Infection dynamics of two renal myxozoans in hatchery reared fry and juvenile Atlantic cod Gadus morhua L.

Abstract

S U M M A R YIn order to study the infection dynamics of 2 renal myxozoans, Zschokkella hildae Auerbach, 1910 and Gadimyxa atlantica Køie, Karlsbakk and Nylund, 2007 in cultured Atlantic cod, Gadus morhua L. aged 3-19 months, a specific single-round PCR assay and a double-label in situ hybridization protocol were developed. The results demonstrated that the 2 myxozoans show spatial separation of their development with regard to spore formation inside the renal tubules versus the collecting ducts and ureters, as well as temporal separation with Z. hildae proliferating and developing spores only once the G. atlantica infection decreases, despite the presence of both myxozoans in the smallest fry studied. These results strongly suggest within-host competition of the 2 myxozoans with potential suppression of Z. hildae by G. atlantica until G. morhua acquires immunity against G. atlantica. The quantification of the G. atlantica infection inside the renal tubules before and after a 29-day experimental growth performance study using fry from hatcheries with differing filtration systems showed that the intensity of infection with G. atlantica seems to be controlled if prolonged exposure to the myxozoan transmission stages takes place from hatching onwards. Surprisingly, growth rates in the trial were inversely affected suggesting that G. atlantica does not negatively influence cod fry growth performance.

Prevalence, site and tissue preference of myxozoan parasites infecting gills of cultured fish in Punjab (India)

“…Mixed infection with more than one species was recorded in 65.15% of fishes examined. Holzer et al (2010) In the present study, the myxozoan gills infection was recorded in the Indian major carps, and no parasite was recorded in the gills of the 3 exotic carps. According to White & Perkins (2012), invasive populations frequently harbour a reduced parasite community as compared with their native counterparts.…”

Myxozoa in high Arctic: Survey on the central part of Svalbard archipelago

“…Zschokkella hildae has been recorded in nine gadid fish including Arctic cod from Arctic region of Greenland (Køie et al, 2008b). Up to now SSU rDNA data of Z. hildae are available from the Atlantic cod only (Holzer et al, 2010). Hypothetically, more species can be revealed from the family Gadidae by molecular characterisation and they can represent hidden or misidentified species as in the case of Z. siegfriedi from Polar cod.…”

Molecular fingerprinting of the myxozoan community in common carp suffering Swim Bladder Inflammation (SBI) identifies multiple etiological agents

“…Thereafter, sequence alignments were performed using Geneious 7.0 (Biomatters Ltd., Auckland, New Zealand) and specific primers were designed/applied for the most abundant myxozoan species (Primo Pro 3.4, Chang Biosciences, http://www.changbioscience.com/primo/primo.html; Table 2). Primers were 5′ DIG labelled (Sigma-Aldrich, http://www.sigmaaldrich.com) and used for in situ hybridisation (ISH) employing a DIG-antiDIG-alkaline phosphatase protocol [17, 18]. PCR assays specific for S. dykovae and Sphaerospora molnari Lom et al, 1983 [15, 18] were used for kidney and blood samples.…”