Vicariant versus dispersal processes in the settlement of Pseudamnicola (Caenogastropoda, Hydrobiidae) in the Mediterranean Balearic Islands
Author
Delicado, Diana
Author
Machordom, Annie
Author
Ramos, Marian A.
text
Zoological Journal of the Linnean Society
2014
Zool. J. Linn. Soc.
2014-03-28
171
1
38
71
http://dx.doi.org/10.1111/zoj.12124
journal article
10.1111/zoj.12124
0024-4082
5305349
9CD3D06C-7D15-4211-9613-D23A67F07938
PSEUDAMNICOLA
(
PSEUDAMNICOLA
)
GRANJAENSIS
GLÖER & ZETTLER, 2007
(
FIGS 4–9
)
Type locality
La Granja
, Majorca,
Balearic Islands
,
39.671°N
,
2.559°E
(
Glöer & Zettler, 2007
)
.
Type material
Holotype
(
ZMH
51002) and
three paratypes
(
ZMH
51003) in
Zoologischen Museum
,
Hamburg
; three in
Glöer’s
collection,
41 in
Zettler’s
collection, and four in
Beckmann’s
collection.
Localities
This species is only known from the
type
locality. After exploring the area of La Granja, we found the species in one fountain near the exit of the gardens of the palace at La Granja, Esporles, Majorca (see Appendix S1).
Material examined for morphometry
Shell, anatomical, operculum, and radular measurements (Appendix S2:
Tables S1–S
7) were taken from specimens collected from a ditch in La Granja, Esporles, Majorca. A total of
ten specimens
was collected in
April 2008
. Two males and a single female were studied anatomically.
New diagnosis
Shell with yellowish periostracum; last body whorl occupying about two-thirds of shell length; central tooth of radula with five tapered lateral cusps; long gastric caecum; black pigmentation on intestine; large pyriform bursa copulatrix; elongate seminal receptacle; renal oviduct black pigmented until insertion of seminal receptacle; penis gradually tapering with a small patch of pigmentation on the tip and attachment area central; supraoesophageal connective about six times longer than suboesophageal one; nervous system elongate (
RPG
ratio 0.60).
Description
Shell ovate-conic, yellowish (
Fig. 4B, E, H
) with 4.75– 5.50 spire whorls and a height of approximately
3.50−5 mm
; protoconch about 500 μm in width with 1.4 whorls and a nucleus around 120 μm in length; protoconch microsculpture grooved (
Fig. 5C, D
); convex whorls and deep sutures; peristome orthocline; inner lip of aperture thicker than outer one; the edge of peristome is straight (
Fig. 4E
).
Operculum with 3.5 whorls and an oval muscle attachment area located near the nucleus (
Fig. 6C, D
; Appendix S2:
Table S2
).
Radula length intermediate (20% of total shell length) and approximately six times longer than wide (
Fig. 7B
; Appendix S2: Table S3); around 55 rows of teeth; central tooth with a tapered median cusp and five pointed lateral cusps (
Fig. 7E, H
); lateral teeth with three tapered cusps shorter than the central one; inner marginal teeth bear approximately 15 tapered cusps, shortening towards the base of tooth; outer marginal teeth also with about 15 tapered cusps (
Fig. 7K
).
Pigmentation and anatomy
Head dark brown pigmented from snout to neck (
Fig. 8E
); the pigmentation is lighter on neck; tentacles with medial longitudinal stripe lacking pigment; no pigment on ocular lobes; snout as long as wide, with a medium distal lobation; foot of intermediate length with pigmentation on dorsal region. Ctenidium in the middle region of pallial cavity with 20–25 gill filaments longer than wide; osphradium of intermediate width under central gill filaments (
Fig. 9B
, Appendix S2: Table S4). Stomach slightly longer than wide and posterior chamber slightly larger than the anterior one (
Fig. 9E
, Appendix S2: Table S4); long gastric caecum; style sac longer than wide and surrounded by intestine, which features a small stripe of brown pigment.
Female genitalia with a pallial oviduct containing a capsule gland and an albumen gland of nearly equal size (Appendix S2: Table S5); large pyriform bursa copulatrix with a duct about two times shorter than bursa length; renal oviduct black pigmented until point of insertion of seminal receptacle; elongate seminal receptacle laying on renal oviduct slightly above the point where the bursal duct joins the renal oviduct (
Fig. 8H
).
Male genitalia contain a prostate gland about three times longer than wide (
Fig. 8B
, Appendix S2: Table S6); penis gradually tapering with folds along the entire surface and a patch of brown pigment on its distal region; the base is attached to central area of the head (
Fig. 8E
).
Nervous system dark brown pigmented; cerebral ganglia equal in size and darker than other ganglia and connectives; supraoesophageal connective approximately six times longer than suboesophageal one (
Fig. 8K
; Appendix S2: Table S7). Mean RPG ratio is 0.60 (elongate).
Remarks
Boeters’ (1988) monograph recorded the species
P.
(
P.
)
subproducta
in Esporles, (‘Font d’en Bassina’). Nevertheless, we did not find this species in Esporles or its surroundings; rather, we found
P.
(
P.
)
beckmanni
and
P.
(
P.
)
granjaensis
.
In addition to being genetically distant (7.9, 2.8, and 0.8% for
COI
,
16S
, and
28S
, respectively),
P.
(
P.
)
subproducta
and
P.
(
P.
)
granjaensis
can be further differentiated by several features: longer and more conic shells in
P.
(
P.
)
granjaensis
; larger penis presenting many folds along its inner surface in
P.
(
P.
)
subproducta
; longer bursa copulatrix and seminal receptacle in
P.
(
P.
)
granjaensis
; and a moderately concentrated nervous system in
P.
(
P.
)
subproducta
, but elongate in
P.
(
P.
)
granjaensis
.
The species
P.
(
P.
)
beckmanni
also lives in the gardens of La Granja and is genetically close to
P.
(
P.
)
granjaensis
(0.5% for
COI
, 0.3% for
16S
, and 0.05% for
28S
). However, some anatomical and morphological differences exist between them.
Pseudamnicola
(
P.
)
granjaensis
is distinguishable from
P.
(
P.
)
beckmanni
by several features: a longer shell (mean of
4.28 mm
, Appendix S2:
Table S1
; this measurement is greater than 2.9–3.0 mm, the length published in the original description of
Glöer & Zettler, 2007
); a larger bursa copulatrix (Appendix S2: Table S5), but a proportionally shorter bursal duct; a larger prostate gland and longer, narrower penis (Appendix S2: Table S6); and longer nervous system connectives, and therefore, a higher RPG ratio.
Although the conic shape and long size of
P.
(
P.
)
granjaensis
shells are two features more commonly associated with the subgenus
Corrosella
, both the molecular data and internal anatomy confirm this species as belonging to
P.
(
Pseudamnicola
).