Unicapsula species (Myxosporea: Trilosporidae) of Australian marine fishes, including the description of Unicapsula andersenae n. sp. in five teleost families off Queensland, Australia

• Published in: Parasitology research (1987) Vol. 112; no. 8; pp. 2945 - 2957
• Main Authors: Miller, T. L., Adlard, R. D.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-08-2013; Springer
• Subjects: Acanthopagrus australis; Animals; Argyrosomus japonicus; Biomedical and Life Sciences; Biomedicine; DNA, Ribosomal - genetics; Eleutheronema tetradactylum; Epinephelus septemfasciatus; Fish Diseases - epidemiology; Fish Diseases - parasitology; Fishes; Health aspects; Host-parasite relationships; Immunology; Kudoa; Lutjanus; Marine; Medical Microbiology; Microbiology; Molecular Sequence Data; Multivalvulida; Myxosporea; Myxozoa - classification; Myxozoa - genetics; Myxozoa - isolation & purification; Myxozoans; Original Paper; Pacific Ocean - epidemiology; Parasitic Diseases, Animal - epidemiology; Parasitic Diseases, Animal - parasitology; Phylogeny; Physiological aspects; Pisces; Queensland - epidemiology; Scolopsis; Seriola lalandi; Sillago ciliata; Teleostei; Pacific Ocean; Queensland; Australia; ISW, Australia, Jurien Bay; ISEW, Australia, Queensland, Great Barrier Reef, Lizard I; ISW, Australia, Western Australia; INW, Japan; Queensland Museum; Caudal Appendage; Polar Capsule; Spore Valve; Yellowtail Kingfish
• ISSN: 0932-0113; 1432-1955
• DOI: 10.1007/s00436-013-3467-3

A survey of the myxosporean fauna of Australian marine fishes revealed the presence of three previously unreported species of
Unicapsula
(Multivalvulida: Trilosporidae) from sites off Southeast Queensland, off Lizard Island on the Great Barrier Reef, Queensland, and from Jurien Bay in Western Australia. Morphometric data (spore, polar capsule and caudal appendage dimensions) combined with Bayesian inference and maximum likelihood analyses of small subunit (SSU) and large subunit (LSU) ribosomal DNA (rDNA) were used for species identification and to explore relationships among these taxa. The four species of
Unicapsula
for which DNA data are now available for comparative purposes (
Unicapsula andersenae
n. sp.,
Unicapsula pflugfelderi
,
Unicapsula seriolae
and
Unicapsula pyramidata
) formed a well-supported monophyletic sister clade to the other major multivalvulidan group, the Kudoidae. The combined morphometric and genetic diagnostic approach identified an undescribed taxon,
U. andersenae
n. sp., from the muscle of
Argyrosomus japonicus
,
Acanthopagrus australis
and
Eleutheronema tetradactylum
off the Southeast Queensland coast and in
Lutjanus russellii
and
Sillago ciliata
off Lizard Island. Intra-specific variation within
U
.
andersenae
n. sp. varied from 2–4 (0.2–0.4 %) nucleotides over the SSU region to 2–20 (0.3–3.2 %) over the LSU region. Inter-specific variation between
U
.
andersenae
n. sp. and the other three species for which genetic sequence data are now available ranged from 15–66 (3–6.5 %) nucleotides over the SSU region to 103–120 (17.6–21.2 %) nucleotides over the LSU region. The host distribution observed here for
U
.
andersenae
n. sp. (five fish species from five different fish families) represents the broadest specificity known for a single species of
Unicapsula
.
U. pyramidata
Naidjenova & Zaika
1970
, whose spore morphology and presence of caudal appendages immediately distinguish it from other species, was recovered from the nemipterid,
Scolopsis monogramma
, off Lizard Island.
U. seriolae
Lester
1982
is reported here from Yellowtail Kingfish,
Seriola lalandi
, from sites off Queensland and from Jurien Bay, Western Australia. Comparative genetic analyses also revealed that an unidentified species of
Unicapsula
from
Epinephelus septemfasciatus
off Japan whose rDNA sequence data are available on GenBank is consistent with
U
.
seriolae
. This suggests that
U
.
seriolae
may also exhibit low host specificity and may be distributed widely throughout the Indo-West Pacific region. In comparison to other myxozoan genera, it is clear that the species richness of
Unicapsula
spp. falls well below that displayed by either
Ceratomyxa
spp. or
Kudoa
spp. The discovery of a further new species of
Unicapsula
in Australia now brings the total worldwide number of formally described
Unicapsula
species to a modest 11. Nonetheless, this taxon remains of significant interest to commercial and recreational fisheries through the potential production of macroscopic pseudocysts in fish muscle and post-mortem muscle liquefaction, both of which can render fish fillets unpalatable and unmarketable.