these parasites to importing countries. Therefore, it
is recommended to intensify measures when
exporting H. eques and other ornamental fishes in
order to avoid the spread of parasitic isopods as B.
nasuta to other locations.
The parasitic cymothoid B. nasuta was originally
proposed from a single specimen (female) by
Schioedte & Meinert (1881) for the Brazilian coast.
Later, Lemos de Castro (1959) considered the
statement of Schioedte & Meinert (1881) that B.
nasuta is a marine species, as vague and probably
wrong, since two other specimens (males) were
found in freshwater. Braga nasuta shows
distribution restricted to the Brazilian territory with
reports for Amazonas, Bahia, São Paulo and Pará
States (Thatcher, 2006; Jesus et al., 2017). In
relation to hosts, B. nasuta was reported originally
for Hypostomus sp. (Siluriformes, Loricariidae)
(Thatcher, 2006) and, more recently, parasitizing
fingerlings of Arapaima gigas (Schinz, 1822)
(Osteoglossiformes, Arapaimidae) (Jesus et al.,
2017).
The main features used to identify the male
cymothoid (reported herein) to species level were
the morphology of cephalon, pleotelson, uropod,
and pereopods, and the color pattern of the dorsal
segments. This specimen exhibits the same
morphology and body color proposed and
illustrated by Lemos de Castro (1959). However, it
differs from the male specimens reported by Jesus
et al. (2017) for fingerlings of A. gigas (see Fig. 3 in
Jesus et al., 2017). Our specimen differs from those
of A. gigas by presenting: (i) large cephalon in
relation to the total body length (vs relative size of
cephalon to the total body length smaller); (ii)
cephalon truncated anteriorly (vs rounded
anteriorly); (iii) uropod extending beyond the apex
of pleotelson (vs smaller than the pleotelson); (iv)
exopod longer than endopod (vs similar in size); (v)
pleotelson triangular and wider than long (vs
rounded and as long as wide). Our specimen also
differs by presenting median pereon stripe and the
posterior stripe of each pereonite thinner (vs
thicker stripes). Because of these differences, we
believe that the specimens found on A. gigas
belong to another species of the genus Braga.
This study reported for the first the time infestation
of H. eques from Mato Grosso do Sul State, Brazil,
with B. nasuta and contributes to expanding the
22
knowledge about the geographical distribution and
the list of fishes parasitized by this isopod in this
country.
The authors thank the Conselho Nacional de
Desenvolvimento Científico e Tecnológico CNPq-
PROTAX (440496/2015-2) and FAPESP
2016/50377-1 for the financial support given to the
study. R. B. Narciso was supported by CNPq
(132844/2018-4) and R. J. da Silva was supported
by (CNPq, 307808/2014-9).
ACKNOWLEDGEMENT
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Hysterothylacium sp. Moravec, Kohn et
Fernandes, 1993 larvae (Nematoda:
Anisakidae) infecting the ornamental fish
Hyphessobrycon eques Steindachner, 1882
(Characiformes, Characidae). Brazilian
Journal of Biology, vol. 75, pp. 638-642.
Carvalho, LN, Arruda, R & Del-Claro, K. 2004.
Host-parasite interactions between the
piranha P y g o c e n t r u s n a t t e r e r i
(Characiformes: Characidae) and isopods
and branchiurans (Crustacea) in the
Araguaia River basin, Brazil. Neotropical
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Carvalho, LN & Del-Claro, K. 2004. Effects of
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of the serpa tetra Hyphessobrycon eques
(Os t ariophysi, Characida e ). Acta
ethologica, vol. 7, pp. 89-93.
Eiras, JC, Takemoto, RM & Pavanelli, GC. 2010.
Diversidade dos parasitas de peixes de
água doce do Brasil. Clichetec. Maringá,
Brazil, 333 pp.
Fujimoto, RY, Almeida, ES, Diniz, DG, Eiras, JC &
Martins, ML. 2013. First occurrence of
Quadrigyrus nickoli (Acanthocephala) in
the ornamental fish Hyphessobrycon eques.
Revista Brasileira de Parasitologia
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Jesus, EC, Cardoso, L, Ferreira, TH, Martins, ML
& Rodrigues, MDN. 2017. Braga nasuta
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