Amynthas tralfamadore, Blakemore, 2012

Blakemore, Robert J., 2012, New earthworm species from NIBR’s Jeju-do biosphere compared to historical and new Japanese types (Oligochaeta: Megadrilacea: Megascolecidae), Journal of Species Research 1 (2), pp. 133-150 : 143-144

Amynthas tralfamadore sp. nov.

[ Fig. 7 ]

Diagnosis. Amynthas with spermathecal pores lateral in 7/8/9. Genital markings near spermathecal and male pores. Intestinal caeca simple with rugose inner face from 27. Spermathecal diverticula rounded rather than elongate and dorsal pores from 9/10.

Material inspected. Holotype (H), NIBR IV0000246 441, mature specimen fixed and stored in 80% ethanol (EtOH), here dissected and figured ( Fig. 7 ), collected 19.III.2012 by RJB & JooLae Cho of NIBR.

Etymology. After writer Kurt Vonnegut’s fictional biosphere reserve and exhibition.

Description. Length 125 mm, segments 125. A dark chocolate brown anterior dorsum with faint mid-dorsal line, clitellum darker and ventrum pale. Dorsal pores minute in 9/10 open from 10/11. Setae 46-50 per segment around segment 12, up to ca. 70 after clitellum. Spermathecal pores ca. 0.4 circumference apart in 7/8/9. Genital markings as small opposed discs just median to spermathecal pores paired either side in 7/8 (only one unilateral after 7/8rhs) and in 8/9 (plus one ‘rogue’ unilateral after 9/ 10lhs); similarly on either side of 18 just ventral to flat male pores.

Internally, small stalked glands correspond to the external genital markings. Peptonephridia fill 5 and 6, septa to 7/8 are thin and absent in 8/9/10 where muscular gizzard occurs, and after this they are also thin. Nephridia meroic. Spermathecae in 8 and 9 each having round ampulla on short duct with rounded clavate diverticulum. Dorsal vessel single; hearts in 10-13. Metandric, testis possibly reduced in 10 but only found in 11 and there not iridescent; seminal vesicles larger posteriorly in 11 and smaller anteriorly in 12. Ovaries and funnels in 13. Prostate glands aborted and only short muscular ducts remain. Oesophagus only slightly dilated in 14-½15; intestine origin in 16 with simple caeca from 27 that are unusual in having a paler rugose and capillaried interior face extending forward to ca. 24. Thin lamellar typhlosole commences around 27. Gut contains organic soil and larger grits.

Distribution. Korea, Incheon NIBR facility, possibly introduced from Jeju Island.

mtDNA COI Barcode result:

> WO2 A. tralfamadore Holotype IV0000246441 from NIBR’s Jeju biosphere: GTGTTGGTATAGGATTGGATCTCCCCCTCCTGC TGGATCAAAGAATGATGTATTGAGGTTTCGATC TGTTAGTAATATGGTAATTGCCCCTGCCAGTAC AGGTAGGGACAATAGTAATAGTACTACAGTGA TTACTACTGCTCACACAAATAGTGGGATTCGTT CTAGACGTAACCCAGATCATCGTATGTTAATTA CTGTTGTGATAAAGTTAATAGCTCCAAGAATTG ACGAGGCACCTGCAAGATGAAGTGAGAAAATT GCAAGGTCTACTGAAGGACCGGCATGTGCTATA TTTCTTGCTAAGGGTGGGTAAACTGTTCAACCT GTGCCAGCCCCCTTTTCTACCGCGGCAGATCTT

ACCAATAAAATTAATGATGGCGGGAGTAGTCA AAATCTTATGTTATTTAATCGAGGGAACGCCAT ATCTGGGGTTCCAAGTATTAGGGGTAGTAACCA GTTTCCGAATCCACCAATAAATACTGGCATTAC TAGAAAGAAGATTATTAAAAATGCATGTGCTGT TACAATTGTATTATATAGCTGGTCCCTACCAAG GAAGGATCCAGGTTGTCTTAACTCAATACGAAT AAGTAGTCTTATTCCTGCACCAATTATTCCTGCT CAAATTCCTAGAATAAAGTATAGGG megaBLAST showed no match better than 94% for voucher specimens, neither based on types, of AB542 533 “ Amynthas robustus ” from Japan or EF077538 “ A. triastriatus ” from China (an erstwhile synonym of M. masatakae ), or only 85% of max identity for DQ224191 “ A. robustus ” from Taiwan (cf. M. ryunome sp. nov.).

Remarks. A parthenogenetically degraded species, lacking prostate glands as with A. masatakae , nevertheless, in the key of Sims & Easton (1972) its incipient metandry corresponds to an A. martiorum -group. If holandric it would approach the large A. aeruginosus -group that contains both A. robustus and A. masatakae .

Distinctive characteristics of A. tralfamadore are the shape of spermathecae with the diverticula bulb spherical rather than elongate as in A. robustus or “paprika-shaped” in A. masatakae -although the importance of this in parthenogenetic morphs is perhaps debatable-and its inner face of intestinal caeca perhaps more rugose than in A. masatakae types. Moreover, its paired sets of markings in 18 are slightly wider apart on each side compared to those in the A. masatakae types ( Fig. 1 ). Its mtDNA COI barcode data serves to definitively characterize this species.

Although type-locality is the NIBR facility, its origin has yet to be clearly determined. The Jeju-do display uses bagged potting soil for bulking, but worms may have been accidentally introduced around roots of trees and shrubs and flowers directly imported from the Island or indirectly via plant nurseries.

This survey only took about 10 minutes and probably other species of earthworms are yet living in the facility, despite periodic replacement of the soil (pers. obs.), but a more extensive search was curtailed in order to protect the public display.

Figures

Fig. 7. Amynthas tralfamadore sp. nov. holotype from NIBR Korea; [boxed is a X2 enlargement of 9 lhs spermatheca and 18rhs male pore].

Fig. 1. Amynthas masatakae lectotype (912), dorsal view of prostomium, ventral view of body with spermathecae and prostatic ducts in situ, intestinal caeca and an enlargement of 9 lhs spermatheca from a separate vial [boxed are X2 details of spermathecal pore 7/8 lhs and male pore 18 lhs of paralectotype (913)] -lhs; Nogeyama specimen [boxed X2 enlargement of its pores in 7/8/9 lhs] - rhs.