ABSTRACT
Although three species of the genus Macrourus are recognized in the Southern Ocean, DNA sequencing of the mitochondrial COI gene revealed four well-supported clades. These barcode data suggest the presence of an undescribed species, a conclusion supported by meristic and morphometric examination of specimens.
Subject(s)
DNA Barcoding, Taxonomic , Gadiformes/genetics , Animals , Electron Transport Complex IV/genetics , Gadiformes/classification , Species SpecificityABSTRACT
Ciliates associated with fish mortalities in a New Zealand hatchery were identified by DNA sequencing of the small subunit ribosomal RNA gene (SSU rRNA). Tissue samples were taken from lesions and gill tissues on freshly dead juvenile groper, brain tissue from adult kingfish, and from ciliate cultures and rotifers derived from fish mortality events between January 2007 and March 2009. Different mortality events were characterized by either of 2 ciliate species, Uronema marinum and Miamiensis avidus. A third ciliate, Mesanophrys carcini, was identified in rotifers used as food for fish larvae. Sequencing part of the SSU rRNA provided a rapid tool for the identification and monitoring of scuticociliates in the hatchery and allowed the first identification of these species in farmed fish in New Zealand.
Subject(s)
Ciliophora Infections/veterinary , Ciliophora/genetics , Fish Diseases/parasitology , Fisheries , Animals , Ciliophora/classification , Ciliophora/isolation & purification , Ciliophora Infections/epidemiology , Ciliophora Infections/mortality , Ciliophora Infections/parasitology , DNA, Ribosomal/genetics , Disease Outbreaks/veterinary , Fish Diseases/epidemiology , Fish Diseases/mortality , Marine Biology , Molecular Sequence Data , New Zealand/epidemiology , Phylogeny , Sequence Homology, Nucleic Acid , Species SpecificityABSTRACT
The phylogenetic relationships among populations of seaperch, Helicolenus spp., in the south-west Pacific were examined with mtDNA markers. Parts of the cytochrome b gene [459 base pair (bp)] and the control region (448 bp) were sequenced in 58 specimens from the south-west Pacific and four specimens of Helicolenus lengerichi from Chile. Only one clade was recognized in New Zealand coastal waters, despite a wide range of colour morphs. This clade also occurred in the mid Tasman Sea on the Norfolk Ridge and around Tasmania and Victoria. A second sympatric clade was identified around Tasmania and Victoria and to the west of New Zealand. A third allopatric clade was identified to the north of New Zealand and in deep water on the Chatham Rise and a fourth clade on the Foundation Seamounts and the Louisville Ridge. Helicolenus lengerichi from Chile formed a fifth clade. Assuming a molecular clock, the clades were estimated to have diverged c. 0.7-2.6 million years ago. Only two clades, around Tasmania and Victoria, were separated using morphology, colour (in live) and dorsal-fin soft ray counts and were confirmed as Helicolenus percoides and Helicolenus barathri. Two characters, orbit diameter and colour variation, previously used to identify two species in New Zealand waters were unreliable characters for species discrimination. Principle component analyses of 11 morphological measures from 67 individuals did not delineate the clades. A canonical discriminant analysis was able to separate four of the five clades, but mean discriminate probabilities were low (77.6%), except for the five Chilean specimens of H. lengerichi (100%).
Subject(s)
Evolution, Molecular , Perches/genetics , Phylogeny , Animals , Chile , DNA, Mitochondrial/genetics , New Zealand , Pacific Ocean , Perches/anatomy & histology , Perches/classification , Principal Component Analysis , Sequence Alignment , Sequence Analysis, DNAABSTRACT
1. Using everted sacs of sheep ileum, selenate uptake was shown to be more rapid than selenite uptake. 2. Sulphate, thiosulphate and ouabain all inhibited the uptake of selenate. A Na+K(+)-ATPase is probably responsible for energizing the ileal brush-border transport of selenate. 3. The isolated, vascularly perfused ileum was shown to absorb selenate more rapidly than selenite. 4. The perfusion system described would appear to be a useful tool for studying the kinetics of intestinal absorption and the measurement of metabolic transformations within the mucosa.