Fróðskaparrit - 01.01.2002, Síða 139

VISTFRØÐIN HJÁ INNVORTIS SNÍKUM f LUNDA
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Newfoundland puffín (Threlfall, 1971).
Dyck (1975) mentioned pentastoines in
Faroese puffíns, but they were not further
identified.
Reighardia is the only known obligatory
one-host pentastome (Thomas etal., 1999).
Regarding its life cycle, Parker (1982)
state: ”Mature nymphs copulate in the ab-
dominal cavity of the host; males then die,
and females migrate to interclavicular air
sacs. The eggs all mature together, and are
liberated in one deposition, after which fe-
males die. Transmission from gull to gull is
primarily by feeding of young by adult re-
gurgitation. No alternate host is known.”
An alternative way of transmission is that
the female doesn’t shed the eggs, but serves
as a living container, climbing up the tra-
chea so irritates the host as to cause it to
vomit or cough up the eggs; a subsequent
bird swallowing the egg bulk may get in-
fested (Riley, 1983; Thomas et al., 1999).
The life-cycle is also supplemented by au-
toreinfestation (Riley, 1983). As puffíns do
not regurgitate when feeding their chick,
that leaves only the latter two possibilities
for transmission.
The specimens found in the intestine,
kidney and liver are evidently nymphs from
the abdominal cavities, while specimens
that occur in the trachea plus primary
bronchi are adult females.
Host-parasite interactions
Infestation
Compared to earlier analyses of the en-
doparasitic fauna of various seabird
species, the fauna of puffíns is sparse both
with respect to the number of species and
the number of individuals. The range for in-
fested puffíns in this study is one to three
species per host (1-39 individuals). Hoberg
and Ryan (1989) found for great shearwa-
ters (Puffinus gravis) two to fíve species per
host (114-4,016 individuals) and Riley and
Owen (1975) found in the intestine of l'ul-
mars (Fulmarus glacialis) three species per
host in the intestines only (7-656 individu-
als). Threlfall (1967) recorded a prevalence
of 98.10 % in herring gulls (Larus argenta-
tus) in Britain. Fulmars, great shearwaters,
and gulls are omnivorous, foraging only in
the surface waters (gulls also over land).
Puffíns on the other hand are more selective
regarding their food and are agile divers.
Diving depths in the order of 40 m are com-
mon among puffíns according to Burger
and Simpson, (1986). This difference in
foraging behaviour is inevitably an impor-
tant variable determinating the prevalence
and intensity of endoparasites in seabirds.
It seems that the puffins of the Faroe Is-
lands are more heavily infested than auks in
Newfoundland (Threlfall, 1971), and in
particular the Newfoundland puffin (preva-
lence 8 %), but the study by Threlfall spans
over three years of fieldwork, while the
fieldwork of present study was accom-
plished during one month, and within the
breeding season, the period in which the
parasitic fauna of birds is richest (Hoberg,
1981; Cox, 1993).
The time of year and duration of collec-
tion in a study of nematodes in Icelandic
puffins (Ólafsdóttir et al., 1996) are the
same as in the present investigation, ren-
dering them comparable. The puffins in