Biology of Philometroides huronensis (Nematoda: Dracunculoidea) in the white sucker (Catostomus commersoni)

1977 ◽  
Vol 55 (9) ◽  
pp. 1430-1441 ◽  
Author(s):  
Leslie S. Uhazy

White suckers (Catostomus commersoni (Lacépède)) collected from various locations in southern Ontario were examined for Philometroides huronensis Uhazy, 1976. Stages of the parasite were recovered from the peritoneum around the swim bladder, bases of the fins, and the fins. Prevalence of infections was high and intensities relatively low. The parasite was less prevalent in longnose (Catostomus catostomus (Forster)) and redhorse (Moxostoma macrolepidotum (LeSucur)) suckers collected from the same area.Males, female fourth-stage larvae, uninseminated. inseminated, subgravid, and gravid females were recovered from fish collected from southern Lake Huron. Prevalence was 83 to 100% throughout the year and showed no significant seasonal trend. Numbers of worms recovered ranged from 1 to 32 per fish; 77% were infected with from 1 to 7 worms. Intensities of infections varied significantly with season, being highest during fall, winter, and early spring. All age groups of white suckers were infected; however, intensity did not vary significantly with host age. Although P. huronensis was highly prevalent throughout the year and from one year to the next, the life cycle was completed in a single year.The evolution of three valid species in the Philometrinae from the white sucker in North America is proposed, based on the evidence that before Pleistocene glaciation there were three separate forms of white sucker.

1976 ◽  
Vol 54 (3) ◽  
pp. 369-376 ◽  
Author(s):  
Leslie S. Uhazy

A new species of nematode, Philometroides huronensis n.sp., is described from the fins and peritoneum around the swim bladder of the common white sucker (Catostomus commersoni). The gravid females and the males of this species are readily distinguishable from those of other members of the genus by the body size, cuticular ornamentation, caudal ventrolateral hypodermal extensions, size and shape of first-stage larva, length of spicules, size and shape of gubernaculum, and location in the host. Measurements of mature and subgravid females are presented.


Viruses ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 144 ◽  
Author(s):  
Miguel F Varela ◽  
Enrique Rivadulla ◽  
Alberto Lema ◽  
Jesús L Romalde

Viral agents of human gastroenteritis affect people of all ages across the globe. As a mainly self-limiting disease, it is difficult to evaluate the real prevalence of etiological agents circulating in each region. Many of the analyzed outbreaks are caused by viruses of the family Caliciviridae, especially the genus Norovirus (NoV). Most studies have focused on other enteric viruses, leaving sapovirus (SaV) underestimated as an important emerging human threat. This one-year study analyzed clinical samples from hospital outpatients with acute gastroenteritis in Spain, with the aim of revealing the importance of human SaV as an emerging viral pathogen. A total of 2667 stools were tested using reverse transcription (RT)-qPCR to detect and quantify SaV. Sapovirus was detected in all age groups, especially in infants, children, and the elderly. The prevalence was 15.64% (417/2667), and was slightly higher in 0–2- and 3–5-year-olds (19.53% and 17.95%, respectively) and much lower in 13–18-year-olds (9.86%). Positive samples were detected throughout the year, with peaks of detection during autumn and the late winter to early spring months. The mean value for the quantified samples was 6.5 × 105 genome copies per gram of stool (GC/g) (range 2.4 × 103–6.6 × 1011 GC/g). RT-nested PCR and sequencing were used for further genotyping. Genetic characterization showed a predominance of genogroup I (GI), followed by GII and GIV. The detection of multiple genotypes suggests the circulation of different strains without any clear tendency. The results obtained suggest SaV as the second major gastroenteritis agent after NoV in the region.


1977 ◽  
Vol 55 (7) ◽  
pp. 1082-1092 ◽  
Author(s):  
Susan M. Bower ◽  
Patrick T. K. Woo

During the summer of 1975, 285 white sucker from 10 localities in southern Ontario were examined for haemoflagellates. Cryptobia catostomi n.sp., found in the blood of 43.4% of the fish examined, occurred in all populations of adult fish and in one of three populations of juvenile fish.The morphology of C. catostomi n.sp. based on over 500 specimens stained with Giemsa's stain, varied considerably. Cloning showed that this species is pleomorphic and has morphological features and body measurements which encompass most other Cryptobia spp. previously described from the blood of fishes. Cryptobia catostomi n.sp. was distinguished by its host specificity. Infections could not be transmitted to 16 other species of fishes by inoculation of blood from infected sucker. Fishes refractive to infection included Cyprinus carpio, Carassius auratus, Rhinichthys atratulus, Semotilus atromaculatus, Salmo gairdneri, Oncorhynchus kisutch, and Esox lucius from which other species of Cryptobia (C. borreli, C. cataractae, C. salmositica, and C. gurneyorum) have been reported in North America.


2010 ◽  
Vol 45 (2) ◽  
pp. 187-200 ◽  
Author(s):  
Joanne L. Parrott ◽  
L. Mark Hewitt ◽  
Tibor G. Kovacs ◽  
Deborah L. MacLatchy ◽  
Pierre H. Martel ◽  
...  

Abstract To evaluate currently available bioassays for their use in investigating the causes of pulp and paper mill effluent effects on fish reproduction, the responses of wild white sucker (Catostomus commersoni) collected from the receiving environment at the bleached kraft mill at La Tuque, Quebec, were compared with responses of fathead minnow (Pimephales promelas) exposed to effluent in a laboratory lifecycle test. White sucker collected at effluent exposed sites had increased liver size but none of the reproductive effects that had been documented in earlier field studies at this site. Exposure to 1, 3, 10, 30, and 100% bleached kraft mill effluent (BKME) in the lab led to significantly decreased length, but increased weight and liver size in male fathead minnow. Female length was also decreased and liver size was increased at high effluent exposures. Most effluent concentrations (1 to 30%) significantly increased egg production compared with controls. The fathead minnow lifecycle assay mirrored the effects seen in wild fish captured downstream of the BKME discharge. These results will be used to select short-term fish tests for investigating the causes of and solutions to the effects of mill effluents on fish reproduction.


Author(s):  
Iván Area ◽  
Henrique Lorenzo ◽  
Pedro J. Marcos ◽  
Juan J. Nieto

In this work we look at the past in order to analyze four key variables after one year of the COVID-19 pandemic in Galicia (NW Spain): new infected, hospital admissions, intensive care unit admissions and deceased. The analysis is presented by age group, comparing at each stage the percentage of the corresponding group with its representation in the society. The time period analyzed covers 1 March 2020 to 1 April 2021, and includes the influence of the B.1.1.7 lineage of COVID-19 which in April 2021 was behind 90% of new cases in Galicia. It is numerically shown how the pandemic affects the age groups 80+, 70+ and 60+, and therefore we give information about how the vaccination process could be scheduled and hints at why the pandemic had different effects in different territories.


2021 ◽  
Vol 63 (1) ◽  
Author(s):  
Per-Arne Åhlen ◽  
Göran Sjöberg ◽  
Margareta Stéen

Abstract Background The parasitic fauna of beavers (Castor fiber and C. canadensis) has been well studied in many parts of their respective areas of distribution. In Scandinavia there have, however, been limited investigations conducted on the parasites of beavers in recent times. The present study is the first quantitative survey of parasites on beavers living in Sweden and elsewhere in Scandinavia. We investigated the parasitic fauna of the Eurasian beaver (C. fiber) in a North–South gradient in Sweden. The aim of the study was to investigate parasite distribution and prevalence in particular, related to average yearly air temperature and different age groups of beavers. A total of 30 beavers were sampled at eight localities, spanning a 720 km North–South gradient during the springs of 1997 and 1998. Results Five parasite taxa were identified. Four of these were present in all of the examined beavers, Stichorchis subtriquetrus (trematode), Travassosius rufus (nematode), Platypsyllus castoris (coleopteran), and Schizocarpus spp. (arachnid). A higher number of new infections of S. subtriquetrus, and more adults of T. rufus, were seen in beavers in southern Sweden where temperatures are higher. One-year old beavers had a higher infestation of S. subtriquetrus, but not of T. rufus, than older individuals. Conclusions The parasite fauna of Swedish beavers mirrored the impoverished parasite fauna of the original Norwegian population, and the high prevalence of parasites could be due to low major histocompatibility complex (MHC) polymorphism. Young beavers had a higher load of trematodes, probably depending on behavioural and ecological factors. Warmer temperatures in southern localities likely contributed to increased endoparasite loads.


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