Search results for "zoo"

Phylogeny and evolution of parthenogenesis in Finnish bagworm moth species (Lepidoptera : Psychidae : Naryciinae) based on mtDNA-markers

2005

We investigated species diversity and evolution of parthenogenesis among bagworm moth species of Dahlica and Siederia using mitochondrial DNA sequencing. Parthenogenesis is rare among Lepidoptera other than Psychidae. Genera Dahlica and Siederia form a confusing group with controversial species boundaries and widely overlapping morphological features that make species determination difficult. We evaluated the reliability of species determination based on wing scale morphology by comparing it with a phylogenetic tree obtained using mtDNA. Species determination based on morphological characteristics did not correspond to species determination based on mtDNA markers. On the basis of the molecu…

El pòlip de Trembley: L'"animal-planta" que va sacsejar la biologia del segle XVIII

2013

Els experiments d’Abraham Trembley amb l’hidra d’aigua dolça no només van sorprendre els seus contemporanis per la seva espectacularitat, sinó que els seus resultats també van causar un enorme trasbals en la comunitat científica del seu temps. Idees com la «cadena del ser», el mecanisme de generació dels éssers vius o la mateixa naturalesa de l’ànima van ser fortament sacsejades.

Gliemeži un gliemenes

2019

Buklets "Gliemeži un gliemenes" iepazīstina ar Latvijas Univeraitātes Muzeja Zooloģijas kolekcijās apskatāmajiem gliemežiem un gliemenēm, to veidiem, formām, un personām, kas šādas kolekcijas ir vākuši un dāvinājuši Latvijas Univeraitātes Muzejam. Bukletu ilustrē Latvijas Universitātes Muzeja kolekciju paraugu fotogrāfijas.

Musiikilliset elementit eläinten ääntelyssä

2017

Tämän integroivan kirjallisuuskatsauksen tarkoituksena oli tutustua eläinten ääntelyn musiikillisuuteen samalla selvittäen, millaisia musiikillisina pidettäviä elementtejä eläinten ääntelystä voidaan löytää. Lähestyin aihetta tutkimalla viittä keskeisintä musiikillista elementtiä: melodiaa, rytmiä, harmoniaa, äänenväriä sekä rakennetta ja selvittämällä aiempia tutkimuksia hyväksi käyttäen, mitkä näistä elementeistä esiintyvät eläinten ääntelyssä. Tutkimuksista kävi ilmi, että kaikki edellä mainitut viisi musiikillista elementtiä ovat - lajista riippuen - löydettävissä eläinten ääntelystä. Lisäksi huomionarvoista oli, että tutkimusten mukaan tietyt eläinlajit kykenevät paitsi hyödyntämään mu…

Terrestrial carbohydrates support freshwater zooplankton during phytoplankton deficiency

2016

Article

Long-term changes in pigmentation of arctic Daphnia provide potential for reconstructing aquatic UV exposure

2016

Abstract Despite the biologically damaging impacts of solar ultraviolet radiation (UV) in nature, little is known about its natural variability, forcing mechanisms, and long-term effects on ecosystems and organisms. Arctic zooplankton, for example the aquatic keystone genus Daphnia (Crustacea, Cladocera) responds to biologically damaging UV by utilizing photoprotective strategies, including pigmentation. We examined the preservation and content of UV-screening pigments in fossil Daphnia remains (ephippia) in two arctic lake sediment cores from Cornwallis Island (Lake R1), Canada, and Spitsbergen (Lake Fugledammen), Svalbard. The aims were to document changes in the degree of UV-protective p…

Phosphorus limitation enhances parasite impact: feedback effects at the population level

2014

Background Nutrient deficiency affects the growth and population dynamics of consumers. Endoparasites can be seen as consumers that drain carbon (C) or energy from their host while simultaneously competing for limiting resources such as phosphorus (P). Depending on the relative demands of the host and the parasite for the limiting nutrient, intensified resource competition under nutrient limitation can either reduce the parasite’s effect on the host or further reduce the fitness of the nutrient-limited host. So far, knowledge of how nutrient limitation affects parasite performance at the host population level and how this affects the host populations is limited. Results We followed the popu…

Oxidative stress biomarkers in the copepod Limnocalanus macrurus from the northern Baltic Sea : effects of hydrographic factors and chemical contamin…

2015

Inferring phytoplankton community composition with a fatty acid mixing model

2015

Abstract. The taxon specificity of fatty acid composition in algal classes suggests that fatty acids could be used as chemotaxonomic markers for phytoplankton composition. The applicability of phospholipid-derived fatty acids as chemotaxonomic markers for phytoplankton composition was evaluated by using a Bayesian fatty acid-based mixing model. Fatty acid profiles from monocultures of chlorophytes, cyanobacteria, diatoms, euglenoids, dinoflagellates, raphidophyte, cryptophytes and chrysophytes were used as a reference library to infer phytoplankton community composition in five moderately humic, large boreal lakes in three different seasons (spring, summer and fall). The phytoplankton commu…

Water chemistry, zooplankton and benthos in small lakes within the distribution area of the rare European pool frog Pelophylax lessonae (Camerano) in…

2020

Summary In June 2018, water chemistry, benthos and zooplankton were investigated in 7 small lakes/ ponds within the key area of the European pool frog Pelophylax lessonae (Camerano) in Norway. The geographic distribution of the Norwegian population is minor, limited to a very few small lakes in the county of Agder in southernmost Norway. Since the species is thermophilic, reproduction success only occurs in warm summers. Accordingly, the pool frog is one of the most rare vertebrates in Norwegian fauna, classified as critically endangered in the Norwegian red list. A breeding program is today established in order to rescue this species.The article deals with potential biotope challenges most…