Y-SNP haplogroups related to the Yqh+ heteromorphism in the Mexican northwestern population

Morphological variation of the Y chromosome has been observed in different populations. This variation is mostly related to the heteromorphic Yq12 band, which is composed of a variable block of constitutive heterochromatin. The Yqh+ heteromorphism has a worldwide frequency of 2.85% and is considered clinically innocuous. The aim of this study was to identify the ancestry of the Yqh+ heteromorphism present in individuals from western Mexico. For this purpose, 17 Y-chromosome single nucleotide polymorphisms were analysed by multiplex polymerase chain reaction and SNaPshot assays. In 28 Yqh+ males, only five haplogroups were observed; with a haplogroup diversity of 0.4841 ± 0.1094, which was less than that observed in a study of unselected Mexican mestizo population. Differences were specifically conferred by the high frequencies of haplogroups R1b1 and P*(xQ,R), and by the absence of the Amerindian haplogroup Q (Q*(xQ1a3a) plus Q1a3a) from the Yqh+ group. This study suggests a post-1492 incorporation for Yqh+ chromosomes into the Mexican northwestern population.     

Phylogenetic patterns of diversification in a clade of Neotropical frogs (Anura: Aromobatidae: Mannophryne)

We used partial sequences of mitochondrial 16S and cytochrome oxidase I genes to perform a phylogenetic study of collared frogs (Anura: Aromobatidae: Mannophryne ), a genus endemic to Venezuela and the islands of Trinidad and Tobago. We analysed 1.2 kb from 13 of the 15 described species of Mannophryne . Maximum parsimony, maximum likelihood and Bayesian analyses support the monophyly of Mannophryne . Mannophryne consists of three deeply differentiated clades that split from each other in a relatively short period of time. The diversification of Mannophryne occurred well before the glacial-interglacial periods of the Quaternary. Our data support the taxonomic validity of M. olmonae , a species endemic to Tobago Island. Mannophryne olmonae is more closely related to the continental species Mannophryne riveroi than to the Trinidad island endemic Mannophryne trinitatis . As in most tropical clades of frogs, molecular evidence indicates that species richness in Mannophryne is largely underestimated and, consequently, current priorities for conservation are inadequate.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 185–199.     

Leaf‐litter colonisation and breakdown in relation to stream typology: insights from Mediterranean low‐order streams

1. Scant information is available on leaf breakdown in streams of arid and semiarid regions, including the Mediterranean, where environmental heterogeneity can be high and the relationship between stream characteristics and leaf breakdown is poorly known. We tested the hypotheses that differences in leaf breakdown metrics would be substantially higher between mountain and lowland Mediterranean streams than among streams within each subregion and that variability among streams would be substantially higher in the lowlands, because permanent reaches in the semiarid lowland streams are rare and isolated. 2. We compared leaf breakdown and associated dynamics of nutrients, fungi and invertebrates in low‐order Mediterranean streams draining sub‐humid forests in the Sierra Nevada Mountains and nearby semiarid lowlands of south‐eastern Spain. Streams differed between the two subregions mainly in water ion content, temperature and riparian tree cover. We detected higher environmental heterogeneity among streams within the lowlands compared to the Sierra Nevada mountain range. In the lowlands, breakdown coefficients (k) of alder leaves spanned almost the entire range reported for this species from temperate streams, overlapping with less variable breakdown coefficients in the Sierra Nevada. 3. The high variability of k values among the lowland sites appeared to be caused primarily by variability in the composition and abundance of a few leaf‐consuming invertebrate taxa, particularly the snail Melanopsis praemorsa. Fungal and nutrient dynamics were less variable among sites within each subregion. 4. These results indicate that the critical condition for stream functional assessment of well‐constrained breakdown rates, or related metrics, could be met at reference sites within homogenous bio‐geo‐climatic regions such as the Sierra Nevada. By contrast, in heterogeneous areas such as the semiarid lowland streams, natural variability of breakdown rates can greatly exceed the magnitude of effects expected in response to anthropogenic disturbances.     

Effect of oceanographic barriers and overfishing on the population genetic structure of the European spiny lobster (Palinurus elephas)

Defining population structure and genetic diversity levels is of the utmost importance for developing efficient conservation strategies. Overfishing has caused mean annual catches of the European spiny lobster (Palinurus elephas) to decrease alarmingly along its distribution area. In this context, there is a need for comprehensive studies aiming to evaluate the genetic health of the exploited populations. The present study is based on a set of ten nuclear markers amplified in 331 individuals from ten different localities covering most of P. elephas distribution area. Samples from Atlantic and Mediterranean basins showed small but significant differences, indicating that P. elephas populations do not behave as a single panmictic unit but form two partially‐overlapping groups. Despite intense overfishing, our dataset did not recover a recent bottleneck signal, and instead showed a large and stable historical effective size. This result could be accounted for by specific life‐history traits (reproduction and longevity) and the limitations of molecular markers in covering recent timescales for nontemporal samples. The findings of the present study emphasize the need to integrate information on effective population sizes and life‐history parameters when evaluating population connectivity levels from genetic data. © 2011 The Linnean Society of London, Biological Journal of the Linnean Society, 2011, 104 , 407–418.     

Karyosystematic study of Potentilla L. subgen. Potentilla (Rosaceae) in the Iberian Peninsula

Chromosome numbers in 80 populations belonging to 18 species of Potentilla L. subgen. Potentilla from the Iberian Peninsula and two of P. maura, a North African endemic taxon, have been counted. The basic number of chromosomes is always x = 7 and these chromosomes are small (between 1 and 2 μm). For three species, the number of chromosomes is reported for the first time and, for another six, this number has been established in Iberian representatives. Moreover, new ploidy levels have been obtained for P. hispanica and P. crantzii with regard to their entire distribution area, and in P. cinerea and P. neumanniana for the Iberian Peninsula. Some taxonomic, phylogenetic and phytogeographic comments are made for several species or groups of species from the West Mediterranean region. In 13 species only one ploidy level has been found, but six species have several ploidy levels. Seven ploidy levels occur in the investigated taxa. The frequency of each ploidy level represented within Iberian Potentilla is analysed and the data are compared with those available for taxa from the rest of the distribution area of the genus.     

Structure and vertical stratification of plant galler–parasitoid food webs in two tropical forests

Abstract 1. Networks of feeding interactions among insect herbivores and natural enemies such as parasitoids, describe the structure of these assemblages and may be critically linked to their dynamics and stability. The present paper describes the first quantitative study of parasitoids associated with gall‐inducing insect assemblages in the tropics, and the first investigation of vertical stratification in quantitative food web structure. 2. Galls and associated parasitoids were sampled in the understorey and canopy of Parque Natural Metropolitano in the Pacific forest, and in the understorey of San Lorenzo Protected Area in the Caribbean forest of Panama. Quantitative host–parasitoid food webs were constructed for each assemblage, including 34 gall maker species, 28 host plants, and 57 parasitoid species. 3. Species richness was higher in the understorey for parasitoids, but higher in the canopy for gall makers. There was an almost complete turnover in gall maker and parasitoid assemblage composition between strata, and the few parasitoid species shared between strata were associated with the same host species. 4. Most parasitoid species were host specific, and the few polyphagous parasitoid species were restricted to the understorey. 5. These results suggest that, in contrast to better‐studied leaf miner–parasitoid assemblages, the influence of apparent competition mediated by shared parasitoids as a structuring factor is likely to be minimal in the understorey and practically absent in the canopy, increasing the potential for coexistence of parasitoid species. 6. High parasitoid beta diversity and high host specificity, particularly in the poorly studied canopy, indicate that tropical forests may be even more species rich in hymenopteran parasitoids than previously suspected.     

Morphology and chaetotaxy of the first instar larvae of six species of the Satyrus (s.l.) series (Lepidoptera: Nymphalidae)

Abstract. The morphology and chaetotaxy of the first instar larvae of six species belonging to the genera Hipparchia, Kanetisa and Chazara are described. Specific characters are stated, drawn mainly from size, setal length and morphology, and the shape of the suranal plate. Several characters, other than chaetotaxy, that are of potential use in nymphalid systematics are discussed. The larval chaetotaxy is briefly compared with that of both heliconiine and danaine first instar larvae.     

The Parvidrilidae – a diversified groundwater family: description of six new species from southern Europe,and clues for its phylogenetic position within Clitellata (Annelida)

The Parvidrilidae Erséus, 1999 constitute the most recently described family of oligochaete microdriles. Prior to this study, Parvidrilus strayeri Erséus, 1999, and Parvidrilus spelaeus Martínez‐Ansemil, Sambugar & Giani, 2002, found in groundwaters of the USA (Alabama) and Europe (Slovenia and Italy), respectively, were the only two species in this family. In this paper, six new species – Parvidrilus camachoi , Parvidrilus gianii , Parvidrilus jugeti , Parvidrilus meyssonnieri , Parvidrilus stochi , and Parvidrilus tomasini – and Parvidrilus gineti (Juget, 1959) comb. nov. are added to the family. With all species being stygobiont, the Parvidrilidae is unique in being the only family of oligochaetes worldwide comprising taxa that are restricted to groundwater habitats. Parvidrilids are exceedingly small worms whose principal morphological characteristics are the presence of hair setae in ventral bundles, the markedly posterior position of setae within the segments, the presence of mid‐dorsal glandular pouches in mesosomial segments, the lateral development of the clitellum, the presence of a single male pore in segment XII, and the presence (or absence) of a single spermatheca. The phylogenetic relationships of the Parvidrilidae within the Clitellata were investigated using the nuclear 18S rRNA gene, and the most representative and taxonomically balanced data set of clitellate families available to date. The data were analysed by parsimony, maximum likelihood, and Bayesian inference. Irrespective of the method used, Parvidrilidae were placed far from Capilloventridae, one family once suggested to be closely related to parvidrilids. Although closer to Enchytraeidae than Phreodrilidae, two other suggested putative sister families, the exact position of Parvidrilidae within Clitellata still remained uncertain in the absence of branch support. The examination of reproductive structures, together with the similarity of other important anatomical traits of the new species herein described, reinforced the idea that phreodrilids were the best candidate to be the sister group to parvidrilids on morphological grounds. A fragment of the mitochondrial cytochrome oxidase I gene, used as a barcode, also genetically characterized a few Parvidrilus species. The observation that two species diverge from each other by high genetic distances, even though their type localities are more or less only 100 km apart, is interpreted in the context of low dispersal abilities of inhabitants of the subterranean aquatic ecosystem, and habitat heterogeneity. The Parvidrilidae appear to be a diversified, Holarctic, and probably widely distributed family in groundwater, but very often overlooked because of the small size and external similarity with the polychaete family Aeolosomatidae of its members. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166 , 530–558.