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
Douthittia
n. g.
(
Fig. 16
)
Etymology.
The name of the new genus refers to Herman Douthitt, a pioneer in the taxonomy of anoplocephalid cestodes of rodents. “
Douthittia
”
is feminine.
Diagnosis.
Strobila long or of moderate length, relatively narrow. Scolex merging gradually with neck. Suckers embedded within scolex or slightly protruding, directed laterally or antero-laterally. Minimum neck width roughly half of scolex width (usually less in
D. nordenskioeldi
). Proglottids slightly or distinctly craspedote. Genital pores unilateral or infrequently (and irregularly) alternating. Genital ducts pass dorsal to longitudinal osmoregulatory canals. Testes mostly anterior to ovary, significantly overlapping latter and being often in contact with vitellarium. Antiporal testes overlap or extend slightly across antiporal ventral longitudinal canal, poral testes usually reaching corresponding poral canal (except in
D. bairdi
), but not overlapping it. Cirrus-sac rather wide, overlapping or extending across poral longitudinal canals. Vagina covered with distinct cell-layer; vagina and vaginal tube widening distally. Vagina slightly shorter than or as long as cirrus sac, position with respect to ventral longitudinal canal variable. Seminal receptacle spherical or subspherical, relatively small. Ovary median, large relative to proglottid size, usually filling whole space between ventral longitudinal canals. Vitellarium median or poral with respect to ovary. Early uterus anterior, ventral to other organs, extending laterally beyond longitudinal canals; lateral parts usually slightly widened posteriorly; reticulations relatively dense. In cricetid (
Arvicolinae
,
Neotominae
) and sciurid rodents in North
America
and Arctic Eurasia.
Type
species:
D. nearctica
(Haukisalmi & Henttonen, 2007)
n. comb.
Paranoplocephala nearctica
Haukisalmi & Henttonen, 2007 Other
species:
D. bairdi
(
Schad, 1954
)
n. comb.
Andrya bairdi
Schad, 1954
Paranoplocephala bairdi
Schad, 1954
Tenora, Murai & Vaucher, 1984
D. nordenskioeldi
n. comb.
Paranoplocephala nordenskioeldi
Haukisalmi, Wickström, Hantula & Henttonen, 2001
Paranoplocephala alaskensis
Haukisalmi & Henttonen, 2007
n. syn.
D. primordialis
(
Douthitt, 1915
)
n. comb.
Andrya primordialis
Douthitt, 1915
Paranoplocephala primordialis
(
Douthitt, 1915
)
Tenora, Murai & Vaucher, 1986
Holotype
of
D. nearctica
:
MSB
Endo 1 (included in the present phylogenetic analysis).
Remarks
.
Douthittia
resembles
Eurotaenia
,
Arctocestus
,
Rauschoides
and
Lemminia
in having a narrow neck and long vagina (relative to the length of the cirrus sac) and ovoid/pyriform (not elongated) seminal receptacle.
Douthittia
differs from
Arctocestus
and
Lemminia
by its more extensive distribution of testes in the poral part of the proglottid, and from
Arctocestus
and
Rauschoides
by its less numerous testes lateral to the antiporal ventral canal.
Douthittia
can be distinguished from
Eurotaenia
by the serrated, distinctly craspedote proglottids and prominently elongated anterior strobila (when fully relaxed) in the latter. For additional differences between
Douthittia
and
Lemminia
, see Remarks section for the latter genus.
Douthittia nearctica
,
D. nordenskioeldi
and
P. alaskensis
consistently formed a strongly supported clade in the present mitochondrial data sets. In
nad1
data, these three species formed an unresolved clade with very low genetic divergence, suggesting that they all might be conspecific. However,
cox1
data and concatenated data suggested that
D. nearctica
and
D. nordenskioeldi
+
P. alaskensis
represent separate sister species with distinct genetic divergence.
As
D. nordenskioeldi
and
P. alaskensis
also show considerable overlap in their morphological features,
P. alaskensis
becomes a synonym of
D. nordenskioeldi
.
Douthittia nearctica
is retained as a valid species because of its phylogenetic and morphological distinction from
D. nordenskioeldi
and
P. alaskensis
(see Haukisalmi & Henttonen 2007).
Douthittia
spp. are part of a larger clade, which also includes an undescribed, basal species of
Douthittia
,
Diandrya composita
(
cox1
data) and
Beringitaenia nanushukensis
n. sp.
The phylogenetic association between
Diandrya
,
D. nordenskioeldi
and
P. alaskensis
(the latter then as
P. primordialis
) has been suggested earlier by the concatenated 28S+ITS1+
cox1
data of Wickström
et al.
(2005). The basal
Douthittia
sp. from
Myodes rutilus
from British
Columbia
(
Canada
) was not described as new because of its morphological similarity with other
Douthittia
species, especially
D. nearctica
.
As
yet, there are no molecular data for
D. primordialis
and
D. bairdi
.