Two new species of myxosporean parasites (Myxosporea: Bivalvulida) from gall bladders of Macruronus magellanicus Lönnberg, 1907 (Teleostei: Merlucciidae)
Author
Kalavati, Chaganti
Author
Mackenzie, Ken
Author
Collins, Catherine
Author
Hemmingsen, Willy
Author
Brickle, Paul
text
Zootaxa
2013
3647
4
541
554
journal article
10.11646/zootaxa.3647.4.4
a5e152ff-81cd-4f14-a49a-35de4daff2c0
1175-5326
223001
D5B8E3C7-36D1-42EE-8785-4C2BB99BC62F
Palliatus magellanicus
n. sp.
Material studied
Host:
Macruronus magellanicus
Lönnberg, 1907
Site of infection:
gall bladder
Locality, date and depth:
(1) Off Chiloe
Island
,
Chile
, 43ºS, 73ºW,
June
2007
,
300m.
Type
locality:
(1)
Prevalence:
4% (1 of 25).
Host length range:
25–42 cm
.
Collection numbers:
NHMUK 2012.3.19.2.
Morphological description.
Sporoblast oval or irregularly shaped, disporic (
Fig.13
). Dimensions, based on 4 fixed specimens: 28.4–38.4 x 28.0–36.0. Developing sporoblasts show deeply staining cords (the origins of the membranous veil) twisted around the body (
Fig. 14
). These are clearly visible only when stained with Indian ink, but are indistinct and lightly stained in Giemsa preparations.
Spore subspherical or broadly oval (
Fig.15
). A smooth membranous veil originating anteriorly extends beyond the spore body posteriorly, enveloping the entire spore. Sutural ridge prominent anteriorly but thinner posteriorly. Keel-like appendages situated along the sutural ridge join together at the posterior extremity. Sporoplasm deeply staining and binucleate. Spore valves thin and smooth. Polar capsules pyriform, subterminal, one on either side of sutural line. Polar filament with 3–4 coils, not clearly visible. Dimensions, based on 15 fixed spores, as ranges with means and ± SD in parentheses: spore length 9.6–19.2 (13.64 ± 3.67); spore width 10.2–22.4 (19.03 ± 3.64); spore thickness 14.0–20.0 (16.09 ± 1.92); spore veil 32.0–48.0 (40.43 ± 6.47); polar capsule length 6.4–8.0 (6.93 ± 0.64); polar capsule width 3.2–5.4 (4.0 ± 0.80); spore length: spore width = 1: 0.8–0.96; polar capsule length: spore length = 1: 1.5–2.4.
Discussion.
This species was not observed during the initial examinations of gall bladders, but was discovered later as a double infection with
Pseudalataspora kovalevae
in a formalin-preserved sample from a fish originally identified as infected only with the latter species. We therefore have no molecular sequence and no photographs of fresh material. Only five species of
Palliatus
have been previously described from marine fishes, four from the gall bladder and one from the pancreas (Shulman
et al.
, 1979; Padma Dorothy & Kalavati, 1998; Aseeva, 2003). The new species differs considerably in morphology from all of these and the host and locality are both new for the genus
Palliatus
(Table 3).