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 richerti
sp. n.
(
Fig. 9
)
Etymology: Named for Mr S. Richert of the
KwaZulu-Natal
Nature Conservation Service, who assisted Dr A. J. Armstrong in collecting the
type
material.
Material
examined:
SOUTH AFRICA
:
KwaZulu-Natal
:
Holotype
NMSA
/Olig.03540 clitellate,
Vergelegen Nature Reserve
(
29º33'41.786"S
:
29º29'36.563"E
), plateau covered by grass and herbs, burnt in
June 2001
, in moist soil at depth of
1–30 cm
,
31 December 2001
.
Paratypes
NMSA
/
Olig.
03541 3 clitellate and
13 juveniles
found together with
holotype
; all collected by
A. J. Armstrong
and
S. Richert.
External characters:
General
: Body cylindrical, extended laterally in area of tubercula pubertatis.
Colour
: In life dorsally violet in preclitellar part, ventrally yellowish-white. Alcohol-preserved dorsally with violet tint, ventrally yellowish-grey.
Dimensions
:
Holotype
preserved slightly contracted, abscised 125+ mm long,
7 mm
wide at segment
10, 9 mm
at tubercula pubertatis.
Paratypes
: Clitellate, abscised,
ca
.
40–80 mm
long; juvenile
30–230 mm
long.
Segment number
: Abscised
holotype
255+, juvenile
paratypes
360–489.
Prostomium
: Prolobous, moderate.
Segmentation
: Secondary annulation present on preclitellar segments; 1 and 2 clearly separated one from another, short, simple, both with irregular longitudinal grooves; 3 simple, longer than 1 or 2; 4–8 with two simple ringlets, similar in size and appearance; 9 with two ringlets, second shorter than first; 10–12 simple; postclitellar simple, randomly annulated.
Setae
: Closely paired; moderate in size; first pairs on 3; on 4–9 on first ringlet; on postclitellar segments
aa
>
bc
,
ab
=
cd
.
Nephridial pores
: Conspicuous, in
cd
setal lines; first pair in 2/3 intersegmental furrow.
Female pores
: Not observed.
Male pores
: Probably in 17/18 intersegmental furrow in area of tubercula pubertatis, where there are small depressions.
Spermathecal pores
: Externally not detected; during dissection found in intersegmental furrows 11/ 12 and 12/13.
Clitellar region (
Fig. 9
):
Clitellum
: On
holotype
and mature
paratypes
marked by brownish colour on segments 13–23; ventral edges in line of tubercula pubertatis.
Tubercula pubertatis
: On
holotype
large, rectangular pads with rounded corners, on 1/n16–20; rimmed at dorsal borders; on
paratypes
markedly less than on
holotype
, rimmed dorsally.
Papillae
: Very small tubercles in line of
ab
setae on variable segments 10–12.
Internal characters:
Septa
: 4/5 5/6 6/7 very thin; 7/8 and 8/9 much thickened, muscular, firm, similar in size and appearance.
Gizzard
: In 7, elongated, muscular.
Calciferous glands
: In 9; moderate in size, laterally; separated dorsally and ventrally.
Intestine
: Commences in 13; in segments 23–28 paired elongated diverticula.
Typhlosole
: Commences immediately with intestine as thin tube, gradually enlarging and becoming U-shaped, thick structure; in abscised
holotype
terminates in segment 178; in juvenile
paratype
consisting of 489 segments and terminates in 180, leaving over 300 segments with no typhlosole.
Dorsal blood vessel
: In segments 4–7 double in posterior parts, separated; in 8 double, widely separated; in 9 double, large, cordiform; single when crossing septa, in 10 and the following segments; 4–8 thin tubes; in 9–11 enlarged, moniliform.
Nephridia
: Meganephridia
; coiled loops with short, thick V-shaped caeca.
Reproductive organs:
Spermiductal funnels
: Proandric arrangement (in segment 10); in
holotype
moderate in size, iridescent. Also in
paratype
with clitellum marked only by brown colour, a trace of iridescence was observed in small spermiductal funnels; both funnels closely connected with seminal sacs at posterior part of segment 10.
Vasa
deferentia
: Single ducts commence at dorsal parts of spermiductal funnels, and run backwards almost medially at each side of the body to segment 17, where they enter body wall.
Seminal vesicles
: One pair of moderate sacs, anteriorly connected at septum 10/11 with spermiductal funnels, extending backward to segments 11 and 12; in
holotype
both vesicles are elongated and of equal size, but when crossing septum 11/12 becoming narrower; in
paratype
both vesicles smaller than in
holotype
, extending equally through segments 11 and 12 (probably the differences in size and shape can be accounted to different states of maturity).
Spermathecae
: Close to septa 11/12 and 12/13; variable in shape and size, very small, bent ampullae; 3–4 at each side in segments 12 and 13.
Ovaries
: Not observed.
Genital glands
: In segment 10 two simple, elongated, straight, narrow glands; in segment 21 similar in size to glands of segment 10, but twice-folded and bent posteriorly; in segment 22 only one gland, finger-shaped.
Biological notes: The
type
locality is located in the Drakensberg foothills at
ca
.
1500 m
, where there is a deep valley with steep hillsides covered by indigenous bushes and open grassveld (
Pooley & Player 1995
). During earlier years the area was used for grazing, but has never been ploughed or been arable land. The
types
were found on the plateau covered by grass and herbs, and were dug out at a depth of
1–30 cm
from moist soil and from between grass roots.A large part of the grassland had been burnt about six months previously. Earthworm presence between the roots of burnt grasses indicates an ability to migrate into deeper soil during unfavorable conditions, and a return to the top layer when conditions permit. The species is probably restricted to the outskirts of the Drakensberg range.
Discussion:
P. richerti
belongs 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. Similar to
bergvillensis
in the backward extension of the seminal vesicles, and relatively short typhlosole. However, extension of the seminal vesicles in
richerti
probably does not cross septum 12/13.Also the shape of the tubercula pubertatis differs in both species. The length of the typhlosole in this new species is worthy of special note, as it is exceptionally short, occupying only a little more than one-third of the body segments. In the other species of the genus, the typhlosole extends to about two-thirds of the segment number, leaving only about one-third of segments without typhlosole. The presence of diverticula is also characteristic of this species.