Search results for "Cnidaria"
showing 10 items of 74 documents
Ocean acidification at a coastal CO2 vent induces expression of stress-related transcripts and transposable elements in the sea anemone Anemonia viri…
2019
Published version, available at: https://doi.org/10.1371/journal.pone.0210358 Ocean acidification threatens to disrupt interactions between organisms throughout marine ecosystems. The diversity of reef-building organisms decreases as seawater CO2 increases along natural gradients, yet soft-bodied animals, such as sea anemones, are often resilient. We sequenced the polyA-enriched transcriptome of adult sea anemone Anemonia viridis and its dinoflagellate symbiont sampled along a natural CO2 gradient in Italy to assess stress levels in these organisms. We found that about 1.4% of the anemone transcripts, but only ~0.5% of the Symbiodinium sp. transcripts were differentially expressed. Processe…
An integrative identification guide to the Hydrozoa (Cnidaria) of Bocas del Toro, Panama
2018
This work is the first attempt to assess the biodiversity of the Hydrozoa in the Archipiélago de Bocas del Toro (Panamá, Caribbean Sea) using morphology and molecular taxonomy, and to produce field identification tools to help future identification and monitoring efforts in the area. We sampled, identified, vouchered, and barcoded 112 specimens of Hydrozoa from shallow coastal waters (0–22 m depth) in the Archipiélago de Bocas del Toro. The specimens belong to 70 taxa, of which 53 were identified at the species level, and 17 were identified at the genus or family level. We produced 64 sequences of the large ribosomal subunit of the mitochondrial RNA (mt lsu-rRNA, 16S), the genetic marker ge…
Seasonal changes in morpho-functional aspects of two Anemonia sulcata (Pennant, 1777) wild populations
2017
Marine benthic organisms can be used as indicators of the quality of environmental status and as monitoring tools to detect natural or anthropogenic perturbations. In temperate waters, metabolic and biochemical responses may be governed by physiological changes driven by seasonal factors. Gathering baseline information on the mechanisms underlying seasonal acclimation patterns is therefore a critical step towards the understanding of the physiological responses of biological indicators. In poikilothermic metazoans, the production of regulatory metabolic enzymes can be used as tools for deciphering the acclimation potential. The aim of this study was to characterize the natural seasonal vari…
Towards a phylogenetic classification of Leptothecata (Cnidaria, Hydrozoa)
2016
AbstractLeptothecata are hydrozoans whose hydranths are covered by perisarc and gonophores and whose medusae bear gonads on their radial canals. They develop complex polypoid colonies and exhibit considerable morphological variation among species with respect to growth, defensive structures and mode of development. For instance, several lineages within this order have lost the medusa stage. Depending on the author, traditional taxonomy in hydrozoans may be either polyp- or medusa-oriented. Therefore, the absence of the latter stage in some lineages may lead to very different classification schemes. Molecular data have proved useful in elucidating this taxonomic challenge. We analyzed a supe…
Cnidarian Interaction with Microbial Communities: From Aid to Animal’s Health to Rejection Responses
2018
The phylum Cnidaria is an ancient branch in the tree of metazoans. Several species exert a remarkable longevity, suggesting the existence of a developed and consistent defense mechanism of the innate immunity capable to overcome the potential repeated exposure to microbial pathogenic agents. Increasing evidence indicates that the innate immune system in Cnidarians is not only involved in the disruption of harmful microorganisms, but also is crucial in structuring tissue-associated microbial communities that are essential components of the Cnidarian holobiont and useful to the animal’s health for several functions, including metabolism, immune defense, development, and behavior. Someti…
Benthic hydroids (Cnidaria, Hydrozoa) from the Weddell Sea (Antarctica)
2019
Hydrozoans are a conspicuous component of Antarctic benthic communitites. Recent taxonomic effort has led to a substantial increase in knowledge on the diversity of benthic hydroids from some areas of the Southern Ocean, including the Weddell Sea, the largest sea in the Antarctic region. However, the study of many hydrozoan taxa are still pending, and the diversity in this huge region is expected to be higher than currently known. In order to contribute to the knowledge of taxonomy, ecology and distribution of these cnidarians, a study of unpublished material collected by several German Antarctic expeditions aboard the RV Polarstern in the eastern sector of the Weddell Sea has been conducte…
Benthic hydroids (Cnidaria: Hydrozoa) from off George V Coast (East Antarctica)
2018
Hydrozoans are one of the main and most characteristic zoological groups of Antarctic benthic communities, yet there are Antarctic areas where the hydrozoan fauna is completely unknown or scarcely known as off George V Coast (East Antarctica). Hitherto, only two studies have dealt with hydroids from this area and only 16 species have been reported. The present study contributes to increase knowledge of the benthic hydroid fauna off George V Coast by studying material collected during a sampling survey associated with the CEAMARC project. A total of 12 species of benthic hydroids were found. Anthoathecata is only represented by Bimeria corynopsis, the remaining species, including Schizotrich…
Effects of global warming on reproduction and potential dispersal of Mediterranean Cnidarians
2019
Water temperature directly affects life cycles, reproductive periods, and metabolism of organisms living the oceans, especially in the surface zones. Due to the ocean warming, changes in water stratification and primary productivity are affecting trophic chains in sensitive world areas, such as the Mediterranean Sea. Benthic and pelagic cnidarians exhibit complex responses to climatic conditions. For example, the structure and phenology of the Mediterranean hydrozoan community displayed marked changes in species composition, bathymetric distribution, and reproductive timing over the last decades. The regional species pool remained stable in terms of species numbers but not in terms of speci…
On several species of Oswaldella Stechow, 1919 (Cnidaria, Hydrozoa), including the description of a new species
2018
Oswaldella is the most speciose genus of Antarctic hydroids, being one of the most characteristic genera of hydrozoans of the Antarctic benthic marine ecosystem. A relatively high number of taxonomic characters allow species identification, but some key ones are difficult to study properly with a light microscope. In order to improve knowledge of species of the genus, a SEM survey of five of the 27 known nominal species of Oswaldella was carried out, including type material of O. grandis and O. terranovae. The study has revealed no significant differences between O. stepanjantsae and O. terranovae and, consequently, the former is considered a junior synonym of the latter. The type material …
Species ofAntarctoscyphusPeña Cantero, García Carrascosa and Vervoort, 1997 (Cnidaria: Hydrozoa: Symplectoscyphidae) collected by US Antarctic expedi…
2017
ABSTRACTAntarctoscyphus is one of the most characteristic genera of Antarctic benthic hydroids, with nine of the 10 known species considered to be endemic to the Antarctic; only Antarctoscyphus elongatus is also present in the sub-Antarctic region of Kerguelen. Accordingly, the genus was considered to have an Antarctic–Kerguelen distribution. Here we present the results of the study of the species of Antarctoscyphus collected from different Antarctic areas and from the Magellan region, during several expeditions under the United States Antarctic Research Program between 1958 and 1986. A scanning electron microscopy survey of all known species of the genus was carried out. Eight of the 10 kn…