Cestode Parasites (Platyhelminthes) of Rodents from New Guinea and Adjacent Islands with a Redescription of Paroniella blanchardi (Parona, 1897) (Davaineidae)
Author
Beveridge, Ian
Author
Smales, Lesley R.
text
Records of the Australian Museum
2017
Rec. Aust. Mus.
2017-11-22
69
6
451
460
http://dx.doi.org/10.3853/j.2201-4349.69.2017.1667
journal article
10.3853/j.2201-4349.69.2017.1667
2201-4349
4677104
0D2DD23D-8B0D-42E6-A7BF-33FBE10255C9
Paroniella blanchardi
(
Parona, 1897
)
Figs. 2–9
Davainea blanchardi
Parona, 1897
Brumptiella blanchardi
(
Parona, 1897
)
, Lopez-Neyra, 1931
Delamurella blanchardi
(
Parona, 1897
)
, Spasskii & Spasskaya, 1976
Material examined
.
From
Paramelomys lorentzii
(Lorentz’s paramelomys):
Wokan Island
,
Aru Islands
,
West Papua
,
5°37'S
143°30'E
(W48821); from
Rattus feliceus
Thomas, 1920
(spiny
Seram Island
rat):
Piliana Village
,
Seram
,
Maluku Province
,
3°15'S
129°30'E
(W23778)
.
Description
Large cestodes up to
110 mm
long,
5 mm
in width; scolex 0.42–0.50 (0.48, n = 5) in diameter; suckers 0.10–0.14 (0.12, n = 5) in diameter, armed with rows of spines; rostellum 0.17–0.24 (0.20, n = 5) in diameter; internal wall of rostellar sac lined with tiny spines; rostellar hooks c.
125 in
number, hammer-shaped, arranged in two circles,
0.025
–0.035
(0.030, n = 5) long; genital pores essentially unilateral; single block of 4 segments with reversed polarity seen in one section of strobila; mature segments elongated laterally, craspedote, 0.17–0.25 (n = 0.21, n = 5) long, 1.84–3.35 (2.47, n = 5) wide, length: width ratio 12; genital atrium close to anterior margin of segment; cirrus sac small, c. 0.10–0.14 long, 0.05 wide, not reaching osmoregulatory canals; distal cirrus armed (visible only in histological sections); vas deferens, sinuous, running along anterior margin of segment; 18–28 (23, n = 5) and 29–40 (34, n = 5) poral and aporal testes respectively; testes 0.04–0.05 (0.05, n = 5) in diameter. Vagina opens to genital atrium posterior to cirrus sac, wall muscular, internal lining of distal vagina armed (visible only in histological sections); female genital complex in mid-line; ovary bilobed, poral lobe slightly smaller, 0.08–0.13 (0.10) × 0.08–0.13 (0.10) with fewer lobules than aporal lobe, 0.12–0.20 (0.17, n = 5) × 0.08–0.11 (0.10, n = 5); Mehlis’ gland posterior to ovarian isthmus, c.
0.04 in
diameter; vitellarium lobulate, posterior to Mehlis’ gland, 0.07–0.14 (0.11, n = 5) × 0.05–0.06 (0.06, n = 5); vagina slender; seminal receptacle evident in gravid but not in mature segments; gravid segments 0.35–0.60 (0.52, n = 5) long, 2.70–4.10 (3.20, n = 5) wide, length; width ratio, 6.2; with eggs in individual capsules, capsules
0.025
–0.040
(0.035, n = 5) in diameter; eggs
0.018
–0.025
(0.021, n = 5) in diamEtEr; Egg capsulEs EntirEly fill gravid sEgmEnts, extending beyond osmoregulatory canals; osmoregulatory system highly reticulate; largest vessels in gravid segments
0.03 in
diameter. Longitudinal musculature composed of tWO bands Of fibrEs; innEr band Of largEr bundlEs Of up tO 20 fibrEs; 40 bundlEs On Each sidE Of sEgmEnt; OutEr band cOmpOsEd Of individual fibrEs Or bundlEs Of up tO 5 fibrEs; transverse muscle forming a broad band medial to inner longitudinal muscles; dorsoventral muscles scattered, individual.
Remarks
. In possessing unilateral pores and a single egg per egg capsule, this species belongs to the genus
Paroniella
.
Sawada (1964)
in a comprehensive list of all known species included only a single species of
Paroniella
from rodents,
P. blanchardi
(
Parona, 1897
)
described from
Leopoldamys siporamus
(Thomas, 1895)
(as
Mus siporanus
) and
Maxomys rajah
(Thomas, 1894)
(as
Mus rajah
) on Sipura Island (as Sipora or Sereinu), part of the Mentawei group of islands Off Sumatra (
ParOna, 1897
). NO spEciEs Of
Paroniella
from rodents has been added since
Sawada (1964)
. The description and illustrations by
Parona (1897)
are limited in detail, but report a maximum length of
75 mm
, a width of
5 mm
, with about 300 segments, a scolex
0.5 mm
in diameter, a rostellum bearing 70–80 hooks
0.032 mm
long and sucker spines
0.006 mm
long. Most of the principal dimensions provided by
Parona (1897)
thus match those of the specimens described above, apart from the number of rostellar hooks. Counting the number of hooks from lateral views of a scolex and then doubling the number gave a value of 70–80, the number estimated by
Parona (1897)
, while examination of an apical view of the scolex (
Fig. 6
) suggested a number of about 125 hooks.
Parona (1897)
provided no details of the mature segment such that comparisons with the data presented here are not possible. He illustrated the lateral region of several gravid segments, which indicate that the genital pores were unilateral. In the fragments available for examination here, genital pores were generally unilateral, but one area of strobila was seen in which a series of four segments in a fragment containing 14 segments, exhibited a reverse polarity. The current re-description, while still incomplete due to the poor nature of the material, increases thE knOWn numbEr Of hOst spEciEs and is thE first rEpOrt Of the species from New
Guinea
.
Figures 2–9.
Paroniella blanchardi
(
Parona, 1897
)
.
(2)
scolex, dorsoventral view;
(3)
rostellar hook;
(4)
sucker spines;
(5)
Anterior extremity of strobila showing reticulated osmoregulatory system;
(6)
scolex, apical view;
(7)
optical transverse section of hand-cut section showing longitudinal and transverse musculature;
(8)
mature segment;
(9)
gravid segment. Scale bars: Figs. 5, 8, 9—1.0 mm; Figs. 2, 6, 7—0.1, mm; Figs. 3, 4, to same scale—0.01 mm.
ThE captiOns tO thE figurEs Of thE Original dEscriptiOn Of this species (p. 124) have November, 1897 as the publication date and in a table of measurements on p. 106, the species is cited as “
D. blanchardi
n. sp.
Parona, 1897
”. However, the initial page of the issue of the journal gives the publication date as 1898. In spite of this discrepancy, the citation date has not been altered from that used in the literature.
Joyeux & Baer (1927) recorded
P. blanchardi
from
Thryonomys swinderianus
(Temminck, 1827)
from
Dahomey
(Abomey) in
Benin
and illustrated the scolex and a rostellar hook but provided no description. The same illustrations were used by
Artykh (1966)
in his summary of the species.
Janicki (1906)
and
Shipley (1908)
included the species (as
Davainea blanchardi
) in their lists of cestodes from rodents (
Rattus
) known at that time, but did not provide any additional details.
No other species of
Paroniella
has been reported from rodents apart from a record of
P. retractilis
(Stiles, 1895)
, described initially as a parasite of lagomorphs in North America, and also from
Rattus rattus
in
Benin
(Joyeux & Baer, 1927).
Of the various species of
Paroniella
known from New
Guinea
(
Sawada, 1964
),
P. conopophilae
(Johnston, 1911)
,
P. corvina
(Fuhrman, 1905)
and
P. paradisiae
(
Fuhrmann, 1909
)
are known from birds (
Sawada, 1964
,
Schmidt, 1986
), but are readily distinguishable from
P. blanchardi
using the metrical data provided in
Sawada (1964)
.
Paroniella appendiculata
(
Fuhrmann, 1909
)
was described from an unknOWn hOst (
Fuhrmann, 1909
), but diffErs frOm
P. blanchardi
in lacking scolex and sucker spines, in having largEr hOOks (
36–43 µm
) and in having charactEristically shaped campanulate segments (
Fuhrmann, 1909
).