Fungi isolated from cultured eggs, alevins and broodfish of brown trout in a hatchery affected by saprolegniosis

P. 510-518The aquatic fungi cultured from eggs, alevins and broodfish of brown trout Salmo trutta belonged to the genus Saprolegnia and were identified as S. diclina, S. australis, S. ferax, S. furcata, S. hypogyna, S. unispora and S. parasitica. The species obtained from infected eggs and alevins were different to those from infected fish. Several Saprolegnia species were isolated from eggs and alevins, whereas all the isolates obtained from broodfish were the pathogenic S. parasitica.S

INVESTIGACIONES EN CAROTENOIDES DE LÍQUENES. XXVII. CAROTENOIDES EN LÍQUENES DEL N. ÁFRICA Y SE. ESPAÑA

Column and thin-layer chromatography revealed the presence of the following carotenoids in the thalli of 12 lichen species from the North Africa and SE Spain: a-carotene, p-carotene, a-cryptoxanthin, β-cryptoxanthin, lutein, 3'-epilutein, zeaxanthin, diatoxanthin, lycopene-5,6-epoxide, the first record from lichens, Pcarotene epoxide, lutein epoxide, antheraxanthin, violaxanthin, mutatoxanthin, neoxanthin, astaxanthin, O-apo- 10'-carotenal and apo- 12'violaxanthal. The total content of carotenoids ranged from 17,20 Ramalina hourgeana to 72,52 mg g-1 dry weight Roccella canariensis.Cromatografía en columna y capa fina revela la presencia de los siguientes carotenoides en el talo de 12 especies de líquenes recolectados en el norte de Africa y SE España: a-caroteno, b-caroteno, a-criptoxantina, b-criptoxantina, luteina, 3'-epiluteina, zeaxantina, diatoxantina, licopeno-5, 6-epoxido, nuevo en líquenes, Pcaroteno epóxido, luteína epóxido, anteraxantina, violaxantina, mutatoxantina, neoxantina, astaxantina, b-apo-10'-carotenal y apo- 12' violaxantal. El contenido total de carotenoides oscila entre 17,20 en Ramalina hourgeana y 72,52 mg g-1 del peso seco en Roccella canariensis

Colouration in amphibians as a reflection of nutritional status : the case of tree frogs in Costa Rica

Colouration has been considered a cue for mating success in many species; ornaments in males often are related to carotenoid mobilization towards feathers and/or skin and can signal general health and nutrition status. However, there are several factors that can also link with status, such as physiological blood parameters and body condition, but there is not substantial evidence which supports the existence of these relationships and interactions in anurans. This study evaluated how body score and blood values interact with colouration in free-range Agalychnis callidryas and Agalychnis annae males. We found significant associations between body condition and plasmatic proteins and haematocrit, as well as between body condition and colour values from the chromaticity diagram. We also demonstrated that there is a significant relation between the glucose and plasmatic protein values that were reflected in the ventral colours of the animals, and haematocrit inversely affected most of those colour values. Significant differences were found between species as well as between populations of A. callidryas, suggesting that despite colour variation, there are also biochemical differences within animals from the same species located in different regions. These data provide information on underlying factors for colouration of male tree frogs in nature, provide insights about the dynamics of several nutrients in the amphibian model and how this could affect the reproductive output of the animals

Out of the rivers: are some aquatic hyphomycetes plant endophytes?

Ingoldian fungi, or aquatic hyphomycetes, are asexual microfungi, mostly ascomycetes, commonly occurring in running freshwater. They grow on dead plant material, such as leaves and twigs, and play a major role in nutrient flows in stream ecosystems (Bärlocher, 1992). They were discovered and first extensively studied by Ingold (1942) and were thus named "Ingoldian" fungi. Ingold described their abundant multicellular asexual spores of sigmoid or, more typically, tetraradiate shape (Fig. 1). He recognized that they probably arose from multiple convergent evolutions, by secondary adaptation to aquatic life, as recently confirmed by molecular markers (Belliveau & Bärlocher, 2005; Baschien et al., 2006). Because of their apparent lack of sexuality, Ingoldian species were placed in asexual genera, such as Tricladium or Tetracladium, based on conidial morphology and/or mode of conidiogenesis. Unexpectedly, several lines of evidence now suggest that some Ingoldian fungi are also plant endophytes, that is, they grow in plants without producing symptoms.[...

Specific Appetite for Carotenoids in a Colorful Bird

Background: Since carotenoids have physiological functions necessary for maintaining health, individuals should be selected to actively seek and develop a specific appetite for these compounds. Methodology/Principal Findings: Great tits Parus major in a diet choice experiment, both in captivity and the field, preferred carotenoid-enriched diets to control diets. The food items did not differ in any other aspects measured besides carotenoid content. Conclusions/Significance: Specific appetite for carotenoids is here demonstrated for the first time, placing these compounds on a par with essential nutrients as sodium or calcium

Carotenoid-Based Colours Reflect the Stress Response in the Common Lizard

Under chronic stress, carotenoid-based colouration has often been shown to fade. However, the ecological and physiological mechanisms that govern colouration still remain largely unknown. Colour changes may be directly induced by the stressor (for example through reduced carotenoid intake) or due to the activation of the physiological stress response (PSR, e.g. due to increased blood corticosterone concentrations). Here, we tested whether blood corticosterone concentration affected carotenoid-based colouration, and whether a trade-off between colouration and PSR existed. Using the common lizard (Lacerta vivipara), we correlatively and experimentally showed that elevated blood corticosterone levels are associated with increased redness of the lizard's belly. In this study, the effects of corticosterone did not depend on carotenoid ingestion, indicating the absence of a trade-off between colouration and PSR for carotenoids. While carotenoid ingestion increased blood carotenoid concentration, colouration was not modified. This suggests that carotenoid-based colouration of common lizards is not severely limited by dietary carotenoid intake. Together with earlier studies, these findings suggest that the common lizard's carotenoid-based colouration may be a composite trait, consisting of fixed (e.g. genetic) and environmentally elements, the latter reflecting the lizard's PSR