Three new species of earthworms belonging to the genus Amynthas (Oligochaeta: Megascolecidae) from Hainan Island, China
Author
Sun, Jing
Author
Zhao, Qi
Author
Qiu, Jiang-Ping
text
Zootaxa
2010
2680
26
32
journal article
10.5281/zenodo.199320
d9b8ba2f-eb22-497c-93a9-68736714ec3f
1175-5326
199320
Amynthas trapezoides
Qiu & Sun
sp. nov.
(
Figs. 1
A, B)
Material.
Holotype
: One clitellate (C-HN008A):
China
, Hainan Province, Mt. Jianfeng (
18°44.45’N
,
108°50.32’E
),
1020 m
. elevation, soil, coll. J. P. Qiu and M. B. Bouché,
5 Jun. 2006
.
Paratype
: Three clitellates (C-HN008B): Same data as for
holotype
. Other material: Seventeen semiclitellates (C-HN008C): Same data as for
holotype
.
FIGURE 1.
(A) Ventral view showing spermathecal pores, female pores and male pores of
Amynthas trapezoides
sp. nov.
; (B) spermatheca of
Amynthas trapezoides
sp. nov.
Locality and habitat.
The specimens were collected from a yellow cinnamon soil under the arbors of Jianfeng Mountain tropical rain forests, Hainan province,
China
.
Etymology.
This species is named after its character of arrangement of spermathecal pores.
Diagnosis.
Dimensions
147–155mm
by
3.2–3.6mm
at clitellum, segments 147–194. Setae 44–
54
/III, 52–
68
/V, 52–
70
/VIII, 58–66/XX, 54–60/XXV; 0 between male pores; 4–6 between spermathecal pores. Spermathecal pores in 6/7–7/8, arranged at corner of trapezoid near the mid-ventral line.
Male
pores on XVIII, with a complicated glandular region on ventral side of 1/2XVII–1/4XIX.
Description.
Preserved specimens grayish on dorsum in segment I–V, and no pigment in other segments. Dimensions
147–155mm
by
3.2–3.6mm
at clitellum, segments 147–194; body cylindrical in cross-section, gradually tapered towards head and tail. Prostomium ½epilobous. Setae numbering 44–54 at III, 52–68 at V, 52–70 at VIII, 58–66 at XX, 54–60 at XXV; 0 between male pores; 4–6 between spermathecal pores, setal formula AA=1.1–1.2AB, ZZ=1.3–2.2ZY. Clitellum annular XIV–XVI, reddish-brown, or grayish-brown, or yellow-brown, or light yellow; setae cannot be seen externally in clitellum.
First dorsal pore 12/13. Two pairs of spermathecal pores in 6/7–7/8, ventral, arranged at corners of trapezoid, each on a small swollen forward extension of segments VII and VIII respectively. The first pair of spermathecal pores is very close to each other as compared to the second ones, being only 0.1 circumference ventrally apart.
Male
pores are paired in XVIII and the male pore region is very complex from 1/2XVII–1/ 4XIX, being twisted into a glandular ventral region which includes a small extended papillae in the front edge and a pair of closely situated protuberant male pores at perichaetine of XVIII, as well as a vertical trench between two male pores from 1/2XVIII to 17/18. This glandular region with three depression in upper place, left and right side near the bottom, has a clear dividing line at perichaetine of XVIII (
Fig. 1
A). Female pore single in XIV.
Septa
5/6–7/8 thick and muscular,
10/11–11/12
slightly thickened,
8/9–9/10
absent. Dorsal blood vessel single, continuous onto pharynx; esophageal hearts in X–XIII, the last two pairs of which are bigger than the anterior pairs. Gizzard in VIII–X, bucket-shaped, covered with white flocs; intestine enlarged gradually from XV and distinctly from XX; intestinal caeca simple, originating in XXVII and extending forward to XXV, horn-shaped sac with a slight incision on dorsal margins at the septa.
Ovaries in XIII, spermathecae paired in VII–VIII; ampulla heart-shaped or oval-shaped, about
2.2mm
long, gradually slender duct as long as 0.33 ampulla; diverticulum shorter than main pouch by 0.5, slender, terminal 0.25 dilated into an oval-shaped chamber; no nephridia on spermathecal ducts (
Fig. 1
B).
Male
sexual system holandric, testis sacs two pairs, developed, ventral in X, XI, in close proximity to two sides on ventrum; seminal vesicles paired in each of XI and XII, anterior pair bigger in size and connected on dorsum, the latter pair separated from each other clearly; prostates in XVII–XXI, glands developed, coarsely lobate, prostatic duct irregular shaped, repeatedly curved, very close to ventral midline. No accessory glands were seen.
Remarks.
Amynthas trapezoides
sp. nov.
keys to the
tokioensis
group which comprised eighteen species in
Sims & Easton (1972)
. After
Sims & Easton (1972)
, twenty more species were reported. They are
A. platycorpus
(
Thai
,1982
)
,
Metaphire jianfengensis
(
Quan, 1985
)
,
A. zhongi
Qiu & Wang, 1991
,
A. quadrapulvinatus
Wu & Sun, 1997
,
A. yongshilensis
Hong & James, 2001
,
A. alveolatus
Hong & James, 2001
,
M. geomunensis
(
Hong & James, 2001
)
,
A. eastoni
Hong & James, 2001
,
A. boletiformis
Hong & James, 2001
,
A. odaesanensis
Hong & James, 2001
,
A. righii
Hong & James, 2001
,
A. fasciiformis
Hong & James, 2001
,
A. sanchongensis
Hong & James, 2001
,
A. songnisanensis
Hong & Lee, 2001
,
A. ephippiatus
Hong & Lee, 2001
,
A. multimaculatus
Hong & Lee, 2001
,
A. mujuensis
Hong & Kim, 2002
,
A. yeoi
Hong & Kim, 2002
,
A. heshanensis
Zhang & Qiu, 2006
,
A. jiangmenensis
Zhang & Qiu, 2006
. The appearance of
Amynthas trapezoides
sp. nov.
is somewhat similar to that of
A. quadrapulvinatus
. They share some similar characters: two pairs of spermathecal pores in 6/7–7/8; absent septa in
8/9–9/10
; heart-shaped ampulla or oval-shaped spermathecae. However, the new species can be distinguished from
A. quadrapulvinatus
in that it lacks pigment, has two pairs of closely spaced spermathecal pore in 6/7 and 7/
8 in
the form of a trapezoid, a special male pore region comprising of a glandular depression divided by a clear line, and two male pores which are very closely spaced,
Amynthas quadrapulvinatus
, on the other hand, has fulvous pigment, spermathecal pores which are equidistantly spaced, and a rectangular pad male pore region with two pairs of larger truncated additional papillae that were 0.2 body circumference ventrally apart. Moreover, the new species is twice as long as
A. quadrapulvinatus
.