MONOGENEAN GILL PARASITES OF THE KINGFISH SERIOLA GRANDIS CASTLENAU (CARANGIDAE) FROM THE GREAT BARRIER REEF

15 Seriola grandis (Carangidae) from near Heron Island, Great Barrier Reef, Australia, were examined for gill parasites. The Monogenea Zeuxapta seriolae (Meserve, 1938) and Paramicrocotyloides reticularis gen. et sp. nov. are described. The new species differs from other genera of the Microcotylidae in its caecal reticulum found in most of the body, in its body proper which is divided into three parts, and in its opisthaptor, which is symmetrical and has two equal rows of clamps. The clamps are of two types, the most anterior ones are symmetrical of a typical Microcotyle-type, all others are asymmetrical of a modified Microcofyle-type. The unarmed common genital atrium is ventral and close to the pharynx, the unarmed vagina is mid-dorsal, a short distance behind the genital atrium. Zeuxaptajaponica is synonymized with Z. seriolae. The distribution of the two Monogenea species and of two copepod species on the gills is described

Example Chapter Section for \u3ci\u3eConcepts in Animal Parasitology\u3c/i\u3e: Manuscript of The Aspidogastrea by Klaus Rohde

This is an example chapter section for Concepts in Animal Parasitology. It is a manuscript of the section titled The Aspidogastrea, written by by Klaus Rohde. This is an example of a section written without using the optional template for Part Two and Part Three of the textbook. The associated images are included in a supplemental file

A Short Introduction to Marine Parasitology: Marine Parasites of Economic and Medical Importance

Introduction Parasitism, in this chapter, is defined as “a close association of two organisms, in which one—the parasite—depends on the other—the host—deriving some benefit from it. The benefit is often food” (Rohde, 2005b). Many bacteria, viruses, and fungi are parasitic but usually not studied by parasitologists sensu stricto; they are the domain of microbiologists. Parasites as defined here do not always harm their host; the border between so-called genuine parasites and other symbionts such as commensals is often blurred, and investigators who work on disease aspects tend to emphasis the pathogenic aspects and may not consider non-pathogenic species as truly parasitic (see also Shields and Overstreet, 2007). Frequently, species that are harmless under certain conditions become pathogenic under others (see, for example, Overstreet and Lotz, 2016). There has been much discussion of marine diversity in general and of diversity of marine parasites specifically. Parasite diversity depends on the diversity of their hosts. The more potential hosts, the more parasites can be expected. Appeltans et al. (2012; see also Costello and Chaudhary, 2017) concluded that between one-third and two-thirds of marine species (including both free-living and parasitic ones) had been described already. Rohde (2002a; 2010) emphasized that a very large number of species, particularly of invertebrates and their parasites in the deep sea, and in the meiofauna, remained to be described, a conclusion supported by the finding that there is a vast pool of environmental DNA (eDNA, metabarcoding) in the deep sea benthos (Sinniger et al., 2016), much of which may belong to bacteria but also to protistan and metazoan parasites. Sinniger et al. (2016) conclude that “the data obtained … reveal pronounced heterogeneity and vast amounts of unknown biodiversity in the deep sea.” Concerning beach meiofauna, in the largest study made by many authors over many years, at the North Sea Island of Sylt, and reviewed by Armonies and Reise (2000), 652 species had been recorded, 25 times as many as found in the macrofauna, and an estimated total of about 200 species still had to be described. No systematic survey of these meiofaunal animals for parasites has been made. Surveys (one not published) have shown that the meiofauna in other geographic regions contains many different species, indicating that a large pool of yet undescribed species exists (Rohde, 2016; see also Poulin (2014) for parasite diversity)

The bioluminescent Listeria monocytogenes strain Xen32 is defective in flagella expression and highly attenuated in orally infected BALB/cJ mice

Abstract Background In vivo bioluminescence imaging (BLI) is a powerful method for the analysis of host-pathogen interactions in small animal models. The commercially available bioluminescent Listeria monocytogenes strain Xen32 is commonly used to analyse immune functions in knockout mice and pathomechanisms of listeriosis. Findings To analyse and image listerial dissemination after oral infection we have generated a murinised Xen32 strain (Xen32-mur) which expresses a previously described mouse-adapted internalin A. This strain was used alongside the Xen32 wild type strain and the bioluminescent L. monocytogenes strains EGDe-lux and murinised EGDe-mur-lux to characterise bacterial dissemination in orally inoculated BALB/cJ mice. After four days of infection, Xen32 and Xen32-mur infected mice displayed consistently higher rates of bioluminescence compared to EGDe-lux and EGDe-mur-lux infected animals. However, surprisingly both Xen32 strains showed attenuated virulence in orally infected BALB/c mice that correlated with lower bacterial burden in internal organs at day 5 post infection, smaller losses in body weights and increased survival compared to EGDe-lux or EGDe-mur-lux inoculated animals. The Xen32 strain was made bioluminescent by integration of a lux-kan transposon cassette into the listerial flaA locus. We show here that this integration results in Xen32 in a flaA frameshift mutation which makes this strain flagella deficient. Conclusions The bioluminescent L. monocytogenes strain Xen32 is deficient in flagella expression and highly attenuated in orally infected BALB/c mice. As this listerial strain has been used in many BLI studies of murine listeriosis, it is important that the scientific community is aware of its reduced virulence in vivo

Counterfactual Statements and Weak Measurements: an Experimental Proposal

A recent analysis [quant-ph/0104062] suggests that weak measurements can be used to give observational meaning to counterfactual reasoning in quantum physics. A weak measurement is predicted to assign a negative unit population to a specific state in an interferometric Gedankenexperiment proposed by Hardy. We propose an experimental implementation with trapped ions of the Gedankenexperiment and of the weak measurement. In our standard quantum mechanical analysis of the proposal no states have negative population, but we identify the registration of a negative population by particles being displaced on average in the direction opposite to a force acting upon them

Early diagenesis of redox-sensitive trace metals in the Peru upwelling area – Response to ENSO-related oxygen fluctuations in the water column

Pore water and solid phase data for redox-sensitive metals (Mn, Fe, V, Mo and U) were collected on a transect across the Peru upwelling area (11°S) at water depths between 78 and 2025 m and bottom water oxygen concentrations ranging from ~0 to 93 µM. By comparing authigenic mass accumulation rates and diffusive benthic fluxes, we evaluate the respective mechanisms of trace metal accumulation, retention and remobilization across the oxygen minimum zone (OMZ) and with respect to oxygen fluctuations in the water column related to the El Nino Southern Oscillation (ENSO). Sediments within the permanent OMZ are characterized by diffusive uptake and authigenic fixation of U, V and Mo as well as diffusive loss of Mn and Fe across the benthic boundary. Some of the dissolved Mn and Fe in the water column re-precipitate at the oxycline and shuttle particle-reactive trace metals to the sediment surface at the lower and upper boundary of the OMZ. At the lower boundary, pore waters are not sufficiently sulfidic as to enable an efficient authigenic V and Mo fixation. As a consequence, sediments below the OMZ are preferentially enriched in U which is delivered via both in situ pre-cipitation and lateral supply of U-rich phosphorites from further upslope. Trace metal cycling on the Peruvian shelf is strongly affected by ENSO-related oxygen fluctuations in bottom water. During periods of shelf oxygenation, surface sediments receive particulate V and Mo with metal (oxyhydr)oxides that derive from both terrigenous sources and precipitation at the retreating oxycline. After the recurrence of anoxic conditions, metal (oxyhydr)oxides are reductively dissolved and the hereby liberated V and Mo are authigenically removed. This alternation between supply of particle-reactive trace metals during oxic periods and fixation during anoxic periods leads to a preferential accumulation of V and Mo compared to U on the Peruvian shelf. The decoupling of V, Mo and U accumulation is further accentuated by the varying susceptibility to re-oxidation of the different authigenic metal phases. While authigenic U and V are readily re-oxidized and recycled during periods of shelf oxygenation, the sequestration of Mo by authigenic pyrite is favored by the transient occurrence of oxidizing conditions.Our findings reveal that redox-sensitive trace metals respond in specific manner to short-term oxygen fluctuations in the water column. The relative enrichment patterns identified might be useful for the reconstruction of past OMZ extension and large-scale redox oscillations in the geological record

Seasonality of Ectoparasites and Pathology of three Species of Didymozoids (Trematoda, Digenea) of Slimy Mackerel, 'Scomber Australasicus' (Teleostei, Scombridae)

The ectoparasitic fauna of slimy mackerel, 'Scomber australasicus', from Eden, New South Wales Australia was examined in 428 fish collected in 12 samples during the period from November 1988 to June 1992. The aim was to study the species composition, microhabitats, seasonal variations and host responses. The host responses were studied in detail in three didymozoid parasites using scanning and transmission electron microscopy in addition to observations made under the light microscope