Amynthas carnosus roki Blakemore, 2013

Blakemore, Robert J. & Lee, Seunghan, 2013, Survey of Busan Oligochaeta earthworms supported by DNA barcodes, Journal of Species Research 2 (2), pp. 127-144 : 129-132

4. Amynthas carnosus roki Blakemore subsp. n.

( Fig. 3 ).

Material. Incheon specimen NIBR-IV0000261264 (DNA w56) H, holotype, mature broken in two parts, anterior dissected; collected by RJB 23 rd Oct., 2012 from Incheon Great Park from infilled ditch just above the park boundary. Busan specimen IV0000261286 (DNA H4) P, paratype, mature 175 mm long, undissected but broken in two parts, 24 th April, 2013 from Yeongdo Island , just down from Temple in woodland on walk to the beach .

Etymology. From acronym of Republic of Korea ( ROK), latinized to “roki”, due to its wide distribution (Incheon ↔ Busan) even though endemicity just in South Korea is not implied.

Description. Lengths H, 270+ 30 mm (= 300 mm); P, 125+ 50 mm (= 175 mm). Segments H, 112+24 (=136). Colour dark brown dorsum, clitellum buff. Prostomium epilobous open. First dorsal pore 12/13. Setae ca. 60 on 12. Spermathecal pores post-intersegmental in U-shaped hemispheres on dorsal aspects of 5/6/7/8/9. Clitellum 14-16. Female pore mid-ventral on 14. Male pores superfical on small mounds within concentric rings ca. 0.3 C apart on 18 with ca. 14 setae intervening. Genital markings absent (from both specimens).

Internally (H) septa 8/9/10 aborted. Spermathecae in 6-9 as figured. Holandric with seminal vesicles in 11 and 12. Last hearts in 13. Prostates racemose in 18. Intestinal caecae simple from 27. Other characteristics comply with nominal taxon (see Blakemore, 2012a).

Remarks. Distinctive characters are the tendency to large size (175-300 mm), U-shaped post-intersegmental spermathecal pores (called “spermathecal papillae” by Kobayashi, 1936: 130) plus lack of genital markings thereby complying with Kobayashi’s (1936, text-figs types II & I) also coded by Blakemore (2012a, fig. 3) [as already noted, segments counts for XVIIrhs are out by one in this latter figure]. On these characters the present sub-species appears to differ from the nominal taxon’s neotype and from other synonyms in Blakemore (2012a: 36), also supported with definitive DNA barcode data from its primary type (w 56 in Appendix). It shows only 91% similarity to other A. carnosus specimens and was just 93% compliant with w54 DNA data from an Ulleungdo specimen. The DNA of sample H4 from Busan has 100% agreement with w56 from Incheon designated as paratype and holotype, respectively.

This taxon is particularly similar to A. monstriferus ( Kobayashi, 1936) , differing not least on the lack of markings on segment 8, and possibly they should be merged. Pending further research, A. carnosus monstriferus is reduced to sub-species status as it complies with Kobayashi’s (1936) types XII & I of A. carnosus !

Blakemore (2012a: 41) stated, “ the genital marking variation in A. carnosus allowed for by Kobayashi in his detailed and most thorough account is excessive, rather representing a congeries of morphs, if not separate species ”. This seems to be borne out by the preliminary DNA results presented here as justified with the new taxon. In particular, sample IV0000261266 (providing DNA w57) was collected at the same time as A. carnosus roki Holotype (w56) yet it complies with Kobayashi (1936) textfig. types IX & III of A. carnosus carnosus . Whereas IV0000261263 (providing DNA w55) also from Incheon Great Park but found crawling on the surface at dusk, complies with Kobayashi’s types VI & VIII and is almost exactly the same as A. carnosus neotype (Tokyo NMST An435). Both these latter specimens are closer morphologically to materials from elsewhere in Korea and, significantly, from Japan that clearly separate out on their genetics from the current taxon.

From the results in the DNA phylogram ( Fig. 1 ) it appears that the specimen from Ulleungdo (providing DNA sample w54) labeled as “? Amynthas pingi (Stephenson, 1925) ” by Blakemore (2013b: 60) may also merit separate sub-specific status, which is investigated further in an accompanying paper based on A. pingi types ( Blakemore, 2013d this issue).

Regarding other putative sub-species of A. carnosus , it was already noted by Blakemore (2012a: 36) that A. pingi chungkingensis ( Chen, 1936) probably merits elevation to separate species level as A. chungkingensis . This taxon was ascribed to “ Am. carnosus chungkingensis ” by Wang and Qiu (2005: 25, tab. 2) when comparing it to their Amynthas carnosus lichuanensis Wang and Qiu, 2005 from Mt. Xingdou, Hubei, China. Herein this is also raised to separate species level as A. lichuanensis stat. nov. since it has no characters in any way similar to revised concepts of A. carnosus . For example, this 300- 400 mm species has rows of 7-8 papillae median to male pores on 18, and corresponding rows of three or four papillae on segment 8 median to spermathecal pores that number only three pairs in 6/7/8/9 with its spermathecae nubby stubs. These authors also record A. carnosus carnosus ( Goto and Hatai, 1899) from this location, but their identification may be suspect since they claim subsumed A. fornicatus (Gates, 1935) (and A. diffringens !) too (see Blakemore, 2013d).

Similar specimens from any region may now be compared genetically to an increasingly refined formulation of A. carnosus , including the present new sub-species. Moreover, as coded by Blakemore (2012a, fig. 3), Kobayashi’s (1936) text-figs types II & I (lacking markings) and possibly types XII & I (with markings in 8), having U-shaped post-intersegmental spermathecal papillae should now be removed as characteristic of A. c. carnosus proper. Kobayashi (1936: 130) tabulated 14 such specimens from 204 from Korea and this may represent an approximate proportion (~7%) of the A. carnosus roki (and A. c. monstriferus ) sub-species, but its area of prevalence is currently indeterminate.

Figures

Fig. 3. A. Amynthas carnosus roki subsp. n. holotype (H, DNA w56) showing habitus, prostomium, spermathecae, caecum and prostate of 18lhs in situ with X2 enlargements of post-intersegmental spermathecal pores of 8rhs and simple male pore of 18rhs. B. Sketch of these from Busan paratype (P, DNA H4 agreeing 100%). 3C and 3D are comparison sketches with similar X2 enlargements for sympatric A. carnosus carnosus (Goto and Hatai, 1899) specimens from Incheon (200 and 280mm long) with pre-intersegmental spermathecal pores that provided DNA samples w55 and w57, respectively, agreeing>99% with each other (see Fig. 1 and Appendix).

Fig. 1. MEGA5 Maximum Likelihood phylogram of DNA code results for Busan specimens compared to similar taxa. Solid squares (■) are Busan samples; open circles (○) are unconfirmed GenBank names (from China, Korea or Japan); closed circles(●) are from the author’s Japanese studies.(Sample codes and provisional or new species names are explained in the Appendix legend).