Proandricus marenzelleri ( Rosa, 1897 )

Plisko, Jadwiga Danuta, 2005, A revision of the species of the Proandricus marenzelleri speciesgroup with new synonyms (Oligochaeta: Microchaetidae), African Invertebrates 46, pp. 93-101 : 94-99

Proandricus marenzelleri ( Rosa, 1897)

Microchaeta marenzelleri Rosa, 1897: 2 ; Michaelsen 1899 a: 107; 1899 b: 416; Reynolds & Cook 1976: 133. (Locus typicus: Algoa Bay)

Microchaetus marenzelleri: Michaelsen 1900: 450 ; 1913: 541; 1918: 312, 327; Pickford 1975: 58.

Microchaeta algoensis Rosa, 1897: 3 ; Michaelsen 1899 a: 108. (Locus typicus: Algoa Bay). Syn. n.

Microchaetus algoensis: Michaelsen 1900: 450 ; 1913: 541; 1918: 312, 327; Pickford 1975: 58.

Microscolex algoensis: Reynold & Cook 1976: 67 [lapsus: Microscolex for Microchaeta ].

Microchaetus modestus Michaelsen, 1899 var. humicultor Michaelsen, 1910: 82 ; Michaelsen 1918: 329; Pickford 1975: 58; Reynolds 1976: 115 [erroneous information: typus amissus] (Locus typicus: Fouriesburg, Free State). Syn. n.

Proandricus marenzelleri: Plisko 1992: 355 ; 1993: 214; 2000: 259; 2003: 293.

Proandricus algoensis: Plisko 2000: 259 ; 2003: 293.

Proandricus humicultor (Michaelsen, 1912) : Plisko 1992: 355 [lapsus: 1912 for 1910].

Proandricus humicultor: Plisko 2003: 293 .

Diagnosis: 103 mm long, 3 mm wide at tubercula pubertatis. Glandular swellings anterior to male pores on 14/15, male pores in intersegmental furrow 15/16. Clitellum on 12–22. Tubercula pubertatis on 16–18. Papillae on 10, 11, 18–21 in setal lines c. Thickened septa: 4/5 thickest, 7/8 and 8/9 less than anterior. Typhlosole commences in 19. One pair of male funnels in 10, enclosed. One pair of vesiculae seminales in 11. Spermathecae near septa 12/13 and 13/14, one pair per segment; tubular, slightly curved or bent. Genital glands in 18–21, variable in shape and size.

Redescription:

External features: Body cylindrical. In life, grey or pinkish-grey, usually not pigmented, but in moist biotopes sometimes slightly pigmented dorsally on anterior segments; yellowish-grey when preserved in alcohol. Body 52–168 mm long, 3–4 mm wide at segment 10 (only one specimen 182 mm long, 5 mm wide at segment 10). Segment number: 140–265. Prostomium: prolobous, small, fused with first segment. Segmentation: secondary annulation present on preclitellar segments; 1 and 2 simple, with irregular longitudinal grooves; 3 simple; 4–9 with two simple ringlets, posterior usually shorter than anterior; 10, 11 and clitellar simple, similar in size; postclitellar randomly annulated. Setae: minute, closely paired, in regular rows in majority of specimens. However, when papillae are shifted laterally or medially, setae are also relocated. Nephridial pores: conspicuous, at the anterior margins of segments near intersegmental furrows, in setal lines cd; first pair in intersegmental furrow 3/4. Male pores: in 15/16, at margins of ventral borders of tubercula pubertatis; glandular swellings precede male pores on 14 and 15, with deep, medial grooves in intersegmental furrow 14/15. Female pores: in 14 between b–c setae. Spermathecal pores: obvious, in intersegmental furrow 12/13 and 13/14.

Clitellar region: Clitellum: saddle-shaped, segmented, yellowish-grey, or white; on 1/n11,12–21,22; occasionally extending on 11 or 23. Anterior and posterior borders well marked; laterally clitellar tissues extending to ab setae. Tubercula pubertatis: oblong ridges, segmented; on 16–18,1/n19,19, preceded by glandular swellings on segments 14–15; separated from clitellum by thickened tissues. Genital papillae: very variable in size, number and position, occurring on preclitellar and clitellar segments; linked with ab setae; located in regular setal lines or shifted laterally or medially. Paired or single, may be coupled with genital glands or rise separately.

Internal characters: Septa: 4/5 heavily thickened, muscular, strong, although its thickness may vary; 5/6 and 6/7 not thickened, thin; 7/8 and 8/9 always thickened less than 4/5; 9/10 and other septa thin. Gizzard: in 7, well developed, globular, muscular. Calciferous glands: in 9–10, separated dorsally and ventrally. Intestine: originating in 13. Typhlosole: commencing in the area of 19–20, terminates in region of two thirds of number of segments. Dorsal blood vessel: 5–9 double tubes, simple when crossing septa, close together, partly or entirely separated within segment; in 8 separated, in 9 cordiform; in 10 and following segments enlarged, simple. Paired dorsoventral vessels: 5–8 thin vessels, 9–11 enlarged, moniliform. Nephridia : many-branched coiled loops, with extended, V-shaped, elongated caeca. Male funnels: proandric arrangement; one pair of funnels, enclosed in sac closely connected posteriorly at septum 10/11 with seminal sacs; in majority of dissected individuals iridescent, confirming presence of sperm. Vasa deferentia: single tube extending to segment 15, entering body wall posteriorly in 15, and male pores in intersegmental furrow 15/16. Seminal vesicles: one pair, swollen sacks, commencing at septum 10/11 extending into 11. Ovaries: fan-shaped, large. Spermathecae: in segment 12 and 13; one pair per segment; occasionally one spermatheca missing; very seldom two spermathecae at one side of segment. Occasional presence of two ampullae at one side or reduction of one ampulla may be local variation, or simple anomaly indicating regeneration of injured segments. Variable size and shape: clubshaped, tubular, U-, J-, S-shaped, occasionally deeply embedded in wall tissue, often iridescent. Genital glands: variable in size, shape, number and position; paired or single; flat or elongated, simple or composed of multiple glands; may occur independently or be associated with genital papillae.

Material:

The following collections housed in ZMUH, NHM, SAMC and NMSA were studied, and observation data are used for the species redescription.

Material housed in ZMUH: Eastern Cape: ‘ V.1759. Microchaetus marenzelleri Rosa, Port Elizabeth [33º58'S: 25º40'E], Kaplands, Brauns’; two specimens, previously dissected, dried, brittle, presently not available for dissection; this is probably the material studied by Rosa and Michaelsen. The sample labelled ‘V.5127. Microchaetus marenzelleri Rosa, Kapland, Brauns, Port Elizabeth’ contains one specimen. Michaelsen probably examined this one, because in this dissected specimen the calciferous glands and some internal organs are missing. I examined and compared it with the other available species material. ‘V.5125. Microchaetus algoensis Rosa, Port Elizabeth, Kaplands , Brauns’contains twenty decomposed specimens. I have examined two of them, previously dissected although less decomposed. Free State: ‘V.3307. Microchaetus modestus Mich. var. humicultor Mich. Kellner, Orange Col. Fouriesburg [28º38'S: 28º15'E]’; this sample contains 22 intact specimens, in various states of maturity, and 19 abscised postclitellarly and decomposed specimens. This sample contains probable syntypes, as Michaelsen (1910: 82) describing humicultor wrote: ‘ Vorliegend ca 40 geschlechtsreife und mehrere unreife order halbreife Exemplare ’. I have examined two that were dissected, with missing internal parts of segments 10–17, and one intact, dissected by myself.

Material housed in NHM: ‘ Microchaetus algoensis (R) Coll. Musei Vindobonensis, Inv. No 4810, Algoa Bay, leg. Penter, AN. 15244 = Microchaeta algoensis Rosa’; two specimens, well preserved, dissected, probably studied by Rosa and Michaelsen, and examined by myself.

The examination was impeded by the very poor condition of the examined specimens and the absence of internal organs from preclitellar segments. However, the position of the clitellum and spermathecal pores, location of papillae, the thickness of septa, and the number of spermathecae, could be ascertained. No data on other internal organs were obtainable.

The material examined by Pickford, housed in SAMC: Western Cape: ‘ Knysna District, Cape Province: Belvedere, Knysna [34º01'S: 23º03'E]; bank of pond not far from beach, in damp rather sandy soil at depth of about 1 ft, below grass roots, G.E. Pickford, Dec. 24. 1926 (2), SAMA21548’. ‘ Uniondale District , Cape Province: Avontuur [33º34'S: 23º10'E] earth below turf near locality 10, G.E. Pickford, Jan. 6. 1927 (3), SAMA21547’. Eastern Cape: ‘ Humansdorp [34º01'S: 24º45'E] district, Cape Province: Witte Els Bosch, in peaty soil, damp area of rather open veld below Damant’s farm; G.E. Pickford, Jan. 11. 1927 (2), SAMA21547 ’.

New material examined: Free State: 14 km NE of Ficksburg (28º53'S: 27º53'E), alt. 1850 m, indigenous bush, dry soil, 7.xii.1991, JDP & A. Zicsi, 1cl + 5 juv, all in aestivation NMSA/Olig.01195. Eastern Cape: 4 km north of Barkly Pass (31º14'S: 27º49'E), alt. approx. 2000 m, 25.i.1990, JDP & BRS, grassland, between roots of various plants, black, moist soil, 1 cl NMSA/Olig.00605 and 6 cl + 8 juv NMSA/Olig.00610; on the bank of local stream, black, moist, or saturated soil, 1cl + 1 semimature NMSA/Olig.00607 & NMSA/ Olig.00551. 26 km N of Umtata (31º35'S: 28º48'E), beside N2, grassland, on bank of local stream, moist soil, 17.i.1990, JDP & BRS, 2 cl + 14 juv NMSA/Olig.00503. 3 km SW of Stutterheim (32º32'S: 27º29'E), alt. approx. 700 m, on the bank of Kubusi River, grassland, between roots of various plants, 20.xi.1991, JDP & A. Zicsi, 16 cl + 12 juv NMSA/Olig.01114, 13 cl + 2 cl much larger than other congeners + 2 juv NMSA/ Olig.01111 and NMSA/Olig.01110. 16 km SW of Stutterheim following R358, alt. approx. 1000 m, Westpointon farm, 19.i.1990, JDP & BRS: pine forest planted 26 years ago on primary grassland, in 1–15 cm of dry soil, 3 cl + 1 juv NMSA/Olig.00526; on the bank of stream, moist, not saturated soil, and under rotten bark, 4 cl + 3 juv NMSA/Olig.00537 and 1 cl + 2 juv NMSA/Olig.00532; indigenous grassland, moist soil, 20.xi.1991, JDP & A. Zicsi, 13 cl + 33 juv NMSA/Olig.01103. 30 km SE of Stutterheim, alt. approx. 350 m, ditch near road, dry rocky soil, 21.xi.1991, A. Zicsi, 3 cl (with spermatophores) + 13 semimature NMSA/Olig.01121 & NMSA/Olig.01119. 6 km SW of Stutterheim, alt. approx. 750 m, Kologha Forest, black moist soil, 20.i.1991, JDP &A. Zicsi, 5 cl + 5 juv, NMSA/Olig.01117. 22 km SW of Stutterheim, Mr Schwarz farm, on the bank of the stream, moist soil, 20.xi.1991, JDP &A. Zicsi, 1 cl NMSA/Olig.01108. Kei Road (32º42'S: 27º37'E) beside R348, grassland and bush, dry soil, 18.i.1990, JDP & BRS, 1 cl + 3 juv NMSA/Olig.00511, 4 semimature + 3 juv NMSA/Olig.00513, 9 cl + 5 juv NMSA/Olig.00519. Pirie Forestry (32º45'S: 27º20'E), 7.xi.1990, JDP: on bank of the dam, at 20 cm depth, moist soil, 8 cl + 5 juv NMSA/ Olig.00681, and 5 semimature NMSA/Olig.00682; primary grassland, dug out by the bulldozer, 14 cl + 5 juv NMSA/Olig.00671. Debe Nek (32º48'S: 27º12'E), primary grassland, on bank of small natural pool, 7.xi.1990, JDP, 5 cl + 1 juv, associated with Proandricus ianthinos Plisko, 1993 , and in close neighborhood of Proandricus skeadi Plisko, 1993 , NMSA/Olig.00670. Middledrift (32º48'S: 27º01'E), 26 km W of King William’s Town, along R63, grassland, dry soil, 20.i.1990, JDP & BRS, 4 cl, associated with Proandricus skeadi, NMSA /Olig.00555. 5 km SW of Grahamstown (33º20'S: 26º31'E), indigenous forest, near small stream, 22.xi.1991, JDP & A. Zicsi, 7 cl + 9 juv NMSA/Olig.01140. 35 km from Port Elizabeth (33º58'S: 25º40'E), ditch near road, very dry soil, 24.xi.1991, JDP & A. Zicsi, 9 cl in aestivation, associated with Proandricus zicsi Plisko, 1993 , NMSA/Olig.01141.

Published records: Eastern Cape: Rosa (1897): *Algoa Bay [35º50'S: 25º45'E]; Michaelsen (1899 a,1900) reported after Rosa, and new site noted by H. Brauns: *Port Elizabeth [33º58'S: 25º40'E]; Pickford (1975): one site in *Humansdorp [34º01'S: 24º45'E] area. Western Cape: Pickford (1975): six sites in the area of *Knysna [34º01'S: 23º03'E]; two sites in the area of *Avontuur [33º34'S: 23º10'E]. Free State: Michaelsen (1910–1912) *Fouriesburg [28º38'S: 28º15'E].

Comments: The inadequate original descriptions of P. marenzelleri and P. algoensis left their systematic position doubtful for decades. The type locality indicated for marenzelleri and algoensis as Algoa Bay suggested that both species had been collected in the Port Elizabeth district, in the province now known as Eastern Cape. Pickford (1975) had not seen the type material, but examined many specimens characterised by features attributed to marenzelleri , algoensis and humicultor and collected across a wide range of places in Eastern Cape. During thorough examination, she noted numerous variations in the external characters accredited to these three species, observing at the same time that the internal anatomical characters were constant and in accordance with the original description of marenzelleri . In conclusion, she considered that algoensis and humicultor may be synonyms of marenzelleri , and published a redescription of the species ( Pickford 1975). However, an apparent lapsus regarding thickness of the septa, a major species character, occurred. It was stated that: ‘... septum 4/5 is strongly thickened, 8/9 and 9/10 moderately so, but the intervening septa (5/6, 6/7 and 7/8) are thin’. In all specimens from the collection of the South African Museum, dissected previously by Pickford and examined by myself, the septum 4/5 is most thickened, 7/8 and 8/9 are thickened less, 5/6, 6/7 and 9/10 are always thin, and this character is in accordance with Rosa’s description of marenzelleri , who wrote: ‘. .. I dissepiment 4–5, 7–8 e 8–9 sono inspessiti, gli intermedii 5–6 e 6–7 sono sottili ed incompleti ’.

Michaelsen (1910–1912) describing var. humicultor assigned specimens with spermathecal pores in intersegmental furrows 12/13 and 13/14 to Microchaetus modestus Michaelsen, 1899 , the species having spermathecal pores in 11/12 and 12/13. Although not having seen the original material, Pickford (1975) noted the discordance in description and suggested separation of humicultor from modestus . At the same time,

Pickford assumed their synonymy, after observing its similarity with marenzelleri and algoensis in an extended study on internal and external characters, with special consideration of the position of the male pores, distribution of papillae and setae in large populations of marenzelleri , algoensis , and humicultor . Present examination of the material of marenzelleri , algoensis and humicultor housed in ZMUH, NHM, SAMC and NMSA confirms that these three species are clearly synonyms. Having page precedence, P. marenzelleri ( Rosa, 1897) is a senior synonym.

Constant morphological and anatomical characters are: proandric condition (male funnels in 10, enclosed); the openings of vasa deferentia into male pores in intersegmental furrow 15/16; glandular swellings anterior to male pores on 14/15; the number and location of spermathecae and their ectal pores in intersegmental furrows 12/13 and 13/14; thickened septa: 4/5 the most, 7/8 and 8/9 less than anterior; well developed gizzard in segment 7; origination of intestine in 13; origination of typhlosole in the area of 19–20. Moderate variability of following characters has been observed: clitellum on 11,1/n11,12–21,22,23; tubercula pubertatis on 16–18,1/n19,19; occasionally one spermatheca reduced or an extra one appears.The following features are highly variable: body size; number of segments; location of setae; size, shape, location of genital papillae; size, shape and location of genital glands.

Biology and distribution: This species is known from a wide variety of habitats: undisturbed, indigenous and cultivated grasslands, stream banks, various types of soil in forests, plantations, bushveld, cultivated farmlands and gardens. It has been recorded in dry, moist and saturated soils, in litter, under logs and stones.

It is usually active throughout year, but in two cases was found in aestivation.

This species is indigenous to South Africa, although it occurs more widely than is known for other microchaetids. It was noted from Free State, Western Cape and Eastern Cape ( Fig. 1 ) .

Figures

Fig. 1. Distribution of species of Proandricus marenzelleri species-group.