Geogenia minnehaha, Nxele, 2015

Nxele, Thembeka C., 2015, A new species of Geogenia Kinberg, 1867 from the south coast of KwaZulu-Natal, South Africa (Oligochaeta, Microchaetidae), African Invertebrates 56 (3), pp. 549-554 : 550-552

Geogenia minnehaha sp. n.

Fig. 1

Etymology: Proper name in apposition, after Minnehaha Farm , the type locality;

Diagnosis: Body length: 57–325 mm, width: 2–3 mm. Clitellum saddle-shaped on 13–25, 26. Female pores in 14. Spermathecal pores in 12/13 and 13/14 intersegmental furrows. Papillae large on 9–15, 19–25, 26. Gizzard in 7, large, well developed. Calciferous glands in 9. One pair of spermathecae per segment. Seminal vesicles paired, in 10, 11 and 12. Intestine begins in 13.

Description:

External characters.

Holotype: Body 100 mm in length, 3 mm wide at tubercula. Segment number 135, slightly abscised. Paratypes: 57–325 mm in length, 3–4 mm wide. Segment number 81–551. Prostomium prolobous, small. Segmentation, preclitellar segments with secondary annulations: segment 1–3 simple, 1–2 with small horizontal grooves, segment 4–7 with two ringlets of equal size, 8–9 with second ringlet smaller; from 10 and postclitellar, simple and randomly annulated. Setae ab visible from 2, closely paired especially on papillae, large. Male pores not observed. Female pores minute on anterior part of segment 14 near ab setae. Spermathecal pores not observed but from inside traced to 12/13 and 13/14 intersegmental furrows. Clitellum saddle-shaped on 13–25, 26 (on one specimen extends to 26), segmented, dorsal borders well marked. TUbercUla pUbertatis on 15–18, flat elongated ridges. Genital papillae on 9–12, 13 or 9–15 and 19–26, paired or single, large nipple-shaped on ab setae.

Internal characters.

Septa 4/5, 7/8, 8/9 thickened but not muscular; 5/6, 6/7 thin; other septa thin. Gizzard well developed in 7, globular, muscular. Calciferous glands in 9, not stalked. Intestinal origin in 13. Dorsal blood vessel double in the anterior segments from 7; in 8 and 9 forms a heart-shaped structure (cordiform organ); simple in the posterior segments. Nephridia , one pair per segment, coiled loops of meganephridia. Holandric , male funnels are in separate sacs, closely paired, pairs close to seminal vesicles, both pairs iridescent in holotype. Seminal vesicles large in 10–12, one pair per segment, pairs in 10, 11 are very large but the one in 12 is highly reduced. Spermathecae in 12/13 and 13/14, one pair per segment, finger-shaped. Genital glands present on 9–13 or 9–14, with large setae. Holotype: SOUTH AFRICA: KwaZulu-Natal: Port Shepstone , Minnehaha Farm , no-till sugarcane plots (30°40'03.2"S 30°14'59.2"E), 05.iii.2014, T. Nxele, P. Mukwevho, B. Mzobe, M. Neethling leg; Clitellate: (NMSA/OLIG. 06725).

Paratypes: Same locality and date as holotype: 3 cl, 5 juv. ( NMSA / OLIG. 06716); 1 cl, 3 juv. in absolute ethanol, T. Nxele, P. Mukwevho, B. Mzobe, M. Neethling leg ( NMSA / OLIG. 06724) .

Remarks: This species is closely related to the species that occurs in Oribi Gorge Nature Reserve, which is in the near vicinity of Minnehaha Farm. This species is longer (reaching 325 mm with 551 segments), with an extended clitellum. The papillae are very large and nipple-shaped with setae in the middle; the number of spermathecae is reduced.

Figures

Fig. 1. Geogenia minnehaha sp. n., side view of the clitellar region. Abbreviations: Cl = clitellum; Tp = tubercula pubertatis; P = papillae of segment 9; 13 = segment 13, the start of the clitellum.