12 research outputs found
Seasonal occurrence of balanomorph barnacle nauplius larvae in the region of the Antarctic Peninsula
Author Posting. © The Author(s), 2010. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Journal of Experimental Marine Biology and Ecology 392 (2010): 125-128, doi:10.1016/j.jembe.2010.04.016.Plankton samples taken along the west coast of the Antarctic Peninsula and in Bransfield
Strait show widespread occurrence of Bathylasma corolliforme nauplius larvae during the
austral spring, mid-October to the third week of December. During autumn, between the
first week of May and early June there was a complete absence of balanomorph nauplii.
This evidence shows periodicity in reproduction. There is a seemingly close correlation
between the presence of these nauplii and the published data on phytoplankton biomass
and seawater surface temperature.The research was supported by
grants from the U.S. National Science Foundation Office of Polar Programs
Assessment of triple bile acid kinetics in humans applying single stable isotope administration and dual blood sampling
Diabetes mellitus: pathophysiological changes and therap
Deep molluscan phylogeny: synthesis of palaeontological and neontological data
The position of the earliest-derived living molluscs, the Polyplacophora (chitons) and shell-less vermiform Aplacophora, remains highly contentious despite many morphological, developmental and molecular studies of extant organisms. These two groups are thought to represent either a basal molluscan grade or a clade (Aculifera) sister to the ‘higher’ molluscs (Conchifera). These incompatible hypotheses result in very different predictions about the earliest molluscs. A new cladistic analysis incorporating both Palaeozoic and extant molluscs is presented here. Our results support the monophyly of Aculifera and suggest that extant aplacophorans and polyplacophorans both derive from a disparate group of multivalved molluscs in two major clades. Reanalysis of the critical Ordovician taxon ‘Helminthochiton’ thraivensis shows that this animal lacks a true foot despite bearing polyplacophoran-like valves. Its position within our phylogenetic reconstruction indicates that many fossil ‘polyplacophorans’ in the order Palaeoloricata are likely to represent footless stem-group aplacophorans. ‘H.’ thraivensis and similar forms such as Acaenoplax may be morphological stepping stones between chitons and the shell-less aplacophorans. Our results imply that crown-group molluscan synapomorphies include serial repetition, the presence of a foot, a mineralized scleritome and a creeping rather than worm-like mode of life
Outcome of isolated gastroschisis; an international study, systematic review and meta-analysis
Research into fetal development and medicin