Novos táxons de Cerambycidae (Coleoptera) das Américas Central e do Sul

Novos táxons descritos: em Cerambycinae, Bomarion caudatum sp. nov., da Bolívia (Ectenessini); Nephalius levigatus sp. nov., do Brasil, Paraíba (Elaphidiini); Bothriospila pulcherrima sp. nov., do Brasil, Bahia (Bothriospilini); Cycnidolon rufescens sp. nov., do Brasil, Paraíba (Neoibidionini). Em Lamiinae: Cicatricallia gen. nov., espécie-tipo: C. cicatricosa sp. nov. de Trindade e Tobago (Calliini); Mimasyngenes clarkei sp. nov., de Trinidad e Tobago e Mimasyngenes fonticulus sp. nov., do Brasil, Piauí; Ibypeba gen. nov., espécie-tipo: I. camiri sp. nov., da Bolívia; Micratelodesmis gen. nov., espécie-tipo: M. minor sp. nov. (Desmiphorini); Lycidola affinis sp. nov. de Trinidad e Tobago (Hemilophini). Novos registros: Lycidola beltii Bates, 1872 para a Costa Rica e Alampyris fuscus Martins & Galileo, 2008 para o Panamá (Hemilophini).

Efecto de la irradiación y el flujo de nutrientes sobre el contenido en polisacáridos ácidos en macroalgas cultivadas

Máster Oficial en Cultivos Marinos. Trabajo presentado como requisito parcial para la obtención del Título de Máster Oficial en Cultivos Marinos, otorgado por la Universidad de Las Palmas de Gran Canaria (ULPGC), el Instituto Canario de Ciencias Marinas (ICCM), y el Centro Internacional de Altos Estudios Agronómicos Mediterráneos de Zaragoza (CIHEAM)

Nanostructuring by templated synthesis of nanowires and controlled crystallization of calcium phosphate on self-assembled monolayers

The idea was to obtain nanowires in a chemical laboratory under convenient and simple conditions by employing templates. Thus it was possible to produce nanochains by interlinking of gold colloids synthesized by the two-phase-method of M. Brust with by making use of vanadiumoxide nanotubes as template. The length of the resulting nanowires is varying between 1100 nm and 200 nm with a diameter of about 16 nm. Due to a flexible linker the obtained nanowires are not completely rigid. These unique structural features could make them interesting objects for structuring and assembling in the nanoscale range. Another way to produce gold nanowires was realized by a two-step surface metallization procedure, using type I collagen fibres as a template. Gold colloids were used to label the collagen fibres by direct electrostatic interaction, followed by growth steps to enhance the size of the adsorbed colloidal gold crystals, resulting in a complete metallization of the template surface. The length of the resulting gold nanowires reaches several micrometers, with a diameter ~ 100 to 120 nm. To gain a deeper insight into the process of biomineralization the cooperative effect of self-assembled monolayers as substrate and a soluble counterpart on the nucleation and crystal growth of calcium phosphate was studied by diffusion techniques with a pH switch as initiator. As soluble component Perlucin and Nacrein were used. Both are proteins originally extracted from marine organisms, the first one from the Abalone shell and the second one from oyster pearls. Both are supposed to facilitate the calcium carbonate formation in vivo. Studies with Perlucin revealed that this protein shows a clear cooperative effect at a very low concentration with a hydrophobic surface promoting the calcium phosphate precipitation resulting in a sponge like structure of hydroxyapatite. The Perlucin molecule is very flexible and is unfolded by adsorbing to the hydrophobic surface and uncovers its active side. Hydrophilic surfaces did not have a deeper impact. Studies with Nacrein as additive have shown that the protein stabilizes octacalcium phosphate at room temperature on carboxylic self-assembled monolayer and at 34 °C on all other employed surfaces by interaction with the mineral. On the hydroxyl-, alkyl-, and amin-terminated self-assembled monolayers at room temperature the octacalcium phosphate get transformed to hydroxyapatite. Main analytical techniques which are used in this work are transmission electron microscopy, high resolution scanning electron microscopy, surface plasmon resonance spectroscopy, atomic force microscopy, Raman micro-spectroscopy and quartz crystal microbalance.

Differentielle Expression und molekulare Evolution von Mollusken-Hämocyanin

Molekularbiologische und biochemische Untersuchungen an den zwei Gastropoden-Arten Haliotis tuberculata und Haliotis asinina zeigten, dass diese jeweils zwei unterscheidbare Hämocyanin-Isoformen (HtH1/HaH1 und HtH2/HaH2) besitzen, die in unterschiedlichen Mengen in der Hämolymphe vorkommen. In situ-Hybridisierungsversuche an H. asinina ergaben, dass die beiden Hämocyanin-Isoformen sowohl entwicklungsspezifisch als auch gewebsspezifisch exprimiert werden. Die Transkription der Hämocyanin-Gene setzt bereits 9 Stunden nach der Befruchtung ein und ist von diesem Zeitpunkt an in allen Stadien der Larvalentwicklung nachweisbar. Während dieser Entwicklungsphase sind die Expressionsmuster der beiden Isoformen weitgehend überlappend, wohingegen in adulten Tieren in verschiedenen Geweben isoformspezifische Expressionsmuster auftreten. Diese Ergebnisse deuten auf funktionelle Unterschiede der beiden Hämocyanin-Isoformen hin, und somit darauf, dass Hämocyanin neben dem Transport von Sauerstoff noch weitere Funktionen ausüben könnte (Streit et al., 2005). Weiterhin wurden Untersuchungen zur Primär- und Sekundärstruktur der Hämocyanine aus H. tuberculata und zwei weiteren Arten (Megathura crenulata und Aplysia californica) durchgeführt. Von den Vetigastropoden M. crenulata und H. tuberculata konnten die für die beiden Hämocyanin-Isoformen kodierenden cDNA-Sequenzen vervollständigt werden. Von HtH1 und HtH2 wurden zudem die Gensequenzen komplettiert. Die Sequenzen des KLH1-Gens wurden bis auf 24 bp der 5’UTR und die für das Signalpeptid 1 kodierenden 33 bp ermittelt. Erstmals ist es gelungen, Promotorsequenzen von Mollusken-Hämocyanin-Genen zu sequenzieren. Für HtH2 wurden 181 bp und für KLH2 906 bp des Promotors analysiert. Beide Gensequenzen weisen das konservierte Sequenzmotiv der TATA-Box auf. Wie bei H. tuberculata treten auch bei M. crenulata die beiden Isoformen in unterschiedlichen Mengenverhältnissen in der Hämolymphe auf. In den bisher analysierten Sequenzen dieser beiden Gastropoden konnten keine regulatorischen Elemente identifiziert werden, welche die differentielle Expression bedingen könnten. Die Genstruktur des Hämocyanins von A. californica konnte ebenfalls aufgeklärt werden. Die kodierenden Bereiche des AcH-Gens werden durch insgesamt 45 interne Introns fragmentiert. Im Gen liegen neun Insertionspositionen vor, in denen paraloge Introns inserieren. Zudem sind neun Introns ortholog zu internen Introns anderer Mollusken-Hämocyanin-Gene. Im Fall der paralogen und orthologen Introns handelt es sich um sehr ursprüngliche Introns, die bereits vor der Radiation der Mollusken inserierten. Damit widerlegen diese Ergebnisse die bisherige Annahme („Intron late”-Hypothese), der zufolge die Insertion interner Introns erst nach der Trennung der Gastropoden und Cephalopoden eingesetzt haben soll. Im Zuge dieser Sequenzanalysen ergaben sich zudem Hinweise auf die Existenz einer weiteren AcH-Isoform, da 13 Fragmente ermittelt wurden, die in den kodierenden Bereichen Sequenzunterschiede von bis zu 20% zu AcH 1 aufweisen. Die detaillierten Studien der Haliotis-Hämocyanine deckten einen weitreichenden phylogenetischen Informationsgehalt der Hämocyanin-Sequenzen auf. In weiterführenden Analysen wurden Teilsequenzen der Hämocyanin-Gene von 12 verschiedenen Haliotis-Arten amplifiziert. Der daraus rekonstruierte Stammbaum liefert entsprechend spezifischer Indels eine deutliche Auftrennung der Haliotidae in eine nordpazifische und eine europäischaustralasische Abstammungslinie. Anhand dieser Analyse lassen sich der phylogeographische Ursprung der Haliotiden aufzeigen (Streit et al., 2006) und deren Wanderungsbewegungen nachvollziehen. Hämocyanin-Daten wurden des Weiteren für phylogenetische Analysen auf höherem taxonomischem Niveau eingesetzt. Innerhalb der Klasse der Polyplacophoren wurden interfamiliäre Verwandtschaftsverhältnisse rekonstruiert. Für diese Analyse wurden Teilsequenzen der Hämocyanin-Gene 17 unterschiedlicher Arten ermittelt. Die phylogenetische Untersuchung zeigt, dass sich die Polyplacophoren eindeutig in die beiden Ordnungen der Lepidopleurida und Chitonida auftrennen, da die Chitonida eine spezifische „Deletion” aufweisen. Anhand dieses Merkmals kann auch Callochiton bouveti, der diese „Deletion” besitzt und dessen phylogenetische Einordnung bisweilen umstritten war, eindeutig den Chitonida zugeordnet werden. Innerhalb der Chitonida bilden sowohl die Chitonina als auch die Acanthochitonina monophyletische Gruppen.

Cryptic invertebrates on subtidal rocky reefs vary with microhabitat structure and protection from fishing

The deployment of flat concrete blocks on subtidal rocky reefs can replicate natural reef microhabitats and provides a means for standardized sampling of cryptic invertebrates. The shape of the cavity beneath the block is related to reef topography and may influence the invertebrate community by affecting the amount of space for cryptic fauna to colonise and influencing the effectiveness of their predator-defence mechanisms. To determine the effect of sub-block reef structure and different levels of external predators on cryptic molluscs and echinoderms, I deployed concrete blocks at locations inside and outside the Maria Island marine reserve in eastern Tasmania, Australia. Relationships between sub-block reef structure and the cryptic invertebrate assemblage were evident between locations, whereas only a small but significant proportion of variation of assemblages between blocks within location was explained by reef surface area. No clear association with external predation pressure was evident in multivariate analyses of variation in assemblage structure. Juvenile abalone Haliotis rubra were not influenced by micro-habitat structure but were significantly less abundant at protected locations, the only species to exhibit such a response. This result follows a decline of emergent adult abalone in the marine reserve and raises the possibility of recruitment failure of abalone at some fully protected locations in the longer term.

Long-term trends in invertebrate–habitat relationships under protected and fished conditions

Few studies examine the long-term effects of changing predator size and abundance on the habitat associations of resident organisms despite that this knowledge is critical to understand the ecosystem effects of fishing. Marine reserves offer the opportunity to determine ecosystem-level effects of manipulated predator densities, while parallel monitoring of adjacent fished areas allows separating these effects from regional-scale change. Relationships between two measures of benthic habitat structure (reef architecture and topographic complexity) and key invertebrate species were followed over 17 years at fished and protected subtidal rocky reefs associated with two southern Australian marine reserves. Two commercially harvested species, the southern rock lobster (Jasus edwardsii) and blacklip abalone (Haliotis rubra) were initially weakly associated with habitat structure across all fished and protected sites. The strength of association with habitat for both species increased markedly at protected sites 2 years after marine reserve declaration, and then gradually weakened over subsequent years. The increasing size of rock lobster within reserves apparently reduced their dependency on reef shelters as refuges from predation. Rising predation by fish and rock lobster in the reserves corresponded with weakening invertebrate–habitat relationships for H. rubra and sea urchins (Heliocidaris erythrogramma). These results emphasise that animal–habitat relationships are not necessarily stable through time and highlight the value of marine reserves as reference sites. Our work shows that fishery closures to enhance populations of commercially important and keystone species should be in areas with a range of habitat features to accommodate shifting ecological requirements with ontogenesis.

Vegetation in the coastal area of East Greenland

This paper deals with the syntaxonomy and ecology of debris, scree and alluvium vegetation of the Ammassalik district, Southeast Greenland, on more or less moist soil. The Oxyria digyna- and Chamaenerion latifoliumvegetation types are classified as Saxifrago-Oxyrietum digynae (Böcher 1933 ap. Nordh. 1943) Gjaerevoll 1950 respectively Chamaenerietum latifolii Böcher 1933 in the class Thlaspietea rotundifolii Br.-BI. ap. Br.-BI. et al. 1947. The chionophytic Saxifrago-Oxyrietum digynae and the Chamaenerietum latifolii occurring on river-banks are classified in the alliance Saxifrago stellaris-Oxyrion digynae Gjaerevoll 1950. This alliance belongs to the order Androsacetalia alpinae Br.-BI. ap. Br.-BI. & Jenny 1926, Thlaspietea rotundifolii Br.-BI. ap. Br.-BI. et al. 1947. The following syntaxa are described as new: Saxifrago-Oxyrietum digynae stellarietosum humifusae and typicum with two variants and one variant of the subassociation inops De Molenaar 1976, and the Chamaenerietum latifolii typicum with two variants and salicetosum herbaceae with three variants.

Effects of ocean acidification caused by rising CO2 on the early development of three mollusks

Increasing atmospheric CO2 can decrease seawater pH and carbonate ions, which may adversely affect the larval survival of calcareous animals. In this study, we simulated future atmospheric CO2 concentrations (800, 1500, 2000 and 3000 ppm) and examined the effects of ocean acidification on the early development of 3 mollusks (the abalones Haliotis diversicolor and H. discus hannai and the oyster Crassostrea angulata). We showed that fertilization rate, hatching rate, larval shell length, trochophore development, veliger survival and metamorphosis all decreased significantly at different pCO2 levels (except oyster hatching). H. discus hannai were more tolerant of high CO2 compared to H. diversicolor. At 2000 ppm CO2, 79.2% of H. discus hannai veliger larvae developed normally, but only 13.3% of H. diversicolor veliger larvae. Tolerance of C. angulata to ocean acidification was greater than the 2 abalone species; 50.5% of its D-larvae developed normally at 3000 ppm CO2. This apparent resistance of C. angulata to ocean acidification may be attributed to their adaptability to estuarine environments. Mechanisms underlying the resistance to ocean acidification of both abalones requires further investigation. Our results suggest that ocean acidification may decrease the yield of these 3 economically important shellfish if increasing CO2 is a future trend.

Seawater carbonate chemistry and hatching rate, malformation rate, metamorphosis rate and shell growth of the Pacific abalone in a laboratory experiment

The hatching process of the Pacific abalone Haliotis discus hannai was prolonged at a pH of 7.6 and pH 7.3, and the embryonic developmental success was reduced. The hatching rate at pH 7.3 was significantly (10.8%) lower than that of the control (pH 8.2). The malformation rates at pH 7.9 and pH 8.2 were less than 20% but were 53.8% and 77.3% at pH 7.6 and pH 7.3, respectively. When newly hatched larvae were incubated for 48 h at pH 7.3, only 2.7% of the larvae settled, while more than 70% of the larvae completed settlement in the other three pH treatments. However, most 24 h old larvae could complete metamorphosis in all four pH treatments. Overall, a 0.3-unit reduction in water pH will produce no negative effect on the early development of the Pacific abalone, but further reduction in pH to the values predicted for seawater by the end of this century will have strong detrimental effects.

Nonsynonymous substitution in abalone sperm fertilization genes exceeds substitution in introns and mitochondrial DNA

Strong positive Darwinian selection acts on two sperm fertilization proteins, lysin and 18-kDa protein, from abalone (Haliotis). To understand the phylogenetic context for this dramatic molecular evolution, we obtained sequences of mitochondrial cytochrome c oxidase subunit I (mtCOI), and genomic sequences of lysin, 18-kDa, and a G protein subunit. Based on mtDNA differentiation, four north Pacific abalone species diverged within the past 2 million years (Myr), and remaining north Pacific species diverged over a period of 4–20 Myr. Between-species nonsynonymous differences in lysin and 18-kDa exons exceed nucleotide differences in introns by 3.5- to 24-fold. Remarkably, in some comparisons nonsynonymous substitutions in lysin and 18-kDa genes exceed synonymous substitutions in mtCOI. Lysin and 18-kDa intron/exon segments were sequenced from multiple red abalone individuals collected over a 1,200-km range. Only two nucleotide changes and two sites of slippage variation were detected in a total of >29,000 nucleotides surveyed. However, polymorphism in mtCOI and a G protein intron was found in this species. This finding suggests that positive selection swept one lysin allele and one 18-kDa allele to fixation. Similarities between mtCOI and lysin gene trees indicate that rapid adaptive evolution of lysin has occurred consistently through the history of the group. Comparisons with mtCOI molecular clock calibrations suggest that nonsynonymous substitutions accumulate 2–50 times faster in lysin and 18-kDa genes than in rapidly evolving mammalian genes.

Structures of two molluscan hemocyanin genes: Significance for gene evolution

We present here the description of genes coding for molluscan hemocyanins. Two distantly related mollusks, Haliotis tuberculata and Octopus dofleini, were studied. The typical architecture of a molluscan hemocyanin subunit, which is a string of seven or eight globular functional units (FUs, designated a to h, about 50 kDa each), is reflected by the gene organization: a series of eight structurally related coding regions in Haliotis, corresponding to FU-a to FU-h, with seven highly variable linker introns of 174 to 3,198 bp length (all in phase 1). In Octopus seven coding regions (FU-a to FU-g) are found, separated by phase 1 introns varying in length from 100 bp to 910 bp. Both genes exhibit typical signal (export) sequences, and in both cases these are interrupted by an additional intron. Each gene also contains an intron between signal peptide and FU-a and in the 3′ untranslated region. Of special relevance for evolutionary considerations are introns interrupting those regions that encode a discrete functional unit. We found that five of the eight FUs in Haliotis each are encoded by a single exon, whereas FU-f, FU-g, and FU-a are encoded by two, three and four exons, respectively. Similarly, in Octopus four of the FUs each correspond to an uninterrupted exon, whereas FU-b, FU-e, and FU-f each contain a single intron. Although the positioning of the introns between FUs is highly conserved in the two mollusks, the introns within FUs show no relationship either in location nor phase. It is proposed that the introns between FUs were generated as the eight-unit polypeptide evolved from a monomeric precursor, and that the internal introns have been added later. A hypothesis for evolution of the ring-like quaternary structure of molluscan hemocyanins is presented.