Proandricus injasuti, 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 : 192-194

Proandricus injasuti sp. n.

( Fig. 6 )

Etymology: Named after the type locality of Injasuti .

Material examined: SOUTH AFRICA: KwaZulu-Natal: Holotype NMSA /Olig.03204 clitellate, Drakensberg, Injasuti (29º09'86"S: 29º50'37"E) section of Giants Castle Game Reserve , found between grasses and on surface of road, after heavy rain. Paratypes: NMSA /Olig.03205 8 clitellate gathered with holotype. Type material collected 24 April 2000 by M. White. Other material: NMSA / Olig. 03203 juvenile specimen found after rain near cave in same area, 1 January 2000 by D. G. Herbert .

Description based on holotype and paratypes.

External characters:

General: Body cylindrical in life; when preserved slightly flattened in clitellar area. Colour: In life dorsally dark-violet, ventrally light-grey; alcohol-preserved dorsally dark-grey, ventrally greyish. Dimensions: In life, holotype not stretched, over 600 mm long, 10 mm wide. Preserved and contracted 452 mm long, 6 mm wide at segment 10, 18 mm at tubercula pubertatis. Paratypes preserved 290–480 mm long, 16–18 mm at tubercula pubertatis. Segment number: Holotype 607. Prostomium: Prolobous, large. Segmentation: Secondary annulation present on preclitellar segments; 1 and 2 very short, both with irregular longitudinal grooves; 3 simple, long as first ringlet of segment 4; 4–6 with two simple ringlets, similar in size and appearance; 7–9 with two irregularly annulated ringlets, decreasing in width; 10 and preclitellar, narrow, irregularly annulated; clitellar segments widened, dorsally smooth, ventrally annulated; postclitellar contracted, short. Setae: Closely paired, minute; postclitellarly aa> bc, ab = cd; first pairs on segment 3; on preclitellar annulated segments on first ringlet. Nephridial pores: Conspicuous in cd setal lines; first pair in intersegmental furrow 2/3. Female pores: In 14, slightly above ventral edges of clitellum. Male pores: Externally not observed; probably in intersegmental furrow 17/18, or in segment 18, where vasa deferentia enter body wall. Spermathecal pores: Minute, numerous openings, dorsolaterally, in intersegmental furrows 11/12 and 12/13.

Clitellar region: Clitellum: Saddle-shaped, yellowish-grey; commences dorsally at middle of segment 13, covering unevenly anterior segments; extends to posterior part of segment 23; ventrally extends to cd setal lines. Tubercula pubertatis ( Fig. 6 ): Large, oval pads, on 16–19, expanding laterally and protruding above clitellum; medially with broad ventral separation; dorsal edges on 17–18 clearly separated from clitellum by soft, protruding tissues and narrow rims; lateral structure of tubercular pads on segment 16 and posterior part of 1/n19 smooth; on segments 17–18 pads are covered by irregular vertical and longitudinal grooves. Papillae: In ab setal lines, prominent on segments 10–13, moderate on 21–25; all associated with genital glands.

Internal characters:

Septa: 4/5 thin, firm; 5/6 and 6/7 thin; 7/8 and 8/9 very much thickened, muscular, massive, very strong; other septa thin, firm. Gizzard: In 7, muscular, posteriorly soft. Calciferous glands: Paired, dorsolateral, dorsally and ventrally with narrow grooves. Intestine: Commences in 13. Typhlosole: Commences parallel with intestine as medium sized V-shaped tube, gradually enlarging in the following segments; in holotype terminates in segment 363. Dorsal blood vessel: In posterior parts of segments 5–7 thin, double vessels; in 8 double, thin; in 9 very much enlarged, cordiform; in 10 and following segments simple. Paired dorsoventral vessels: In 5–8 thin, in 9–11 enlarged, moniliform. Nephridia: Meganephridia ; coiled loops with V-shaped caeca.

Reproductive organs: Spermiductal funnels: Proandric arrangement (in segment 10); one pair of iridescent funnels, enclosed in separated sacs. Vasa deferentia: Two single ducts proceed from spermiductal funnels at their lateral sides in segment 10, and immediately turn backward and run nearly medially and parallel to axis of body, to segment 18 where they enter body wall; it was not established if they enter into male pores at intersegmental furrow 17/18 or in segment 18. Seminal vesicles: One pair of large, elongated vesicles commences at septa 10/11, in close connection with sacs of spermiductal funnels; both sacs extend backward through segments 11 and 12, and medially displace septum 12/13 into segment 13; it is difficult to establish if septum 12/ 13 is partly broken or only much extended to allow placement of vesicles in segment 13. S permathecae: Elongated, irregularly-shaped, curved, bent or tubular twisted thecae, with slightly thicker bases entering body wall in intersegmental furrows 11/12 and 12/ 13; 5–6 spermathecae at each side; iridescence was observed in some spermathecae, confirming presence of sperm. Ovaries: Not observed. Genital glands: Flat, multidivided, thick glands, in segments 10–13 and 21–24, 25.

Biological notes: Collected in Injasuti , an area of the Giants Castle Game Reserve, under protection of the KwaZulu-Natal Nature Conservation Services. There are large open areas of indigenous grassland with small patches of indigenous bushes. Specimens were gathered on the soil surface, between grasses, on paths and open roads, after heavy rainfall. Large casts were observed between tall grasses. The clitellate specimens with iridescent spermiductal funnels and spermathecae collected in April, indicate maturity in summer and sexual activity extended into autumn.

Discussion: Characterised by thickened septa 7/8 and 8/9, and spermathecal pores in two intersegmental furrows 11/12 and 12/13; injasuti belongs to the P. colletti speciesgroup. Similar to ortyi and thornvillensis being large, having the tubercula pubertatis extended laterally and typhlosole commencing in segment 13. Similar to bergvillensis in extension of the seminal vesicles through segments 11–12 and penetration into segment 13, a character not observed in thornvillensis . P. injasuti differs from the other species of this group in the shape of the tubercula pubertatis, number and allocation of papillae, and number and shape of genital glands.

Figures

Figs 6–7. Proandricus species. Clitellar region, ventral view. 6. P. injasuti sp. n. 7. P. martensi sp. n. [C = clitellum; T = tuberculum pubertatis.]