Metaphire kinki Blakemore, 2022

Blakemore, Robert J., Miller, Shawn & Lim, Shu Yong, 2022, Two New Species of Japanese Earthworms (Annelida, Oligochaeta, Megadrilacea, Megascolecidae) Update Biodiversity on Okinawa and at Lake Biwa to ca. 30 Species, Bulletin of the Kanagawa Prefectural Museum (Natural Science) 51, pp. 95-104 : 98-100

Metaphire kinki Blakemore , sp. nov.

Distribution: Kinki Region, Shiga-ken, Otsu-shi, Katsuragawa, Boumura-cho (35.247719, 135.868247) and stream at Sakamoto just below the Mt. Hiei cable-car station (35.069342, 135.865797); Kyotofu, around Mt Kumotori/Kibune River (35°10'25.7"N 135°46'05.2"E) (Wes Lang pers. comm.: found “coiled up in the middle of the hiking path” from the bus stop at Hanase Kogen). Searches by RJB assisted by Dr Grygier in rivers and on hills at Sakamoto in Feb., 2016 failed to find further specimens.

Etymology: The name is derived from its regional location (noun in apposition).

Material examined (see Figs. 5–7 ): Holotype (H), LBM FY 2015-8-1 mature, dissected (DNA tissue samples #K7–9, sample #K8 now KPM-NJL 83 ) collected by Kazuhiro Masunaga “ 2015/8/1 ”; “ On road where water runs across. Captured alive but died overnight. 80–85 % EtOH ” ; Paratype 1 (P1) FY 2015-8-2 large, macerated specimen (no DNA) ditto “2 015-8-2 ” ; Paratype 2 (P2) FY2010-24 “ Sakamoto coll. Masunaga ” March, 2011; Paratype 3 (P3) FY2011-19 ditto, “ 25.III.2012 ” .

Description: Large and dark blue with light grey intersegmental bands (i.e., striped). Lengths, H 260 mm x 15 mm wide; P 2, 210 mm; P 3, 195 mm. Segments (H) ~140. Prostomium epi-lobous, open. First dorsal pore 12/13. Setae about 80 on segment 12. Spermathecal pores in line with male pores three pairs in 6/7/8/9. Clitellum 14- 16. Female pore on 14. Male pores slits on 18 with about 16 (H) setae intervening. No genital markings (GMs) found. Septa 8/9/10 absent around muscular gizzard in 8. Spermathecae three pairs in 7-9 with single, coiled diverticulum longer than ampulla when unravelled. Seminal vesicles in 11 and 12. Ovaries and last hearts in 13. Racemose prostates in 18. Intestinal caeca from 27, deeply incised on one side at the base (not strictly manicate, more like intermediate or multiple, as found in M. megascolidioides – see Blakemore (2016a: Fig. 3 and Supplementary Materials, Appendix 1: Fig. 12).

Diagnosis: The only known native Metaphire species currently from Shiga-ken with three pairs of spermathecae in segments 6/7/8/9 is reported as “ M. sieboldi ” sensu lato by Minamiya et al. (2009). Major differences from the original and most subsequent species diagnoses of proper M. sieboldi (Horst, 1883) – the first species described from Japan – are lack of bright and uniform blue iridescent colouration and less defined manicate caecae; also the spermathecal diverticula may be longer than the ampullae even when they are coiled. The most definitive difference is the mtDNA COI barcode (in Appendix 1) that differs by 4.13 % from its closes match of AB482078 “ Metaphire sieboldi ” from Nara-ken that was part of Minamiya et al. ’s (2009) “Group I” mostly confined to the Kinki region and also most diverged of their study samples. Only their AB482080, also Group I, was from Shiga-ken and it differs by 4.57 %. These authors’ found: “ Among the M. sieboldi samples, the infraspecific sequence divergences of the COI gene ranged from 0.1 % to 18.1 %, and the mean infraspecific sequence divergences between phylogenetic groups of our study ranged 5.7 % to 15.9 % (Table 2).” However, an accepted COI barcode range for inter-specific differentiation is as low as 2–3 % (e.g. Hebert et al. 2003, 2004; Smith et al. 2005), also by Zhang & Zhang (2014) and by Wang et al. (2018) who found: “ almost 98 % of the species can be correctly distinguished for both COI and 16S when a threshold of 3 % nucleotide divergence was used for species discrimination ”. As the current specimen divergence is>4 % from other known samples it would qualify, on the information currently available, for specific status. Its furthest BLASTn result differs from other sampled concepts of “ M. sieboldi ” by up to 14 % (see Appendix 1).

Other examples in the Appendix support an interspecific COI gene division at>3–4 %.

Metaphire sieboldi proper is defined by its Leiden type ( RNHL 1825 ) and any substantial derivation or deviation from this (e.g. DNA>3–4 %) warrants separate specific, or at least sub-specific status, seemingly as do most of Minamiya et al. ’s (2009) group taxa .

Three LBM collection worms from Hokkaido dated “ 2014 09 11 ” sent by Y. Minamiya were identified (by RJB in 2016) as common exotic Aporrectodea rosea (Savigny, 1826) .

About 35 species occur on the Ryukyu (Okinawan) Islands and all 30+ earthworm species reports from Lake Biwako’s satoyama habitats are summarized in Appendix 1, several supported by mtDNA. Along with ~50 aquatic worm taxa, Biwako is Japan’s most megadrile & microdrile biodiverse site due to intensity of eco-taxonomic survey.

Figures

Fig. 5. Metaphire kinki sp. nov. P2 specimen (photo courtesy Kazuhiro Masunaga March, 2011 with LBM permission via M.J. Grygier pers. comm. 22nd July, 2015).

Fig. 6.“Kumotori/Kibune”worm, likely M. kinki in Nature (image permissions courtesy Wes Lang https://tozantales. wordpress.com). Compare with uniformly-coloured, bright electric-blue M. sieboldi from Fukuoka and Kumamoto, Kyushu www.flickr.com/photos/pokoroto/2950708988; www.flickr.com/photos/anaguma/7540289876.

Fig. 7. Metaphire kinki sp. nov. holotype spermatheca 9lhs and caecum.

Fig.3. Amynthas kume sp. nov. from Kumejima Island (photo courtesy of Shawn Miller).