J Lovey
Paul Hershberger
Sarah E Friend
2016
<p><span>Surveillance for pathogens of Atlantic herring, including viral hemorrhagic septicemia virus (VHSV),</span><i>Ichthyophonus hoferi</i><span>, and hepatic and intestinal coccidians, was conducted from 2012 to 2016 in the NW Atlantic Ocean, New Jersey, USA. Neither VHSV nor </span><i>I. hoferi</i><span> was detected in any sample. </span><i>Goussia clupearum</i><span> was found in the livers of 40 to 78% of adult herring in varying parasite loads; however, associated pathological changes were negligible. Phylogenetic analysis based on small subunit 18S rRNA gene sequences placed </span><i>G. clupearum</i><span> most closely with other extraintestinal liver coccidia from the genus </span><i>Calyptospora</i><span>, though the </span><i>G. clupearum</i><span> isolates had a unique nucleotide insertion between 604 and 729 bp that did not occur in any other coccidian species. </span><i>G. clupearum</i><span> oocysts from Atlantic and Pacific herring were morphologically similar, though differences occurred in oocyst dimensions. Comparison of </span><i>G. clupearum</i><span> genetic sequences from Atlantic and Pacific herring revealed 4 nucleotide substitutions and 2 gaps in a 1749 bp region, indicating some divergence in the geographically separate populations. Pacific </span><i>G. clupearum</i><span> oocysts were not directly infective, suggesting that a heteroxenous life cycle is likely. Intestinal coccidiosis was described for the first time from juvenile and adult Atlantic herring. A novel intestinal coccidian species was detected based on morphological characteristics of exogenously sporulated oocysts. A unique feature in these oocysts was the presence of 3 long (15.1 ± 5.1 µm, mean ±SD) spiny projections on both ends of the oocyst. The novel morphology of this coccidian led us to tentatively name this parasite </span><i>G. echinata</i><span> n. sp.</span></p>
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10.3354/dao03016
en
Inter-Research
Disease surveillance of Atlantic herring: molecular characterization of hepatic coccidiosis and a morphological report of a novel intestinal coccidian
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