophores and oocytes were present. The gonadosomatic index showed that intersex male had a GSI three times more higher than normal males. The ultrastructure of spermatozoa in three cambarid species Cambarus robustus, Orconectes propinquus, Orconectes rusticus were described and compered with eight previously studied species from family of Astacidae, Cambaridae and Parastacidae. In the studied cambarids, the crest-like protrusions in the anterior part of the acrosome is one of the most remarkable differences in case of morphological feature in spermatozoa and can be used for distinguishing the members of Cambaridae. The results of biometrical data showed that the smallest and biggest acrosome sizes in the studied species were in Parastacidae and Astacidae, respectively. The duration of post-mating spermatophore storage as well as the timing and temperature of spawning in two crayfish species (Pacifastacus leniusculus and Astacus astacus) were investigated in the Chapter 4. Seventy-one pairs of adult signal crayfish (Pacifastacus leniusculus) and thirty six pairs of noble crayfish (Astacus astacus) were used for experiment. The results indicated that there was a significant difference (P<0.05) between noble crayfish and signal crayfish in average duration of the post-mating spermatophore storage. The duration of the post-mating spermatophore storage is longer in the noble crayfish with 34.6 ? 1.7 days than the signal crayfish with 3.9 ? 0.5 days. There were also differences in the timing of mating and egg laying between the signal crayfish and noble crayfish. In the population of signal crayfish both mating and egg laying overlapped, but in the population of noble crayfish there was at least two weeks gap between last mating and first egg laying individuals. Water temperature was significantly (P<0.05) higher during mating and egg laying in the signal crayfish than the noble crayfish. The average temperatures for mating in both species were significantly (P<0.05) higher than the temperatures that they utilized for egg laying. As a conclusion more research is needed for better understand of the reproduction strategies in invasive crayfish.
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Structure of zooplankton in reservoirs of the Jizera Mountains during the peaking anthropogenic acidification and recovery from acidification (1992-2011)
Bímová, Tereza ; Hořická, Zuzana (advisor) ; Seďa, Jaromír (referee)
Acidic atmospheric deposition and acidification of soil and water on the Earth's surface, due to emissions of sulfur and nitrogen into the atmosphere, have led to drastic changes in the composition of surface waters and their biota in many regions of the world over the last century. The number of species and biomass of phytoplankton, zooplankton and benthos were reduced, or some components (zooplankton, zoobenthos, fish) became extinct. In the Jizera Mountains (Northern Bohemia, Czech Republic), the man-made acidification has always been combined with a natural acidity (dystrophy) of waters, caused by a high amount of organic acids. Despite a strong recovery of water chemistry from acidification, that has started in the 1990s, biological recovery is delayed and much more complex. This master thesis is a study of the succession of zooplankton (crustaceans) in mountain reservoirs Souš, Bedřichov and Josefův Důl after decades of strong acidification. Biological recovery from acidification has been in progress differently in the drinking water reservoir Souš, which has long been limed, in the Bedřichov reservoir with naturally high content of organic material, and in the drinking water reservoir Josefův Důl, which is the largest and deepest one and which was most affected by acidification. Recovery of...
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Branchiobdellidan population on alien species of crayfish in the Czech Republic
LOŽEK, Filip
The thesis summarizes the current knowledge about the class Branchiobdellae including their anatomy, ecology and geographic distribution with respect to the presence of introduced species in Europe. Using samples of Branchiobdellidan obtained from two introduced species of crayfish caught in a pond near Čáslavice u Moravských Budějovic (signal crayfish, Pacifastacus leniusculus) and in Černíský stream (eastern crayfish, Orconectes limosus), two out of seven European species of Branchiobdellidan were identified, namely B. parasita with 100% presence in the eastern crayfish and 58.7% presence in the signal crayfish, and B. pentodonta with 41.3% presence. Based on data collected from the caught crayfish and samples of Branchiobdellidan, the individual weight of eastern crayfish was proved to influence the quantity and biomass of Branchiobdellidan on the body of crayfish (p<0.001), i.e. increased quantity and biomass of Branchiobdellidan was found on more robust specimens of crayfish, however the effect of gender was not statistically significant. With respect to the signal crayfish, a significant difference was observed in the quantity and biomass of Branchiobdellidan depending on the weight of the crayfish (p<0.001), and the influence of the gender of the crayfish was detected (p<0.001), i.e. the quantity and biomass of Branchiobdellidan was higher on the surface of male specimens of crayfish. The presence of eggs in some female signal crayfish had no significant effect on the quantity and biomass of Branchiobdellidan (p=0.052), however in combination with the weight, the influence of the presence or absence of eggs was proved (p=0.011), more robust females showed increased quantity and biomass of Branchiobdellidan.
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Krajinně-ekologické‚ vodohospodářské‚ ekonomické a legislativní hodnocení záměru výstavby kanálu Dunaj - Odra - Labe
ŠINDLAR s.r.o, Býšť ; Servus, Michal ; Zeman, Jan ; Šťovíčková, Leona ; Novotná, Pavla ; Zapletal, Jan ; Šindlar, Miloslav
Přílohy obsahující tabulky s přehledy těchto lokalit ovlivněných průplavem DOL: MZCHÚ, evropsky významné lokality, ptačí oblasti, VZCHÚ, přírodní parky, lokality s výskytem chráněných a ohrožených druhů lumbricidae, lokality s výskytem chráněných a ohrožených druhů crustacea, carabidae, odonata, lokality s výskytem významných zástupců druhů edafonu, s výskytem chráněných a ohrožených druhů amphibia, reptilia, aves, mammalia, lokalit s výskytem chráněných a ohrožených druhů rostlin. Hydrologické ovlivnění úseku toků se zástupci mollusca a se zástupci pisces.
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A novel function of red pigment-concentating hormone in crustaceans: \kur{Porcellio scaber} (Isopoda) as a model species
ZRALÁ, Jana
The HPLC and LC/MS analyses of the CNS from isopod crustacean the woodlouse, Porcellio scaber revealed a presence of the red pigment-concentrating hormone (Panbo-RPCH) in this species. It has been shown that this neuropeptide plays a role in mobilization of energy stores: topical treatments of P. scaber individuals by Panbo-RPCH in a concentration 20 pmol/{$\mu$}l increased the level of glucose in haemolymph about 4 times. Glucose was the main carbohydrate mobilized by the Panbo-RPCH treatment. Despite the demonstration of hyperglycaemic activity of Panbo-RPCH, no stimulatory effect of this hormone on the locomotory activity of P. scaber was observed. The present study is the first discovery of an occurrence of Panbo-RPCH and its hyperglycaemic activity in the representative of the isopod crustacean.
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