Article

Potential environmental and host gender influences on prevalence of Haemogregarina platessae (Adeleorina:Haemogregarinidae) and suspected Haemohormidium terraenovae (incertae sedis) in Brazilian flounder from the Patos Lagoon Estuary, southern Brazil.

School of Life Sciences, Faculty of Science, Kingston University, Penrhyn Road, Kingston upon Thames, Surrey KT1 2EE, UK.
Folia parasitologica (Impact Factor: 1.21). 10/2008; 55(3):161-70.
Source: PubMed

ABSTRACT Flounder, Paralichthys orbignyanus (Valenciennes), were captured in polluted and non-polluted sites within the Patos Lagoon Estuary, southern Brazil, over four seasons. Blood films showed a high prevalence of infection with a haemogregarine, or mixed parasitaemias of this and an organism resembling Haemohormidium terraenovae So, 1972. Haemogregarine gamont stages conformed to existing descriptions of Desseria platessae (Lebailly, 1904) Siddall, 1995 from flatfishes, but intraerythrocytic division of meronts was observed, leading to the recommendation for nomenclatural correction, placing the haemogregarine in the genus Haemogregarina (sensu lato) Danilewsky, 1885. Statistical analyses suggested that although sample sizes were small, infections with meront stages, immature and mature gamonts were all influenced by site, and possibly therefore, by pollution. Season also appeared to determine likelihood of infection with meronts and immature gamonts, but not mature gamonts, while adult fish gender apparently affected infection with immature and mature gamonts, but not meronts. The H. terraenovae-like organism exhibited unusual extracellular forms and did not match closely with the type description of H. terraenovae; precise identification was therefore difficult. Data analyses suggested that parasitism by this organism was influenced by site and fish gender, since females and males from non-polluted water were infected, but only females from the polluted site. Season was also important and significantly more adult fish of both sexes were infected with this parasite in the Brazilian summer and autumn, compared with winter and spring. Finally, these appeared to be the first observations of Haemogregarina platessae, and possibly H. terraenovae, from the southern hemisphere.

Full-text

Available from: Adalto Bianchini, Apr 07, 2015
0 Followers
 · 
196 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This paper reviews past, current and likely future research on the fish haemogregarine, Haemogregarina bigemina Laveran et Mesnil, 1901. Recorded from 96 species of fishes, across 70 genera and 34 families, this broad distribution for H. bigemina is questioned. In its type hosts and other fishes, the parasite undergoes intraerythrocytic binary fission, finally forming mature paired gamonts. An intraleukocytic phase is also reported, but not from the type hosts. This paper asks whether stages from the white cell series are truly H. bigemina. A future aim should be to compare the molecular constitution of so-called H. bigemina from a number of locations to determine whether all represent the same species. The transmission of H. bigemina between fishes is also considered. Past studies show that young fish acquire the haemogregarine when close to metamorphosis, but vertical and faecal-oral transmission seem unlikely. Some fish haemogregarines are leech-transmitted, but where fish populations with H. bigemina have been studied, these annelids are largely absent. However, haematophagous larval gnathiid isopods occur on such fishes and may be readily eaten by them. Sequential squashes of gnathiids from fishes with H. bigemina have demonstrated development of the haemogregarine in these isopods. Examination of histological sections through gnathiids is now underway to determine the precise development sites of the haemogregarine, particularly whether merozoites finally invade the salivary glands. To assist in this procedure and to clarify the internal anatomy of gnathiids, 3D visualisation of stacked, serial histological sections is being undertaken. Biological transmission experiments should follow these processes.
    Folia parasitologica 07/2004; 51(2-3):99-108. DOI:10.14411/fp.2004.015 · 1.21 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: American plaice held in captivity for a period of 8 months over winter exhibited increasing erythrocyte osmotic fragility and decreasing haematocrit values until December. In December, osmotic fragility parameters and haematocrit were strongly correlated, suggesting anaemia due to disruption of circulating erythrocytes. Intensity of infection with Haemohormidium terranovae increased through the winter months until March but was not correlated either with osmotic fragility or haematocrit. These results are explained in terms of compensatory haemopoetic changes occurring in plaice. Mortality was apparently unrelated to any of the parameters investigated.
    Journal of Fish Biology 04/2005; 47(1):1 - 6. DOI:10.1111/j.1095-8649.1995.tb01867.x · 1.73 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Haemohormidium terranovae infections in American plaice and infections with a similar parasite in oceanpout were examined by light and electron microscopy. All plaice were infected at the time of capture and remained infected for over 2 yr. Prevalence in oceanpout varied seasonally between 0% and 80%. Uninucleate, binucleate, and tetranucleate forms were found in both species. In addition, octonucleate stages were observed in some erythrocytes of infected plaice. The presence of DNA in parasite nuclei was confirmed. There was no evidence of any ultrastructural feature characteristic of the phylum Apicomplexa. It is proposed that the genus Haemohormidium Henry, 1910 be considered incertae sedis and the senior synonym to Haematractidium Henry, 1910.
    Journal of Parasitology 01/1995; 80(6):1018-25. DOI:10.2307/3283452 · 1.26 Impact Factor