The Parvidrilidae - a diversified groundwater family: description of six new species from southern Europe, and clues for its phylogenetic position within Clitellata (Annelida)
Author
Martínez-Ansemil, Enrique
Author
Châtelliers, Michel Creuzé Des
Author
Martin, Patrick
Author
Sambugar, Beatrice
text
Zoological Journal of the Linnean Society
2012
2012-11-30
166
3
530
558
https://academic.oup.com/zoolinnean/article-lookup/doi/10.1111/j.1096-3642.2012.00857.x
journal article
10.1111/j.1096-3642.2012.00857.x
0024-4082
5408987
PARVIDRILUS CAMACHOI
MARTÍNEZ- ANSEMIL & SAMBUGAR
SP. NOV.
(
FIG. 4
)
Holotype
:
MNCN 16.03
/3070, mature specimen, longitudinal sectioned at 0.4
Mm
, stained with toluidine blue and mounted in
Canada
balsam.
Estaragüeña cave
(
43°17′58.2′′N
,
4°36′23.5′′W
, Z
53 m
asl
), Puentellés,
Cantabria
,
Spain
,
4.ix.2002
,
leg
.
Ana Camacho.
Etymology
:
Named
after
Ana Camacho
, responsible for the
PASCALIS
project for the
Spanish
partners, in honour of her important contribution to the knowledge of
European
biospeleology.
Figure 4.
Parvidrilus camachoi
sp. nov.
A, main components of the genitalia (schematic view). B–C, sections in anterior body region. D–J, sections in genital region. Abbreviations: a, atrium; b, brain; cl, clitellum; cr, crotchet; e, egg; ed, ejaculatory duct; g, gut; gm, granular material; gp, glandular pouch; mo, morula; mp, male pore; mt, mouth; nc, nerve cord; ne, neuropile; o, ovary; oe, oesophagus; p, porophore; pg, pharyngeal gland; sa, spermathecal ampulla; sd, spermathecal duct; sp, spermatozoa; sv, seminal vesicle; t, testis; vd, vas deferens; VI–XIII, segments. Scale bars = 10 Mm.
Description:
Body wall thin (especially in dorsal part), and unpapillated. Large globular clitellar cells observed on lateral sides of XI–
XIII
(
Fig 4D
, cl); porophore and surrounding area glandular. Brain long, extending into segment IV, deeply incised posteriorly (
Fig. 4B, b
). Ventral nerve cord in contact with epidermis, beneath muscles of the body wall (
Fig. 4B, C
, nc). Most setigeral segments have a mid-dorsal glandular pouch opening posteriorly on each segment, at or near the transversal setal line (
Fig. 4B, C
, gp); glandular pouches absent from IV-
VI
.
Digestive tract complete, entirely ciliated, and ending in a terminal anus. Eversible pharynx, with small dorsal pad set off from oesophagus, followed by a narrow winding tube extending into
VIII
, with thick muscular walls at about VII–
VIII
(
Fig. 4C
, oe); alimentary canal completed by a gut, clearly enlarged from segment
XIII
(
Fig. 4E–J, g
). Compact pharyngeal glands present in IV–
VI
(
Fig. 4B, C
, pg). Digestive tract from
V
, surrounded by a well-developed layer of chloragogen cells. Coelomocytes and nephridia not observed.
Two narrow testes attached to septum 10/11 (
Fig. 4H–I, t
). Free germ cells and morulae floating in the coelomic cavity of segment XI (
Fig. 4G
, mo). A small seminal vesicle in
XII
(
Fig. 4E, G
, sv). Sperm funnels not observed. A piece of vas deferens (about 1.5 Mm wide) observed near the basal part of an atrium (
Fig. 4A, F
, vd). Atria tubular, somewhat curved, moderately elongated (about 32 Mm long, 8–10 Mm wide), extending into the beginning of
XIII
(
Fig. 4A, F–J, a
) merging, below the nerve cord, into a common ejaculatory duct which opens at the tip of a mid-ventral porophore located on the transversal setal line of segment
XII
(
Fig. 4A, G–J
, ed, mp, p). Atrial wall thin (less than 2 Mm thick) and muscular (?); ejaculatory duct surrounded by a thin layer of muscles. Atrial lumen filled in with a granular material (secretions?, or remains of old epithelial cells?), and with a large amount of spermatozoids, their heads distally attached to atrial wall, and their long flagella orientated to the proximal atrial end, with a clear flamigerous appearance (
Fig. 4H–I
, gm, sp). Prostate glands absent. Two ovaries attached to septum 11/12 (
Fig. 4E, o
). A large vitellogenic mature egg in segment
XII
, slightly protruding into
XIII
(
Fig. 4E, e
). Oviducts not observed. A single spermatheca is present in
XIII
. Spermathecal ampulla round (about 18 Mm in diameter), with a fine epithelial wall (1–3 Mm thick); spermathecal duct (about 10 Mm long) as a loosely defined structure, hollowed by a very narrow duct (?), ending near the septum 12/
13 in
a somewhat lateral position, at the left side of the worm (
Fig 4A, E–H
, sa, sd). Ampulla filled with spermatozoids, attached around the wall, and with a fine secretion.
Remarks:
The description of external anatomy cannot be given in detail as the individual was sectioned. Nevertheless, prior to sectioning, we noted that the external anatomy of this specimen agrees in all respects with that of
P. spelaeus
, including size of the worm, absence of modified genital setae (
Fig. 4A, E
, cr), and shape and number of dorsal and ventral somatic setae.
Parvidrilus camachoi
sp. nov.
is one of three
Parvidrilus
species
known so far that have a single spermatheca in segment
XIII
. The narrow and moderately elongated, tubular, bent atria and the roundish spermathecal ampulla filed with spermatozoids attached around the wall are diagnostic traits for this new species. The closest relative to
P. camachoi
sp. nov.
is
P. spelaeus
but in the latter, atria are pyriform, the spermatheca is very large and irregular in shape, and sperm is arranged in large masses of agglutinated spermatozoids into the spermatheca.
Distribution and habitat:
Parvidrilus camachoi
is known only from the
type
locality in the Estaragüeña cave Puentellés,
Cantabria
,
Spain
. Estaragüeña corresponds to a resurgence of the Diva River. The cave is hardly accessible, as there is a siphon a few metres from the entrance of the gallery. The species was found in the entrance hall, along the edge of the siphon, in wet sands with abundant organic matter.