Metaphire paka Blakemore

Blakemore, Robert J., Csuzdi, Csaba, Ito, Masamichi T. & Kaneko, Nobuhiro, 2007, Taxonomic status and ecology of Oriental Pheretima darnleiensis (Fletcher, 1886) and other earthworms (Oligochaeta: Megascolecidae) from Mt Kinabalu, Borneo, Zootaxa 1613, pp. 23-44 : 25-27

Metaphire paka Blakemore sp. nov.

(Fig. 1)

Diagnosis: Metaphire with a single pair of spermathecae in 8/9 ca. 0.25 circumference apart ventrally. Male pores on small penes on 18 ca. 0.25 circumference apart protuberant from small copulatory pouches. Genital markings as paired clusters of 1–9 disc-like papillae anteriorly on 9, 18–19 and sometimes 20 (sessile glands correspond internally). Holandric. Intestinal caeca simple in or near 27.

Distribution: Paka Cave, Mt Kinabalu , Sabah, Malaysia; 2,970 m, 06°05' N, 116° 33' E.

Material examined: Holotype (H) – NSMT-An 366, weakly clitellate, mature specimen, dissected and figured by RJB, stored in 80% ethanol (EtOH) after fixation in dilute formalin at time of collection, from vicinity of Paka Cave collected by Tatsuya Kawaguchi, 13.vii.2005 (sample labelled: “ 050713 PAKA 5-B”). Paratypes – NSMT-An 367-9, three specimens, one clitellate (P1, dissected), two aclitellate sub-adults (P2-3), all fixed in formalin and stored in 80% ethanol with same collection data as Holotype. An additional specimen “ 060307 R4-2” collected 07.iii.2006 by T. Kawaguchi along with several other samples from lowlands to east of Mt Kinabalu appears superfically similar to M. paka .

Etymology: named after locality of its Paka cave collection site and type locality.

Lengths: range 42–62 mm long, (H) 57, (P1) 62, (P2) 44, (P3) 42 mm.

Width: ca. 2 mm.

Segments: count range 74–120; (H) 104 with first segment poorly differentiated, (P1) 120, (P2) 74 – possibly a posterior regenerate, (P3) 76.

Colour: faint brown pigment dorsally with darker mid-dorsal line after segment 11 or 12; clitellum pale (H, P1).

Prostomium: open epilobous.

First dorsal pore: 11/12.

Setae: range 32–46 per segment; no ventral and dorsal gaps nor crowding; 6 setae intervene between male pores (H, P1); [actual counts: (H) 44–46 on 7, ca. 32 on 20, ca. 40 posteriorly; (P1) 44 on 7, 32 on 20, ca. 40 posteriorly].

Nephropores: diffuse, not detectable.

Clitellum: annular 14–16, weak and setae retained (H) or more pronounced (P1).

Male pores: on 18 ca. 0.25 circumference (1 mm) apart on small penes within small copulatory pouches [(H) 18rhs protruding] with 6 setae intervening (H, P1).

Female pores: single, midventral on 14.

Spermathecal pores: paired in 8/9 approximately 0.25 circumference apart; (P1) has apparent additional pore on 7/8rhs only.

Genital markings: paired clusters of one to nine small papillae below spermathecal pores in 9 and on either side of male pores anteriorly on 18 and 19 and sometimes a single papilla on either or both sides of 20; [actual counts: (H) 9lhs 5–6, 9rhs 7, 18lhs 5, 18rhs 5–6. 19 lhs 5, 19rhs 5; (P1) 9lhs 3, 9rhs 1, 18lhs 6, 18rhs 7, 19lhs 4, 19rhs 3; (P2) 9lhs 2, 9rhs 4, 18lhs 4, 18rhs 4, 19lhs 5, 19rhs 5, 20lhs 1, 20rhs 1; (P3) 9lhs 6, 9rhs 4, 18lhs 8, 18rhs 8, 19lhs 4, 19rhs 5, 20lhs 1, 20rhs 0]. Sessile glands correspond internally.

Septa: 8/9 thin, 9/10 absent; 10/11 and subsequent also thin.

Dorsal blood vessel: single.

Hearts: 10,11–13.

Gizzard: large between 8/9 and 10/11 but mostly in 9.

Calciferous glands: none.

Intestine origin (caeca, typhlosole): in 15; caeca simple with slight indentation from 26,27–23; simple lamellar typhlosole present, commencing from about 23. The gut contains yellow soil, woody organic debris and quartz grits.

Metaphire paka sp. nov. Holotype showing a, ventral view; b, dorsal view of prostomium; c, a spermatheca (also enlarged) with internal glands; and d, prostate in situ also with internal glands; e, lateral view of 18rhs penis; f, lateral view of an intestinal caecum also showing lamellar typhlosole; and g, dorsal view of the posterior segments. The weakly developed clitellum is shaded and scale bars are 1mm.

Nephridia: meroic, absent from spermathecal ducts.

Testes/sperm funnels: holandric, testes in 10 and 11 in testis sacs, seminal vesicles paired anteriorly in 11 and 12.

Ovaries: paired in 13 with funnels posteriorly; ovisacs not found.

Prostates: large racemose in 17–19,20; muscular ducts pass into small copulatory pouches concealed within base of each duct containing a small conical penis.

Spermathecae: paired in 9, saccular ampulla on shortish duct with small clavate diverticulum (iridescent); (P1) has an abnormal, adiverticular, spermatheca-like sac on 8lhs (as seen from dorsal dissection) corresponding to extra pore in 7/8rhs (as seen from ventrum).

Remarks. The rudimentary, ancillary spermatheca in segment 8 of paratype (P1) is considered an aberration. Nine previously known pheretimoid species have spermathecae only in 9 (Blakemore, unpublished), viz. Amynthas antefixus (Gates, 1935) from Szechuan, Metaphire cai ( Michaelsen, 1916) from Java, Amynthas dinghumontis Zhang et al., 2006 and Amynthas liaoi Zhang et al., 2006 from China, Metaphire michaelseni ( Ude, 1925) from Sarawak Borneo, Amynthas pataniensis labuhensis (Michaelsen, 1896: 224) from Moluccas, Pheretima (Pheretima) racemosa (Rosa, 1891: 399) from Java, Indonesia and Kalimantan Borneo, Amynthas supuensis (Michaelsen, 1896: 225) from Moluccas, and Pheretima arayatensis James et al. in James, Hong & Kim, 2004 from Luzon, Philippines (and, co-incidentally, several of these species are also montane). Of these, M. michaelseni that is also sympatric on Borneo but has a single, dorsal spermatheca with paired diverticula, and Ph. racemosa that has nephridia on its spermathecal ducts (thereby qualifying for Pheretima ) and multiloculate diverticula, perhaps come closest to the present species. Of the Amynthas spp., apart from having superficial male pores, each has a different arrangement of genital markings (when present). Metaphire cai is especially similar with spermathecal pores in 8/9 (0.2 circumference apart) and penes within small copulatory pouches – thereby just qualifying for inclusion in the genus, as with M. paka – but it differs in its lack of genital markings and in other minor respects. Metaphire cai ( Michaelsen, 1916) was originally a sub-species of Perichaeta inflata Horst, 1893 that is now a junior synonym of Metaphire javanica (Kinberg, 1867) , hence its present elevation to species level. M. cai was from Mt Pangerango, Java (in jungle at 1,000 m) and named after the collector, identified only as “ C.A. April 1899 ” (from whence the species name derives); its types are listed in Museums of Stockholm (NHRWS 153) and Hamburg (ZNUH 8503). From this and other Metaphire species, Metaphire paka appears distinct in its paired spermathecae in 9 combined with its arrangement of genital markings.

Because the primary male pores are on small penes, they are classed as ‘non-superficial’ [i.e. not “ discharging directly onto the surface of xviii [18]” ( Sims & Easton, 1972: 211) as required for inclusion in Amynthas ] and therefore this species is attributed to Metaphire . However, retraction of the penes (presumably the normal case in life) may result in the male pores being mistaken as ‘superficial’, thus dissection (or suction by syringe) are required for confirmation of this, as for other, marginal species.