DAO 76:123-129 (2007)  -  doi:10.3354/dao076123

ABSTRACT: Two species of Parvicapsula were found in the kidney tubules and the urinary bladder of 2 pleuronectid fish from the northern Øresund, Denmark. The coelozoic, spherical, disporic trophozoites of both species are 10 to 12 µm in diameter. The myxospores of both species are elongate, asymmetrical and slightly curved, and have spherical polar capsules. Parvicapsula bicornis n. sp. (6–8 × 5–6 µm, polar capsule 2.5 µm in diameter) occurs in Pleuronectes platessa. The polar capsules of P. bicornis are arranged symmetrically on either side of the longitudinal axis and its spores differ from other species of Parvicapsula in having two 2–3 µm long posterior processes of different length. Parvicapsula limandae n. sp. (8–11 × 4–5 µm, polar capsule 1.6 µm in diameter) is found in Limanda limanda. The polar capsules are arranged along the longitudinal axis. It differs from Parvicapsula unicornis Kabata, 1962, recorded from L. limanda, in the arrangement of the polar capsules and in the absence of a posterior horn-like projection. The phylogenetic relationship between P. bicornis n. sp., P. limandae n. sp. and other Parvicapsula spp. was examined with their partial small subunit rDNA (SSU rDNA) sequences. P. limandae n. sp. and P. asymmetrica appear to be closely related, while P. bicornis n. sp. and P. minibicornis are the most divergent members of the genus.

KEY WORDS: Myxozoan · Parasites · Parvicapsula bicornis n. sp. · Parvicapsula limandae n. sp. · Sphaerospora irregularis · Parvicapsula unicornis · Pleuronectes platessa · Limanda limanda · SSU rRNA gene sequences · Denmark