n macrophyte-rich lentic ecosystems, higher numbers of damselfly larvae occur in areas where there is structurally complex vegetation than in those where the plant architecture is relatively simple. Biotic interactions rather than morphological constraints are considered to underlie this pattern. We investigated whether the preference of the larvae of the damselfly Enallagma cyathigerum for a particular habitat was retained in absence of prey, predators and/or conspecifics. A series of laboratory choice experiments was conducted in which combinations of sediment and artificial plants differing in structural complexity were offered simultaneously to the larvae. Larvae preferred patches with structurally complex vegetation over patches with simply structured vegetation or lacking vegetation. Patches with simply structured vegetation were preferred over those with bare sediment, but the number of larvae showing a clear choice, which is regarded as an indication of the strength of the preference for a particular habitat, was relatively low compared to the number of individuals responding when complex vegetation was present. Based on the results presented, we conclude that the preference of E. cyathigerum larvae for structurally complex vegetation is independent of the presence of predators, prey or competitors. This suggests that this behaviour of the larvae is either learned or an innate response., Ralf C.M. Verdonschot, Edwin T.H.M. Peeters., and Obsahuje seznam literatury
Někteří zástupci třídy hmyzu patří k chladově nejodolnějším organismům na Zemi. Přežijí podchlazení až pod -50°C nebo kompletní zmrznutí (přeměnu tělní vody na led). Dokonce je dokážeme, jako celé komplexní organismy, téměř neomezeně dlouho skladovat v kapalném dusíku. Výzkum principiální podstaty této výjimečné schopnosti hmyzu může přinést poznatky využitelné pro praktické technologie kryokonzervace biologického materiálu., Some insects are to the most cold-tolerant organisms on Earth. They survive supercooling down to -50°C or complete freezing (transition of body water to ice). Moreover, we can store the insect organism in its whole complexity in liquid nitrogen almost indefinitely. Research on the principles behind this exceptional ability of insects can provide knowledge that will be useful for the development of practical protocols for the cryopreservation of biological material., and Vladimír Košťál.
Progeny of the flesh fly Sarcophaga bullata exposed to short day length show a maternal effect that prevents the expression of pupal diapause. Although ecological aspects of this effect are well studied, not enough is known about the molecular mechanisms underlying this maternal effect. In this study, two-dimensional electrophoresis was performed to detect differences of the abundance of certain proteins in the ovaries of this fly kept under long day and short day conditions for 2 days after eclosion. Eleven proteins that were abundant and showed significant changes were selected for mass spectrometric identification. Ovary proteins that increased in abundance under short-day conditions were similar to twinstar CG4254-PA, muscle protein 20-like protein, GA13413-PA, gene analogous to small peritrophins (Gasp CG10287-PA) and Ribosomal protein LP1 CG4087-PA. Ovary proteins that decreased in abundance under short-day conditions were similar to the ATP synthase beta subunit, fk506-binding protein and storage protein-binding protein. The 2-D proteome maps included 2 additional unknown proteins that were more abundant and 1 that was less abundant in the ovaries of 2-day old short-day females. Twinstar CG4254-PA, muscle protein 20-like protein and GA13413-PA harbour an actin-binding domain. That the 3 actin-binding proteins increase in abundance suggests that it is likely that an alteration in the actin cytoskeleton is involved in this maternal effect in the flesh fly., Aiqing Li ... [et al.]., and Obsahuje seznam literatury
A half-century of zoological investigations in the region of Podblanicko (Central Bohemia) published in the regional collection Nature and History of Podblanicko Region.