14 research outputs found
A unique Valanginian paleoenvironment at an iron ore deposit near Zengővárkony (Mecsek Mts, South Hungary), and a possible genetic model
Abstract
The spatially restricted Early Valanginian iron ore (limonite) and manganese deposit at Zengõvárkony (Mecsek Mts, southern Hungary) contains a rich, strongly limonitized, remarkably large-sized (specimens are 30–70% larger than those at their type localities) brachiopod-dominated (mainly Lacunosella and Nucleata) megafauna and a diverse crustacean microfauna, which indicates a shallow, nutrient-rich environment possibly linked to an uplifted block, and/or a hydrothermal vent
What's left in the tank? Identification of non-ascribed aquarium's coral collections with DNA barcodes as part of an integrated diagnostic approach
The unprecedented threats to coral reef ecosystems from global climate change require an urgent response from the aquarium community, which is becoming an increasingly vital coral conservation resource. Unfortunately, many hermatypic corals in aquaria are not identified to species level, which hinders assessment of their conservation significance. Traditional methods of species identification using morphology can be challenging, especially to non-taxonomists. DNA barcoding is an option for species identification of Scleractinian corals, especially when used in concert with morphology-based assessment. This study uses DNA barcodes to try to identify aquarium specimens of the diverse reef-forming genus Acropora from 127 samples. We identified to our best current knowledge, to species name 44% of the analysed samples and provided provisional identification for 80% of them (101/127, in the form of a list of species names with associate confidence values). We highlighted a sampling bias in public nucleotide sequences repertories (e.g. GenBank) towards more charismatic and more studied species, even inside a well-studied genus like Acropora. In addition, we showed a potential "single observer" effect with over a quarter of the reference sequences used for these identifications coming from the same study. We propose the use of barcoding and query matching as an additional tool for taxonomic experts and general aquarists, as an additional tool to increase their chances of making high confidence species-level identifications. We produce a standardised and easily repeatable methodology to increase the capacity of aquariums and other facilities to assess non-ascribed species, emphasising the value of integrating this approach with morphological identification optimising usage of authoritative identification guides and expert opinion. Supplementary Information: The online version contains supplementary material available at 10.1007/s12686-021-01250-3
A unique Valanginian paleoenvironment at an iron ore deposit near Zengõvárkony (Mecsek Mts, South Hungary), and a possible genetic model
First record of the new alien sea jelly species Marivagia stellata Galil and Gershwin, 2010 off the Syrian coast
The importance of mangroves, mud and sand flats, and seagrass beds as feeding areas for juvenile fishes in Chwaka Bay, Zanzibar: gut content and stable isotope analyses
Item does not contain fulltextThe relative importance of bay habitats, consisting of mangrove creeks and channel, seagrass beds, and mud and sand flats, as feeding grounds for a number of fish species was studied in Chwaka Bay, Zanzibar, Tanzania, using gut content analysis and stable isotope analysis of carbon and nitrogen. Gut content analysis revealed that within fish species almost the same food items were consumed regardless of the different habitats in which they were caught. Crustaceans (mainly copepods, crabs and shrimps) were the preferred food for most zoobenthivores and omnivores, while fishes and algae were the preferred food for piscivores and herbivores, respectively. The mean d13C values of fishes and food items from the mangrove habitats were significantly depleted to those from the seagrass habitats by 6_9 and 9_7% for fishes and food items, respectively, and to those from the mud and sand flats by 3_5 and 5_8%, respectively. Fishes and food items from the mud and sand flats were significantly depleted as compared to those of the seagrass habitats by 3_4 and 3_9%, for fishes and food, respectively. Similar to other studies done in different geographical locations, the importance of mangrove and seagrass themselves as a primary source of carbon to higher trophic levels is limited. The different bay habitats were all used as feeding grounds by different fish species. Individuals of the species Gerres filamentosus, Gerres oyena, Lethrinus lentjan, Lutjanus fulviflamma, Pelates quadrilineatus and Siganus sutor appeared to show a connectivity with respect to feeding between different habitats by having d13C values which were in-between those of food items from two neighbouring habitats. This connectivity could be a result of either daily tidal migrations or recent ontogenetic migration