Phylogenetic relationships and taxonomic revision of Paranoplocephala Lühe, 1910 sensu lato (Cestoda, Cyclophyllidea, Anoplocephalidae)
Author
Haukisalmi, Voitto
Author
Hardman, Lotta M.
Author
Hoberg, Eric P.
Author
Henttonen, Heikki
text
Zootaxa
2014
3873
4
371
415
journal article
42366
10.11646/zootaxa.3873.4.3
3762132e-7358-44b3-a430-0708f1fe15f5
1175-5326
229232
7FCB1765-9A81-4BA7-9633-F896B2B808BA
Microticola
n. g.
(
Fig. 10
)
Etymology.
The name of the new genus refers to
Microtus
(representing the tribe Microtini), the hosts of all known species of
Microticola
. “
Microticola
” is masculine.
Diagnosis.
Strobila of intermediate length; wide. Scolex relatively wide. Suckers directed laterally or anterolaterally. Neck short, wide relative to scolex width (minimum width 68–85%), usually expanded; expanded region attaining or slightly exceeding scolex width. Proglottids transversely elongated; length/width ratio of mature proglottids 16–20%. Proglottids distinctly craspedote. Genital pores unilateral or frequently (and irregularly) alternating. Genital ducts pass dorsal to longitudinal osmoregulatory canals. Testes mainly antiporal, maximally reaching poral margin of vitellarium; position of testes with respect to antiporal ventral longitudinal canal variable (non-overlapping, overlapping, beyond). Testes usually slightly overlapping margins of ovary. Cirrus sac usually overlapping or extending across ventral longitudinal canal. Vagina short (usually less than half of cirrus sac length), with thick external cell layer slightly widening distally. Seminal receptacle long, elongate. Ovary poral. Vitellarium median with respect to ovary. Early uterus densely reticulated, anterior, ventral to other organs, partly overlapping ovary, extending across longitudinal canals bilaterally, with lateral parts slightly widened posteriorly. In voles of the genus
Microtus
(
Cricetidae
:
Arvicolinae
) in North
America
and Eurasia.
Type
species:
M. etholeni
(
Haukisalmi, Henttonen, Niemimaa & Rausch, 2002
)
n. comb.
Paranoplocephala etholeni
Haukisalmi, Henttonen, Niemimaa & Rausch, 2002
Other species:
M. blanchardi
(
Moniez, 1891
) sensu
Tenora
et al.
1985b
n. comb.
Anoplocephala blanchardi
Moniez, 1891
Taenia blanchardi
(
Moniez, 1891
)
Braun, 1894
Anoplocephaloides blanchardi
(
Moniez, 1891
)
Baer, 1923
Paranoplocephala blanchardi
(
Moniez, 1891
)
Baer, 1927
FIGURE 10
.
Microticola etholeni
from
Microtus pennsylvanicus
from Alaska (USA). A. Scolex and neck. B. Mature proglottid. Redrawn from Haukisalmi
et al.
(2002).
Holotype
of
M. etholeni
:
USNPC
91874.
Remarks
.
Microticola
resembles
Chionocestus
,
Parandrya
and
Beringitaenia
in having a wide (>65% of the scolex width) and usually short neck, transversely elongated mature proglottids (length/width ratio 10–29%), primarily antiporally positioned testes that do not reach the poral ventral canal, and porally positioned ovary.
Microticola
distinctly differs from the related genera by its short vagina (relative to the cirrus sac length). In addition,
Microticola
differs from
Parandrya
in the length of the neck, cirrus sac (all shorter in
Microticola
) and seminal receptacle (longer in
Microticola
).
Microticola
also has a characteristic “neck swelling”, which is missing in
Parandrya
and other related genera. The latter feature also serves to distinguish
Microticola
from
Beringitaenia
. Other differences concern the length of the body and neck (both shorter in
Beringitaenia
), shape and length of the seminal receptacle (ovoid/pyriform and short in
Beringitaenia
) and poral position of the vitellarium in
Beringitaenia
.
Microticola
has been compared with
Chionocestus
in the Remarks section for the latter species.
The three
Microticola
species formed an exclusive, strongly supported (99%) monophyletic group in the
nad1
data and moderately supported (90%) group in the concatenated data, but did not show a supported association in the
cox1
data. Therefore, an alternative solution would be to treat the basal
P. blanchardi
separate from the other two species, and propose two new genera instead of one. However, there seems to be no taxonomically important morphological differences among the three species, which favours the idea that they should represent the same genus.
Microticola
does not show phylogenetic affinity with the morphologically most similar genera (
Chionocestus
,
Parandrya
and
Beringitaenia
). The sister group of
Microticola
remains undefined.
All sequence data sets showed that
Microticola
sp. from
Microtus
sp. from
China
(Fenglin) is genetically divergent from the other
Microticola
species and therefore probably represents an independent species. However, the only available specimen in
Microtus
sp. could not be unambiguously separated from the other congeneric species (especially
P. blanchardi
) and was therefore not described as new. The sister species of
Microticola
sp. from
China
is
M. etholeni
from North
America
.