Ciliate species diversity and host-parasitoid codiversification in Pseudocollinia infecting krill, with description of Pseudocollinia similis sp. nov.

TitleCiliate species diversity and host-parasitoid codiversification in Pseudocollinia infecting krill, with description of Pseudocollinia similis sp. nov.
Publication TypeJournal Article
Year of Publication2014
AuthorsLynn, DH, Gómez-Gutiérrez, J, Strüder-Kypke, MC, Shaw, CT
JournalDiseases of Aquatic Organisms
Volume112
Issue2
Pagination89 - 102
Date PublishedFeb-12-2014
ISSN0177-5103
KeywordsEuphausiids · Apostomatida · Small subunit rRNA · SSUrRNA · Cytochrome c oxidase subunit 1 · cox1 · Oregon
Abstract

All parasitoid apostome ciliates infecting krill in the northeastern Pacific are currently
assigned to the genus Pseudocollinia. Each krill specimen is apparently infected by only 1
Pseudocollinia species. We describe Pseudocollinia similis sp. nov., discovered infecting the krill
Thysanoessa spinifera off Oregon, USA. Its protomite-tomite stage resembles that of P. beringensis,
which infects T. inermis (type host species), T. longipes, and T. raschii females in the Bering
Sea. These ciliates have similar numbers of somatic kineties (18−21 vs. 16−20) and typically have
3 oral kineties. Furthermore, these 2 apostomes are sister species on gene trees based on
sequences of small subunit rRNA (0.06% difference) and cytochrome c oxidase subunit 1 (cox1;
30% difference). P. brintoni and P. oregonensis are closely related as a separate group from P. similis
and P. beringensis. The similar tree topologies based on the cox1 sequences of 21 host krill
individuals representing 6 krill species (Euphausia pacifica, Nyctiphanes simplex, T. inermis,
T. longipes, T. raschii, and T. spinifera) and the apostomes isolated from these krill suggest
host−parasitoid codiversification. However, this hypothesis was statistically rejected by an
approximately unbiased test in which the host tree topology was used to model parasitoid evolution
(p ≤ 0.05).

URLhttp://www.int-res.com/abstracts/dao/v112/n2/p89-102/http://www.int-res.com/articles/dao2014/112/d112p089.pdf
DOI10.3354/dao02796
Short TitleDis. Aquat. Org.