How did sea spiders recolonize the Chilean fjords after glaciation? DNA barcoding of Pycnogonida,with remarks on phylogeography of Achelia assimilis (Haswell, 1885)

The present paper reports on a first attempt at resolving the taxonomy of Chilean Pycnogonida using a combination of DNA sequence and morphological data. In a subproject of the Marine Barcode of Life (MarBoL) campaign we analysed a fragment (about 657 base pairs) of the mitochondrial protein-coding gene COI (cytochrome c oxidase subunit 1) from 76 Chilean/Subantarctic pycnogonids. Since most molecular data on pycnogonids are from the Antarctic region, the new information constitutes a significant extension. The phylogenetic consensus tree displays 10 distinct, well-supported branches corresponding to the studied species, namely Achelia assimilis (Haswell, 1885), Ammothea spinosa (Hodgson, 1907), Tanystylum cavidorsum Stock, 1957, T. neorhetum Marcus, 1940 Marcus, E. 1940. Os Pantopoda brasileiros e os demais sul-americanos. Boletin da Faculdade de Filosofia, Ciencias e Letras da Universidade de São Paulo, Ser. 4, Zoologie, 19: 1–179.  [Google Scholar], Colossendeis macerrima Wilson, 1881, C. megalonyx Hoek, 1881, C. scoresbii Gordon, 1932 Gordon, I. 1932. Pycnogonida. – Discovery Reports Vol. VI., 1–137. London: Cambridge University Press.  [Google Scholar] , Callipallene margarita (Gordon, 1932 Gordon, I. 1932. Pycnogonida. – Discovery Reports Vol. VI., 1–137. London: Cambridge University Press.  [Google Scholar]), Pallenopsis patagonica (Hoek, 1881), and Anoplodactylus californicus Hall, 1912. These represent four superfamilies, and five of the 11 existing pycnogonid families (Bamber & El Nagar, 2011 Bamber, R. N. and El Nagar, A., eds. 2011. Pycnobase: World Pycnogonida Database http://www.marinespecies.org/pycnobase, accessed June 2012 [Google Scholar]): Ammotheidae Dohrn, 1881, Colossendeidae Hoek, 1881, Callipallenidae Hilton, 1942, Pallenopsidae Fry, 1978 and Phoxichilidiidae Sars, 1891. Within Achelia assimilis, four distinct subbranches correspond to the different geographic regions represented in our samples. While these include a total of 11 distinct haplotypes, the morphological differences among the corresponding specimens lie well within the variation described in the literature for this cosmopolitan species. Therefore, the four branches of A. assimilis might represent geographically limited subspecies rather than cryptic species. Repeated drastic glaciation of the fjord region during the Cenozoic resulting in alternating extinction and recolonization phases and the holobenthic lifecycle of sea spiders are discussed as the main factors resulting in the observed phylogeographic pattern. Standard barcoding sequences are confirmed as a suitable tool in addition to morphology for taxonomic analyses in Pycnogonida. The corresponding haplotype distribution patterns allow inferences on the biogeographical history of the relatively unexplored Chilean fjord region.     

Is Cadlinella ornatissima a chromodorid? Sperm ultrastructure in an enigmatic nudibranch (Opisthobranchia,Mollusca)

Summary

Sperm ultrastructure is described for the nudibranch gastropod Cadlinella ornatissima, type species of the genus Cadlinella (Thiele). Although C. ornatissima exhibits most of the sperm features characteristic of other Opisthobranchia and the Pulmonata (a small, rounded acrosomal vesicle, a complex, helical, mitochondrial derivative—partially paracrystalline, coarse fibres associated with the axoneme), it also possesses a number of previously undescribed and possibly unique features (a longitudinally inrolled acrosomal pedestal, an axial structure within the cavity of the acrosomal pedestal, an electron-dense collar at the anterior region of the acrosomal pedestal, the presence of crystalloid bodies within the glycogen helices of the mitochondrial derivative). To our knowledge this is the first report of crystalloid bodies in mature sperm of any mollusc. Collectively this evidence raises questions concerning the affinities and systematic position of Cadlinella within the Nudibranchia. The peculiar nature of the sperm differences, in comparison with other investigated nudibranchs, suggest that Cadlinella is not easily linked to either the Cadlinidae or Chromodorididae, and should be considered incertae sedis.     

Reproductive strategy of a small endemic cyprinid, the Yarqon bleak (Acanthobrama telavivensis), in a mediterranean-type stream

A mediterranean-type climate exists in five widely separated regions; the Mediterranean basin, parts of western North America, parts of western and southern Australia, southwestern South Africa and parts of central Chile. Streams in these regions feature seasonal disturbances of contrasting hydrology with high predictability of the timing of flooding and drying but low constancy. We would expect fish living in these streams to avoid scouring flow and breed after cessation of the flood period. The aim of the present study was to examine the adaptation of the Yarqon bleak, Acanthobrama telavivensis, an endemic cyprinid in the coastal streams of Israel, to mediterranean-type stream (mediterranean—written with a small m, is used in connection with climate or ecological region and is distinguished from Mediterranean that is used in a geographical context, referring to the Mediterranean basin.) conditions. For that we studied its reproductive strategy (age at maturity and life span, gonad activity, oocyte maturation, spawning activity and habitats, appearance of juveniles), in a major costal stream (Yarqon). Our findings show that the Yarqon bleak exhibits life history traits attuned with a mediterranean-climate hydrologic regime. It breeds in late winter and early spring, a window of opportunity between flash floods and habitat desiccation. Being a multiple spawner allows the fish to compensate for the potential loss of part of its reproductive output due to scouring flows of late floods. The ability of the Yarqon bleak to spawn on different substrate-types enables it to take advantage of different stream conditions that pertain in different years. The fish attains pre-adult size (ca. 33–42 mm) within the first year, prior to drying out of most stream reaches, and matures by the beginning of the second year (males >41; females >42 mm). The cost of these tactics is a short life span (4–5 age groups). The reproductive strategy of the Yarqon bleak falls into the category of in-channel breeding but, unlike the case suggested by a low flow recruitment model, the fish breed during the period of flood cessation, a transitional time between high and low flows, rather than at the time of low flow. Breeding at this time of the year in mediterranean-type streams puts early stages somewhat at risk of being washed away by late floods, but gains them a longer period of growth under favorable conditions. We suggest an additional positive tradeoff that should be investigated: the reduced competition with age 0 of other fish that breed later in the season. This suggested model of recruitment during the period of flood cessation seems appropriate for fish in streams with seasonal contrasting flows of high predictability but low constancy.     

Azathioprine, a clastogen in human somatic cells? Analysis of chromosome damage and SCE in lymphocytes after exposure in vivo and in vitro

Chromosomal analyses in lymphocytes of 28 patients with multiple sclerosis were carried out before, during and after Azathioprine (Aza) therapy. Only a higher incidence of gaps was found in treated patients than in a group of healthy persons but not in comparison with untreated patients. Similarly, no significant clastogenic effect was observed in vitro after short-term and long-term treatment of unstimulated and stimulated lymphocytes with concentrations of 1--100 microgram Aza per ml. Treatment of cultures with 0.0001--4.0 microgram/ml did not yield increased SCE frequencies. The absence of any significant clastogenic effect of therapeutic doses of Aza on human somatic cells is deduced from an evaluation of previously published data and from the present results.     

Azathioprine,a clastogen in human somatic cells? Analysis of chromosome damage and SCE in lymphocytes after exposure in vivo and in vitro

Chromosomal analyses in lymphocytes of 28 patients with multiple sclerosis were carried out before, during and after Azathioprine (Aza) therapy. Only a higher incidence of gaps was found in treated patients than in a group of healthy persons but not in comparison with untreated patients. Similarly, no significant clastogenic effect was observed in vitro after short-term and long-term treatment of unstimulated and stimulated lymphocytes with concentrations of 1–100 μg Aza per ml. Treatment of cultures with 0.0001–4.0 μg/ml did not yield increased SCE frequencies. The absence of any significant clastogenic effect of therapeutic doses of Aza on human somatic cells is deduced from an evaluation of previously published data and from the present results.     

Can macroalgae recover, 13 months after the 2004 Tsunami?: a case study at Talibong Island, Trang Province, Thailand

The tsunami that hit the coast of Thailand along the Andaman Sea on 26 December 2004 caused great damage to human life, property and coastal resources. Here we report the effect of the tsunami on the seaweed community, and its recovery, at Talibong Island, one of the affected areas in Trang province. We made surveys at three sites around the island from April 2004 to January 2006. Fifteen 0.5 m × 0.5 m permanent plots were set up on the west coast of the island to monitor changes in the seaweed community. Eighteen species were found. Sargassum stolonifolium and Laurencia composita were the most abundant, covering 90% and 39%, respectively, of the rocky substrate. Thirteen species varied among sites and seasons. Eleven species, however, were strongly affected by the tsunami. L. composita and Padina sanctae-crucis, for example, were initially washed up onto the shore by the strong wave action, which clearly resulted in a decrease in percentage cover. Also, many permanent plots were covered by sediment causing anoxic conditions, an indirect impact of the tsunami. A difference in species composition revealed a change in overall diversity. Particular morphologies and life forms were more sensitive to the extremes of the tsunami than others. Therefore, the recovery ability of populations of the affected species varied. We did not find any seasonal pattern to the recovery of seaweed after the tsunami within the 13 months of this study.     

Analysis of airborne pollen in the town of Almería (South-East Spain), 1995–1996

The first results are presented of an aerobiological analysis of the atmosphere of the town of Almería, carried out between November 1995 and October 1996. A Lanzoni volumetric spore trap was used for sample collection. The composition and seasonal evolution of the pollen spectrum were determined over a 1-year period in relation to the vegetation and climatic conditions of the study area. Twenty-six pollen types were identified as accounting for >0.05% of the total pollen collected. The main sources of airborne pollen were Palmae (17.76%),Olea (16.10%), Chenopodiaceae/Amaranthaceae (13.99%), Urticaceae (10.18%) and Poaceae (8.64%). The annual pollen variation presented a period of maximum emission from March to June, with a subsequent, less intensive period from August to November. The minimum pollen values were obtained from December to February. The highest concentrations occurred in May, which was also the month which presented the highest pollen diversity, whereas the lowest values were observed in January.     

Two new species of Lecithoceridae (Lepidoptera,Gelechioidea), with a revised check list of the?family?in?Taiwan

Two species of Lecithoceridae (Lepidoptera, Gelechioidea), Caveana senuri sp. n. and Lecithocera dondavisi sp. n., are described from Taiwan. The monotypic Caveana Park was described from Thailand, based on Caveana diemseoki Park, 2011. Lecithocera Herrich-Schäffer, 1853 is the most diverse genus of the family, comprising more than 300 species worldwide. Lecithocera dondavisi sp. n. is the largest species of the genus so far, and closely resembles the Indian species, Lecithocera praeses Meyrick, 1919. A revised check list of the family in Taiwan is provided.     

What Are the Proteolytic Enzymes of Honey and What They Do Tell Us? A Fingerprint Analysis by 2-D Zymography of Unifloral Honeys

Honey is a sweet and healthy food produced by honeybees (Apis mellifera L.) from flower nectars. Using bidimensional zymography, we have detected the, until now unrevealed, proteolytic activities present in row honey samples. The resulting zymograms were specific for each type of the four unifloral honey under study, and enzymes were identified as serine proteases by the use of specific inhibitors. Further, using bidimensional electrophoresis, we have shown that honey proteases are able to degrade the major Royal Jelly proteins and in particular MRPJ-1, the protein that promotes queen differentiation in honeybees. Our findings open new perspectives for the better understanding of honeybee development, social behaviour and role in honey production. The now discovered honey proteases may influence honey properties and quality, and bidimensional zymograms might be useful to distinguish between different honey types, establish their age and floral origin, and allow honey certification.     

Mollusc/algal chloroplast symbiosis: how can isolated chloroplasts continue to function for months in the cytosol of a sea slug in the absence of an algal nucleus?

A marine sea slug, Elysia chlorotica, has acquired the ability to carry out photosynthesis as a result of forming an intracellular symbiotic association with chloroplasts of the chromophytic alga, Vaucheria litorea. The symbiont chloroplasts (kleptoplasts) are functional, i.e. they evolve oxygen and fix CO₂ and actively transcribe and translate proteins for several months in the sea slug cytosol. Considering the dependency of plastid function on nuclear genes, the level of kleptoplast activity observed in the animal cell is quite remarkable. Possible factors contributing to this long-lasting functional association that are considered here include: the presence of an algal nuclear genome in the sea slug, autonomous chloroplasts, unusual chloroplast/protein stability, re-directing of animal proteins to the kleptoplast, and lateral gene transfer. Based on our current understanding, the acquisition and incorporation of intact algal plastids by E. chlorotica is aided by the robustness of the plastids and the long-term functional activity of the kleptoplasts appears to be supported by both plastid and protein stability and contributions from the sea slug.     

Philosophy, Instinct, Intuition: What Motivates the Scientist in Search of a Theory?

This article questions whether philosophical considerations play any substantial role in the actual process of scientific research. Using examples mostly from the nineteenth century, it suggests that scientists generally choose their basic theoretical orientation, and their research strategies, on the basis of non-rationalized feelings which might be described as instinct or intuition. In one case where methodological principles were the driving force (Charles Lyell's uniformitarian geology), the effect was counterproductive.     

Why be a rewarding trap? The evolution of floral rewards in Arum (Araceae), a genus characterized by saprophilous pollination systems

Plant species of the genus Arum typically have lure-and-trap pollination systems that are saprophilous (i.e. attracting flies or beetles searching for breeding sites in decaying organic matter). They have been assumed to always attract and trap their pollinators by deception because the inflorescences provide unsuitable breeding grounds for pollinators. The present study explored the possibility that one species, Arum creticum Boiss. & Heldr., which has yellow, sweet-smelling inflorescences, rewards its pollinators and that this increases its success in attracting pollinators over its close relative, Arum idaeum Coust. & Gadoger. The relationship between rewards provided, floral structure, insect attraction, and pollen import and export was examined in two naturally occurring sympatric populations of A. creticum , A. idaeum , and their natural hybrids. The results showed that plants providing more pollen were visited by larger numbers of females of a mining bee Lasioglossum marginatum Brullé as well as adults and nymphs of a hemipteran bug Dionconotus cruentatus creticus Heiss. In A. creticum , L. marginatum was found to be a better outcrossing vector than D. cruentatus in areas where both pollinators occurred because L. marginatum individuals carried more pollen on their bodies and travelled greater distances between inflorescences, thus increasing the potential for outcrossing. The finding that floral rewards may result in increased fitness, compared to nonrewarding systems that rely on attracting saprophilic pollinators, suggests that it is possible for rewarding species to evolve from saprophilous systems.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 88 , 257–268.     

Vertical zonation of megabenthic taxa on a deep photosynthetic reef (50–140 m) in the Au’au Channel,Hawaii

This study surveyed several locations at depths between 50 and 140 m within the Au’au Channel, Hawaii to characterize the deep reef habitat and determine the depth distribution and relative abundance of the dominant, habitat forming megabenthic taxa. In the Au’au Channel, the depth distribution of megabenthic taxa exhibited a pattern of vertical zonation with relatively few taxa dominating each zone. Macroalgae particularly Halimeda spp. and to a lesser extent scleractinian corals Leptoseris spp. were dominant between 50 and 80 m; Leptoseris spp. were dominant between 80 and 90 m as macroalgae decreased in abundance; the invasive octocoral Carijoa riisei was dominant between 90 and 100 m primarily on rugose features; Antipathes spp. and Leptoseris spp. were dominant between 100 and 120 m on exposed fossil reef; and small wire corals were dominant between 120 and 140 m. In general, the percentage of live benthic cover decreased with depth, particularly below 90 m where a large majority of the area was uncolonized, soft substrata. The gradient of downwelling light intensity appears to play a major role in regulating the depth distribution of photosynthetic organisms, skilophilous organisms, and other benthic fauna, which compete for space with dominant photosynthetic species. The depth of the seasonal thermocline also appears to play an important role in limiting the distribution of tropical benthic species.     

Community structure and photosynthetic activity of epilithon from a highly acidic (pH≤2) mountain stream in Patagonia,Argentina

We explored a benthic community living on stones in an acidic (pH2) stream of active volcanic origin from Patagonia, Argentina, by combining in situ measurements (temperature, pH, conductivity, dissolved oxygen), photosynthesis of intact biofilms (measured with microsensors by the light–dark shift method), pure-culture experiments on isolated algae, and confocal laser scanning microscopy on the biofilms. The epilithon of the Agrio River was dominated (99% of total biomass) by one species: Gloeochrysis (Chrysophyceae). This species was observed as brown, mucilaginous, 200-m-thick films on stones, growing in clumps in a dense matrix of fungal hyphae, bacteria, and inorganic particles held together by extracellular polymeric substances. Gloeochrysis was isolated and cultivated. The photosynthetic rate measured at saturation irradiance was 120 mol oxygen (mg chlorophyll a)^–1h^–1 under laboratory conditions, and the saturation rate of photosynthesis by carbon dioxide was 90 mol oxygen (mg chlorophyll a)^–1 h^–1 for oxygen evolution. Photosynthetic activity of the biofilm was light-dependent and saturated above 200 mol photons m^–2 s^–1. In the dark, the stone surface became anoxic. Our data suggest that primary production in the Agrio River was not limited by light, carbon, or phosphorus but instead, nitrogen-limited.     

Does down‐regulation of photosynthetic capacity by elevated CO2 depend on N supply in Dactylis glomerata?

Dactylis glomerata was grown hydroponically in a controlled environment at ambient (360 μl l⁻¹) or elevated (680 μl l⁻¹) CO₂ and four concentrations of nitrogen (0.15, 0.6, 1.5 and 6.0 m M NO₃⁻), to test the hypothesis that reduction of photosynthetic capacity at elevated [CO₂] is dependent on N availability and mediated by a build-up of non-structural carbohydrates. Photosynthetic capacity of the youngest fully expanded leaf (leaf 5, 2 days after full expansion) was reduced in CO₂-enriched plants at low, but not high N supply and so the stimulation of net photosynthesis by CO₂ enhancement was less at low than at high N supply. CO₂ enrichment resulted in a decrease in ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) content on a leaf area basis at 0.6 and 1.5 m M NO₃⁻, but not at 0.15 and 6.0 m M NO₃⁻, and had no effect on the total N content of the leaf on an area basis. However, decreases in Rubisco content could be primarily accounted for by a decrease in total N content of leaves, independent of [CO₂]. A doubling of the Rubisco content by increasing the N supply beyond 0.6 m M had only a marginal effect on the maximum carboxylation velocity in vivo, suggesting that the fraction of inactive Rubisco increased with increasing N supply. Although CO₂-enriched plants accumulated more non-structural carbohydrates in the leaf, the reduction of photosynthetic capacity at low N supply was not mediated simply by a build-up of carbohydrates. In D . glomerata , the photosynthetic capacity was mainly determined by the total N content of the leaf.     

Archaeobotanical remains found in a house at the archaeological site of Cardonal,valle del Cajón,Argentina: a view of food practices 1,800 years ago

This paper explores food and daily activities in domestic areas at the archaeological site of Cardonal, Provincia de Catamarca, Argentina. It is based on archaeobotanical carpological macro remains recovered by flotation techniques in a residential compound. A set of five taxa including wild plants such as Geoffroea decorticans (chañar), Phaseolus vulgaris var. aborigineus (wild bean), Prosopis sp. (algarrobo) and the crops P. vulgaris var. vulgaris (domesticated bean) and Zea mays (maize) were identified. These well-known staples of ancient communities in this area suggest that the Cardonal people combined agriculture with foraging practices, taking advantage of a diversified environment and extensive social networks. The most abundant plant food remains were bean cotyledons and maize cupules, which were densely concentrated in the “kitchen”, near the hearth. Conversely, chañar endocarps, algarrobo seeds and also Chenopodium sp. seeds were almost exclusively confined to the “patio”, in the hearth area. As a result, two distinct food-related activity areas could be identified, defined by the relative density of plant remains, occurrence of plant taxa and the different practices of processing and consumption which they evoke.     

Streptanthus bracteatus (Brassicaceae), a rare annual woodland forb, thrives in less cover: evidence of a vanished habitat?

One of the challenges of understanding habitat requirements of endangered species is that the remaining populations may not be in optimal habitat, requiring experimentation to determine optimal habitat and to guide management. A better knowledge of its habitat requirements is important for the conservation of Streptanthus bracteatus, a rare annual of central Texas woodlands. The habitat requirements of a rare, declining species like S. bracteatus can also provide insights into anthropogenic habitat degradation and into previous disturbance regimes. We conducted a garden experiment and a transplant experiment to determine the effect of different light environments on the growth and reproduction of S. bracteatus. Higher levels of light improved S. bracteatus performance, especially fecundity. The optimum level of combined canopy and understory cover at the height of a S. bracteatus plant (??0.5?m above ground) was less than 50?%. The remaining populations of S. bracteatus are in sub-optimal habitat because it is not open enough. The results are consistent with the hypothesis that this species was a ??fire-follower.?? The results also support the hypotheses that central Texas woodlands were once more open and that fire played an ecological role in these woodlands, an example of the ecological requirements of a rare species revealing past community structure and dynamics.     

DNA barcoding of African fruit bats (Mammalia, Pteropodidae). The mitochondrial genome does not provide a reliable discrimination between Epomophorus gambianus and Micropteropus pusillus

Sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene have been shown to be useful for species identification in various groups of animals. However, the DNA barcoding approach has never been tested on African fruit bats of the family Pteropodidae (Mammalia, Chiroptera). In this study, the COI gene was sequenced from 120 bats collected in the Central African Republic and belonging to either Epomophorus?gambianus or Micropteropus?pusillus, two species easily diagnosed on the basis of morphological characters, such as body size, skull shape and palatal ridges. Two additional molecular markers were used for comparisons: the complete mitochondrial cytochrome b gene and the intron 7 of the nuclear β-fibrinogen (FGB) gene. Our results reveal an unexpected discordance between mitochondrial and nuclear genes. The nuclear FGB signal agrees with our morphological identifications, as the three alleles detected for E.?gambianus are divergent from the fourteen alleles found for M.?pusillus. By contrast, this taxonomic distinction is not recovered with the analyses of mitochondrial genes, which support rather a polyphyletic pattern for both species. The conflict between molecular markers is explained by multiple mtDNA introgression events from M.?pusillus into E.?gambianus or, alternatively, by incomplete lineage sorting of mtDNA haplotypes associated with positive selection on FGB alleles of M.?pusillus. Our work shows the failure of DNA barcoding to discriminate between two morphologically distinct fruit bat species and highlights the importance of using both mitochondrial and nuclear markers for taxonomic identification.