ABSTRACT
Wild organisms are regularly exposed to a wide range of parasites, requiring the management of an effective immune response while avoiding immunopathology. Currently, our knowledge of immunoparasitology primarily derives from controlled laboratory studies, neglecting the genetic and environmental diversity that contribute to immune phenotypes observed in wild populations. To gain insight into the immunologic variability in natural settings, we examined differences in immune gene expression of two Alaskan stickleback (Gasterosteus aculeatus) populations with varying susceptibility to infection by the cestode Schistocephalus solidus. Between these two populations, we found distinct immune gene expression patterns at the population level in response to infection with fish from the high-infection population displaying signs of parasite-driven immune manipulation. Further, we found significant differences in baseline immune gene profiles between the populations, with uninfected low-infection population fish showing signatures of inflammation compared to uninfected high-infection population fish. These results shed light on divergent responses of wild populations to the same parasite, providing valuable insights into host-parasite interactions in natural ecosystems.
Subject(s)
Cestoda , Cestode Infections , Fish Diseases , Smegmamorpha , Animals , Smegmamorpha/immunology , Smegmamorpha/genetics , Smegmamorpha/parasitology , Fish Diseases/immunology , Fish Diseases/parasitology , Cestode Infections/veterinary , Cestode Infections/immunology , Cestode Infections/parasitology , Cestoda/immunology , Cestoda/physiology , Host-Parasite Interactions/immunology , Alaska , Immunity, Innate/geneticsABSTRACT
Free endings of peripheral neurosecretory neurons (NNs) were found in the tegument of plerocercoids of five species of parasitic cestodes of fish in an ultrastructural study. The free terminals secreted vesicles on the tegument surface and into the host body. Secretion was experimentally shown to increase in response to the host fish blood serum. In the cestode body, NNs form paracrine-type contacts near the cell membranes of the frontal glands, the tegument, and muscles, functioning as endocrine glands. Simultaneously, NNs function as exocrine glands and secrete the so-called manipulative factors, which influence the physiology of the host.
Subject(s)
Cestoda , Animals , Cestoda/physiology , Neurons , FishesABSTRACT
Studies on fish parasites in Pampulha dam, Belo Horizonte, Minas Gerais, Brazil, found specimens of Poecilia reticulata Peters, 1859 harboring natural infection by larval stages of tapeworms. A total of 250 specimens of P. reticulata were collected and analyzed between February and August 2010, of which 23 were found infected (prevalence 9.2 percent) with one metacestode each (mean intensity 1, mean abundance 0.09). The analyses of the parasites, particularly the morphology of rostellar hooks, made it possible to identify Glossocercus auritus (Rudolphi, 1818). This is the first report of G. auritus metacestode in South America and P. reticulata is a newly known host for this parasite.
Em estudo da helmintofauna de peixes oriundos da represa da Pampulha, Belo Horizonte, Minas Gerais, Brasil, exemplares de Poecilia reticulata Peters, 1859 foram encontrados naturalmente infectados por larvas de cestóides. De 250 espécimes de P. reticulata coletados e analisados entre fevereiro e agosto de 2010, 23 (prevalência de infecção 9,2 por cento) apresentavam-se infectados por um metacestóides cada (intensidade média 1, abundância média 0,09). A análise dos parasitos, em especial a morfologia dos acúleos rostelares, permitiram a identificação de Glossocercus auritus (Rudolphi, 1818). Este é o primeiro registro de metacestóide de G. auritus para a América do Sul, sendo P. reticulata um novo hospedeiro conhecido para o parasito.
Subject(s)
Animals , Cestoda/physiology , Poecilia/parasitology , Brazil , LarvaABSTRACT
O objetivo desta pesquisa foi registrar a presença de cestoides Trypanorhyncha, suas prevalências e intensidades de infecção, na musculatura e serosa abdominal parietal de 50 exemplares de Macrodon ancylodon, capturados no litoral Norte do Brasil e beneficiados em Belém, Estado do Pará, durante o período de junho de 2004 a janeiro de 2005. A musculatura e serosa abdominal dos peixes foram examinadas em mesa de inspeção candling table após o filetamento das amostras. Oito peixes encontravam-se parasitados por plerocercoides da espécie Poecilancistrium caryophyllum, com prevalência de 16 por cento e intensidade média de infecção de um plerocerco por peixe, tendo como único sítio de infecção a musculatura. A espécie Poecilancistrium caryophyllum é, pela primeira vez, registrada para M. ancylodon.
The aim of this research was to report the presence of Trypanorhyncha cestodes, their prevalence and mean intensity in the muscles musculature and abdominal serose in commercial fish processed in Belém, Pará State. Fifty specimens of M. ancylodon were captured in the North Coast of Brazil. The musculature and adjacent abdominal serose of fish were analized in a "candling table" after filleted. Eight specimens were parasitized by plerocercoids of Poecilancistrium caryophyllum, with a prevalence of 16 percent and mean intensity of infection of one plerocercus per fish, varying from the unique site of infection was the musculature. The species P. caryophyllum is reported by the first time on M. ancylodon.
Subject(s)
Animals , Cestoda/physiology , Perciformes/parasitology , BrazilABSTRACT
Cestóides hiperparasitos säo descritos de espécies de proteocefalídeos, que ocorrem em peixes pimelodídeos de diferentes regiöes do Brasil. Referimos ainda, a ocorrência de nematóide hiperparasito em espécimes de Choanoscolex abscissus, do peixe pimelodídeo, Pseudoplatystoma carruscans. Säo citadas as referências anteriores de cestóides e nematóides hiperparasitos, e discutida a possível identificaçäo dos mesmos