Tritogenia qudeni, Plisko, 2003

Plisko, Jadwiga Danuta, 2003, Eleven new South African earthworms (Oligochaeta: Microchaetidae) with new information on some known species, and an inventory of the microchaetids of KwaZulu-Natal, African Invertebrates 44 (2), pp. 279-325 : 314-316

Tritogenia qudeni sp. n.

( Fig. 17 )

Etymology: Named after the type locality, Qudeni Forest Reserve.

Material examined: KwaZulu­Natal: Holotype NMSA / Olig. 03441 Qudeni Forest Reserve (28º39'40"S: 30º47'53"E), valley, short grassland, from top soil, 11 April 2001, AJA, PN. Paratypes: NMSA / Olig. 03647, 6 cl + 2 juv, collected with holotype; NMSA / Olig. 03436 Qudeni Forest Reserve (28º39'42"S: 30º47'53"E) hillside, short grassland in top soil, 11 April 2001, 2 with tubercula pubertatis, AJA, PN; NMSA / Olig. 03434 Qudeni Forest Reserve (28º39'43"S: 30º47'54"E) hillside, grassland, between roots, 11 April 2001, 2 with tubercula pubertatis, AJA, PN. Other material: NMSA / Olig. 02093, 6 km south­east of Qudeni (28º38'S: 30º52'E) near road, grassland, moist soil, 23 January 1995, 3 semi­mature with tubercula pubertatis + 8 juv, JDP, BRS .

Description based on holotype and paratypes.

External characters:

General: body cylindrical, compact after preservation. Colour: grey in life, preserved in formalin whitish­grey. Dimensions: preserved and contracted holotype 36 mm long, 3 mm wide at 10, 4 mm at tubercula pubertatis; clitellate paratypes 24–40 mm long, 3– 4 mm wide; juvenile 14–18 mm long. Segment number: holotype 79, paratypes 80–84. Prostomium: prolobous, not clearly separated from first segment. Segmentation: secondary annulation present on preclitellar segments; 1–3 simple with irregular longitudinal grooves; 4–9 with 2 simple ringlets, second ringlet shorter than first; 10, clitellar and postclitellar simple. Setae: minuscule, closely paired; in preclitellar segments noted only ab on first ringlets of 4–9, and on 10–17; postclitellarly ab and cd observed sporadically. Nephridial pores: not observed. Female pores: externally not observed. Male pores: probably in intersegmental furrow 18/19 or in anterior part of segment 19, where are paired, small invaginations. Spermathecal pores: conspicuous, in intersegmental furrows 11/12 and 12/13, paired small invaginations with round swellings. Clitellar region ( Fig. 17 ): Clitellum: saddle­shaped, segmented, whitish­grey; on holotype on 13–23; 13–17 clitellar tissues extending to ab seta; on 18–23 ventral edges run parallel to borders of rims separating clitellum and tubercula pubertatis.On paratypes clitellar borders not clearly marked. Tubercula pubertatis: on 18–22, below clitellar rims, ventrally distantly separated ( Fig. 17 ); oblong glandular swellings randomly grooved by irregular shallow furrows running parallel with intersegmental furrows; longitudinally with shallow furrows separating clitellar rims from glandular tubercula. Papillae: on 10–17, 23, paired, round swellings around ab setae.

Internal characters:

Septa: 4/5 5/6 6/7 thickened very much, muscular, similar in thickness and appearance; 7/8 8/9 thickened less than anterior; 9/10 aborted; other septa in preclitellar segments thin; in posterior segments slightly thicker. Gizzard: large, muscular, in 6–7; commencing abruptly at septum 5/6, extends and occupies whole of 6 and partly 7; septum 6/7 attached to gizzard in its middle portion, extending posteriorly, and ending with termination of gizzard. Calciferous glands: stalked, dorsal; in 9–10; separated widely ventrally, by very short distance dorsally; stalks extend through 9–10. Intestine: commences in 13. Typhlosole: commences gradually as thick, V­shaped in area of 20, enlarging increasingly into large tube, terminates in area of 48. Dorsal blood vessel: 4–11 double; double when crossing septa 4/5–10/11; 12 slightly enlarged, simple; in following segments simple. Paired dorsoventral commissural vessels: 4–8 thin, gradually enlarging; 9–11 thick, moniliform. Nephridia : two pairs: ventral pairs close to median body line, second pairs dorsally. Spermiductal funnels: holandric arrangement; iridescent, similar size and appearance in 10 and 11 respectively; each pair enclosed in mutual sac connected with seminal vesicles; in dissected holotype sperm was observed in all four funnels. Seminal vesicles: two pairs of small sacs, linked with testis sacs; in 10 and 11 respectively. Spermathecae: very small, thin, elongated; close to genital glands of 12 and 13. Ovaries: paired, in 13; large, funnel­like. Genital glands: paired, small, flat, round, in 12–15, associated with papillae.

Biological notes: Qudeni Forest Reserve , located almost at the northernmost limit of the midland mistbelt area, contains semi­coastal forest mixed with Podocarpus and other species of trees characteristic of afromontane forests, and also with grassland patches. The species was found between roots of various plants in topsoil, in the forest patches of grassland, and also in open grassland outside of the forest. Mature and juvenile specimens were collected together in early autumn. In some sites the species was associated with alveata and juvenile Proandricus sp.

Distribution: Known from the type locality and few sites in its close neighbourhood, all situated in central KZN ( Fig. 14 ).

Discussion: The species belongs to the sulcata species­group having spermathecal pores in two intersegmental furrows 11/12 and 12/13. Similar to ataxia , but distinguished by the shape of tubercula pubertatis, the spermathecae, and the arrangement of setae.

Figures

Fig. 17. Tritogenia qudeni sp. n., holotype, ventral side of clitellar region [C = clitellum, T = tuberculum pubertatis].

Fig. 14. The distribution of Tritogenia species in KZN. 1 = alveata; 2 = annetteae; 3 = ataxia; 4 = benhami; 5 = crassa; 6 = curiosa; 7 = curta; 8 = debbieae; 9 = diversa; 10 = douglasi; 11 = herbana; 12 = hiltonia; 13 = howickiana; 14 = insolita; 15 = karkloofia; 16 = koilia; 17 = liversagei; 18 = lunata; 19 = melmothana; 20 = miniseta; 21 = monosticha; 22 = morosa; 23 = mucosa; 24 = ngelensis; 25 = ngomensis; 26 = qudeni; 27 = shawi; 28 = soleata; 29 = sulcata; 30 = tetrata; 31 = zuluensis.