Amynthas corticis ( Kinberg, 1867 )

Blakemore, Robert J., 2013, Megascolex (Perichaeta) diffringens Baird, 1869 and Pheretima pingi Stephenson, 1925 types compared to the Amynthas corticis (Kinberg, 1867) and A. carnosus (Goto & Hatai, 1899) species-groups (Oligochaeta: Megadrilacea: Megascolecidae), Journal of Species Research 2 (2), pp. 99-126 : 103-109

Amynthas corticis ( Kinberg, 1867)

( Figs. 4 -7)

A partial annotated synonymy from ( Blakemore, 2012d) with discussion in Remarks.

Perichaeta corticis Kinberg, 1867: 102 . [Type locality Oahu, the main Hawaii Island. Types in the Stockholm Museum: 1947, possibly immature].

Megascolex (Perichaeta) diffringens Baird, 1869a: 40 and 1869b: 387. [Original account of this species is presented below in full under A. diffringens ].

?[ Megascolex (Perichaeta) sanctaehelenae Baird, 1873: 96 . See A. diffringens below].

Perichaeta subquadrangula Grube, 1877: 553 . [Type locality Fiji. Types in Berlin, 705]. [Note: Due to its poor description, Sims & Easton (1972: 224) had this (misdated as “1868: 36”) incertae sedis, but Easton (1984: 118) placed it in synonymy of corticis ].

Megascolex indicus Horst, 1883: 186 (part? Non types). [Type-locality: Sumatra and Java. Types reportedly in Leiden Museum 1917-8 - see Sims & Easton (1972: 260)].

Perichaeta peregrina Fletcher, 1886 /7: 969. [Type locality plant pots from a nursery in Sydney, believed introduced from Mauritius. Types in Sydney? Untraceable at Macleay Museum, at the University of Sydney - Dr Margaret Humphrey, Curator, Entomology pers. comm. to RJB, April, 2005]. [Authorship dated “1886” eg by Michaelsen (1900); dated “1887” by Sims & Easton (1972: 239, 260); Easton (1984: 119). “The part containing Fletcher’s paper was actually published on 17 November 1886 ” - M.L. Augee, Editor, Proc. Linn. Soc. NSW pers. comm. to RJB (Oct. 2004) although the journal, now pubished online, is clearly dated “1887”]; Michaelsen, 1900: 293 (syn. ? molokaiensis ). Amyntas peregrinus : Beddard, 1900: 414 (syns. molokaiensis , floweri).

? Perichaeta mirabilis Bourne, 1887: 668 . [Naduvatam,

A

1 mm

Amynthas corticis ( NZ & ROK)

Nilgiris , India. Types ?].

Perichaeta heterochaeta Michaelsen, 1891: 6 . [Azores. Types lost]; Michaelsen, 1900: 275 (under indica with other synonyms ? corticis , diffringens , ungulata (laps. pro cingulata), heteropoda and nipponica ).

Amyntas heterochaeta ; Beddard, 1900: 416 (Hawaiian earthworms, syn. nipponica ? - described with no GMs or paired or unilateral in some of 6-9).

Pheretima heterochaeta : Michaelsen, 1900; etc.

? Perichaeta ijimae Rosa, 1891: 402 . [Type locality Japan. Types Vienna?]. [Spermathecae adiverticulate in 5/6/ 7/8, cf A. gracilis , A. micronarius ].

[ Perichaeta divergens Michaelsen, 1892: 243 , tab. 13, fig. 21. Type locality Japan. Types Berlin , 2116 “ Hilgendorf rp.”, now lost and not located in BMNH either - RJB pers. obs.. Prostates aborted, seems separable on its serrate intestinal caeca].

[ Pheretima divergens : Michaelsen, 1900: 264, 314- 317 (?syn. fuscata , campestris , kamakurensis, parvula, heteropoda , obscura, scholastica, decimpapillata, flavescens, producta, micronaria - all Goto & Hatai, 1898; all from Japan; but the latter one, at least, is doubtful); Ohfuchi, 1937: 67-108, tabs. 1-25, figs. 11- 28 (without including any synonyms of Michaelsen!)].

Perichaeta nipponica Beddard, 1892: 760 . [ Japan. Type BMNH 1904:10:5:993 - no longer traceable in the collection there, E. Sherlock per. comm., RJB pers. obs. VI.2013]. Pheretima nipponica : Michaelsen, 1900; Ohfuchi, 1937: 108-133, fig. 29-36.

? Perichaeta perkinsi Beddard, 1896: 198 . [From Hawaii. Types missing? Not found in BMNH pers. obs. RJB VI.2013]. [Spermathecae 5/6/7/8/9; possibly a separate, although exotic, species/variety].

? Perichaeta molokaiensis Beddard, 1896: 201 . [From Hawaii. Types missing? Not found in BMNH pers. obs. RJB VI.2013]. [Spermathecae 5/6/7/8/9].

Perichaeta heteropoda Goto & Hatai, 1898: 69 . [ Japan. Types none - confirmed RJB ( Blakemore & Ueshima (2011)]. [Spermathecae 5/6/7/8/9. GM in 6-9 paired and pre-setal - only markings in 6 separate it from A. diffringens types, pers. obs. Name yet retained by some contemporary Japanese and/or Koreans sometimes as “ Amynthas heteropodus ” or “ A. heteropoda ”, or misspelt as “ heteropadus ”; for example Hong & Kim (2009) and Dr Young Hong again presented this as a contemporary Korean species at a seminar in Incheon in September, 2012]. Pheretima heteropoda : Ohfuchi, 1937: 42-50, figs. 4- 7 (part? cf A. diffingens here).

Pheretima marenzelleri Cognetti, 1906: 780 , figs. 5-6. [From Yokohama. Type Vienna? Kobayashi, 1938: 407, figs. 1a-b (recorded from Hokkaido and, p. 408 footnote: “non Ohfuchi, 1936”]); redescribed by Blakemore (2012c); yet quoted as valid by Shen et al. (2013) for some reason].

? Pheretima silvestrii Cognetti, 1909: 266 . [ From Hawaii. Types Turin 194].

Pheretima divergens yunnanensis Stephenson, 1912: 274 . [From Yunnan. Type Calcutta (5062)]. [Mistaken by some subsequent workers as “ P. browni yunnanensis ”. Gates (1939: 430) inspected the fragmented type (s) - described below with A. diffringens ].

[? Pheretima pingi Stephenson, 1925: 891 (cf A. carnosus ) description below].

? Pheretima indica var. cameroni Stephenson, 1932: 47 , fig. 4. [From Cameron Highlands, Malaya. Type in London, possibly missing? Not found in BMNH pers. obs. RJB VI.2013]. [A single poorly preserved specimen with spermathecae in 5/6-8/9 no nephridia on ducts; no markings - probable syn. nov. of corticis ].

? Pheretima sheni Chen, 1935: 38 . [From Hong Kong, eight specimens three of them aclitellate and all lacking spermathecae. Type described in the Museum of Fan Institute of Biology, Peiping (Beijing) but also claimed in US National Museum]. [Cf Amynthas robustus , A. illotus ].

? Pheretima directa Chen, 1935: 47 . [ From Hong Kong; three specimens, the type described in the Museum of Fan Institute of Biology, Peiping but also claimed in US National Museum: 20183]. [Because some genital markings are lateral to the male pores it is possible that this is a valid species but cf A. hatomajimensis as described below].

? Pheretima oyamai Ohfuchi, 1937 : fig. 10, Pl. I, 3. [From Morioka, Iwate-ken and Odate, Akita-ken. Types? The 1 mm

5 5 10 25 26 27 10 25 26 27 15 15 20 20 1 mm

Fig. 7. Amynthas corticis - author’s 1990 specimens from Queensland, Australia showing (lhs) complete and (rhs) Monocystis parasitized spermathecae (after Blakemore, 2012d).

August 2013 BLAKEMORE-HISTORICAL EARTHWORM TYPES 107

spermathecae are adiverticulate and GMs only on 18, exactly as he shows for his subsequent redescription of Ph. divergens but caeca are simple and smooth. Cf A. carnosus as an adiverticulate morph?].

Pheretima tajiroensis Ohfuchi, 1938: 46 , figs. 12-14. [From Tajiro Island, Miyagi-ken. Types not known. Parasitized spermathecae & prostates mistaken as characteristics].

? Pheretima homoseta Chen, 1938: 414 . [From Hainan. Types? Restored in some latest accounts as Amynthas homosetus but without good reason. Originally as Pheretima homochaeta , an ‘incorrect original spelling’ (under ICZN, 1999: Art. 32.5.1.1) subsequently corrected to P. homoseta by Chen (1938) in an ERRATA sheet].

? Pheretima morii Kobayashi, 1938: 161 , fig. 15. [From Korea. Types unknown. Spermathecae 5/6/7/8/9, GMs in 7-9, and just before male pores; prostates aborted].

? Pheretima toriii Ohfuchi, 1941: 244 , fig. 2. [From cave, Oita-ken. Types? Small ~ 40 mm and lacking GMs].

? Pheretima clerica Benham 1947: 423 , Pl. 1, figs. 1-5. [ From Gisborne district in NZ. Types? There appears some slight difference in that male pores are in small slits and there is a genital papilla on the inside of each; prostates are present].

Pheretima campestris Lee, 1952: 39 . [From New Zealand (and Kermadec). Types Te Papa, W.000494]. [Placed in synonymy of P. peregrina (Fletcher, 1887) (= Amynthas corticis ) non P. campestris Goto & Hatai, 1898 (?= Amynthas robustus )]. [Non senior secondary synonym P. campestris Goto & Hatai, 1898: 67 ].

? Pheretima hatomajimensis Ohfuchi, 1957: 245 [ From Japan. Types? - described below].

Amynthas corticus (sic lapsus pro corticis ): Sims & Easton, 1972: 235, 241; Easton, 1981: 49-50 (syn. diffringens , divergens , ? hatomajimensis , heterochaeta , heteropoda , ? ijimae , indica Horst, 1883: 186 (sic lapsus Easton, 1981 pro indicus ), ? marenzelleri , nipponica , oyamai , tajiroensis , toriii ).

Amynthas corticis : Easton 1982: 726-728 (syn. diffringens , peregrina , heterochaeta ); Easton, 1984: 118 (syn. subquadrangula ); Sims & Gerard, 1985 (syn. diffringens , indicus , nipponica ); Blakemore, 2012d (listing above syns. plus about a dozen extra synonyms from Japan).

Taxonomic Notes. The name corticis is sometimes misspelt “ corticus ” or “ coritcis ”. It is not certain that all subspecis of Megascolex indicus Horst, 1883 s. strict. (cf Pheretima darnleiensis ( Fletcher, 1886)) follow it into synonymy of corticis ; these subspecies are listed by Sims & Easton (1972: 235) as: Amynthas indicus cameroni (Stephenson, 1932) from the Malay Peninsula; Amynthas indicus ceylonicus (Michaelsen, 1897: 246) from Sri Lanka; and Amynthas perkinsi (Beddard, 1896) from Halemanua and Kauai, Hawaii which was included by Michaelsen (1900: 276) as a ‘variety’ of indica . It appears to me that there is nothing substantial in the description of A. cameroni to differentiate it from A. corticis ; and certainly the latter two taxa are not endemic to their localities. Stephenson (1923: 302) includes ceylonica (and its variant mispelling “ceylanensis” in P. heterochaeta (= A. corticis ); and Gates (1972: 149) includes A. perkinsi as a possible synonym of corticis in a footnote where he lists the names under which specimens of P. diffringens have been referred to as, or have been types of A. perkinsi was based on two specimens, neither with genital markings, that, however, had complete spermathecae and prostates; probably the same as A. corticis as is the almost identical A. molokaiensis (Beddard, 1986) .

Diagnosis. Amynthas with four pairs of spermathecal pores ca. 0.3 body circumference apart in furrows 5/6/7/ 8/9 [all, or just posterior pair (?or anterior pair) rarely lacking]; genital markings small paired and variable near spermathecal and male pores, often widely paired. Intestinal caeca simple with smooth margins (or incised with age in older specimens cf A. divergens ?) originating near segment 27. Prostates often aborted, sometimes present. Parthenogenetic and parasitized morphs common (eg lacking prostate glands and/or with partially or wholly aborted or adiverticulate spermathecae).

Distribution. According to Gates (1972) its synonym occurrence is “ everywhere, including Europe ”. It is the most widely distributed of the allochthonous species of the pheretimoid group, having been recorded from temperate and tropical regions throughout the world.

Remarks. Amynthas corticis ( Kinberg, 1867) type-locality was in Oahu and it was also from Hawaii that Beddard (1900: 415) claimed “ Amyntas peregrinus Fletcher ” [= A. peregrinus (Fletcher, 1896/7) originally from Sydney] and placed in synonymy his own P. molokaiensis Beddard, 1896 that seems indistinguishable from his subsequent description ( Beddard, 1900: 416) of “ Amyntas heterochaeta Mich. ” (sic) [= Amynthas heterochaetus (Michaelsen, 1891) ] from there. These four taxa are identified as having spermathecal pores in 5/6/7/8/9 and either having or lacking posterior GMs and prostate glands and have since been placed under A. corticis . Their superficial male pores and lack of copulatory sacs qualifies them for Amynthas and, moreover, they thus comply within the range of characters allowed for in Ohfuchi’s (1937: 42) detailed account of Pheretima heteropoda ( Goto and Hatai, 1899) that should also be considered at least a partial synonym due to his “variations” with many arrangements, including total absence, of anterior GMs ( Ohfuchi, 1937: text-figs. 5, 6). This situation may be compared to Blakemore (2013a: fig. 2) where anterior markings in an A. corticis are present or unilaterally absent making use of this distinction for taxa separation irrelevant.

Ohfuchi (1937: 108) was inconsistent when he described prior P. nipponica (Beddard, 1893) that seems indistinguishable from his A. heteropoda ( Goto & Hatai, 1899) since he claimed both lacked markings around male pores - the only difference was in length of spermathecal diverticula, but these he described as highly variable in P. nipponica . Thus, Ohfuchi’s concept of P. heteropoda should have been subsumed under P. nipponica . All these taxa are now included in A. corticis as indicated by Easton (1981) and remain so unless proven otherwise, except perhaps for P. divergens ( Michaelsen, 1892) with its serrate caeca.

Michaelsen (1900: 264, 314-317) redescribed his Pheretima divergens with possible synonyms P. fuscata , campestris , kamakurensis, parvula, heteropoda , obscura, scholastica, decimpapillata, flavescens, producta, and micronaria - all by Goto & Hatai (1898) and all from Japan (and all ignored by Ohfuchi, 1937!); and all but the latter one, at least, doubtfully separate, even to this day. Ohfuchi (1937: 100, text-fig. 23, 3-5) differentiated his specimens of Pheretima divergens ( Michaelsen, 1892) from other taxa due to their serrate (or at least deeply indented) intestinal caecal ventra. On this latter basis alone the taxon Amynthas divergens is apparently separable from both A. corticis and A. diffringens , as well as from A. carnosus ( Goto & Hatai, 1899) which Ohfuchi (1937: 56; text-fig. 9) also describes in some detail (he retained it because he found it to have markings around the male pores, as in his A. divergens , but to lack the serrate caeca). Gates (1972) kept P. divergens in synonymy of P. diffringens , although Ohfuchi’s (1937: 67-108) detailed redescription showed divergens to have great variation in GMs and wide distribution in Japan. It is likely this taxon, herein restored, also occurs in Korea (and elsewhere?) either as a native or an introduction.

A more complete descriptions of A. corticis , its synonymy, distribution and bibliography are found in Blakemore (2012d; 2013a; 2013b) where some DNA data are also presented (but unfortunately not from historical primary types).

Korean specimens providing DNA samples WM9, WO4, WO5, WO6 and WO56 (from Jeju) all had mega BLAST agreement of 100% along with other A. corticis specimens from Biwa (JET-120-121) and Mishima (JET 138-139) in Japan. These differed substantially from other specimens identified as “ A. corticis ” or “ A. cf. heteropodus ” that provided DNA samples w59 (from Incheon), WM7 from NZ plus other specimens from Biwa (JET-122-123) and Mishima (JET 140-141) in Japan (in Appendix but without repeats). There seems to be at least two genetically distinct A. corticis lineages sharing the same name ( Fig. 1 ). Further work is required to resolve this issue of identity of the two groups under the taxonomic Principal of Priority.

Samples providing DNA codes JET153-154 from NSW Australia that I tentatively labeled as A. cf. corticis differ substantially and are most likely closer related to A. gracilis ( Kinberg, 1867) ; it is a small concern that the single specimen (Tokyo An-477) provided the two samples that gave slightly different results from PCR analysis ( Fig. 1 ; Appendix).

Figures

Fig. 4. Amynthas corticis - specimens A from Arataki, New Zealand (providing DNA WM7 specimen in Auckland Museum) and B Korea (providing DNA WM9) plus male pores of its two sympatric specimens for comparison (specimens NIBRIV249903-4). Note: these superficially similar specimens separate genetically (see Fig. 1).

Fig. 1. Phylotree from MEGA5 program Maximum Likelihood defaults - sample codes explained in the Appendix; ◆- samples have figured specimens; ◇- ex GenBank. Appears to show significant genetic difference between specimens superficially compliant with broad A. corticis definition as discussed below that taxon herein. Synonym priority for either Gp 1 or Gp 2 is currently unresolved.