then were stained with carmine and cleared in
eugenol or creosote. The identification of cestodes
was based on Diaz (2006) and trematodes on
Travassos et al. (1969), Yamaguti (1971) and Diaz
(2006).
All collected helminths were deposited in the
Coleção Helmintológica do Instituto de
Biociências de Botucatu (CHIBB), Universidade
Estadual Paulista, municipality of Botucatu, São
Paulo State, Brazil.
Prevalence, mean intensity of infection and mean
abundance were calculated according to Bush et al.
(1997).
RESULTS
All individuals (n = 28) studied were parasitized
(overall prevalence = 100%), and a total of 3811
parasites was recovered. The mean intensity of
infection was 146.6 ± 19.4. All hosts were
juveniles, and their biometrics presented as
follows: body length - 44.6 ± 3.4 cm,
circumference of the body - 38.3 ± 2.1 cm, wing
length - 16.6 ± 2.5 cm, length of the nozzle - 5.4 ±
0.5 cm and length of the foot - 11 ± 0.7 cm.
The helminthfauna S. magellanicus was composed
only by three species: Contracaecum pelagicum
Johnston & Mawson, 1942 (Nematoda),
Cardiocephaloides physalis Sudarikov, 1959
(Digenea) and Tetrabothrium lutzi Parona, 1901
(Cestoda). All species were found in the digestive
tract, distributed between the stomach and small
intestine (Table 1).
Contracaecum pelagicum was found in the
stomach and small intestine of the studied birds. In
the first organ it was found in abundance,
occupying its entire length, making a total of 2435
individuals among 23 hosts. In the small intestine,
relative abundance was lower, since it was found
only 727 individuals in 21 hosts. Considering both
site of infection, the prevalence was 96.4%, with
high mean abundance and mean intensity of
infection. Cardiocephaloides physalis was found
only in the small intestine and there were 460
individuals among 19 hosts. This species occurred
in high prevalence but low abundance and intensity
of infection. Tetrabothrium lutzi, in the same way
of C. physalis, was located exclusively in the small
intestine, more specifically in the duodenum. It
was found 189 individuals in 10 hosts (Table 1).
DISCUSSION
This study evaluated the helminth fauna of S.
magellanicus from the municipality of Ilha
Comprida, São Paulo State, Brazil. Among the
three helminth species found, two of them were
core species (C. pelagicum and C. physalis) and
one was satellite (T. lutzi), as defined by Bush et al.
(1997). All specimens studied were infected with at
least one species of helminth, a fact also noted by
Diaz (2006). However, studies with S.
magellanicus in Chile (66.6%) (González-Acuña et
al., 2008) do not found a high prevalence as
reported in this study.
Contracaecum pelagicum showed high prevalence
and mean intensity of infection as observed in the
studies of Pazos (2006) and Díaz et al. (2000). This
nematode can infect several hosts and it was first
recorded in black brow albatross (Diomedea
melanophris Temmick, 1828) in Australia and
since then the infection was reported in other
seabirds as brown booby (Sula leucogaster
Boddaert, 1783) (Silva et al., 2005). In Brazil, this
parasite was identified in populations of S.
magellanicus from various regions, such as Rio
Grande do Sul (Bassi et al., 2008) and Espírito
Santo (Ederli et al., 2009) and has been found
distributed between the stomach and intestine.
Larvae of C. pellagicum were found in fish (Timi,
2003) and cephalopods (Cremonte & Laurenti,
2005 apud Diaz, 2006), preys that serve as food for
these birds and, therefore, act in the transmission of
this parasite to birds. During the pelagic time, S.
magellanicus presents changes in eating patterns
and the main food items are cephalopods,
Argonauta nodosa Lightfoot, 1786, Loligo plei
Blainville, 1823 and Loligo sanpaulensis
Brakoniecki, 1984 (Pinto et al., 2007). This change
creates a nutritional deficiency making juvenile
weaker and more propense to death (Pinto et al.,
2007, González-Acuña et al., 2008), which would
explain the high mortality rate of individuals that
reach the coast (Pinto et al., 2007).
For C. physalis, prevalence also was high, but the
mean intensity of infection was low in comparison
to data presented by Díaz (2006), in which a high
prevalence (55.6%) and intensity of infection (153)
was observed. This genus has very similar
morphology between their representatives and it is
composed by seven species (Dubois, 1968).
Among the birds, their hosts are distributed in three
families Laridae, Anatidae and Procellaridae
Neotrop. Helminthol., 5(1), 2011
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