1. Although populations harbour considerable diversity, most ecological studies still assume they are homogeneous. However, mounting evidence suggests that intraspecific diversity is not only common, but also important for interactions with community members. Here, intraspecific variation in Daphnia dentifera in haemoglobin content is shown to be a marker of hypolimnion use. 2. Hypolimnion use ...

The North American ecological species Daphniapulicaria and Daphniapulex are thought to have diverged from a common ancestor by adaptation to sympatric but ecologically distinct lake and pond habitats respectively. Based on mtDNA relationships, European D. pulicaria is considered a different species only distantly related to its North American counterpart, but both species share a lactate dehydr...

Statistical mechanics provides the link between microscopic properties of many-particle systems and macroscopic properties such as pressure and temperature. Observations of similar "microscopic" quantities exist for the motion of zooplankton, as well as many species of other social animals. Herein, we propose to take average squared velocities as the definition of the "ecological temperature" o...

Very little is known about the ability of the zooplankton grazer Daphnia pulicaria to reduce populations of Giardia lamblia cysts and Cryptosporidium parvum oocysts in surface waters. The potential for D. pulicaria to act as a biological filter of C. parvum and G. lamblia was tested under three grazing pressures (one, two, or four D. pulicaria grazers per 66 ml). (Oo)cysts (1 x 10(4) per 66 ml)...

We studied the habitat choice of juvenile and adult Daphnia pulicaria in thermally stratified water columns (plankton towers) with a deep water algal maximum (DCM). The DCM consisted of either filamentous cyanobacteria (Planktothrix agardhii), non-filamentous Chlorophyceae (Scenedesmus obliquus) or a mixture of both. Adult D. pulicaria spent more time at colder temperatures in the presence of P...

A total of 30 chloroform and methanol extracts from the following endemic Soqotran plants Acridocarpus socotranus Olive, Boswellia socotranao Balf.fil, Boswellia elongata Balf. fil., Caralluma socotrana N. Br, Cephalocroton socotranus Balf.f, Croton socotranus Balf. fil.., Dendrosicycos socotrana Balf.f., Dorstenia gigas Schweinf. ex Balf. fil., Eureiandra balfourii Cogn. & Balf. fil., Kalancho...

The molecular mechanisms leading to asexuality remain little understood despite their substantial bearing on why sexual reproduction is dominant in nature. Here, we examine the role of hybridization in the origin and spread of obligate asexuality in Daphnia pulex, arguably the best-documented case of contagious asexuality. Obligately parthenogenetic (OP) clones of D. pulex have traditionally be...

Asteraceae familyası hem dünyada de ülkemizde geniş cins ve tür zenginliğine sahip bitki familyaları arasında yer almaktadır. Bu öneme binaen bu büyük önemli aileye ait beş farklı cinsten türün (Pulicaria vulgaris (L.) Gaertner, Picris strigosa Bieb., Cichorium intybus L., Lactuca viminea J. Presl & C. Chondrilla juncea L.) Feulgen boyama tekniği kullanılarak kromozom sayımı detaylı kar...

Background and objectives: Several natural compounds have been identified for the treatment of leishmaniasis. Due to a few safe drugs and the side effects caused by available chemotherapy, some new drugs for treatment of leishmaniasis are requested. The genus Pulicaria (Asteraceae) is represented in the flora of Iran by five species. Phytochemical studies on Pulicaria species have revealed some...

Understanding the drivers and consequences of disease epidemics is an important frontier in ecology. However, long-term data on hosts, their parasites, and the corresponding environmental conditions necessary to explore these interactions are often unavailable. We examined the dynamics of Daphnia pulicaria, a keystone zooplankter in lake ecosystems, to explore the long-term causes and consequen...