Three sisters in the same dress: cryptic speciation in African odonates

The discovery of cryptic species (i.e. two or more distinct but morphologically undistinguishable species) has grown exponentially in the last two decades, due mainly to the increasing availability of DNA sequences. This suggests that hidden in the known species, many of which have been described based solely on morphological information, there might be a high number of species waiting to be discovered. In this issue Damm et al. (2010) use a combination of genetic, morphological and ecological evidence to identify the first cryptic species complex found within dragonflies (insect order Odonata). Their findings add more evidence for the importance of combining information from different disciplines to new species’ discovery ( DeSalle et al. 2005 ).     

Bumble bee workers drift to conspecific nests at field scales

1. Workers in several bee species travel to conspecific nests (‘drifting’), enter them, and produce male offspring inside them, so acting as intra‐specific social parasites. This adds a new dimension to bees' reproductive behaviour and spatial ecology, but the extent to which drifting occurs over field scales, i.e. at natural nest densities in field conditions, has been unclear. 2. Using the bumble bee Bombus terrestris (Linnaeus) as a model system, we sought to determine rates of worker drifting at field scales and the frequency of potential drifter workers in wild nests. 3. A field experiment with 27 colonies showed that workers travelled to, and became accepted in, conspecific nests that were up to 60 m away, although the number of accepted drifter workers within nests fell significantly with distance. The rate at which nests were entered by drifters was relatively high and significantly exceeded the rate at which drifters became accepted. 4. Microsatellite genotyping of eight field‐collected nests from Greater London, U.K., showed that a low frequency (3%) of workers were not full sisters of nestmate workers and hence were likely to have been drifter workers. 5. It is therefore concluded that workers can drift to conspecific nests over field scales and confirmed that successful drifting occurs in natural populations. Drifting appears to be a natural but low‐frequency behaviour permitting B. terrestris workers to gain direct fitness.     

Isolation and characterization of microsatellite loci from yellowtail Seriola dumerilii (Perciformes: Carangidae)

The Mediterranean yellowtail Seriola dumerilii (Risso, 1810) is a semi‐pelagic fish economically important to fisheries and aquaculture. We developed nine microsatellite primer pairs for this species. Microsatellites were isolated from a partial genomic library enriched for an AC motif. The developed loci proved to be polymorphic showing three to 11 alleles per locus. They can be employed for population studies as well as for parentage assessment. Cross‐species amplification was successfully tested in Seriola fasciata and Seriola rivoliana.     

Development and characterization of 11 microsatellite markers in the rock sparrow,Petronia petronia

Eleven polymorphic microsatellite loci were isolated in the passeriform Petronia petronia using the enrichment protocol FIASCO (fast isolation by AFLP of sequences containing repeats). We detected three to 13 alleles per locus in 25 specimens collected from an Italian population. The level of expected heterozygosity ranged from 0.439 to 0.856. One locus is sex linked to the Z chromosome. The total exclusionary probabilities using these loci for the first and the second parent were 0.978 and 0.999, respectively. These are the first microsatellite loci characterized from the rock sparrow that can be used for estimating population structure and for large‐scale parentage analysis.     

Effects of small‐scale grassland fragmentation and frequent mowing on population density and species diversity of orthopterans: a long‐term study

Abstract 1. Habitat fragmentation is considered one of the major threats to invertebrate diversity in semi‐natural grassland. However, the effects of habitat fragmentation through mowing on the rich insect fauna of these grasslands have not been sufficiently investigated and experiments are especially rare. 2. We studied the impact of small‐scale grassland fragmentation on orthopterans over 7 years in an experiment which allowed us to additionally investigate the effect of frequent mowing on Orthoptera communities. 3. Overall, Orthoptera density and species richness increased over time. This was likely a result of increased small‐scale habitat heterogeneity and the provision of a short‐turf habitat suitable for xerophilous species. The fragmentation affected orthopteran density and species composition but not species richness whose response lagged behind the changes in abundance. 4. Responses differed between suborders. Ensifera density was higher in fragment than in control plots. Caelifera density did not differ between fragment and control plots. The mown matrix was an unsuitable habitat for most of the species, particularly within the Ensifera. 5. Our experiment shows that even small‐scale fragmentation can affect Orthopteran communities and that the effects became more pronounced over time. As the mown matrix was unsuitable for many Ensifera species, they may go locally extinct when large areas are mown simultaneously.     

Molecular Evidence for the Existence of Two Species of Marteilia in Europe

Marteilia refringens is one of the most significant pathogens of bivalve molluscs. Previous sequencing of the small subunit ribosomal RNA gene of M. refringens isolates derived from the infected mussels (Mytilus edulis and Mytilus galloprovinciallis) and the oyster (Ostrea edulis) in Europe did not reveal genetic polymorphisms despite indications from epizootiological data that distinct types may exist. We investigated the existence of polymorphisms in the internal transcribed spacer region of the ribosomal RNA genes. The sequences of this region proved to be clearly dimorphic among Marteilia from five sampling sites. The distribution of the two genetic types, named "O" and "M", appeared to be linked to the host species, oysters and mussels, respectively. We therefore support the recognition of two species of Marteilia in Europe and propose that the "O" type corresponds to M. refringens and the "M" type to M. maurini.     

A New Procedure for the Calculation of Oxygen Diffusion Resistance in Legume Nodules from Flow-through Gas Analysis Data

Plants of white lupin (Lupinus albus L cv Multolupa) and soyabean(Glycine max L cv Clarke) were grown in controlled-environmentcabinets, subjected to various stresses and their nodular nitrogenaseactivity and total root respiration measured When these measurementswere used to calculate nodular oxygen diffusion resistance,using a simplified equation for Fick's first law of diffusion,it was found that the apparent resistance of stressed nodulesincreased anomalously with decreases in external oxygen concentrationA new analysis procedure is proposed to alleviate this anomalyThis procedure also uses the simplified Fick's law equationbut includes a respiratory contribution to the total oxygenflux across the diffusion barrier which is not coupled to nitrogenaseactivity Also, resistance is modelled as an exponential functionof external oxygen concentration Use of this analysis procedureproduces realistic values for total resistance and providesa characterisation of this resistance into a minimum value andan adjustment factor for changes in external oxygen It is postulatedthat the additional respiration component represents the activityof nodule cortex cells involved in the diffusion barrier, particularlythat of vascular bundles Oxygen diffusion resistance, nodule, nitrogen fixation, respiration     

A review of the fossil record of the Pomacentridae (Teleostei: Labroidei) with a description of a new genus and species from the Eocene of Monte Bolca, Italy

The fossil record of the Pomacentridae has been based on species from six genera. The status of these taxa is reviewed. Only two are tentatively accepted as belonging to the Pomacentridae: Chromis savomini from the Miocene of Algeria and Izuus nakamurai from the Miocene of Japan. In addition, a new genus and species Palaeopomacentrus orphae is described from the lower Middle Eocene of Monte Bolca, Northern Italy. This is the first substantiated record of a pomacentrid from the Eocene, and represents the oldest record of the family.     

Effects of sodium on mineral nutrition in rose plants

The effects of sodium (Na⁺) ion concentration on shoot elongation, uptake of ammonium (NH₄⁺) and nitrate (NO₃^?) and the activities of nitrate reductase (NR) and glutamine synthetase (GS) were studied in rose plants (Rosa hybrida cv. “Lambada”). The results showed that shoot elongation was negatively correlated with sodium concentration, although no external symptoms of toxicity were observed. Nitrate uptake decreased at high sodium levels, specifically at 30 meq litre4 of sodium. As flower development was normal under high saline conditions, this could suggest that nitrogen was being mobilised from shoot and leaf reserves. Ammonium uptake was not affected by any of the salt treatments applied probably because it diffuses through the cell membrane at low concentrations. Nitrate reductase activity was reduced by 50% at 30 meq litre 1 compared with control treatment, probably due to a decrease in the free nitrate related to nitrate uptake pattern. None of the salt treatments used affected total leaf GS activity (both chloroplastic and cytosolic isoforms) or leaf NPK mineral contents. Nitrate reductase activity in leaves increased at 10 meq litre^?1 of sodium and GS activity in roots (cytosolic isoform only) followed the same pattern as NR. It is suggested that the activation of both enzymes at low salt level could be attributed to the beneficial effect of increased sulphur in the nutrient solutions.     

Gagea tisoniana, a new species of Gagea Salisb. sect. Gagea (Liliaceae) from central Italy

Gagea tisoniana Peruzzi et al. sp. nov. is described and its taxonomic relationship is discussed. The new species, which appears to be endemic to central Italy, is close to G. pratensis (Pers.) Dumort., G. pusilla (F. W. Schmidt) Sweet, and other mainly poorly known [i.e. G. succedanea Griseb. et Schenk, G. transversalis Stev., and G. paczoskii (Zapal.) Grossh.] or as yet undescribed taxa from eastern Europe and the eastern Mediterranean area. The recognition of the new taxon G. tisoniana is claimed on the basis of anatomical, karyological, ecological, and phytogeographical data. Maps of the Italian distribution of G. pratensis (2 n  = 60), G. pusilla (2 n  = 24), and G. tisoniana (2 n  = 24) are presented, together with an analytical identification key. Finally, G. pratensis is recorded here for the first time in Tuscany (Monte Cetona).  © 2007 The Linnean Society of London, Botanical Journal of the Linnean Society , 2007, 155 , 337–347.