Amynthas jinburi, Blakemore, Robert J., Lee, Seunghan, Lee, Wonchoel & Seo, Hong-Yul, 2013

Blakemore, Robert J., Lee, Seunghan, Lee, Wonchoel & Seo, Hong-Yul, 2013, Two new Korean earthworms (Annelida, Oligochaeta, Megadrilacea, Megascolecidae), ZooKeys 307, pp. 35-44 : 37-39

Amynthas jinburi sp. n.

Material examined.

IV0000213690, sub-mature specimen, figured and dissected. From Gangwon-do, Goseong-gun, Ganseong-eup, Jinbu-ri (ca. 38.2961N, 128.3546E) just north of Seoraksan Park on East coast; collected 1st - 2nd June, 2000 by unknown person(s) and deposited in NIBR. DNA tissue sample w61b (unsuccessful at this time).

Etymology.

Noun from location.

Diagnosis.

Amynthas with two pairs of spermathecal pores in 5 & 6; long, clavate spermathecal diverticula; simple caeca; and GMs absent except for large patches surrounding male pores.

Distribution.

Known only from single specimen from type locality.

Habitat.

Jinburi is a remote, mountainous and forested area

Behaviour. Possibly deep burrowing and geophageous (from gut contents).

Description.

Length. 210 mm.

Width. ca. 10 mm at male pore level.

Segments. 143 with some secondary annulation (from preservation?).

Colour. Bleached pale yellow in aged alcohol, possibly darker in life.

Prostomium. Open epilobous.

First dorsal pore. 11/12.

Setae.>100 per segment; e.g. 100+ on 11 and 112 counted on segment 12; approximately 16 setae intervene between male pore pads that are asetal on 18.

Nephropores. Not found.

Clitellum. Slightly darker at 14-16.

Male pores: On 18 on small, rounded and flat porophores.

Female pores. Single on 14.

Spermathecal pores. At posterior of 5 and 6 approximately 0.3 C apart.

Genital markings. None (sub-adult?).

Septa. Nephridial forests on septa 5 & 6; 5/6/7/8 thick, 8/9 thin to base of gizzard, 9/10 aborted.

Hearts. Seen in 11-13 (aborted in 10?).

Gizzard. Single in 8-9.

Calciferous glands. Absent.

Intestine. From 15; caeca simple elongate from 27; typhlosole not noted.

Nephridia. Meroic.

Male organs. Holandric, testes small in 10 &11; seminal vesicles in 11 & 12.

Ovaries. Compact in 13; ovisacs not found in 14.

Prostates: Racemose glands not fully developed in 18 on short, muscular duct.

Spermathecae. Two pairs in 6 & 7 exiting to anterior of 5/6 and 6/7 in 5 & 6 (Fig. 2).

Gut contents. Filled with yellow soil, i.e. probably a deep-burrowing subsoil geophage.

DNA COI barcode.

>w61 b– nil result, DNA not extractable on this older material that may have been fixed in formalin (although there was no odour) or denatured by pH.

Remarks.

Of all 970 pheretimoid species ( Blakemore 2008a), only two are known to have spermathecal pores in 5 & 6: viz. Amynthas serenus (Gates, 1936) from Pahang, Malaysia that also lacks GMs, and Amynthas? breviclitellatus (Do & Tran, 1995) from Vietnam that differs, at least, in its GMs in 7, 18 and 19. From “Kôryô” Korea (about 30 Km from Seoul), Amynthas fibulus fibulus (Kobayashi, 1936: 159) is superficially similar but has spermathecal pores anteriorly in 6 & 7 (rather than posteriorly in 5 & 6) plus its caeca are incised ventrally (rather than smooth); ditto for Amynthas fibulus ranunculus (Kobayashi, 1936: 162) that further has slits lateral to male pores. Interestingly, Kobayashi’s (1936: fig. 6) sketch of a prostate gland of Amynthas fibulus closely resembles the current specimen’s gland (Fig. 2).

It should be here noted that Sims and Easton (1972) inadvertently place these two fibulus taxa in an Amynthas morrisi -group defined with spermathecae in 5/6/7 despite Kobayashi (1936: 159) stating " Spermathecal pores , minute, 2 pairs anteriorly located on VI and VII, closely to the intersegmental furrows", i.e. strictly complying with Sims & Easton’s canaliculatus-group (then comprised of benignus Chen, 1946; canaliculata Gates, 1932; ralla Gates, 1936: 104; and rallida Gates, 1936: 106). It appears that many of Hong and James’ (2001: 67, 68, 69, 75) taxa have a similar attribute although their descriptions are ambiguously stated, such as: " Spermathecal pores in 5/6 and 6/7...at or near leading edge of vi, vii" and no useful figures are provided for the reader to decide.

If spermathecal pores were in 5/6/7 in any of the above taxa, then the morrisi-group’s possible nearest relatives from Korea would likely be Amynthas koreanus (Kobayashi, 1938: 115) that, however, has manicate caeca; or Amynthas kobayashii (Kobayashi, 1938: 119) and Amynthas geojeinsulae (Song & Paik, 1970) that both have male fields from 17-19 but differ in simple or incised caeca, respectively; or Amynthas assimilis Hong & Kim, 2002 that, like many of its similar cited taxa, has seminal grooves on 18.

The current species has simple, superficial male pores on large disc-like pads on 18. Although not fully mature, it appears unique in the Korea fauna on its combination of this aspect of its male field, spermathecal pores in 5 & 6 and its profusion of setae that number more than 100 per segment, combined with simple elongate intestinal caeca.

Fresh topotypic material is required to confirm these conclusions and to provide definitive DNA data, unless refinement of techniques allows extraction from older types.