Topic
Ceratomyxa
About: Ceratomyxa is a research topic. Over the lifetime, 131 publications have been published within this topic receiving 2470 citations.
Papers published on a yearly basis
Papers
TL;DR: It is indicated that the Myxozoa are closely related to Cnidaria, and marine taxa at the genus level branch separately from genera that usually infect freshwater fishes; taxa cluster more by development and tissue location than by spore morphology.
Abstract: In the last few years two factors have helped to significantly advance our understanding of the Myxozoa. First, the phenomenal increase in fin fish aquaculture in the 1990s has lead to the increased importance of these parasites; in turn this has lead to intensified research efforts, which have increased knowledge of the development, diagnosis. and pathogenesis of myxozoans. The hallmark discovery in the 1980s that the life cycle of Myxobolus cerebralis requires development of an actinosporean stage in the oligochaete. Tubifex tubifex, led to the elucidation of the life cycles of several other myxozoans. Also, the life cycle and taxonomy of the enigmatic PKX myxozoan has been resolved: it is the alternate stage of the unusual myxozoan, Tetracapsula bryosalmonae, from bryozoans. The 18S rDNA gene of many species has been sequenced, and here we add 22 new sequences to the data set. Phylogenetic analyses using all these sequences indicate that: 1) the Myxozoa are closely related to Cnidaria (also supported by morphological data); 2) marine taxa at the genus level branch separately from genera that usually infect freshwater fishes; 3) taxa cluster more by development and tissue location than by spore morphology; 4) the tetracapsulids branched off early in myxozoan evolution, perhaps reflected by their having bryozoan, rather than annelid hosts; 5) the morphology of actinosporeans offers little information for determining their myxosporean counterparts (assuming that they exist); and 6) the marine actinosporeans from Australia appear to form a clade within the platysporinid myxosporeans. Ribosomal DNA sequences have also enabled development of diagnostic tests for myxozoans. PCR and in situ hybridisation tests based on rDNA sequences have been developed for Myxobolus cerebralis, Ceratomyxa shasta, Kudoa spp., and Tetracapsula bryosalmonae (PKX). Lectin-based and antibody tests have also been developed for certain myxozoans, such as PKX and C. shasta. We also review important diseases caused by myxozoans, which are emerging or re-emerging. Epizootics of whirling disease in wild rainbow trout (Oncorhynchus mykiss) have recently been reported throughout the Rocky Mountain states of the USA. With a dramatic increase in aquaculture of fishes using marine netpens, several marine myxozoans have been recognized or elevated in status as pathological agents. Kudoa thyrsites infections have caused severe post-harvest myoliquefaction in pen-reared Atlantic salmon (Salmo salar), and Ceratomyxa spp., Sphaerospora spp., and Myxidium leei cause disease in pen-reared sea bass (Dicentrarchus labrax) and sea bream species (family Sparidae) in Mediterranean countries.
627 citations
TL;DR: The actinosporean life stage of Ceratomyxa shasta, a myxozoan parasite of salmonids, and the annelid worm that serves as its alternate host were identified and their roles were confirmed using molecular techniques.
Abstract: The actinosporean life stage of Ceratomyxa shasta, a myxozoan parasite of salmonids, and the annelid worm that serves as its alternate host were identified in laboratory transmission experiments and their roles were confirmed using molecular techniques. Infection by the parasite occurred in susceptible fish that were either exposed to or force fed the freshwater polychaete, Manayunkia speciosa, infected with the actinosporean. These observations were confirmed using the polymerase chain reaction with primers designed from the C. shasta 18S rDNA sequence. DNA was amplified from polychaetes harboring the actinosporean that caused infection in the fish but not from uninfected polychaetes. Amplified DNA from an infected polychaete was sequenced and its homology with the 18S rDNA sequence of C. shasta spores verified the proposed life cycle. Ultrastructural examination of the actinosporean in the polychaete showed developmental stages in the epidermis rather than within the intestinal epithelium as described for other myxozoans. The methods described will be useful in identifying alternate hosts and morphologically diverse life stages in the complex life cycles of other myxosporea and in understanding the relationships between these parasites and their hosts.
238 citations
TL;DR: The occurrence of two ceratomyxid species in each host species supports that the genus Ceratomyxa is host-specific not only in sparids but also in serranids, which agrees with data previously obtained from Sparidae in Mediterranean Sea and from Serranidae in GBR, Australia.
Abstract: First parasitological surveys of Myxozoa are performed on the sparid saddled seabream Oblada melanura (Linnaeus, 1758) and the serranid painted comber Serranus scriba (Linnaeus, 1758) caught from the Bay of Bizerte and the Gulf of Tunis respectively in Northeast Tunisia, Western Mediterranean In this study, 6 bivalvulid myxosporean species belonging to the 3 genera Ceratomyxa Thelohan, 1892, Myxodavisia Zhao, Zhou, Kent & Whipps, 2008 and Zschokkella Auerbach, 1910, are isolated infecting their hosts Two species Ceratomyxa sp 1 ex O melanura (Prevalence (P) = 36%) and Ceratomyxa sp 2 ex O melanura (P = 13%) infected the saddled seabream and four species Ceratomyxa sp 1 ex S scriba (P = 117%), Ceratomyxa sp 2 ex S scriba (P = 67%), Myxodavisia sp (P = 83%) and Zschokkella sp (P = 56%) infected the painted comber These myxosporeans differ, in vegetative stages and/or in mature spores, from all the previously known congeneric species, and are described here on the basis of their morphological and morphometric features, their host and tissue specificities and their biogeographical distribution This is the first report of myxosporean infections in O melanura and S scriba The occurrence of two ceratomyxid species in each host species supports that the genus Ceratomyxa is host-specific not only in sparids but also in serranids, which agrees with data previously obtained from Sparidae in Mediterranean Sea and from Serranidae in GBR, Australia A member of the myxosporean genus Myxodavisia is recorded from the Mediterranean Sea for the first time, and Zschokkella spp infections have not previously been recorded from a host in Serranidae During the examination, a several cases of Co-infection among myxosporeans, both with two and three species, are provided and statistically studied Indeed, 5% of the breams and 94% of the combers are infected with more than one myxosporean parasite The relationship between myxosporean infections and some biological parameters are pointed out A higher prevalence of myxosporean infection is coincided with the peak period of spawning activity in May-June for S scriba For both hosts, analysis using Fulton’s condition factor (K) has revealed no significant difference between infected and non-infected fishes Clinically, no external signs of disease have been occurred in infected hosts, but some changes in the bile fluid, colour, and viscosity and in the gall bladder ’s tissue are examined in S scriba
101 citations
TL;DR: The position of C. shasta as a sister species to the Ceratomyxa clade contradicts previous estimates of marine myxozoan phylogeny and indicates a review of the diagnostic characters and possible division into more genera is warranted when further data are available.
82 citations
TL;DR: The secondary structural elements of V4 and V7 of the myxozoan 18S rRNAs were found to be highly informative and revealed evolutionary trends of various regions of the gene hitherto unknown, since previous analyses have been based on primary sequence data excluding these regions.
74 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 7 |
| 2020 | 3 |
| 2019 | 3 |
| 2018 | 6 |
| 2017 | 7 |
| 2016 | 5 |