Search results for "Systematics"
showing 10 items of 6702 documents
Induction of heat-shock (stress) protein gene expression by selected natural and anthropogenic disturbances in the octocoral Dendronephthya klunzinge…
2000
Previously it was found that the expression of selected heat-shock proteins is upregulated in corals after exposure to elevated temperature. We published that HSPs are suitable markers in sponges to monitor the degree of environmental stress on these animals. In the present study the heat-shock proteins (HSPs) with a molecular weight of 90 kDa have been selected to prove their potential usefulness as biomarkers under controlled laboratory conditions and in the field. The studies have been performed with the octocoral Dendronephthya klunzingeri from which the cDNA coding for HSP90 was cloned first. The expression of the HSP90 gene is upregulated by thermal stress; treatment of the animals fo…
REINSTATEMENT OF THE DINOFLAGELLATE GENUS Tripos TO REPLACE Neoceratium, MARINE SPECIES OF Ceratium (DINOPHYCEAE, ALVEOLATA)
2013
Morphological and molecular data support the split at the genus level of the marine and freshwater species of the dinoflagellate Ceratium (Gonyaulacales, Dinophyceae). A new genus name Neoceratium F. Gomez, D. Moreira & P. Lopez-Garcia was proposed for the marine species. However, it is considered illegitimate (type species is type of Biceratium Vanhoffen), and the nomenclatural priority is here given for the genus Tripos Bory (type species Tripos muelleri ) which replaces Neoceratium . New combinations are proposed for the existing names of species and infraspecific taxa. Reinstalacion del genero de dinoflagelados Tripos para reemplazar a Neoceratium , especies marinas de Ceratium (Dinophy…
Female bank voles ( Clethrionomys glareolus ) prefer dominant males; but what if there is no choice?
1996
Both intra-sexual competition between males and female mate choice have been found to affect mating behaviour in rodents. We studied female choice in the bank vole (Clethrionomys glareolus) under circumstances where male-male competition was excluded and the female could interact and mate freely with the males. Mating behaviour was observed in two situations: (1) the female encountered two males with a clear dominance relationship; and (2) the two males were equal in their social status. In all tests where a female in postpartum oestrus had a choice between males of different social rank she mated with the dominant one. When choosing between an even pair of males there was no difference in …
Intestinal helminth fauna of striped dolphins (Stenella coeruleoalba) in the western Mediterranean: No effects of host body length, age and sex
2014
The intestine of 52 (28 males and 24 females) striped dolphins (Stenella coeruleoalba) from western Mediterranean waters was examined for helminths. Animals were found stranded along the Spanish coasts during the morbillivirus epizootic in 1990. In accordance with observations from other pelagic tetrapods, including cetaceans from other geographical regions, the intestinal helminth community was depauperate. Four helminth species were found: three tetrabothriid cestodes, Tetrabothrius forsteri (prevalence: 96.2%; mean intensity [95% CI]: 47.4 [34.4–68.2]), Trigonocotyle globicephalae (9.6%; 1.8 [1.0–2.2]), and Strobilocephalus triangularis (23.1%; 5.3 [2.9–10.2]), and immature individuals o…
On Harvestmen from the Soutpansberg, South Africa, with Description of a New Species ofMonomontia(Arachnida: Opiliones)
2008
The harvestman fauna of the Western Soutpansberg was investigated during two collecting trips. Comments are made on the variability, ecology and remarkable morphological features of the collected material. Characters are displayed and differences to type series are highlighted. Monomontia neglecta sp. n. is described from material housed at the Natal Museum. Metabiantes leighi Pocock, 1902 is recorded for the first time for the Soutpansberg area. A species list is provided, listing all known records and the state of endemism. The relative species richness of the eastern Soutpansberg is discussed in comparison with the western area.
Determinants of the Mating Success of Polyterritorial Pied Flycatcher Males
2010
Much attention has been paid to the polyterritorial mating system of some passerine birds. Here we report how a male's mating success is related to the behavioral traits of polyterritorial pied flycatcher (Ficedula hypoleuca) males. We found no evidence that the timing of polyterritoriality in relation to egg laying in the primary nest or the singing behavior of males have any influence on mating success. However, results show clearly that male mating success was improved with an increase in the distance between territories up to a distance of about 200–300 m whereupon there was no further enhancement of mating success. This finding is crucial for both the deception hypothesis and female-fe…
Culturable endophytic microbial communities in the circumpolar grass,Deschampsia flexuosain a sub-Arctic inland primary succession are habitat and gr…
2014
Summary Little is known about endophytic microbes in cold climate plants and how their communities are formed. We compared culturable putative endophytic bacteria and fungi in the ecologically important circumpolar grass, Deschampsia flexuosa growing in two successional stages of subarctic sand dune (68°29′N). Sequence analyses of partial 16S rRNA and internal transcribed spacer (ITS) sequences of culturable endophytes showed that diverse bacteria and fungi inhabit different tissues of D. flexuosa. A total of 178 bacterial isolates representing seven taxonomic divisions, Alpha, Beta and Gammaproteobacteria, Actinobacteria, Bacteroidetes, Firmicutes and Acidobacteria, and 30 fungal isolates …
Predatory behavior in the genusLeptogenys: A comparative study
1997
We studied the predatory behavior of seven species of the genusLeptogenys from Mexico and Cameroon. The ants of this genus are armed with long, thin, curved mandibles articulated at the extreme corners of the anterior margin of the head, permitting them easily to seize oniscoid isopods, the obligate or the principal prey of mostLeptogenys species. Workers hunt these prey, which are able to roll themselves up, solitarily. Foraging behavior comprises sequences of up to eight activities. The prey can be seized by the body (rolled up or not), or alternatively by the edge of the shell, then turned over and stung on the ventral face. A relationship between the mandible size of the workers and the…
Mycorrhizal benefit differs among the sexes in a gynodioecious species
2010
Both plant sex and arbuscular mycorrhizal (AM) symbiosis influence resource acquisition and allocation in plants, but the interaction between these two components is not well established. As the different plant sexes differ in their resource needs and allocation patterns, it is logical to presume that they might differ in their relationship with AM as well. We investigate whether the association with AM symbiosis is different according to the host plant sex in the gynodioecious Geranium sylvaticum, of which, besides female and hermaphrodite plants, intermediate plants are also recognized. Specifically, we examine the effects of two different AM fungi in plant mass allocation and phosphorus …
Evidence for an even sex allocation in haplodiploid cyclical parthenogens
2002
Recent theoretical work has shown that haplodiploid cyclical parthenogens, such as rotifers, are expected to have an equal frequency of male-producing and resting-egg producing females during their sexual phase. We tested this prediction by following sexual reproduction dynamics in two laboratory populations and one field population of the rotifer Brachionus plicatilis through two growing seasons. We recorded population density, proportion of sexual females, and sex allocation (the proportion of male-producing sexual females as a fraction of total sexual females). We found this sex allocation ratio to vary from 0.3 to 1.0 in single sampling events. However, when we computed sex allocation b…