Proandricus michelleae, Plisko, 2002

Plisko, Jadwiga Danuta, 2002, Nine new earthworm species of Proandricus Plisko, 1992 from South Africa and Lesotho (Oligochaeta: Microchaetidae), African Invertebrates 43, pp. 183-204 : 196-198

Proandricus michelleae sp. n.

( Fig. 8 )

Etymology: Named for Dr M. Hamer of the School of Botany & Zoology, University of Natal, Pietermaritzburg, who collected and donated the type material to the Natal Museum.

Material examined: SOUTH AFRICA: KwaZulu-Natal: Holotype NMSA /Olig.02713, Drakensberg Gardens, Mzimkulwane area (29º42'S: 29º19'E) on surface of path during rainy day, 16 February 1998, M. Hamer and K. Martens leg. Paratype: NMSA / Olig. 02714 collected together with holotype .

Description based on holotype and paratype.

External characters:

General: Body cylindrical, flattened at clitellum and in the area of tubercula pubertatis. Colour: Alcohol-preserved yellowish-grey. Dimensions: Preserved holotype 110 mm long, 4 mm wide at segment 10, 7 mm at tubercula pubertatis. Paratype 134 mm long, 5 mm wide at 10, 7 mm at tubercula pubertatis. Segment number: Holotype 383. Prostomium: Prolobous, moderate. Segmentation: Secondary annulation present on preclitellar segments; 1 and 2 short, with longitudinal grooves; 3 simple, as long as first ringlet of segment 4; 4–8 with two simple ringlets, similar in size and appearance; 9 with two ringlets, second shorter than first; segments 10–12 simple, irregularly annulated, postclitellar simple. Setae: Moderate in size, closely paired; first pairs on segment 3; on annulated segments on first ringlet; setal distances of aa are not constant on some preclitellar and on some postclitellar segments; on 9–13 aa setae are slightly closer than these on 15– 16; on 17–20, covered by tissue of the tubercula pubertatis, probably located similarly to these on16; on 21–30 distances slightly increasing; ab = cd on all segments; on segments 31 and the following aa> bc. Nephridial pores: Conspicuous, in cd setal lines; first pair in intersegmental furrow 3/4. Female pores: In posterior part of 14, between b and c setal lines. Male pores: It is difficult to establish exact position: two clear, elongated depressions in segment 16 slightly above ab setae suggest presence of male pores; however, in the same segment, medially, near to intersegmental furrow of 16/17, is a longitudinal, single concavity. It can include the pore or pores into which vasa deferentia enter; in dissected specimen vasa deferentia were observed in anterior part of segment 17, close to the external middle cavity; however, in intersegmental furrow 17/18, laterally to tubercula pubertatis are two clear openings that may be male pores. Spermathecal pores: Not observed externally; position of spermathecae noted during dissection indicates they are in intersegmental furrows 11/12 and 12/13.

Clitellar region ( Fig. 8 ): Clitellum: Saddle-shaped, segmented; on segments 13–23, although clitellar tissues cover segment 13 only dorsally in the middle portion; on 13– 15 ventral edges terminate at cd setae; on 16–20 at edges of tubercula pubertatis; on 21–23 clitellum extends slightly below cd setae. Tubercula pubertatis: On segments 16–20, segmented; on 17–19 marked by brownish colour; vertically stretched rectangles, medially separated and rimmed with narrow strips, extended laterally to clitellar borders; bordering clitellum on 1/n16–1/n20 with clear, enlarged rims. Papillae: A pair of moderately sized, swollen tubercles around ab setae on 12, associated with genital glands.

Internal characters:

Septa: 4/5 5/6 6/7 thin, not thickened; 7/8 and 8/9 thickened very much, muscular, similar in size and appearance; other septa thin, firm. Gizzard: In 7; small, anteriorly muscular, posteriorly soft. Calciferous glands: In 9, lateral; separated dorsally and ventrally. Intestine: Commences in 13. Typhlosole: Commences in 13 as large U-shaped tube; in holotype terminates in segment 170. Dorsal blood vessel: In 5 and 6 double, close; in 7 double in only posterior part, close; in 8 double, separated; 9 double, cordiform; single when crossing septa, in 10 and following segments. Paired dorsoventral vessels: Thin vessels in 5–8; in 9–11 enlarged, moniliform. Nephridia: Meganephridia ; coiled loops and V-shaped caeca.

Reproductive organs: Spermiductal funnels: Proandric arrangement (in segment 10); one pair of large funnels enclosed in common sac; closely connected with seminal sacs at posterior part of segment 10; iridescence confirms presence of sperm. Vasa deferentia: Single ducts run medially at each side of body to anterior part of segment 17, when they enter body wall; it is difficult to establish which cavities noted externally on segment 16 or intersegmental furrow 17/18 correspond with vasa deferentia. Seminal vesicles: One pair of large vesicles anteriorly connected at septum 10/11 with spermiductal funnels; elongated, confined to segment 11; bent vertically and closely touching each other dorsally. Spermathecae: One pair per segment near septa 11/12 and 12/13; tiny, tubular, bent or coiled tubes based on small thickenings. Ovaries: Not observed, covered by body wall tissue. Genital glands: A pair of moderately sized and similar appearance, ventrally in segment 12; twice-folded, elongated glands; associated with papillae.

Biological notes: Collected in outskirts of Drakensberg escarpment, in a patch of Afromontane forest invaded by alien plantations of wattle and pine trees. Associated with the new species martensi , described above.

Discussion: This species belongs to the colletti species-group. It is similar to the new species martensi , having spermathecal pores in intersegmental furrows 11/12 and 12/ 13 and clitellum on segments 13–23. However, the shapes of the clitellum and tubercula pubertatis are distinct in both species.

Figures

Figs 8–9. Proandricus species. Clitellar region, ventral view. 8. P. michelleae sp. n. 9. P. richerti sp. n. [C= clitellum; T = tuberculum pubertatis.]