Five new earthworm species of the genera Amynthas and Metaphire (Megascolecidae: Oligochaeta) from Matsu, Taiwan
Author
Shen, Huei-Ping
Zoology Division, Endemic Species Research Institute, Nantou, Taiwan;
Author
Chang, Chih-Han
Department of Earth and Planetary Sciences, Johns Hopkins University, Baltimore, MD 21218, USA;
Author
Chih, Wen-Jay
Department of Life Sciences and Institute of Zoology, National Taiwan University, Taipei, Taiwan
text
Journal of Natural History
2013
J. Nat. Hist.
2014-01-22
48
9 - 10
495
522
http://dx.doi.org/10.1080/00222933.2013.826742
journal article
10.1080/00222933.2013.826742
1464-5262
5199325
Amynthas dongyinensis
Shen
,
sp. nov.
(
Figure 5
)
Type material
Holotype
.
Clitellate (mature) specimen (
62 mm
in length, dissected) collected
28 June 2012
beside the Yanhsiu Fort (elevation
19 m
), Dongyin by H.P. Chen and W.J. Chih (TESRI-O-H-40) (voucher number: MTS 120).
Paratypes
.
Four clitellates [one dissected (voucher number: MTS 114)] collected
28 June 2012
from roadside ditches outside Stronghold No. 33 (elevation
40 m
), Hsiyin by H.P. Chen and W.J. Chih (TESRI-O-P-35).
Figure 5.
Amynthas dongyinensis
sp. nov.
Holotype (TESRI-O-H-40) (voucher number: MTS 120). (A) Right lateral view of spermathecal pore region (sp, spermathecal papilla); (B) ventral view of male pore region (mp, male porophore); (C) dorsal view of right spermathecae (amp, ampulla; dv, diverticulum; ag, accessory gland); (D) dorsal view of left prostate gland (pd, prostatic duct). Scale bar 1 mm.
Other material
Three clitellates (voucher number of specimen used for DNA barcoding analyses: MTS 113) and two aclitellates collected
28 June 2012
under a tree at Stronghold No. 33 (elevation
61 m
), Hsiyin by H.P. Chen and W.J. Chih (coll. no. 2012–72); three clitellates (voucher number of specimen used for DNA barcoding analyses: MTS 117) and two aclitellates collected
28 June 2012
near Northernmost Frontier (elevation
79 m
), Hsiyin by H.P. Chen and W.J. Chih (coll. no. 2012–75); two clitellates collected
28 June 2012
from a roadside ditch near Stronghold No. 26 (elevation
19 m
), Hsiyin by H.P. Chen and W.J. Chih (coll. no. 2012–76) (voucher number of specimen used for DNA barcoding analyses: MTS 119); one clitellate collected
28 June 2012
beside the Yanhsiu Fort (elevation
19 m
), Dongyin by H.P. Chen and W.J. Chih (coll. no. 2012–78); one clitellate collected
30 August 2012
from a ditch under Drum Rock (elevation
99 m
) on the way to Dongyong Lighthouse, Dongyin by H.P. Chen and H.H. Huang (coll. no. 2012–121) (voucher number: MTS 122); one clitellate collected
31 August 2012
from Chingshuiao (elevation
15 m
), Hsiyin by H.P. Chen and H.H. Huang (coll. no. 2012–124) (voucher number: MTS 125); three aclitellates collected
31 August 2012
around Dongyong Reservoir (elevation
40 m
), Dongyin by H.P. Chen and H.H. Huang (coll. no. 2012–126); one clitellate collected
31 August 2012
from a ditch beside the coastline between Huangpaitan and Mopantou (elevation
68 m
), Dongyin by H.P. Chen and H.H. Huang (coll. no. 2012– 129) (voucher number: MTS 128); nine aclitellates collected
31 August 2012
near Zhongling Temple (elevation
76 m
), Dongyin by H.P. Chen and H.H. Huang (coll. no. 2012–130).
Diagnosis
Small to medium; length (clitellates)
49–91 mm
. Segments numbering 91–113. Setae
38–54 in
VII,
38–57 in
XX, 7–9 between male pores. First dorsal pore in 12/13. Spermathecal pores three pairs in 6/7–8/9, 0.28–0.31 body circumference ventrally apart, each pore on a tubercle or papilla about
0.3 mm
in diameter. Male pores 0.26– 0.3 body circumference ventrally apart in XVIII, each on a round porophore surrounded by one or two circular or diamond-shaped folds. Genital papillae absent. Spermathecae three pairs in VII–IX. Accessory glands sessile, each corresponding to external spermathecal papilla. Seminal vesicles large, two pairs in XI and XII, each vesicle with a round, prominent dorsal lobe. Prostate glands large, occupying five to six segments in XVI–XXI. Prostatic duct small, C- or U-shaped in XVIII. Accessory glands absent in the postclitellar region.
Description
External characters.
Total length (clitellates)
49–91 mm
. Weight
0.37–1.08 g
. Segments numbering 91–113. Clitellum XIV–XVI, setae and dorsal pores absent, length
1.43–4.98 mm
and width
2.84–4.06 mm
. Prostomium epilobous. Setal number
38–54 in
VII,
38–57 in
XX, and 7–9 between male pores in XVIII. First dorsal pore in 12/13. Spermathecal pores three pairs in intersegmental furrows of 6/7–8/9, distance between paired pores 0.28–0.31 body circumference ventrally apart, each pore on a tubercle or papilla about
0.3 mm
in diameter (
Figure 5A
). No other genital papilla in the preclitellar region. Female pore single, mid-ventral in XIV.
Male pores paired in XVIII, 0.26–0.3 body circumference ventrally apart. Each pore on a round porophore surrounded by one or two circular or diamond-shaped folds (
Figure 5B
). Genital papillae absent in the postclitellar region.
Preserved specimens brown in colour with dark brown clitellum.
Internal characters.
Septa 5/6–7/8 thick, 10/11–13/14 thickened, 8/9/10 absent. Nephridial tufts on anterior faces of 5/6/7. Gizzard large in VIII–X. Intestine enlarged from XV. Intestinal caeca paired in XXVII, extending anteriorly to XXII–XXIII, each simple, slender, straight. Oesophageal hearts in XI–XIII.
Spermathecae three pairs in VII–IX, varied in size and shape (
Figure 5C
). Each ampulla round, peach-shaped or elongated oval-shaped, surface wrinkled,
0.81–1.81 mm
long and
0.65–1.57 mm
wide, with a stout spermathecal stalk of
0.2–0.6 mm
in length. Diverticulum with an iridescent, oval- or rod-shaped seminal chamber of
0.4–0.85 mm
long and a long, slender to stout stalk of
0.84–2.1 mm
in length. Accessory glands sessile, round or slightly lobed,
0.3 mm
in diameter, each corresponding to external spermathecal papilla (
Figure 5C
).
Holandry: testes large, oval, two pairs in ventrally joined sacs in X and XI. Seminal vesicles large, smooth, two pairs in XI and XII, anterior pair occupying the full segmental compartment, posterior pair smaller, about one-half to two-thirds of segment, each vesicle with a round, prominent dorsal lobe. Prostate glands large, lobed with follicular surface, occupying five to six segments in XVI–XXI (
Figure 5D
). Prostatic duct small, C-shaped or U-shaped in XVIII. Accessory glands absent.
DNA barcodes
GenBank accession numbers
KC897044
(MTS 120,
holotype
),
KC897049
(MTS 114, dissected
paratype
),
KC897047
,
KC897046
,
KC897043
,
KC897042
,
KC897045
and
KC897048
(MTS 113, 117, 119, 122, 125 and 128, respectively)
.
Etymology
The name
dongyinensis
is given to this species with reference to its
holotype
locality in
Dongyin
,
Matsu
.
Remarks
Amynthas dongyinensis
sp. nov.
is only found on the islands of Dongyin and Hsiyin. It is a sexthecate earthworm with three pairs of spermathecal pores in intersegmental furrows of 6/7–8/9, belonging to the
sieboldi
species-group of the genus
Amynthas
(
Sims and Easton 1972
)
. It has simple male pore structure and no genital papillae (except spermathecal papillae). Among the species of the
sieboldi
-group listed by
Sims and Easton (1972)
,
Amynthas udei
(
Rosa, 1896
)
from
Sumatra
, and
Amynthas buitendijki
(
Michaelsen, 1922
)
and
Amynthas dammermani
(
Michaelsen, 1924
)
from
Java
also have simple male pore structure without any preclitellar or postclitellar papilla. Both the latter two species described by Michaelsen have heavily coiled diverticulum, which is distinctly different from the simple diverticulum structure of
A. dongyinensis
(
Michaelsen, 1922
,
1924
).
Amynthas dongyinensis
is morphologically fairly similar to
A. udei
(
Table 2
). However,
A. dongyinensis
has longer diverticular stalk and large prostate glands occupying five to six segments in XVI–XXI and
A. udei
has short diverticular stalk and small, transversely oval prostate glands in XVIII (
Rosa 1896
).
Table 2. A comparison of characters among
Amynthas dongyinensis
sp. nov.
,
Amynthas udei
,
Amynthas kamitai
and
Amynthas minjae
.
Character |
Amynthas
|
Amynthas udei
|
Amynthas
|
Amynthas
|
dongyinensis
|
kamitai
|
minjae
|
sp. nov. |
(
Rosa 1896
)
|
(Kobayashi |
(Hong et al. |
1934) |
2001) |
Locality |
Matsu |
Sumatra |
Korea |
Korea |
Body length (mm) |
49–91 |
66 |
106–136 |
88–127 |
Segment number |
91–113 |
90 |
116–120 |
76–112 |
First dorsal pore |
12/13 |
12/13 |
12/13 |
12/13 |
Setal number |
VII |
38–54 |
About 40 |
56–58 (VI) |
55 |
XX |
38–57 |
– |
70–71 (XIX) |
71 |
Between male |
7–9 |
8 |
13–15 |
13–14 |
pores |
Spermathecal |
6/7–8/9 |
6/7–8/9 |
5/6–7/8 |
5/6–7/8 |
pores |
Diverticulum |
Long stalk with |
Short stalk with |
Slender stalk |
Short, stick- |
an oval- or |
an oval- |
with a |
shaped |
rod-shaped |
shaped |
small |
without |
seminal |
seminal |
seminal |
terminal |
chamber |
chamber |
chamber |
expansion |
Hearts |
XI–XIII |
Last heart in |
Last heart in |
X–XIII |
XIII |
XIII |
Seminal vesicles |
Large |
Large |
Small |
Less developed |
Prostate glands |
Large in |
Transversely |
3 lobes in |
2 lobes in |
XVI–XXI |
oval in |
XVII–XIX |
XVII–XX |
XVIII |
Prostatic ducts |
Small, C- or U- |
Short, curved |
Slender, |
Short, |
shaped in |
hook- |
muscular |
XVIII |
shaped |
The simple male pore structure and absence of genital papillae of
A. dongyinensis
are also similar to that of
Amynthas kamitai
(
Kobayashi, 1934
)
and
Amynthas minjae
Hong, 2001
from
Korea
. However, both species from
Korea
are sexthecate with three pairs of spermathecal pores in 5/6–7/8, and have small seminal vesicles and smaller prostate glands (XVII–XIX in
A. kamitai
and XVII–XX in
A. minjae
) (
Kobayashi 1934
; Hong et al. 2001).
Amynthas kamitai
and
A. minjae
are fairly similar and not easily distinguishable (
Table 2
). The former has small seminal chamber and prostate glands divided into three main lobes in XVII–XIX, while the latter has stick-shaped diverticulum without terminal expansion and prostate glands divided into two main lobes in XVII–XX (
Kobayashi 1934
; Hong et al. 2001). Since only
two specimens
of
A. kamitai
were collected (
Kobayashi 1934
), it is possible that such differences might be due to individual variation.
Zhao et al. (2013)
recently described
Amynthas apapillatus
based on a single specimen collected from
Hainan
Island,
China
. It is fairly similar to
A. dongyinensis
in that both species belong to the
sieboldi
species-group, and have simple male pore structure and no genital papillae. However,
A. dongyinensis
has oesophageal hearts in XI–XIII and large prostate glands occupying five to six segments in XVI–XXI, while
A. apapillatus
has oesophageal hearts in X–XIII and small prostate glands in XVII– XVIII. Molecular analyses also show that
A. dongyinensis
is distinctly different from
A. apapillatus
(
Figure 2
).