The genetic basis of early‐life morphological traits and their relation to alternative male reproductive tactics in Atlantic salmon

Although heritability estimates for traits potentially under natural selection are increasingly being reported, their estimation remains a challenge if we are to understand the patterns of adaptive phenotypic change in nature. Given the potentially important role of selection on the early life phenotype, and thereby on future life history events in many fish species, we conducted a common garden experiment, using the Atlantic salmon (Salmo salar L.), with two major aims. The first objective is to determine how the site of origin, the paternal sexual tactic and additive genetic effects influence phenotypic variation of several morphological traits at hatching and emergence. The second aim is to test whether a link exists between phenotypic characteristics early in life and the incidence of male alternative tactics later in life. We found no evidence of a site or paternal effect on any morphological trait at hatching or emergence, suggesting that the spatial phenotypic differences observed in the natural river system from which these fish originated are mainly environmentally driven. However, we do find significant heritabilities and maternal effects for several traits, including body size. No direct evidence was found correlating the incidence of precocious maturation with early life characteristics. We suggest that under good growing conditions, body size and other traits at early developmental stages are not reliable cues for the surpassing of the threshold values associated with male sexual development.     

Pollen morphology of the tribes Eritrichieae and Cynoglosseae (Boraginaceae) in the Iberian Peninsula and its taxonomic significance

DÍEZ, M. J. & VALDÉS, B., 1991. Pollen morphology of the tribes Eritrichieae and Cynoglosseae (Boraginaceae) in the Iberian Peninsula and its taxonomic significance.
The pollen morphology of 33 species of Boraginaceae from the Iberian Peninsula belonging to the tribes Eritrichieae and Cynoglosseae has been studied by light and scanning electron microscopy. The results confirm the eurypalinous character of this family, in which a large number of species can be recognized by their pollen characters.
The pollen of these two tribes is basically heterocolpate, a type which is very uncommon in the angiosperms, with 6, 8 or 10 apertures, sometimes with ectoapertures anastomosed at the equator (ectocingulum), or diorate, minute or small in size, outline elliptic or rectangular-elliptic in equatorial view, with or without a constriction at the equator, exine 0.5-1.0 urn thick and the tectum psilate with granules around the colpi. The similarity in shape and apertural system found in several genera such as Asperugo, Gyrocarion and Omphalodes, and some species of Myosotis, does not permit the two tribes to be distinguished on pollen characters. The generic limits of Cynoglossum and the infrageneric classification of Myosotis are discussed.     

A new species of Festuca L.from Spain

A new species of Festuca (Festuca rivas-martinezii de la Fuente & Ortúñez) is described from the Sierra de Ayllón, Sierra de Guadarrama, Sierra de Gredos and associated chains (northcentral Spain: provinces of Avila, Guadalajara, Madrid and Segovia. Some morphological, anatomical and cytological characters of the taxon are presented.     

Patterns and causes of morphological population differentiation in the Tenerife skink, Chalcides viridanus

Recent studies indicate that differential selection between mesic and xeric habitats is the most plausible explanation of within-island geographic variation in the Gran Ganarian skink, Chalcides sexlineatus. The island of Tenerife shows mesic/xeric heterogeneity similar to that on Gran Canaria, so we tested the prediction of parallel geographic patterns of morphological population differentiation in the Tenerife skink, Chalcides viridanus. Geographic variation was found to be complex; patterns of differentiation in body dimensions and scalation show evidence of both mosaic and latitudinal facets. Using randomization and regression methods, significant relationships were found between a hypothesized xeric/mesic model of population differentiation and geographic variation in female body dimensions, as well as with substantial proportions of the geographic variation in male and female scalation and, to a lesser extent, body dimensions. Matrix comparisons based on the entire morphological distance matrices show that the patterns of variation are not concordant with an alternative hypothesis of historical secondary contact, or with an isolation-by-distance model. It is argued that a substantial component of the geographic variation in body dimensions and scalation of C. viridanus is due to differential selection along an aridity gradient.     

Morphometric correlates of karyotype and host plant in genus Euceraphis (Hemiptera: Aphididae)

Abstract Samples of birch- and alder-feeding aphids of genus Euceraphis were measured and analysed using multiple discriminant analysis (canonical variates) to find out if morphological variation correlated with previously reported differences of karyotype and host association. The dataset comprised groups of specimens defined solely by locality and collection date. Mean scores on the first two canonical variates clustered the samples fully in accordance with their karyotypes and host plants, confirming the existence of a number of morphologically similar but distinct host-specific taxa within the E. betulae group. Three new species are described: Euceraphis borealis Blackman, sp.n. on Betula glandulosa and B. nana , Euceraphis papyrifericola Blackman, sp.n. on B. papyrifera , and Euceraphis quednaui Blackman, sp.n. on B. occidentalis . A key is provided to alate viviparae of the genus.     

The regional variation of aboveground live biomass in old-growth Amazonian forests

The biomass of tropical forests plays an important role in the global carbon cycle, both as a dynamic reservoir of carbon, and as a source of carbon dioxide to the atmosphere in areas undergoing deforestation. However, the absolute magnitude and environmental determinants of tropical forest biomass are still poorly understood. Here, we present a new synthesis and interpolation of the basal area and aboveground live biomass of old‐growth lowland tropical forests across South America, based on data from 227 forest plots, many previously unpublished. Forest biomass was analyzed in terms of two uncorrelated factors: basal area and mean wood density. Basal area is strongly affected by local landscape factors, but is relatively invariant at regional scale in moist tropical forests, and declines significantly at the dry periphery of the forest zone. Mean wood density is inversely correlated with forest dynamics, being lower in the dynamic forests of western Amazonia and high in the slow‐growing forests of eastern Amazonia. The combination of these two factors results in biomass being highest in the moderately seasonal, slow growing forests of central Amazonia and the Guyanas (up to 350 Mg dry weight ha^?1) and declining to 200–250 Mg dry weight ha^?1 at the western, southern and eastern margins. Overall, we estimate the total aboveground live biomass of intact Amazonian rainforests (area 5.76 × 10⁶ km² in 2000) to be 93±23 Pg C, taking into account lianas and small trees. Including dead biomass and belowground biomass would increase this value by approximately 10% and 21%, respectively, but the spatial variation of these additional terms still needs to be quantified.     

Hypoderma actaeon: an emerging myiasis in roe deer (Capreolus capreolus)

Subcutaneous larvae of Hypoderma spp. (Diptera: Oestridae) were detected in the dorsal region in 10 roe deer, Capreolus capreolus (Artiodactyla: Cervidae), hunted in central Spain between January and March 2016. All larvae were found in the inner side of the hide during the skinning of the animals. The study of the morphological features of eight larvae of different stages collected from two animals allowed the identification of Hypoderma actaeon Brauer. The small size (4–5 mm) of some of the first instars suggests that the internal lifecycle of H. actaeon may be exclusively subcutaneous. This is the first confirmation of H. actaeon in roe deer; however, further studies to assess the spread of the parasite and to follow the evolution of this myiasis in roe deer are needed.     

Biogeographical analysis of two Polypodium species complexes (Polypodiaceae) in Mexico and Central America

We analyzed the geographical and elevational distributions of two Polypodium complexes from Mexico and Central America. Distribution data of nine species of the Polypodium colpodes complex and the Polypodium plesiosorum complex were obtained from almost 1500 herbarium specimens, field collections in Mexico and Costa Rica, and literature studies. The presence of each species was recorded for each Mesoamerican country, in 1° × 1° grid‐cells and biogeographical provinces. The rarity of species was also evaluated. Although the two complexes show extensive overlap, the P. colpodes complex is distributed mainly along the Pacific versant of Mexico and Central America, whereas the P. plesiosorum complex occurs mainly along the Atlantic versant. Those biogeographical provinces with maximum species diversity are Chiapas (seven species), Sierra Madre del Sur (six species), and the Trans‐Mexican Volcanic belt (six species). Grid‐cells with more species are located mainly in the mountains of central‐southern Mexico and northern Central America. Richness does not decrease or increase with latitude. Elevation distributions showed that most Polypodium species are concentrated in the montane interval and three species groups were recognized based on elevational preferences. Polypodium colpodes and P. plesiosorum are the most widely distributed species, whereas Polypodium castaneum and Polypodium flagellare are the only two species that possess the three attributes of rarity (narrow geographical distribution, high habitat specificity, and scarce local populations). Polypodium species of both complexes are present mainly in the montane regions of the study area and show some degree of geographical sympatry, especially in southern Mexico and northern Central America. This overlapping is explained by the elevation tolerance within montane systems and because most species inhabit three or more vegetation types. The distributional patterns of these complexes coincided with the three regional highlands of Mesoamerica, which are separated from each other by the Isthmus of Tehuantepec and by the lowlands of Nicaragua. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.     

Does interference competition explain why White Terns of Aride Island,Seychelles, breed predominantly when marine productivity is lower?

White Terns Gygis alba breed throughout the year on Aride Island but show a marked preference to nest during the northwest monsoon (November–March), when interspecific competition and also marine productivity are considered to be lower. In this study we investigated and compared breeding and foraging parameters of White Terns between the northwest and southeast (May–September) monsoons to assess whether interspecific competition affected foraging activity and explained the timing of breeding of White Terns. Goatfish (Mullidae) dominated the diet of White Terns and no significant differences were found in diet composition between the northwest and southeast monsoons. Similar diets and patterns of food provisioning of White Terns between the two monsoons do not support the hypothesis of strong exploitation competition during the southeast monsoon. On the other hand, foraging behaviour and frequency of capture attempts of White Terns differed between the two monsoons. The percentages of multi‐species flocks with White Terns and of large flocks with more than 25 noddies Anous and terns Onychoprion were significantly higher during the southeast monsoon. Moreover, capture attempt frequencies of White Terns foraging in multi‐species flocks were lower than those of solitary individuals, and both solitary and flocking White Terns had significantly lower capture attempt frequencies during the southeast monsoon in comparison with the northwest monsoon. These results suggest that interference competition depresses foraging activity of flock‐foraging White Terns, particularly during the southeast monsoon, which could potentially explain why White Terns breed preferentially during the northwest monsoon. However, and despite avoiding interference competition, White Terns nesting during the northwest monsoon did not show higher breeding success than those nesting during the southeast monsoon. Other hypotheses that might explain the preference of White Terns for breeding during the northwest monsoon, such as avoidance of agonistic interactions with Lesser Noddies Anous tenuirostris at nest sites, should also be investigated.     

Mobility and Persistence of Petroleum Hydrocarbons in Peat Soils of Southeastern Mexico

Spilled crude petroleum from oil wells contains numerous hydrocarbons, some of which are toxic and threaten life. We have studied the mobility and persistence of hydrocarbons in waterlogged soils that contain large proportions of fermented organic matter (Histosols) and large concentrations of dissolved organic carbon (DOC) in the State of Tabasco, Mexico. We sampled soil and phreatic water at sites polluted by oil spills for several decades, as well as at sites that had only recently (few weeks) been polluted, and compared their hydrocarbon contents with those of unaffected sites in the same area. Samples were analyzed for 16 non-alkylated polyaromatic hydrocarbons (PAHs) and n-alkanes from nC9 to nC34. The spilled hydrocarbons had remained predominantly in the organic surface horizons of the soil where spillage occurred; there was little evidence of movement within the soil. The fraction of low molecular weight compounds was larger at sites of recent spills than where spills happened several decades ago. Nevertheless, sites of old spills still contained large concentrations of hydrocarbons, among which those of low molecular weight represented from 30 to 49% of total PAHs and from 50 to 84% of total n-alkanes, indicating that volatilization or microbial degradation is slow in these soils. In the peat horizons the measured organic carbon partition coefficients (K _oc ) for the higher molecular weight PAHs were consistently smaller than those estimated by empirical equations by up to two orders of magnitude. The dissolved organic carbon of these peat soils seems to influence this behavior. At sites of old spills, partition coefficients for the PAHs were larger than at sites of recent spills.