Fish parasites in the Arctic deep-sea - Marine Parasitology Site
Fish parasites in the Arctic deep-sea - Marine Parasitology Site
Fish parasites in the Arctic deep-sea - Marine Parasitology Site
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1178<br />
ARTICLE IN PRESS<br />
S. Klimpel et al. / Deep-Sea Re<strong>sea</strong>rch I 53 (2006) 1167–1181<br />
demonstrated that Copepoda (Calanoida) get <strong>in</strong>fested<br />
with free-swimm<strong>in</strong>g cercariae and function as<br />
<strong>in</strong>termediate hosts. The life cycle of Anisakis simplex<br />
varies with habitat. Calanoid Copepoda or Euphausiacea<br />
are first <strong>in</strong>termediate hosts for Anisakis<br />
simplex third-stage larvae at different localities<br />
(Klimpel et al., 2003, 2004). Small pelagic fish<br />
species, such as pearlside (Maurolicus muelleri), and<br />
Cephalopoda act as obligatory (second) <strong>in</strong>termediate<br />
or transport hosts, while Cetacea and sometimes<br />
P<strong>in</strong>nipedia are def<strong>in</strong>itive hosts (e.g., Klimpel et al.,<br />
2003, 2004). Studies on Argent<strong>in</strong>a silus along <strong>the</strong><br />
Scotian Shelf and St. Pierre Bank revealed that<br />
young specimens are mid-water plankton feeders<br />
(Scott, 1969). Cohen (1958) found digested ‘‘shrimplike<br />
crustaceans’’, which are supposed to be<br />
Euphausiacea <strong>in</strong> <strong>the</strong> stomach of western Atlantic<br />
specimens. The stomach contents also revealed<br />
fragments of salps and Ctenophora (Mauchl<strong>in</strong>e<br />
and Gordon, 1983). Dur<strong>in</strong>g <strong>the</strong> present study, only<br />
crustaceans were identified <strong>in</strong> <strong>the</strong> stomachs of<br />
Argent<strong>in</strong>a silus. The predom<strong>in</strong>ant prey was Euphausiacea,<br />
followed by Copepoda. While <strong>the</strong><br />
copepods can be considered as second <strong>in</strong>termediate<br />
hosts for D. varicus, both crustacean groups<br />
represent important first and second <strong>in</strong>termediate<br />
hosts for Anisakis simplex <strong>in</strong> <strong>the</strong> studied area.<br />
4.4. Borostomias antarcticus<br />
The mesopelagic Borostomias antarcticus is distributed<br />
<strong>in</strong> <strong>the</strong> eastern Atlantic and from Greenland<br />
south to <strong>the</strong> Bay of Biscay (Froese and Pauly, 2005)<br />
at a depth between 500 and 1200 m (Roberts, 1991)<br />
(Fig. 3). Sigurjsson et al., (2002) reported that <strong>the</strong>y<br />
belong to a group of most common species with a<br />
relatively uniform distribution <strong>in</strong> <strong>the</strong> Irm<strong>in</strong>ger Sea.<br />
Borostomias antarcticus preys ma<strong>in</strong>ly upon pelagic<br />
fishes and Crustacea (Froese and Pauly, 2005).<br />
Stomach analyses of Borostomias antarcticus from<br />
<strong>the</strong> Rockall Through conta<strong>in</strong>ed semi-digested Mysidacea<br />
(Mauchl<strong>in</strong>e and Gordon, 1983), and Copepoda<br />
and fishes were <strong>the</strong> dom<strong>in</strong>ant prey items<br />
dur<strong>in</strong>g <strong>the</strong> present study. While <strong>the</strong> Copepoda serve<br />
as <strong>in</strong>termediate hosts for <strong>the</strong> anisakid Anisakis<br />
simplex (see above), <strong>the</strong> predatory Borostomias<br />
antarcticus acquires and accumulates larval tetraphyllideans<br />
<strong>in</strong> high numbers by <strong>in</strong>gest<strong>in</strong>g copepods<br />
or small pelagic fish species that are <strong>in</strong>fested and<br />
serve as carriers. These cestodes are very common <strong>in</strong><br />
all k<strong>in</strong>ds of predatory oceanic fish and also <strong>in</strong> <strong>the</strong><br />
<strong>deep</strong>-<strong>sea</strong> (e.g., Klimpel et al., 2001). Mar<strong>in</strong>e<br />
Crustacea (Copepoda) are probably first <strong>in</strong>termediate<br />
hosts, different fish species act as second<br />
<strong>in</strong>termediate hosts, and Elasmobranchii serve as<br />
f<strong>in</strong>al hosts.<br />
4.5. Chauliodus sloani<br />
The mesopelagic Chauliodus sloani is distributed<br />
<strong>in</strong> <strong>the</strong> North Atlantic, <strong>the</strong> Mediterranean Sea and<br />
<strong>the</strong> Indian Ocean (Froese and Pauly, 2005) at a<br />
depth of 500 m (Sigorjsson et al., 2002) (Fig. 3). The<br />
predom<strong>in</strong>ant <strong>parasites</strong> were unidentified tetraphyllidean<br />
larvae (Scolex pleuronectis) from <strong>the</strong> <strong>in</strong>test<strong>in</strong>e<br />
at a prevalence of 47.6%. Gartner and Zwerner<br />
(1989) already detected tetraphyllideans <strong>in</strong> <strong>the</strong><br />
<strong>in</strong>test<strong>in</strong>e of <strong>the</strong> same species. In addition, we<br />
isolated <strong>the</strong> Digenea D. varicus from <strong>the</strong> stomach<br />
at a prevalence of 4.8%. These data also correspond<br />
to <strong>the</strong> f<strong>in</strong>d<strong>in</strong>gs of Gartner and Zwerner (1989) <strong>in</strong> <strong>the</strong><br />
western North Atlantic. The authors recorded one<br />
unidentified Digenea species <strong>in</strong> Chauliodus sloani at<br />
a prevalence of 2.8%.<br />
Williams et al. (2001) exam<strong>in</strong>ed <strong>the</strong> stomach of 57<br />
Chauliodus sloani from <strong>the</strong> sou<strong>the</strong>rn Tasmanian Sea<br />
and found Myctophiformes and Stomiiformes fish<br />
as ma<strong>in</strong> food items. Dur<strong>in</strong>g <strong>the</strong> present study, <strong>the</strong><br />
stomachs of three specimens of Chauliodus sloani<br />
conta<strong>in</strong>ed fragments of fish, and a fur<strong>the</strong>r specimen<br />
fragments of Cephalopoda. Consequently, Chauliodus<br />
sloani seems to accumulate tetraphyllideans by<br />
<strong>in</strong>gest<strong>in</strong>g <strong>in</strong>fected juvenile fish or Cephalopoda. The<br />
small <strong>in</strong>festation rate with D. varicus can be<br />
expla<strong>in</strong>ed by <strong>the</strong> separation of <strong>the</strong> mollusc first<br />
<strong>in</strong>termediate hosts from <strong>the</strong> mesopelagic environment<br />
(Køie, 1979).<br />
4.6. Lampanyctus macdonaldi<br />
The mesopelagic Lampanyctus macdonaldi is<br />
distributed <strong>in</strong> <strong>the</strong> North Atlantic Ocean, at <strong>the</strong><br />
Antarctic polar front and between <strong>the</strong> subtropical<br />
convergence and Antarctic polar front (Hulley,<br />
1984). In <strong>the</strong> Irm<strong>in</strong>ger Sea, this fish is a component<br />
of <strong>the</strong> <strong>deep</strong>-scatter<strong>in</strong>g layer at a depth range of<br />
60–1000 m (Hulley, 1984; Magnu´ sson, 1996; Sigurjsson<br />
et al., 2002) (Fig. 3).<br />
The exam<strong>in</strong>ed specimens of Lampanyctus macdonaldi<br />
revealed only two parasite species. One fish<br />
harbored three unidentified Nematoda with<strong>in</strong> a cyst<br />
and one nematode <strong>in</strong> <strong>the</strong> <strong>in</strong>test<strong>in</strong>e. Two fur<strong>the</strong>r<br />
specimens were <strong>in</strong>fested with larval stages of<br />
Tetraphyllidea <strong>in</strong>det. (Scolex pleuronectis). Gartner