Tritogenia phinda, Plisko, 2005

Plisko, Jadwiga Danuta, 2005, Five new South African earthworm species of the family Microchaetidae (Oligochaeta) with exceptional anatomical features, African Invertebrates 46, pp. 103-113 : 112-113

Tritogenia phinda sp. n.

Fig. 8 Etymology: Named after the type locality Phinda .

Description:

External features: Body cylindrical, compact after preservation. Grey in life; whitishgrey when preserved in alcohol. Contracted during preservation, abscised holotype 55+ mm long, 5 mm wide at 10 and 6 mm in region of tubercula pubertatis. Segment number: 125+. 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 with second ringlet shorter than first; segment 10, clitellar and postclitellar simple. Setae: minuscule, closely paired; in preclitellar segments noticeable on first ringlets of segments 4–9, and on segments 10–12. Nephridial pores: not observed. Female pores: externally not observed. Male pores: probably in intersegmental furrow 18/19. Spermathecal pores: externally not observed.

Clitellar region ( Fig. 8 ): Clitellum: saddle-shaped, segmented, white; on 12–26; laterally extends to ab setae. Tubercula pubertatis: on 20–24; right tuberculum developed as oblong glandular swellings randomly grooved by irregular shallow furrows running parallel with intersegmental furrows; left compact, with shallow furrows (deformation probably occurred during collection). Papillae: small blisters around ab setae on 8–18; on 19 and 25, 26 moderate swellings in front of and behind tubercula.

Internal characters: Septa: 4/5, 5/6 thin, not thickened; 6/7, 7/8, 8/9 thickened moderately, not muscular, similar in thickness and appearance; 9/10 absent; other septa in preclitellar segments thin; in posterior segments slightly thicker. Gizzard: large, muscular, in 6–7; commencing in 6, extending to and occupying whole 7, terminating abruptly at septum 7/8; septum 6/7 attached to anterior part of gizzard. Calciferous glands: not stalked, in 9–10, separated dorsally and ventrally. Intestine: commences in 13, not clearly separated from thick oesophagus. Irregularly shaped diverticulum in segments 20–24. Typhlosole: commences in 20 as thick, V-shaped, gradually enlarging tube; terminates in 64. Dorsal blood vessel: double in 4–11 and when crossing septa 4/5–10/11; in 12 slightly enlarged, single; in following segments narrow, single. Paired dorsoventral commissural vessels: in 4–8 thin, gradually enlarging; in 9–11 thick, moniliform. Nephridia: Meronephridia ; two pairs; ventral pairs close to median body-line, second pairs dorsally. Male funnels: holandric arrangement; similar size and appearance, in 10 and 11 respectively, free, iridescent. Seminal vesicles: two pairs; in 11 and 12 respectively. Spermathecae: clubshaped, small; in 9 one pair with ectal parts near intersegmental furrow 9/10; in 10 only one spermatheca at right side, with its ectal part at 10/11. Ovaries: not observed. Genital glands: not observed.

Comparison and comments: T. phinda is unique in the genus for having the anterior pair of spermathecae located in intersegmental furrow 9/10. The clitellum located on segments 12–26 suggests similarity to T. kruegeri Plisko & Zicsi, 1991 , although the position of the tubercula pubertatis on 19–24, and the number and position of spermathecae in segments 9 and 10 are different. Location of spermathecal pores in intersegmental furrows 9/10 and 10/11 is known only in species of Proandricus (Table 1), with no other external or internal similarity between them and T. phinda .

Holotype: clitellate, NMSA /Olig.03907: KwaZulu-Natal: Phinda (27.87726ºS: 32.33983ºE), 18.iii.2004 (Earthwatch Team 7, 15242).

Biological notes and distribution: This species was found together with Microchaetus natalensis , P. notabilis sp. n., and juvenile specimens of Proandricus sp. This species is known only from the type locality in northern KwaZulu-Natal.

Figures

Figs 5–8. (5) Proandricus notabilis sp. n., holotype, lateral part of clitellum and tuberculum pubertatis, 60 X; (6, 7) Proandricus zeugosus sp. n., holotype: (6) anterior part of body, laterally, 60 X, (7) spermathecae of segment 12, 140 X; (8) Tritogenia phinda sp. n. holotype, clitellar region, ventral view, 60 X. Abbreviations: C–clitellum, T–tuberculum pubertatis, P–papilla of segment 25, Sp–spermathecae.