A taxonomic revision of the genus Anoplocephaloides Baer, 1923 sensu Rausch (1976), with the description of four new genera (Cestoda: Anoplocephalidae)
Author
Haukisalmi, Voitto
text
Zootaxa
2009
2057
1
31
journal article
10.5281/zenodo.186734
6fda694f-2d1b-4a55-b7ec-079f8c487e19
1175-5326
186734
Anoplocephaloides
Baer, 1923
(Fig. 1)
Diagnosis:
Strobila short and wide. Scolex large with prominent suckers directed anteriorly. Neck (unsegmented region) usually absent. Proglottides craspedote, much wider than long; velum curved posteriorly. Genitalia single. Genital pores unilateral, positioned slightly anterior to middle of proglottis margin. Genital atrium weak; genital papilla absent. Ventral osmoregulatory canals narrow, strongly arched. Genital ducts cross osmoregulatory canals dorsally. Internal and external seminal vesicles present. External seminal vesicle large in postmature proglottides, attaining or approaching size of cirrus sac. Cirrus sac short, barely extending across ventral longitudinal canal. Retractor muscle of cirrus sac absent. Testes arranged in single transverse group in antiporal part of proglottis, usually not extending beyond antiporal ventral longitudinal canal. Ovary large relative to proglottis size, transverse, more or less poral, sparsely lobed. Vagina short, not extending across ventral longitudinal canal; enters genital atrium ventral or postero-ventral to cirrus sac. Early uterus transverse tube in anterior part of proglottis, ventral to testes, extending ventrally and bilaterally across longitudinal osmoregulatory canals; poral end terminates anterior to cirrus sac and external seminal vesicle or partly overlaps them. Fully developed (pregravid) uterus sparsely sacculated with wide anterior and posterior sacculi that are pressed against adjacent sacculi throughout their development; distinct transverse trunk absent. Pyriform apparatus present. Female reproductive organs mature slightly earlier than male organs; testes persist after resorption of female glands overlapping developing uterus. Parasitic in geomyid (
type
hosts) and cricetid (
Arvicolinae
) rodents, exceptionally in other rodents.
Type
species:
A. infrequens
(
Douthitt, 1915
)
Baer, 1923
[syns.
Anoplocephala infrequens
Douthitt, 1915
,
Paranoplocephala infrequens
(
Douthitt, 1915
)
Baer, 1923
]; cotypes USNPC 49515 and 49520 from the plains pocket gopher
Geomys bursarius
(Shaw)
. Other species:
A. dentata
(
Galli-Valerio, 1905
)
Rausch, 1976
[syns.
Anoplocephala dentata
Galli-Valerio, 1905
,
Paranoplocephala dentata
(
Galli-Valerio, 1905
)
Spasskii, 1956
],
A. troeschi
(
Rausch, 1946
)
Rausch, 1976
(syn.
Paranoplocephala troeschi
Rausch, 1946
),
A. lemmi
(Rausch, 1952)
Rausch, 1976
(syn.
Paranoplocephala lemmi
Rausch, 1952
),
A. kontrimavichusi
Rausch, 1976
,
A. dentatoides
Sato, Kamiya, Tenora & Kamiya, 1993
and
A. bulmeri
Haukisalmi & Eckerlin, 2009
. Notice that
A. dentata
-like cestodes include at least 6 more or less cryptic species, as determined by molecular methods (Haukisalmi
et al.
2009).
Remarks.
The genus
Anoplocephaloides
is restricted to a monophyletic group of species with the above features (see also Haukisalmi
et al.
2009).
Anoplocephaloides
differs unequivocally from the other genera considered here with respect to the transverse, longitudinal and/or dorso-ventral position of the early uterus, except
Microcephaloides
,
Paranoplocephaloides
,
Hokkaidocephala
and
Gallegoides
Tenora & Mas-Coma, 1978
(Table 2).
Anoplocephaloides
differs markedly from
Microcephaloides
by its shorter and wider body, much larger scolex with anteriorly directed suckers, absence of a neck, posteriorly curved velum, slightly anterior position of the genital openings and antiporal extent of the testes (see also
Haukisalmi
et al.
2008b
).
Anoplocephaloides
can be unequivocally separated from
Paranoplocephaloides
by its short, ”wedgeshaped” body, larger scolex, shape of the velum, position of the genital openings and unilateral genital pores (see also
Gulyaev 1996
). In addition to the differences in the direction of the suckers, shape of the velum and lateral position of the genital openings,
Hokkaidocephala
differs from
Anoplocephaloides
(and other genera) by the peculiar structure of its fully developed (pregravid) uterus (see also
Haukisalmi
et al.
2008a
).
Gallegoides
has antiporal
and
anterior testes positioned mainly in the posterior part of the proglottis and alternating genital pores, which differentiates it unambiguously from
Anoplocephaloides
.
Anoplocephaloides lemmi
differs from the other species of
Anoplocephaloides
by its larger body with more numerous proglottides, more elongated anterior strobila and presence of a neck (
Rausch 1976 and the present study
). A recent molecular phylogenetic study shows unequivocally that
A. lemmi
forms a monophyletic group with the other
Anoplocephaloides
species (Haukisalmi
et al.
2009). In the phylogram based on sequences of the partial cytochrome I (COI) gene,
A. lemmi
formed the basal lineage within
Anoplocephaloides
, which seems to provide grounds for the separation of
A. lemmi
at the generic level. However, the phylogram based on sequences of the 28S ribosomal RNA, which is a more conservative region than COI, placed
A. lemmi
and
A. kontrimavichusi
as independent basal lineages within
Anoplocephaloides
. Because the phylogenetic relationships within
Anoplocephaloides
are still partly obscure and because
A. lemmi
confirms morphologically with the other
Anoplocephaloides
species (with a few deviations), it is retained in this genus.
Anoplocephaloides
spp., including
A. lemmi
, all inhabit the posterior small intestine, caecum or junction between them, in which respect they differ from all other species in the arvicoline clade of cestodes and phylogenetically related taxa.
FIGURE. 1.
Anoplocephaloides
spp.
A
. Strobila of
A.
cf.
dentata
from
Microtus arvalis
(scale-bar 1.0 mm).
B
. Mature proglottis of
A. infrequens
(cotype) from
Geomys bursarius
(scale-bar
0.50 mm
).
C, D
. Development of uterus in
A.
cf.
dentata
from
Microtus pennsylvanicus
(scale-bars
0.30 mm
).
E
. Male ducts of
A.
cf.
dentata
from
Microtus miurus
(scale-bar
0.20 mm
).
F
. Female ducts and early uterus of
A.
cf.
dentata
from
M. miurus
(scale-bar
0.20 mm
).