Nine new earthworm species of Proandricus Plisko, 1992 from South Africa and Lesotho (Oligochaeta: Microchaetidae)
Author
Plisko, Jadwiga Danuta
text
African Invertebrates
2002
2002-12-31
43
183
204
journal article
10.5281/zenodo.7666001
2305-2562
7666001
Proandricus dwesa
sp. n.
Figs 4–5
Etymology: Named after the
type
locality,
Dwesa
.
Material
examined:
SOUTH AFRICA
:
Eastern Cape
:
Holotype
NMSA
/Olig.02807 well preserved, with distinct clitellum and slightly developed tubercula pubertatis,
Dwesa
Nature Reserve
(
32.304ºS
:
28.828ºE
) coastal forest, under fallen log.
Paratype
:
NMSA
/
Olig.
03524 with tubercula pubertatis not clearly marked, collected together with holotype.
All
material collected by
D. G. Herbert
of the
Natal Museum’s Department of Malacology
.
Description based on
holotype
and
paratype
.
Figs 4–5.
Proandricus dwesa
sp. n.
4. Clitellar region, ventral view. 5. Dorsally dissected preclitellar part of body. [C = clitellum; G = gizzard; S = seta
b
; SS = septa 7/8 and 8/9.]
External characters:
General
: Body cylindrical.
Colour
: In life dorsally dark-grey with violet tint, ventrally yellowish-grey; alcohol-preserved dorsally and ventrally grey.
Dimensions
: In life, not stretched
350 mm
long, in preclitellar area
10 mm
wide,
12 mm
at clitellum; preserved and contracted,
holotype
243 mm
long,
10 mm
wide at segment
10, 15 mm
at clitellum;
paratype
250 mm
long,
14 mm
at clitellum.
Segment number
:
Holotype
208,
paratype
204.
Prostomium
: Prolobous, moderate in size; 1 and 2 simple, short with longitudinal grooves; 3 simple, as long as first ringlet of segment 4; 4–9 with two simple ringlets, first longer than second; 10 and 11 short, simple, similar in size to first ringlet of segment 9.
Setae
: Large; closely paired on segment 3, and on first ringlets of segments 4–9; on clitellar segments paired more distantly than preclitellarly; postclitellarly closely paired with
aa
>
bc, ab
similar to
cd
.
Nephridial pores
: Conspicuous in
cd
setal lines.
Female pores
: In 14, medially between setae
aa
.
Male pores
: Difficult to trace; in area of tubercula pubertatis are small depressions in intersegmental furrow 14/15, and are probably male pores.
Spermathecal pores
: In intersegmental furrows 11/12 and 12/13.
Clitellar region (
Fig. 4
):
Clitellum
: Saddle-shaped, segmented with simple segments; extending onto segments 11–22, clearly bordered anteriorly and posteriorly, with ventral borders below
cd
setae.
Tubercula pubertatis
: Not distinctly marked, however, on ventral clitellar edges of segments 1/n14–1/n19 are oblong, segmented ridges, with medial shallow, longitudinal furrows and narrow rims.
Papillae
: Paired, small indistinct swellings in the line of
ab
setae; first pair on first ringlet of segment 9, the following on segments 10–26.
Internal characters:
Septa
: 4/5 5/6 6/7 thin; 7/8 thickened moderately, muscular; 8/9 thickened the most, muscular, nearly twice size of 7/8; the following septa thin, but firm.
Gizzard
(
Fig. 5
): In 7, bell-shaped, muscular, posteriorly soft.
Calciferous glands
: Large, in 9–10, ventrolaterally, distinctly separated dorsally.
Intestine
: Commences in 13.
Typhlosole
: Commences in 20 as large U-shaped tube; extends to nearly 2/3 of body length; terminates in
holotype
in segment 130, in dissected
paratype
in 128.
Dorsal blood vessel
: In 5–6 partly double, very close; double in whole length of segment 7, but very close; in 8 double, widely separated; in 9 double, cordiform; single when crossing septa and posterior to 9.
Paired dorsoventral vessels
: Very thin vessels in 5–8; in 9–11 enlarged, moniliform.
Nephridia
: Meganephridia
; large coiled loops, and large V-shaped caeca; in some clitellar segments caeca extends laterally, becoming ribbon-folded; postclitellarly caeca simple.
Reproductive organs:
Spermiductal funnels
: Proandric (in segment 10); one pair of funnels enclosed in separated sacs, very close ventrally; at septum 10/11 closely connected with seminal sacs.
Vasa
deferentia
: Single ducts, connected with spermiductal funnels dorsally, run backward to segment 14, where covered by thick tissue of body wall enter male pores at probably intersegmental furrow 14/15.
Seminal vesicles
: One pair of large sacs anteriorly connected with spermiductal funnels at septum 10/11; in segment 11 extended transversely.
Spermathecae
: Elongate ampullae, close to septa 11/12 and 12/13; two pairs in anterior segment, three pairs in segment 12.
Ovaries
: Not observed, covered by folded nephridial loops and large caeca.
Genital glands
: Not present.
Biological notes: Collected in the
Dwesa
Nature Reserve, which is controlled by the
Eastern Cape
Department of Nature Conservation. The Reserve is situated along the coastline in the northeastern part of the
Eastern Cape
, in the area previously known as the Transkei. There is a mixture of vegetation ranging from coastal forest to open grassland, with
Cape
and
KwaZulu-Natal
elements, and a strong afromontane component.
Discussion: Belonging to the
P. colletti
species-group, having only septa 7/8 and 8/9 thickened, and spermathecal pores in intersegmental furrows 11/12 and 12/13. It is noteworthy that although the tubercula pubertatis in
dwesa
are not well developed, there is some similarity to the shapes seen in
belli
, which is assigned to the
P. belli
species-group characterised by thickened three septa 4/5 7/8 8/9.
P
.
dwesa
differs from the other species known in both species-groups by an anterior extension of the clitellum on segment 11, and very specific shapes of nephridia.