Comparative Parasitology 67(1) 2000 - Peru State College

strongylus pluteus differs from P. pearsoni in
the shape of the mouth opening, circular not
quadrangular in apical view; the buccal capsule
circular in cross section rather than slightly oval;
and the amphids not on extremely prominent lateral
projections. The nerve ring and excretory
pore of P. pearsoni are more posterior (Mawson,
1977, Fig. 31, p. 57), with the nerve ring surrounding
the junction of the isthmus and corpus
of the esophagus, than in P. pluteus, which has
the nerve ring and excretory pore in the midesophageal
region. The branchlets of the dorsal
ray of P. pluteus arise closer to its bifurcation
than do those of P. pearsoni.
Popovastrongylus pluteus is similar in general
features to P. wallabiae but differs in the features
of the cephalic end, particularly in the form
of the inner lining of the buccal capsule. Popovastrongylus
wallabiae does not have an internal
shelf, and the shape of the mouth opening is
circular, not quadrangular. The deirids, nerve
ring, and excretory pore of P. pluteus, although
located in the mid-region of the esophagus, are
each more anterior than their counterparts on P.
wallabiae (135, 402, and 463 compared with
270, 440, and 560, respectively, for males). The
dorsal lobe of the bursa of P. pluteus is about
the same length as the lateral lobes, but in P.
wallabiae it is longer. The vagina of P. wallabiae
(370-400) is shorter and its eggs (95-105
by 42-52) are smaller (135 by 70) than in P.
pluteus.
Popovastrongylus pluteus can be distinguished
from P. macropodis, which also occurs
in M. robustus, by the presence of a shelf in the
buccal capsule and in having a circular, not triangular
mouth opening. The buccal capsule is
more slender than that of P. macopodis (40 X
26 compared with 37 X 30), and the inner lining
is not as inflated as that of P. macropodis. The
vagina is longer (400-595) in P. pluteus, compared
with 360—400 in P. macropodis.
SMALES—POPOVASTRONCYLUS FROM MARSUPIALS 57
Discussion
This study has increased the number of
known hosts of Popovastrongylus to include T.
billardierii and extended the known distribution
of the genus to include New South Wales. Of
the 2 new species, P. tasmaniensis has been
found only in T. billardierii, the Tasmanian pademelon,
from Tasmanian localities, and P. pluteus
only in M. robustus, the common wallaroo
from New South Wales.
Of the previously known species, P. macropodis
is found in wallaroos as well as the other
large kangaroos, M. rufus and M. giganteus, the
red and eastern grey kangaroos, but only in
northern Queensland (Beveridge, 1986; Arundel
et al., 1979, 1990). Popovastrongylus thylogale,
also found in pademelons, has a distribution limited
to T. stigmatica, the red-legged pademelon,
and T. thetis, the red-necked pademelon in
Queensland. There is a single report of an accidental
infection of P. thylogale from a captive
agile wallaby, Macropus agilis (Gould, 1842)
(Spratt et al., 1991). Popovastrongylus thylogale
does not, however, occur in free-ranging agile
wallabies (Speare et al., 1983). Other northern
hosts of this parasite are P. persephone, the
Proserpine rock-wallaby, a host that harbors several
nematode species that normally occur in pademelons
and are not normally found in other
species of rock-wallaby (Begg et al., 1995; Beveridge,
1986), and T. brunii, the dusky pademelon,
found only in Papua New Guinea. This
latter occurrence emphasizes the northern distribution
of P. thylogale as it has been found in
neither the red-legged pademelon nor the rednecked
pademelon in New South Wales (Beveridge,
1986; Smales, 1997).
Popovastrongylus wallabiae occurs only in
the red-necked wallaby, M. rufogriseus, and is
the most widely distributed species of the genus,
being found in southern Queensland and Tasmania
(Mawson, 1977). It has not been reported
Figures 9-21. Popovastrongylus tasmaniensis sp. n. from Thylogale billardierii. 9. Anterior end (ventral
view). 10. Cephalic end, optical section (lateral view). 11. Cephalic end, optical section (ventral view). 12.
Buccal capsule, transverse optical section, at mid-level. 13. Spicule, anterior end (lateral view). 14. Spicule
tip (lateral view). 15. Cephalic collar (lateral view). 16. Cephalic end (dorsal view). 17. Buccal capsule,
transverse optical section at posterior level. 18. Genital cone (dorsal view). 19. Mouth opening (en face
view). 20. Bursa (apical view). 21. Bursa (lateral view). Scale bars: Figure 9 = 200 u.m; Figures 10, 11,
13-16, 18 = 25 jjim; Figures 12, 17, 19 = 10 |xm; Figures 20, 21 = 50 u.m.
Copyright © 2011, The Helminthological Society of Washington