First reports of Grania (Clitellata: Enchytraeidae) from Africa and South America: molecular phylogeny and descriptions of nine new species
Author
Prantoni, Alessandro Lívio
Author
Wit, Pierre De
Author
Erséus, Christer
text
Zoological Journal of the Linnean Society
2016
2016-02-10
176
3
485
510
http://dx.doi.org/10.1111/zoj.12333
journal article
10.1111/zoj.12333
0024-4082
4720622
GRANIA SIMONAE
SP.
NOV.
FIGURE 6
Holotype
SAMC
A82476
,
CE14111
, whole-mounted, sexually mature specimen, 11 posterior segments amputated, from
Van Dyks Bay
,
Overberg District
,
Overstrand Local Municipality
,
Province
of the
Western Cape
,
South Africa
,
34°37′00″S
,
19°21′21″E
, intertidal crevice between rocks. Collected by
N. Bekkouche
,
16 December 2011
.
COI
barcode sequence,
GenBank
acc. no.
KT428100
; for other sequence data, see
Table 1
.
Etymology
Named for the South African annelid specialist, Dr Carol Simon, who arranged and generously assisted with the workshop/fieldwork that led to the collection of this species.
Paratypes
Six
whole-mounted, sexually mature specimens, all from the type locality and date, and collected by
N. Bekkouche.
SAMC
A82482
, complete, not DNA barcoded specimen.
SAMC
A82477
,
CE14110
, with 14 midbody segments amputated.
SAMC
A82478
,
CE14112
, with 14 middle body segments amputated.
SAMC
A82479
,
CE14058
, with some segments amputated.
SAMC
A82480
,
CE14060
, with eight posterior segments amputated.
SAMC
A82481
,
CE14093
, with some segments amputated, from the type locality too, but in shallow subtidal. For
COI
barcodes of
paratypes
, see
Table 1
.
Description
Body of only complete specimen
16 mm
long, 79 segments (
paratype
SAMC
A82482
),
0.16–0.20 mm
wide at segment III,
0.15–0.22 mm
wide at segment XII (
n
= 7). Prostomium rounded, 55–87 μm long, 62– 80 μm wide, epidermis 7–10 μm thick (
n
= 7), not reduced at front tip. Ventral chaetae present from segment IV, lateral chaetae absent. Chaetae (
Fig. 6A
) L-shaped, 45–90 μm long, 5–6 μm thick at midpoint, shaft straight and broad at the base, foot 16–20 μm long, with slight heel, and sometimes with slight toe. Chaetal index (
Rota & Erséus, 2003
) 4.70 ± 0.39 (
n
= 5). Free chaetae scattered in the coelomic cavity, sometimes numerous. Epidermal gland cells inconspicuous. Clitellum maximally 22 μm thick, extending from segments XII to XIII, comprising rows of large granular cells, absent between male pores. Spermathecal pores in lateral lines, immediately posterior to 4/5. Male pores located ventrolaterally in mid-segment XII. Female pores not observed.
Figure 6.
Grania simonae
sp. nov.
A, chaetae. B, spermatheca. C, coelomocytes. D, penial bulb and sperm funnel. See text for abbreviations.
Brain posteriorly indented. Head organ (
sensu
Rota & Erséus, 1996
) absent. Pharyngeal glands in segments IV–VI, dorsal lobes in segment IV (one pair), in segment V (one pair), and in segment VI (one pair), ventral lobes present in segment IV (one pair), in segment V (two pairs), and in segment VI (two pairs); glands not connected dorsally. Nephridia not observed. Chloragogen cells from segment VII distinctive, containing dark granules, dense in posterior segments. Dorsal blood vessel from segments XXI or XXIV (
n
= 3). Coelomocytes irregular, at least 10 μm wide, most abundant posteriorly (in complete specimen) (
Fig. 6C
). Sperm sac extending into segment XVI, egg sac reaching segment XX. Sperm funnels in segment XI about two times longer than wide, folded, occasionally directed posteriorly (
holotype
) (
Fig. 6D
). Vasa deferentia reaching at least segment XIV, coiled, internally ciliated, 15 μm wide near sperm funnel, narrowing to about 10 μm. Glandular penial bulb type 1 (
sensu
Coates, 1984
), 75–80 μm long, 50–68 μm wide (
n
= 6); stylet absent (
Fig. 6D
). Copulatory gland (in segment XIV) absent. Spermathecal ampulla small, more or less spherical, 37–55 μm long, 37–52 μm wide (
Fig. 6B
). Sperm rings up to 15 μm wide. Ectal duct slender, 90–115 μm long, 17–25 μm wide, not narrowing at ends. No gland at spermathecal pore.
Remarks
Grania simonae
sp. nov.
is unique among the South African species described here and all other members of the genus by the combination of the following characters: lack of lateral chaetae, spermathecae with small and spherical ampulla, dense chloragogen cells, dorsal blood vessel commencing in segment XXIV, and absence of head organ and a midventral copulatory gland in segment XIV. This is the only South African species with numerous and conspicuous coelomocytes scattered throughout the body, but as stated by
Rota
et al
. (2007)
and
De Wit & Erséus (2007)
, the apparent lack of coelomocytes in the other species described herein may be an artifact, caused by the fixation and staining procedures.
The absence of lateral chaetae has been recorded for at least 13 different species of
Grania
to date. Among them,
G. simonae
sp. nov.
is reminiscent of the Antarctic species
Grania carchinii
Rota & Erséus, 1996
, by the absence of penial stylets and head organ, and the possession of dense chloragogen cells; however, the adult specimens of
G. simonae
sp. nov.
are at least twice as large as those of
G. carchinii
known so far. These two species are also distinguished from each other by the morphology of the spermatheca.
Grania carchinii
has a larger (pear-shaped) spermathecal ampulla and a shorter spermathecal duct than
G. simonae
sp. nov.
; the latter has a spherical spermathecal ampulla. Moreover,
G. carchinii
has a midventral copulatory gland in segment XIV, which is lacking in
G. simonae
sp. nov.
The Western Australian
G. conjuncta
and
G. vacivasa
also resemble
G. simonae
sp. nov.
by the absence of lateral chaetae, stylets, and head organ, but they both differ from the latter by possessing a midventral copulatory gland in segment XIV and by extremely long sperm funnels; the funnels are only about twice longer than wide in
G. simonae
sp. nov.
, but 19 times longer than wide in
G. conjuncta
, and 11–15 times longer than wide in
G. vacivasa
.