Amynthas masatakae ( Beddard, 1892 )

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 : 134-138

Amynthas masatakae ( Beddard, 1892)

[ Fig. 1 ]

Perichaeta masatakae Beddard, 1892: 761 . Published December, 1892 according to Michaelsen (1900). From “ Japan ”. Syntypes listed by Sims & Easton (1992: 181) as BMNH: 1904:10:5:91/92 but actually 1904:10.5. 912-913 (pers. obs.). Beddard, 1895: 414.

?[ Perichaeta campestris Goto & Hatai, 1898: 67 , textfig. From Kamakura, Japan. No types. Non Ph. campestris Lee, 1952 (= A. corticis ). Most often synonymized under A. robustus proper (see Fig. 2), but here provisionally retained separately].

? Perichaeta parvicystis Goto & Hatai, 1899: 18 , figs. 8, 8a, 8b. From Uwajima (Ehime-ken, Shikoku) and Oarai (Ibaraki-ken, Honshu). No types. (See Fig. 3 ).

Amyntas masatakae : Beddard, 1900: 632 (syn. campestris ).

Pheretima masatakae : Michaelsen, 1900: 282; Kobayashi, 1937: 337, fig. 2, 1938: 137 (?part.); Ohfuchi, 1938: 62, figs. 6-7.

Pheretima masatake (sic lapsus): Ohfuchi, 1956: 132, fig. 11 (?part. cf. A. robustus ).

Amynthas mastakae (sic lapsus): Sims & Easton 1972: 181, 234, 244.

Amynthas masatakae : Chuang & Chen, 2002: 73, fig. 1.

Note. Easton (1981: 56) had “ mastakae ” (sic lapsus) in synonymy of A. robustus ( Perrier, 1872) as per Gates (1939: 473), but this, like many of Gates’ “synonymies”, not necessarily the original species, for some reason (or none), just a later citation requiring that all these references are again re-checked from original sources-see Remarks below. Following Easton, Blakemore (2003: 7) had it in A. robustus too with syns.: masatakae , campestris ,? zavatarii, ornata,? sheni, lauta , corrugata .

Material examined. BMNH: 1904:10.5.912-913, label- ed “ SYNTYPES 1904: 10.5.912-3 Perichaeta masatakae Beddard 1892 Coll. by Mr Masatake Rokugo” (lapsus for Masataka Rokugo-cf. his Perichaeta rokugo ). Two mature specimens, both previously dissected and rather macerated in mid-body, plus a spermatheca (9lhs) in a small vial in the jar ( Fig. 1 ). In order to enhance the stability of nomenclature, under ICZN (1999: Art. 72; et Decl. 44), the specimen newly figured (912) I hereby designate the LECTOTYPE since it was the basis of Beddard’s description (being donor of the removed spermatheca), it is 115 mm long but missing its posterior tip. Specimen (913) in the same jar, that had had its 18lhs prostate duct and GM glands removed (missing), thus becomes the PARALECTOTYPE.

Japan: Lake Biwa Museum ( LBM 1380000087 ), from Hikone (collected 18.VI.2009) four specimens that I initially mislabeled “ Metaphire spex” or as A. robustus (as it was then known in 2010); NIBR ( IV0000251098 ), from Nogeyama, Yokohama, collected 4.VI.2012 by RJB and T. J. Tansy, mature specimen found stranded and distress- ed on road in early evening after rain (dissected and figured, Fig. 1 ) .

Diagnosis (from Beddard, pers. obs. and good references in synonymy above). Colour dark brown. Length 105-150+ mm by 4.0- 7.5 mm wide; body cylindrical caudally tapering, segments 88-138. Lectotype and paralectotype 110+ and 130 mm, respectively the latter with 88 segments and a tapering tail (cf. 125 mm with 90 segments by Beddard for the same specimen), Nogeyama specimen 150+mm, Ohfuchi (1938) has size up to 189 mm with 125 segments. Prostomium open epilobous. First dorsal pore at 11/12 or 12/ 13 in Ohfuchi’s specimens. Setae ca. 30-52 (40-50 in lectotype), (cf. 20-64 by Kobayashi). Spermathecal pores lateral in 7/8 and 8/9. Clitellum annular, 14-16. Female pore single on 14. Male pores superficial on 18 with 9-15 setae intervening. Genital markings small papillae, most with glands internally, typically immediately median to spermathecal pores anteriorly and posteriorly, i.e. in some of 7-9 (Kobayashi has them sometimes in successive segment 10); each male pore typically with two genital papillae just median, one presetal and one postsetal on 18 (Kobayashi has some in 19 too). [Note that in the Nogeyama specimen ( Fig. 1 ) some markings lacked internal glands while at least one gland had no noticeable external manifestation, i.e., their pores may be superficial and easily overlooked and not all papillae appear to have glands].

Septa 5/6/7 and 10/11-13/14 thickened; 8/9/10 absent around muscular gizzard. Hearts in 10-13. Spermatheca paired in 8 and 9 each with oval ampulla and elongate or paprika-shaped diverticulum (GM glands often nearby). Testis in sacs in 10 and 11, seminal vesicles paired anteriorly in 11 and 12, pseudovesicles in 13 (what Beddard calls ‘egg-sacs’ and Ohfuchi an ‘ovisac’). Ovaries in 13, ovisacs absent from 14 (pers. obs.). Prostate glands absent with only curved prostatic duct in 18 (or present in some of Kobayashi’s specimens), GM glands adjacent. Intestine from 15,½15, caeca simple with jagged inner edge originating from 26-28 [or simple and without indentations in Kobayashi’s (1938: 138) specimens], vascular and lamellar typhlosole starts from around 26-30 (in lectotype and Nogeyama specimen, pers. obs.) with guts mostly containing amorphous soil with some grits (geophagous diet).

Behaviour. Ohfuchi (1938: 62) reported mostly clitellate specimens from organic soil near houses at 12-16 cm depth in Feb., 1937 that he thought indicative of hibernation.

Distribution and habitat. “ Japan ” (Beddard); Michaelsen (1903: 97) gave locality as Kamakura [mistakenly quoted by Kobayashi (1938: 139) as “ Yokohama ”] but this just for its erstwhile junior synonym, P. campestris ; the report by Ohfuchi (1938) is from Wakayama-ken on the Kii Peninsula in the Kansai region. New material found at Nogeyama in Yokohama, between Tokyo and Amynthas robustus

Fig. 2. Amynthas robustus type after original illustrations ( Perrier, 1872: figs. 67-68).

Kamakura, suggests an original location. For Korea, Kobayashi (1937, 1938) recorded it from Quelpart (= Jeju), several other smaller islands and from the mainland at Mokpo but, in light of current knowledge presented in the current paper, these are possible misidentifications of A. tralfamadore (or M. ryunome ?) or some other taxon as noted in Remarks below.

Chuang & Chen (2002) newly reported A. masatakae as an introduction to northern Taiwan at Mt Dongyan (1000 m elevation on fruit farms) but were mistaken to say this was the first record outside Japan (cf. Kobayashi, 1937, 1938).

A. masatakae is now more restricted in its distribution compared to its treatment whilst in synonymy of A. robustus variously by Gates (1939), Ljungström (1971) and successively (cf. attempts to unravel the confusion of A. robustus by Blakemore, 2003, 2010b and herein).

Remarks. When we carefully read Gates’ (1939: 474) voluminous account of Pheretima robustus we discover that in some cases he only considered citations of some species to be synonyms and, in other cases, the species themselves, these barely differentiated. Thus he claimed the Korean record of “1937. Pheretima masatakae KOBAYASHI, Sci. Rep. Tohoku Univ. , ser. 4. vol. 11. p. 337” to be in synonymy and ignored all its other citations above, including the type description! Thus Gates (1939) is assumed by de facto default to have falsely given an impression of synonymy of the name P. masatakae in A. robustus . This misinterpretation thereby expanded not only the definition of both combined species, but also their ranges. Being an earlier described species, and possibly having parthenogenetic variability in spermathecae and genital markings as introduced by Gates’ bizarre scheme, allowed A. robustus in name to collect several synonyms in subsequent work, e.g. by Ljungström (1971) and Easton (1981), for specimens with two (or fewer?) pairs of spermathecae, ultimately accruing about a dozen synonymic names.

Chuang & Chen (2002: 75) restored A. masatakae . However, the key character these authors gave for separation of A. masatakae from A. robustus -its lack of prostates-is not necessarily valid: Lack of prostates merely indicates parthenogenetic degradation and it is entirely permissible for sexual forms to occur under this species’ name, possibly in manifestations not dissimilar to A. robustus or to any of a dozen other taxa, as (validly or invalidly) included under this name by Gates (1939) and successively (full A. robustus synonymy provided in Blakemore, 2010b).

Meanwhile, Amynthas campestris ( Goto & Hatai, 1898: 67) has prostatic glands, but its synonymy by Beddard (1900) is unacceptable, due not to its glands but rather to the fact that its spermathecal pores are possibly closer together, and, moreover, its GMs certainly differ being post-setal pairs in 7 & 8 and 17-19 approximately as wide as the spermathecal pores in 7/8/9. Its true relationship to A. robustus is yet to be determined.

Conversely, Ohfuchi’s (1938: 65) suggestion that closely similar A. parvicystis ( Goto & Hatai, 1899: 18) is not a synonym of A. masatakae merely because spermathecae in the former were said to be located in 7 & 8 while in the latter they are in 8 & 9, is perhaps less of a valid reason due to known flaws in his mentor Hatai’s work whereby he frequently miscounted segments (e.g. for A. carnosus as shown in Blakemore, 2012a). Described with spermathecal pores anteriorly in 7 & 8 and with GMs in 6/7/8 (their fig. 8, here Fig. 3 ), but these are probably vice versa transposition mistakes (i.e., spermathecae in 6/7/8 and markings in 7 & 8) making it superficially similar to A. tokioensis . Then again, the spermathecal pores may be mistaken (as for their P. vesiculata and P. carnosa !) and actually occur in 7/8/9, in which case this name is possibly a synonym of A. masatakae proper.

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Fig. 8

In an instance of further confusion, Hatai in Goto & Hatai (1899) described A. parvicystis with a single pair of caeca having “ external margins frizzled ” said to be similar to the condition found in Amynthas digitatus (Benham, 1896) and A. bonthainensis (Benham, 1896) . Sims & Easton (1972: 173, fig. 1I) show A. digitatus with multiple (=manicate) intestinal caeca although Hatai may not have known this. Moreover, Goto & Hatai (1899: 23) fail- ed to include A. parvicystis in their list of species with manicate caeca (although they also miss their own agrestis and mistakenly include divergens in this list), and they had earlier overlooked the caeca of their P. iizukai as well as misdescribing the multiple caeca of their P. megascolidioides . Possibly the caeca were single but incised and if so, plus its spermathecae were really in 8 & 9, then it would be similar to specimens reported from Kyushu by Yasuaki Sugi (unpublished http://www.geocities.jp/ homantaro/AmyMeta/AmyMeta1.doc, http://www.geo cities.jp/homantaro/AmyMeta/Robustus.htm, April, 2012) under the name “ Amynthas robustus ( Perrier, 1872) ?” that are, however, now seemingly closer to A. masatakae as revived herein.

Nothing resembling Goto & Hatai’s A. parvicystis has been reported since its original definition [except for a dubious report by Kobayashi (1941a)] and, although it is probably a poorly-described junior synonym of A. masatakae , if its caeca are indeed manicate, most likely it is yet another synonym of A. tokioensis [for which Ishizuka’s Ph. verticosa is also a synonym with his figures ( Ishizuka, 1999 b: 50, figs. 75-83) complying almost exactly with Goto & Hatai’s parvicystis figures]. Perhaps the most sensible policy, for the time being at least, is to treat A. parvicystis as a species incertae sedis or dubius.

In the present author’s current view, the way that A. robustus proper differs from Beddard’s A. masatakae , according to Perrier’s original description and figures (presented here as Fig. 2) are its genital markings in 8 & 9 directly below the spermathecal pores plus a pair mid-ventrally and presetally between the male pores. The spermathecal diverticula also appear longer ( Fig. 1 vs. Fig. 2). Another differentiating characteristic, as describ- ed by Perrier (1872: 116) is “ deux coecums lisses ” (two smooth caeca) from segment 26, while the inner edge of the caeca in A. masatakae are indented or serrate. Compare this to Kobayashi’s (1938) account where the caeca are without indentations, and to Ohfuchi (1956) who describes serrate caeca plus markings between the male pores, and see A. tralfamadore and M. ryunome herein. Gates (1939: 479) has his “ Pheretima robusta ” with caecal margins incised but this not based on its types and, as already noted, his work is very confused (he provides no figures), quite unreliable (his errors go unchecked) and highly suspect.

Types of Amynthas robustus will need to be checked for details of genital markings, spermathecae and smoothness of their caeca. Without inspection of these, Gates (1939) then Ljungström (1971) discussed supposedly parthenogenetic forms of Pheretima robusta , and considered (parts?) of both P. aspergillum and P. masatakae to be synonymous. However, types of A. masatakae ( Fig. 1 ) and some specimens (including some of Kobayashi’s Korean specimens that seem mostly compliant despite some retaining prostates) from the synonymy presented above, differ from A. robustus in their markings being typically small and paired mesially on inner sides of spermathecal and/or male pores, but typically not mid-ventral on 18.

Kobayashi (1937) described “ masatakae ” specimens from Korea, some with prostates, that lacked marking between the male pores as in masatakae yet had smooth caeca as in robustus (and ryunome herein); conversely, Ohfuchi (1956: 155, 160) described prostatic “ masatakae ” specimens from Okinawa having both mid-ventral markings on 18 as in robustus and serrate caeca as in masatakae . Ohfuchi confounded his descriptions by putting these specimens under two names: “ Pheretima masatake ” [sic lapsus pro masatakae ] and P. lauta Ude, 1905: 405 - this latter with synonyms P. siemsseni Michaelsen, 1931: 17 and P. fokiensis Michaelsen, 1931: 19 types of which were inspected by Gates (1939: 420) under the species name Pheretima aspergillum ( Perrier, 1872) along with its other erstwhile synonyms P. takatorii ( Goto & Hatai, 1898) and P. corrugata Chen, 1931: 131 . This latter taxon was also allegedly redescribed by Ohfuchi (1956: 162) from Okinawa.

Nevertheless, it seems likely that both Kobayashi (1937; 1938) and Ohfuchi (1956) were describing specimens that would now qualify for neither A. robustus nor A. masatakae , i.e., they possibly represent one or more new and undescribed taxa (cf. Amynthas tralfamadore and Metaphire ryunome herein).

Thus, while appearing intermediate between robustus and masatakae , yet possibly more compliant with the former, these Okinawan and Korean specimens require revaluation with all earlier species’ types and also with Taiwanese specimens attributed to either species names of robustus or masatakae , allowing in each case for parthenogenetic degradations (as noted by Blakemore, 2003), i.e., with reduced relevancy of prostates, spermathecae and GMs as key defining characteristics.

Intestinal caecal indentations are perhaps unreliable characters too and may vary interspecifically (as noted by Sims & Easton, 1972 and Blakemore, 2003). Moreover, Amynthas aspergillum ( Perrier, 1872) should, for the time being at least, remain separate retaining its supposed synonyms: Perichaeta takatorii Goto & Hatai, 1889 and Pheretima paraglandularis Fang, 1929 , albeit Chen (1959: fig. 13) shows its intestinal caeca deeply incised whereas Chang et al. (2003: fig. 9) have them smooth.

It is further possible that A. robustus proper has non-superficial male pores in which case it would qualify for genus Metaphire as for M. ryunome sp. nov. below.

Figures

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.

Fig. 3. Amynthas parvicystis after original (Goto & Hatai, 1899: fig. 8)-possibly a composite for different species and with segments 7 & 8 miscounted?