Some new Korean Megascolecoid earthworms (Oligochaeta)
Author
Hong, Yong
Author
James, Samuel W.
text
Journal of Natural History
2009
2009-05-21
43
21 - 22
1229
1256
http://dx.doi.org/10.1080/00222930902894096
journal article
10.1080/00222930902894096
1464-5262
4651894
Amynthas baekamensis
sp. nov.
(
Figure 6
)
Type material
Holotype
:
Clitellate
(NIBRIV0000120467) specimen:
Korea
,
Jeollanam-do
,
Jangseong-gun
,
Mt Baekam
,
Baekyangsa
,
200–400 m
, litter layers,
2 August 2000
,
Y. Hong
coll.
1 paratype
: 1 clitellate (NIBRIV0000120478):
Same
data as for holotype.
Other material
Same
data as for holotype: 3 semiclitellate; 21 aclitellate;
Jeollanam-do
,
Jangseong-gun
,
Mt Baekam
,
Baekyangsa
,
200–400 m
, litter layers,
20 August 2001
,
Y. Hong
coll.
Etymology
The species is named for its
type
locality.
Diagnosis
Paired spermathecal pores in VI, VII close to 6/7/8,
0.17–0.18 mm
circumference apart; male field with bean-sprout-shaped raised pads, each pad extending from 17/18 to 18/19,
0.15–0.21 mm
circumference apart.
Description
Light brown dorsal pigment. Dimensions
73–102 mm
by
4.1–4.2 mm
at segment X,
4.5–4.8 mm
at XXX,
4.3–4.4 mm
at clitellum; body cylindrical throughout, segments 89–96. Setae regularly distributed around segmental equators, numbering 65 at VII, 52 at XX; 0 between male pores; setal formula AA: AB: YZ: ZZ = 3: 1.5: 2: 3 at XIII. Female pore single in XIV,
0.3 mm
oval shape. First dorsal pore 12/13.
Male field with bean-sprout-shaped raised pads, head end lateral; each pad extending from 17/18 to 18/19; male pores small superficial white spots in 18/19 at posterior ends of paired longitudinally oriented ridges, faint seminal grooves along ridge crests; hardened dark grooves around pad margins,
0.15–0.21 mm
circumference apart. Paired spermathecal pores in VI, VII close to 6/7, 7/8, very small, inconspicuous, mid-lateral, spermathecal pores
0.17–0.18 mm
circumference apart. Genital markings lacking.
Figure 6.
Amynthas baekamensis
sp. nov.
: ventral view and spermathecae.
Septa 5/6, 6/7 thick, 7/8 thin, 8/9, 9/10 absent, 10/11–13/14 thin. Gizzard large in VIII–X. Intestine begins in XV, lymph glands from XV. Typhlosole low simple fold from XXVII. Intestinal caeca simple, originating in XXVII, extending anteriorly about to XXI, each consisting of a large finger-shaped sac. Oesophageal hearts X–XIII, IX lateral left large.
Ovaries in XIII. Paired spermathecae in VI, VII; each ampulla small pouch; ducts short, meet body wall in posterior of VI, VII, diverticula shorter than ampulla, chamber tightly coiled; no nephridia on spermathecal ducts, but nephridia dense on body wall of VII. Male sexual system holandric, testes sacs paired, ventral. Seminal vesicles, two pairs XI and XII; enclosed in testes sac in XI. Prostates XVIII extending to XVII–XX; short and thick ducts, both glandular portions consist of two main lobes, each lobe deeply divided into leaflets, prostatic ducts join body wall 18/19. Genital papillae glands lacking.
Remarks
The species has a unique intrasegmental location of the spermathecal pores. Most Korean
Amynthas
have presetal spermathecal pores, but the species has postsetal pores near the intersegmental furrows. This species with simple caeca is different from the manicate
canaliculatus
-group, and it is also separated by male field shape. The location of the male pores near 18/19 is also unusual, because
Amynthas
male pores are usually equatorial.