Myxosporea (Cnidaria: Myxozoa) infecting the saddled seabream Oblada melanura (L. 1758) (Teleostei: Sparidae) and the painted comber Serranus scriba (L. 1758) (Teleostei: Serranidae) in Tunisia
Author
Laamiri, Sayef
text
Zootaxa
2017
4269
1
61
100
journal article
33012
10.11646/zootaxa.4269.1.3
32e7aaf6-319c-48a3-9daf-cfb5fd21c39c
1175-5326
581304
1266D96E-57FC-4768-A347-A9D395FCDBCF
Ceratomyxa
sp. 1 ex
S. scriba
Host
:
Serranus scriba
Linnaeus, 1758
painted comber (
Perciformes
:
Serranidae
).
Locality
:
Mediterranean
off
Tunisia
,
Sidi Daoud
, Gulf of
Tunis
(
37° 01’ N
10° 55’ E
).
Site of infection:
Within gall bladder.
Prevalence:
The overall prevalence is 11.7% (21/180). The frequency of infection is distributed as following, 03/2012: 3.3% (1/30); 04/2012: 6.7% (2/30); 05/2012: 20% (6/30); 06/2012: 20% (6/30); 07/2012: 13.3% (4/30); 08/2012: 6.7% (2/30) (
Table 10
).
Mean intensity:
154±44 spores/20µl bile/infected fish (++++++) (
Table 10
).
Vouchers:
Digitized photos of spores are deposited in the parasitological collection of the Museum National d’Histoire Naturelle (
MNHN
), Paris,
Coll. No. ZS
136.
Morphological description. Vegetative stages.
No vegetative stages are observed. The bile is turbid due to the presence of large number of free floating spores with bile salts and cell debris. Infrequently, the spores of this parasite are remarked in the bile mixed with scarce
Triangula
sp. infection (
Fig. 3
H).
FIGURE 3.
Photomicrographs of
Ceratomyxa
sp. 1
from the gall bladder of
Serranus scriba
. (A–F) Variable forms of fresh mature spores in sutural view presenting the pyriform polar capsules (
pc
), the straight suture line (
sl
), the sporoplasmic nuclei (
sn
), the capsulogenic nucleus (
cn
) and the unequal valves. Scale bar = 10 µm.
Myxospores.
Spores typical for the genus
Ceratomyxa
(n = 30 fresh spores). Mature spores are crescentshaped to arched with anterior margin convex and posterior slightly concave one in sutural view, transversely elongate in lateral view (
Figs. 3
A–I, 8A–B) measuring 8.6±1.1 (7.0–10.8) µm in length and 52.6±5.8 (42.8–61.1) µm in thickness. Posterior angle is slightly concave to slightly convex 153.8±16.9 (120–174°). Two elongated shell valves strikingly attenuate towards the extremities with pointed ends in sutural view (
Figs. 3
A–H, 8A) and with rounded ends in lateral view (
Figs.
3
I, 8B). They are sub-equal in some spores but the most, are unequal in size, with one tapering to a significantly greater degree than the other (
Figs. 3
A–I, 8A–B). The longer valve measuring 34.5±3.0 (30.6–40.5) µm while the shorter one 27.7±3.8 (20.6–33.2) µm. The suture line is straight and visible
TABLE ³.
Comparison of the spore measurements of the present
Ceratomyxa
sp.]
ex
S. scriba
with taxonomic affinities species (measurements are in µm). Abbreviations: SL, Spore Length;, Spore Thickness; PCL, Polar Capsule Length; PCW, Polar Capsule Wiđth; ND, Not Determineđ.
Species Host (s) Locality Spore Polar capsule
SL ST PCL PCW
Ceratomyxa
sp.]
(Present stuđy)
Serranus scriba
Tunisia
(Gulf of
Tunis
) 8.6 52.6 4.2 3.6
(7/10.8) (42.8/61.1) (4/4.5) (3.2/4)
sphaerulosa
Thélohan (1892)
*Mustelus vulgaris
France (Roscoff, Monaco) (10/12) (90/100) (6/7) 5
*Galeus canis
Clupea harengus
Scullium canicula
attenuata
Davis (1917)
Scoliodon terranovae
USA (Atlantic Ocean) 9 115 4.5 4.5
flagellifera
Davis (1917)
Carcharhinus
sp.
USA (Atlantic Ocean) 12 118 6 6
mesospora
Davis (1917)
*
Cestracion
USA (Atlantic Ocean) 8 (50/60) 4.5 4.5
zygaena
Cestracion tiburo
streptospora
Davis (1917)
Choetodipterus faber
USA (Atlantic Ocean) 4 (34/39) 3 3
robusta
Fujita (1923)
*Atherestes
Japan (Sea of Japan) (18/20) (115/120) 5.6 4.5
evermani
Lepidopsetta mochgorei
Microstomus kitt
tenuis
Fujita (1923)
*
Hippoglossoides
Japan (Sea of Japan) (10/15) (108/112) (4/5) (3/4)
hamiltoni
Limanda aspera
Microstomus kitt
orientalis
Dogiel (1948) Shulman
*Sardinops sagax
Russia (Sea of Japan) (7/11) (33/72) 3 3.3 1966)
melanosticta
Clupea harengus pallasi
porrecta
Dogiel (1948) Shulman
*Gymnacanthus
Russia
(
Sea
of
Japan
) (4/6) (50/60)
3 3 1966
)
herzensteini
Myoxocephalus brandti
Bero elegans
lepidopusi
Meglitsch (1960)
Lepidopus candatus
New Zealanđ (Pacific Ocean) 9.9 91(72.6/99) 3(2.2/3.3) 3(2.2/3.3)
(7.7/11)
auerbachi
Kabata (1962)
Clupea harengus
Scotlanđ (North sea) 10 75(57/92) 5(3/6) 5(3/6)
(7/13)
swaisi
Abđel-Ghaffar
et al
. (2008a)
Saurida undosquamis
Egypt (Ređ sea) 7.8 51.5(43/55) 3.2 1.8
(7/9) (3/4) (1.5/2)
carcharhini
Glees
-on & Ađlarđ
Carcharhinus melanopterus
Australia
(Great Barrier 10 58.1 3.8 3.7 2011) Reef) (9/11.5) (46/77.5) (3.5/4) (3.5/4) Original host.
between valves (
Figs. 3
C–D). Sporoplasm homogenous with numerous sporoplasmosomes, are symmetrically situated, but extending only a short distance into each valve and contain two nuclei which each one occupied one side and rarely migrated both to one side (
Figs. 3
A–B). One capsulogenic nucleus is situated beneath one of the polar capsules (
Fig. 3
B). Two polar capsules are pyriform conspicuously separated from each other and measuring 4.2±0.2 (4.0–4.5) µm in length equaling 52.5% of spore length and 3.6±0.2 (3.2–4.0) µm in width (n = 30), they are positioned medially in the apex of spore in sutural view (
Figs. 3
A–I, 8A) and centrally of spore cavity in apical view. The polar filament forms four to five turns arranged along the longitudinal axis of the capsule. Occasionally, aberrant spores with 3 polar capsules and 3 valves are observed among the spores (
Fig. 3
J).
Taxonomic affinities.
Our attempts at identification of the recent finding species follow the same considerations mentioned in the preceding species. In Mediterranean Sea, none of the
Ceratomyxa
spp. recorded in the study of
Siau & Sakiti (1981)
from some serranids in Southeast Tunisian coasts resemble morphologically or overlap within the measurements range of the current species (
Table 6
). The only Mediterranean marine
Ceratomyxa
that shows some superficial similarity in shape and form to our species, is
C. sphaerulosa
Thélohan, 1892
reported from the gall bladders of numerous unrelated fishes hosts from Bergen in
Norway
and from Roscoff and Mediterranean off
Monaco
,
France
(Table 3). The recent species distinguishes from
C. sphaerulosa
by having two unequal shell valves and smaller spores and polar capsules. Furthermore, the sporoplasm deposits asymmetrically within the spores of this species on the contrary to the current studied form.
According to the parasitological reports, several species of
Ceratomyxa
have been properly reported from
Serranidae
family among the wide word;
C. angusta
,
C. gemmaphora
Meglitsch, 1960
,
C. epinephela
,
C. reniforma
,
C. guishanensis
Wu,
Wu & Dingke, 1993
,
C. brayi
,
C. whippsi
,
C. gleesoni
,
C. hooperi
,
C. nolani
,
C. yokoyamai
Gunter & Adlard, 2009
, C.
hamour
Mansour, Al-Qahtani, Al-Quraishy & Abdel-Baki, 2014
and most recently
C. husseini
Abdel-Baki, Mansour, Al-Qahtani, Al Omar & Al-Quraishy, 2015
(
Table 6
). From all these above mentioned congeneric species, the recent species is superficially similar in form to
C. angusta
,
C. epinephela
and
C. yokoyamai
. Nevertheless, only
C. angusta
has unequal shell valves as the present species, but its spores and spherical polar capsules seem to be significantly smaller. Likewise, both
C. epinephela
and
C. yokoyamai
are thinner in all levels and posses each one two spherical polar capsules.
Among the remaining
Ceratomyxa
spp. from clearly distinct geographical areas and hosts,
C.
sp. 1
is superficially closer to numerous species from unrelated marine fishes:
C. attenuata
,
C. flagellifera
,
C. mesospora
,
C. streptospora
Davis, 1917
,
C. robusta
,
C. tenuis
Fujita, 1923
,
C. orientalis
and
C. porrecta
Dogiel, 1948
(cited from
Shulman 1966
),
C. lepidopusi
Meglitsch, 1960
(previously
C. elongata
, see Gunter & Adlard 2010),
C. auerbachi
Kabata, 1962
,
C. swaisi
Abdel-Ghaffar, Ali, Al-Quraishy, Al-Rasheid, Al-Farraj, Abdel-Baki & Bashtar, 2008a
and
C. cacharhini
Gleeson & Adlard, 2011
(Table 3).
However, every time the recent finding myxosporean exhibits one or more distinguishing characteristics. It differentiates from
C. attenuata
by having thinner spores and two pyriform polar capsules. Furthermore, the shell valves of this later species are unequal and dissimilar while one being about 15 shorter than the other and ending abruptly, the longer valve tapering gradually to a point disagreeing with the morphological features of our species.
C. flagellifera
is the closest to the current species in form and shape, however it has larger and thicker spores. Besides, its polar capsules are typically spherical and bigger. Although, most of the morphometric measurements coincide between the present species and
C. mesospora
, this later possess two equal valves and two spherical polar capsules. Furthermore, the sporoplasm are asymmetrically situated within its spores and sometimes being entirely confined to the larger valve on the contrary to the current finding.
C. streptospora
appears to have shorter and thinner spores compared to those of the present species and its polar capsules are spherical.
C. robusta
resembles to our species only in shape but no measurements overlap between both species. The spores of
C. tenuis
are much bigger.
C. orientalis
has two smaller polar capsules. The spores of
C. porrecta
are shorter, its shell valves are thinner and contain two spherical smaller polar capsules. The spores of both
C. lepidopusi
and
C. auerbachi
are thicker than those of our species, its valves are equal in size and its polar capsules are spherical.
C. swaisi
is separated from the current species by having smaller polar capsules. Moreover, the shell valves of the present finding are unequal in size and much narrower than those of
C. swaisi
. The average range of spores of
C. carcharhini
is bigger than that of our species and their polar capsules are spherical. In addition,
C. carcharhini
has morphologically a strongly convex anterior end and more concave posterior one compared to the slightly convex anterior end and slightly posterior one of the recent finding and is, therefore a distinct species. In light of these differences with closely related species and since no
Ceratomyxa
species recorded thus so far is identical, we propose to mention the recent myxozoan
Ceratomyxa
sp. 1
as a special species has found infecting, by the first time, the gall bladder of
S. scriba
in Mediterranean Sea.