Browsing by Subject "morfologia"
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(2021)Kurtturuusu (Rosa rugosa) on haitallinen vieraslaji Suomessa. Se on levinnyt alkuperäisiltä esiintymisalueiltaan Koillis-Aasiasta Itämeren ja Pohjanmeren rannikolle sekä Pohjois-Amerikan koillisosiin. Se uhkaa luonnon monimuotoisuutta erityisesti merenrannoilla. Suomessa kaikki hiekkarantojen ja dyynien luontotyypit ovat uhanalaisia ja kurtturuusu vaikuttaa erityisesti niiden ekosysteemeihin muodostamalla suuria tiheitä kasvustoja. Kurtturuusukasvustossa muut lajit vähenevät. Vieraslajilain nojalla kurtturuusun kasvattaminen on kielletty, mutta kasvatuskielto astuu voimaan vasta siirtymäajan jälkeen 1.6.2022. Kurtturuusu on suosittu koristepensas. Siitä on myös jalostettu uusia lajikkeita. Niiden kasvatusta kielto ei koske, koska niiden lisääntymiskyvyn on ajateltu olevan heikko. Tutkimuksen tavoitteena oli selvittää kurtturuusun levinneisyyttä Espoon rannoilla sekä tutkia sen lisääntymiskykyä. Tutkimuksessa kartoitettiin Espoon merenrantoja järjestelmällisesti maastossa havainnoiden ja etsittiin niiltä kurtturuusua. Kasvustojen ominaisuuksia tutkittiin ja selvitettiin morfologisten tuntomerkkien avulla, ovatko ne kurtturuusun perusmuotoa vai jotakin jalostettua lajiketta. Kasvustoista valittiin osa tarkempaa siementutkimusta varten. Siementen elinkykyä tutkittiin tetrazoliumtestin avulla ja kelluntakykyä vesiastioissa. Siementutkimuksessa selvitettiin, eroaako kurtturuusun perusmuodon ja jalostettujen lajikkeiden siementuotto tai siementen elinkyky toisistaan ja kuinka hyvin pähkylät kelluvat. Tilastollisina menetelminä käytettiin varianssianalyysiä ja t-testiä. Kurtturuusua kasvoi Espoon rannoilla runsaasti monenlaisilla kasvupaikoilla sekä istutettuna että villiytyneenä. Mantereella sitä oli enemmän kuin saaristossa. Villiytyneenä tai mahdollisesti villiytyneenä kasvoi vain muutamia kasvustoja jalostettuja kurtturuusulajikkeita. Istutettuina niitä oli enemmän. Kurtturuusun siementuotto vaikuttaa olevan suurempi perusmuodolla kuin jalostetuilla lajikkeilla. Perusmuoto tuotti myös keskimäärin enemmän elinkykyisiä siemeniä. Hajonta molemmissa ryhmissä oli kuitenkin suurta. Osa jalostetuista lajikkeita tuotti melko runsaastikin elinkykyisiä siemeniä, toiset taas hyvin vähän. Kurtturuusun pähkylät kelluivat hyvin. Tulokset tukevat käsitystä siitä, että jalostetut kurtturuusulajikkeet eivät olisi yhtä haitallisia kuin perusmuoto. Sekä perusmuodon että jalostettujen lajikkeiden siementuoton ja elinkyvyn hajonta oli kuitenkin suurta. Eri lajikkeiden eroja olisikin tarpeen selvittää järjestelmällisesti. Kurtturuusulla on hyvät edellytykset levitä veden välityksellä uusille kasvupaikoille, koska se kasvaa rannoilla ja sen siementen kelluntakyky on hyvä. Kurtturuusun kartoitus Espoossa auttaa sen torjunnan suunnittelussa myös muissa kaupungeissa.
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(2019)Twisted-winged parasitoids (Insecta: Strepsiptera) are parasites of other insects, which are characterized by complex life cycles and extreme sexual dimorphism. They have three endoparasitic larval stages. In most Strepsiptera only the motile first instar larvae and adult males are free living whereas the adult females are endoparasites during their entire life. The winged males slightly resemble flies, while females are neotenic. Around 630 extant Strepsiptera species are known but this is probably an underestimation since many species are cryptic. The genus Stylops, parasitoids of mining bees of genus Andrena, is one of the biggest genera of Strepsiptera. Until recently it was thought that only one species, Stylops melittae, occurs in Europe. Studies using DNA-methods revealed that it is in fact a species complex of 30 species. This study investigated which of these species occur in Finland. In addition, it was examined if the female morphology of the species could be used in species identification, since males are rarely found. Andrena host specimens were examined from three major entomological collections and the collecting data of the observed Stylops was recorded to a database. Suitable specimens were DNA barcoded and the acquired DNA barcodes were compered for the ones in databases (BOLD, GenBank). The females were separated from their hosts and photographed for the morphological examination using different imaging methods (focus stacking, SEM). Based on this study there are five species of Stylops in Finland instead of one as previously thought: S. thwaitesi, S. ater, S. japonicus, S. nevinsoni and S. spreta. In addition, there is one species, which is most likely undescribed. All females of these species can be identified based on their morphology. The results include summaries of each species containing information about their morphology, ecology, distribution and abundance. This study gives valuable new information about the twisted-winged parasitoids in Finland. The occurrence of the genus Stylops in Finland based on current taxonomy was examined for the first time. The study gave novel information about the distributions of Stylops-species. Deviating from previous information Stylops japonicus is also found in Europe. Furthermore, the study revealed new information about the host-parasite relationships of the species. Many of the Andrena host species had not been associated with certain Stylops species before. There has not been research focusing on Strepsiptera in Finland for a long time. The material collected for this study works as a good foundation for the possible future studies in Finland. The results were used in the 2019 Red List assessment and two of the Stylops species were in the Red List of threatened species.
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(2013)Lepidurus arcticus (Pallas, 1793) is a keystone species in High Arctic ponds, which are exposed to a wide range of environmental stressors. This thesis provides information on the ecology of this little studied species by paying particular focus on the sensitivity of L. arcticus to acidification and climate change. Respiration, reproduction, olfaction, morphology, salinity and pH tolerance of the species were studied in the laboratory and several environmental parameters were measured in its natural habitats in Arctic ponds. Current global circulation models predict 2–2.4 °C increase in summer temperatures on Spitsbergen, Svalbard, Norway. The L. arcticus respiration activity was tested at different temperatures (3.5, 10, 16.5, 20, 25 and 30 °C). The results show that L. arcticus is clearly adapted to live in cold water and have a temperature optimum at +10 °C. This species should be considered as stenothermal, because it seems to be able to live only within a narrow temperature range. L. arcticus populations seem to have the capacity to respond to the ongoing climate change on Spitsbergen. Changes can be seen in the species' reproductive capacity and in the individuals' body size when comparing results with previous studies on Spitsbergen and in other Arctic areas. Effective reproduction capacity was a unique feature of the L. arcticus populations on Spitsbergen. L. arcticus females reached sexual maturity at a smaller body size and sexual dimorphism appeared in smaller animals on Spitsbergen than anywhere else in the subarctic or Arctic regions. L. arcticus females were able to carry more eggs (up to 12 eggs per female) than has been observed in previous studies. Another interesting feature of L. arcticus on Spitsbergen was their potential to grow large, up to 39.4 mm in total length. Also cannibalistic behaviour seemed to be common on Spitsbergen L. arcticus populations. The existence of different colour morphs and the population-level differences in morphology of L. arcticus were unknown, but fascinating characteristic of this species. Spitsbergen populations consisted of two major (i.e. monochrome and marbled) and several combined colour morphs. Third interesting finding was a new disease for science which activated when the water temperature rose. I named this disease to Red Carapace Disease (RCD). This High Arctic crustacean lives in ponds between the Arctic Ocean and glaciers, where the marine environment has a strong impact on the terrestrial and freshwater ecosystems. The tolerance of L. arcticius to increased water salinity was determined by a LC50 -test. No mortality occurred during the 23 day exposure at low 1–2 ‰ water salinity. A slight increase in water salinity (to 1 ‰) speeded up the L. arcticus shell replacement. The observations from natural populations supported the hypothesis that the size of the animals increases considerably in low 1.5 ‰ salt concentrations. Thus, a small increase in water salinity seems to have a positive impact on the growth of this short-lived species. Acidification has been a big problem for many crustaceans, invertebrates and fishes for several decades. L. arcricus does not make an exception. Strong acid stress in pH 4 caused a high mortality of mature L. arcticus females. The critical lower limit of pH was 6.1 for the survival of this acid sensitive species. Thus, L. arcticus populations are probably in danger of extinction due to acidification of three ponds on Spitsbergen. A slight drop (0.1–1.0) in pH values can wipe out these L. arcticus populations. The survival of L. arcticus was strongly related to: (1) the water pH, (2) total organic carbon (TOC) and pH interaction, (3) the water temperature and (4) the water salinity. Water pH and TOC values should be monitored in these ponds and the input of acidifying substances in ponds should be prevented.
Now showing items 1-3 of 3