Parasitic association of the mycetophagous wood nematode,Bursaphelenchus fraudulentuswith the honey fungusArmillaria ostoyae

2017 ◽  
Vol 47 (3) ◽  
pp. e12325 ◽  
Author(s):  
M. Tomalak
Keyword(s):  
Parasitic Association

Freshwater Perkinsea: diversity, ecology and genomic information

2019 ◽  
Vol 42 (1) ◽  
pp. 3-17 ◽  
Author(s):  
M Jobard ◽  
I Wawrzyniak ◽  
G Bronner ◽  
D Marie ◽  
A Vellet ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Meta Analysis ◽  
Freshwater Ecosystems ◽  
Protein Coding ◽  
Lake Ecosystems ◽  
Operational Taxonomic Units ◽  
Clade 1 ◽  
Almost All ◽  
Parasitic Association

Abstract Studies on freshwater Perkinsea are scarce compared to their marine counterparts; they are therefore not well ecologically characterized. In this study, we investigated the diversity, distribution and ecological role of Perkinsea in freshwater ecosystems. Our approach included (1) the phylogenetic analyses of near full-length SSU and LSU sequences of freshwater Perkinsea, (2) a meta-analysis of public Perkinsea 18S ribosomal RNA gene sequences available from the freshwater environments (25 lakes, 4 rivers), (3) microscopic observations of Perkinsea associated with planktonic communities and (4) single amplified genome analysis. Whereas Perkinsea appear to be rare in river ecosystems (85 reads), they are found in almost all of the lakes studied. However, their diversity does vary considerably between lakes (from 0 to 2 463 Operational Taxonomic Units (OTUs)). Phylogenetic analysis showed that the Parvilucifera/Dinovorax/Snorkelia and Perkinsus/Xcellia/Gadixcellia clades resulted from an initial speciation event. This second clade is further split into well-supported, monophyletic groups, including a clade dominated by freshwater representatives, which is further structured into three distinct subclades: freshwater clade 1, freshwater clade 2 and a freshwater and brackish clade. The Perkinsea Single Amplified Genome (SAG) as well as most of the abundant Operational Taxonomic Units (OTUs) fall into freshwater clade 2. The tyramide signal amplification-fluorescent in situ hybridization method showed an internal association between Perkinsea and the colonial phytoplankton Sphaerocystis. The Single Amplified Genome (SAG) annotation contained 698 genes and gene ontology terms could be assigned to 486 protein-coding genes. Although the number of genes appears to be low (10.6% of the entire gene set assessed by BUSCO), the analysis of the proteome revealed some putative secreted virulence factors. This study showed a large distribution of Perkinsea across lake ecosystems and potential parasitic association with phytoplankton. However, further investigations are needed for a better knowledge on the role of these microorganisms in freshwater ecosystems.

Evolutionary factors influencing the nature of parasite specificity

Parasitology ◽  
1994 ◽  
Vol 109 (S1) ◽  
pp. S85-S95 ◽  
Author(s):  
M. L. Adamson ◽  
J. N. Caira
Keyword(s):  
Final Host ◽  
Feeding Styles ◽  
Host Defense System ◽  
Host Ecology ◽  
Parasite Evolution ◽  
The Right ◽  
Parasitic Association ◽  
Host Tissues ◽  
The Way

SUMMARYThis article considers how specificity patterns are shaped during the course of parasite evolution. Parasites are first and foremost specific to site, or microhabitat; host ranges are far more subject to change than is microhabitat. Specificity results from a number of convergent phenomena starting with habits (microhabitat and feeding styles) of free-living progenitors and the way in which the parasitic association arises (e.g., passive oral contamination as opposed to intrusive entry). These bias the types of interaction parasites have with the host, and, through this, the way specificity develops. Host ecology acts as an external factor affecting specificity and predominates in parasites that interact minimally with the hosts physiological and immune systems. Coevolutionary factors are more important in parasites that feed on host tissues or occur in extraintestinal sites. Here, parasites must present the right cues, and respond appropriately to the host defense system. The ability to generalize these cues and responses across host boundaries may act as a constraint on host range. The functional role of the host in the parasite life history also affects the degree of specificity; thus, parasites may act as host generalists in hosts that act as trophic channels to the final host. The role of competition in determining specificity is difficult to assess. However, competition has been reported to influence microhabitat and host distribution through interactive site selection and/or competitive seclusion.

A Parasitic Association Between a Pycnogonid and a Scyphomedusa in Midwater

1986 ◽  
Vol 66 (1) ◽  
pp. 113-117 ◽  
Author(s):  
C. Allan Child ◽  
G. R. Harbison
Keyword(s):  
Water Column ◽  
Feeding Habits ◽  
The Philippines ◽  
Brittle Star ◽  
Feeding Preferences ◽  
Benthic Habitats ◽  
Parasitic Association

The feeding habits and host specificities of the Pycnogonida are poorly known. These usually small, cryptically coloured animals are difficult to observe alive and are mostly collected fortuitously in gross samples taken from trawls and dredges. Any association between the pycnogonids and their food is disrupted in the trawl. Further, the possibility that some of the pycnogonids may have been captured in the water column rather than on the bottom cannot be ascertained from trawl and dredge samples. King (1973) lists only twelve records of pycnogonids actually seen browsing on food organisms. Most occur on hydroids and other cnidarians, and all are from benthic habitats. In more recent papers, Stock reports a pycnogonid seen on a brittle star in the Seychelles (1979), feeding preferences of pycnogonids on benthic cnidarians (1978), and an association between a pycnogonid and a starfish from the Philippines (1981).

scholarly journals Shell Infestation of the Farmed Pacific Oyster Magallana gigas by the Endolith Bivalve Rocellaria dubia

Diversity ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 526
Author(s):  
Barbara Mikac ◽  
Alessandro Tarullo ◽  
Marina Antonia Colangelo ◽  
Marco Abbiati ◽  
Federica Costantini
Keyword(s):  
Pacific Oyster ◽  
Negative Effects ◽  
Age Classes ◽  
Northern Adriatic Sea ◽  
Northern Adriatic ◽  
Oyster Aquaculture ◽  
The Pacific ◽  
Emilia Romagna Region ◽  
Oyster Farm ◽  
Parasitic Association

Oyster shells are substratum for different epibiontic and endobiontic organisms, including pests and parasites. Rocellaria dubia is endolithic and facultative tube-dwelling bivalve, boring in different calcareous substrates, including the shells of bivalves. In 2020, R. dubia was found as endolithic in the shells of the Pacific oyster Magalana gigas, from an oyster farm off the Sacca di Goro lagoon (Emilia-Romagna region, Northern Adriatic Sea, Italy). The purpose of this study was to describe this newly recorded association. Altogether, 136 specimens of R. dubia were found in 15 oysters, photographed under a stereoscope, and their length was measured. Heavily infested oysters hosted tens of R. dubia borers, which were perforating the whole thickness of the oyster valves. The flesh of these oysters was heavily damaged, suggesting parasitic association. R. dubia specimens were categorized into three age classes (0–1, 1–2, and 2–3 years old). M. gigas/R. dubia might be a widespread association, overlooked due to the very scarce research on macrofauna associated with M. gigas. Considering the negative effects of R. dubia endobiosis on oyster fitness, and possible impacts on oyster aquaculture, further research should be conducted in order to elucidate the distribution and ecological characteristics of this parasitic association.

scholarly journals First record of endoparasitism of Pycnogonida in Hydrozoan polyps (Cnidaria) from the Brazilian coast

2013 ◽  
Vol 13 (2) ◽  
pp. 319-325 ◽  
Author(s):  
Ariane Lima Bettim ◽  
Maria Angélica Haddad
Keyword(s):  
Exotic Species ◽  
20Th Century ◽  
Short Communication ◽  
First Record ◽  
Brazilian Coast ◽  
Early 20Th Century ◽  
Complete Disappearance ◽  
Southern Coast ◽  
South Of Brazil ◽  
Parasitic Association

Despite the relatively high number of recent studies on Cnidaria off the Brazilian coast, we have observed only two records of parasitism on macromedusae and none on polyps. Endoparasitic associations between Pycnogonida larvae and hydroids have been well known since the early 20th century. Protonymph larvae develop inside the gastrovascular cavity of polyps, typically gastrozooids, which are then called gallzooids. This short communication is an unprecedented record of parasitism on the polyps of Brazilian cnidarian fauna. The parasitic association between Pycnogonida Anoplodactylus stictus and a new hydroid species of Podocoryna has been casually detected on the encrusting communities of experimental polyethylene plates installed at the Paranaguá Yacht Club, Paranaguá, south of Brazil from February 2007 to February 2008. This hydrozoan host is most likely an exotic species because it had not been observed in previous studies of Paranaguá Bay or beaches along the southern coast of Brazil in the previous 20 years. Eighty-eight hydroid colonies were analyzed, of which 19 were parasitized mainly from June to August 2007. Protonymphs were pink-red colored, similar to gallzooids and all other polyps of the colony, thus indicating that they had eaten the hosts' tissues. Up to six protonymphs were observed inside the gallzooids. The gallzooid column was elongated, and the tentacles were atrophied or even absent because of the development of the larvae. Some observations of endoparasitism in two live colonies that were maintained in aquaria until their complete disappearance (one month) are also described in this note.

Development, regeneration, and parasitic interactions between the lichens Fulgensia bracteata and Toninia caeruleonigricans

1995 ◽  
Vol 73 (S1) ◽  
pp. 595-602 ◽  
Author(s):  
Sieglinde Ott ◽  
Thomas Meier ◽  
Hans Martin Jahns
Keyword(s):  
Key Words ◽  
Developmental Stages ◽  
Lichen Substances ◽  
Parasitic Interactions ◽  
Parasitic Association

A possible source of Trebouxia algae for lichens are the thalli of lichens that are attacked by another mycobiont that captures the algae for its own symbiotic use. Such a process is described for Fulgensia bracteata living in parasitic association with Toninia caeruleonigricans. The development of the thalli of Toninia and the parasitic attack of Fulgensia are analysed in detail. The infection of Toninia is achieved by ascospores and can be demonstrated by the presence of secondary lichen substances typical for Fulgensia, which occur in infected thalli of Toninia. Fulgensia also overgrows other lichens, but these thalli are not invaded. The special abilities of Toninia and various methods for distribution and regeneration compensate for the parasitism and the association remains stable. The ecology of the small developmental stages of Toninia and Fulgensia shows important differences. Key words: Fulgensia, Toninia, Trebouxia development, parasitism, ecology.

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