Parvicapsula bicornis n. sp. and P. limandae n. sp. (Myxozoa, Parvicapsulidae) in Pleuronectidae (Teleostei, Heterosomata) from Denmark

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 Resale or republication not permitted without written consent of the publisherDis Aquat Org 76: [123][124][125][126][127][128][129] 2007 capture, but some were kept in aquaria for up to 1 wk. Most organs including the musculature, the eyes, the gall bladder and urinary system were examined. Fresh squash preparations of the urinary bladder and various parts of the kidney were examined for Myxosporea. Smears were air-dried, methanol-fixed, stained with Giemsa and embedded in DPX. Measurements (n = 10) are based on fresh smears and are given as the mean with the range in parenthesis.DNA was extracted from kidney tissue or urinary bladders containing Parvicapsula spp. trophozoites or spores, using the DNeasy protocol for animal tissues (Qiagen). The DNA were eluted in 100 µl AE buffer supplied with the Qiagen-kit and stored at -20°C before use in a PCR.The PCR primers used were Ecf and Myxgen4r (Kent et al. 2000, Nylund et al. 2005) with additional primers constructed based on small subunit rDNA (SSU rDNA) sequences from Parvicapsula spp. and other members of the marine group of Myxosporea: forward MarF1 (RRG CGT GCC TTG AAT AAA GC) and MyxF2 (CGC GCA AAT TAC CCA ATC CAG AC), reverse LyR2 (CCT TGC GAT TGT ACT CTC CC) and MarR2 (STA GCG ACG GGC GGT GTG).The PCR amplifications were performed in a total volume of 50 µl, using 2 µl of template DNA and a reaction mixture consisting of 5 µl 10 × PCR buffer, 5 µl 10 mM dNTP, 2 µl (10 mM) of the rever...

Ellipsomyxa syngnathi sp. n. (Myxozoa, Myxosporea) in the pipefish Syngnathus typhle and S. rostellatus (Teleostei, Syngnathidae) from Denmark

“…However, these three morphologically distinct myxosporeans show low sequence divergence in their SSU rDNA, only 0.5%. A similar case was encountered by Køie et al (2007a) regarding the morphologically dissimilar Parvicapsula asymmetrica Shulman, 1953 and P. limandae Køie et al, 2007, showing 99.3% identity of their partial SSU rDNA sequences. Clearly, sequence identity alone may be inadequate to identify new myxosporean species but can be used together with morphological characters (Whipps et al 2003).…”

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

“…This species was later assigned to other genera: Myxoproteus (Gaevskaya and Kovaleva, 1984), and Ortholinea (Arthur and Lom, 1985). After re-examination, Køie et al (2007b) suggested S. irregularis may belong to Parvicapsula . Despite S. irregularis was reported from another host, Pleuronectes platessa (MacKenzie et al, 1976), this report most probably corresponds to Parvicapsula bicornis later described from this host (Køie et al, 2007b).…”

“…After re-examination, Køie et al (2007b) suggested S. irregularis may belong to Parvicapsula . Despite S. irregularis was reported from another host, Pleuronectes platessa (MacKenzie et al, 1976), this report most probably corresponds to Parvicapsula bicornis later described from this host (Køie et al, 2007b). Unfortunately, the report of “ S. irregularis ” by MacKenzie et al (1976) lacked sufficient morphological documentation and comparison with similar species.…”

“…part. of S. irregularis (Køie et al, 2007b). Since this species is now re-examined and molecularly characterised we claim that P. bicornis and the re-described P. irregularis are two morphological and molecularly different species.…”

The marine herring myxozoan Ceratomyxa auerbachi (Myxozoa: Ceratomyxidae) uses Chone infundibuliformis (Annelida: Polychaeta: Sabellidae) as invertebrate host

“…DNA was extracted from two pieces of infected tissue per host type (duplicate DNA samples) using the DNeasy ® Tissue Kit protocol for animal tissues (Qiagen, Hilden, Germany). The PCR primers used were the forward primers Erib1, MarF1 and MyxF2, and the reverse primer Myxgen4r (Barta et al 1997, Kent et al 2000, Nylund et al 2005, Køie et al 2007a) with the addition of two new reverse primers MybiR (5'AAT TTC ACC TCT CGC GGC AA) and RosR2 (5'ATC CTT CCG CAG GTT CAC CTA CGG). The PCR amplifications were performed in a total volume of 50 µl using 2 µl of template DNA and a reaction mixture consisting of 5 µl 10 × PCR buffer (NE Biolabs), 5 µl 10 mM dNTP, 2 µl (10 mM) of the reverse and forward primer, 2 U of thermostable DNA polymerase (Qiagen) and 34 µl dH 2 O.…”