Redescription of some species of Bryozoa described by J. Jullien and L. Calvet in the NE Atlantic
Author
Reverter-Gil, Oscar
Departamento de Zooloxía e Antropoloxía Física, Facultade de Bioloxía, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain. & Corresponding author: oscar. reverter @ usc. es & urn: lsid: zoobank. org: author: 001 DFC 48 - 0 F 01 - 43 AF- 90 EC- 452 BE 6954 DDF
oscar.reverter@usc.es
Author
Souto, Javier
E14FC8A9-40B5-4BF6-8551-3F2A1D991463
Departamento de Zooloxía e Antropoloxía Física, Facultade de Bioloxía, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain. & Institut für Paläontologie, Fakultät für Geowissenschaften, Geographie und Astronomie, Geozentrum, Universität Wien, Althanstrasse 14, 1090 Vienna, Austria. & Email: javier. souto @ usc. es & urn: lsid: zoobank. org: author: E 14 FC 8 A 9 - 40 B 5 - 4 BF 6 - 8551 - 3 F 2 A 1 D 991463
javier.souto@usc.es
text
European Journal of Taxonomy
2015
2015-11-30
157
1
17
journal article
22388
10.5852/ejt.2015.157
f9d4e0e3-9e60-47c5-9ad0-b1339758d187
2118-9773
3788028
7FDDCF57-1F93-4266-B0F7-0486344055DE
Escharina alderi
(
Busk, 1856
)
Figs 4
A–E, 5A–E;
Table 2
Alysidota alderi
Busk, 1856: 311
, pl. 9, figs 6–7.
?
Lepralia barleei
Busk, 1860: 143
, pl. 26, figs 1–2.
Schizoporella ovum
Jullien, 1882: 16
, pl. 15, figs 36–37.
Schizoporella alderi
–
Hincks 1880: 243
, pl. 36, figs 9, 9a, 10.
Schizoporella ovum
–
Jullien 1883: 512
, pl. 15, figs 36–37. —
Calvet 1907: 422
.
Escharina alderi
–
Hayward & Ryland 1999: 228
, figs 94c–d; 96.
Schizomavella ovum
–
Reverter-Gil & Fernández-Pulpeiro 2001: 120
.
Material examined
Lectotype
of
Schizoporella ovum
(here designated)
SPAIN
:
Travailleur
st. 40,
44°05’00’’ N
,
07°14’46’’ W
, NW Iberian Peninsula,
15 Aug.
1881
, 392 m, Jullien coll., one colony on a shell, figured specimen (
NHMUK
1899.7.1.2348).
Paralectotypes
of
Schizoporella ovum
SPAIN
: same data as
lectotype
(
MNHN
1025,
MNHN
2347).
Other material examined
NORWAY
:
Alysidota alderi
, Busk
coll., one uniserial colony, with some avicularia but no ovicell, on a shell (
NHMUK
1899.7.1.2143).
UNITED KINGDOM
:
Alysidota alderi
,
Shetland
, 1859, Busk coll.,
paratype
(
NHMUK
1899.7.1.2144);
Alysidota alderi
,
Shetland
, 1859, Busk coll., type (
NHMUK
1899.7.1.2145);
Escharina alderi
var.
barleii
,
Shetland
, Busk coll., marked as ‘Type?’ (
NHMUK
1911.10.1.1197);
Escharina alderi
, Scotland,
22 Oct. 1958
, st. 12, 52 m, Ryland coll. (
NHMUK
1994.3.14.8).
LOCALITY UNKNOWN:
Schizoporella ovum
,
Talisman
1883
, 340 m, no further data, Calvet coll. (
MNHN
3770).
Description
Colony encrusting, composed of linear series of autozooids, or unilaminar, multiserial. Autozooids oval to hexagonal, separated by sutures. Frontal shield convex, granular, uniformely perforated by some 25 small rounded pores, often inconspicuous, plus a row of small marginal pores. Distolateral vertical walls with several dietella. Primary orifice as long as wide. Inner distolateral orifice rim with immersed, very narrow shelf. Anter slightly horseshoe-shaped, proximal margin straight, with U-shaped sinus, as deep as wide, occupying one third of proximal border. Primary orifice encircled by smooth, broad band of gymnocystal calcification. Oral spines absent. A low, conical umbo may be developed proximal to sinus. Avicularia rare, lateral to orifice, sporadically present in uniserial colonies, apparently absent in multiserial colonies. Rostrum triangular, raised, directed proximally or proximo-laterally. Ovicell globular, recumbent on distal autozooid and partially covering orifice of maternal zooid. Surface granular, with single series of septular pores around basal periphery and sometimes raised into a central umbo. Ancestrula not observed.
Fig. 4.
Escharina alderi
(
Busk, 1856
)
.
A
. Group of autozooids (NHMUK 1911.10.1.1197, type of
Alysidota alderi
Busk, 1856
).
B
. Same, ovicellate zooid; note the distal marginal pores in the ovicell.
C
. Same, detail of a broken ovicell.
D
. Same, primary orifice.
E
. Ovicellate zooid and one adventitious avicularium in a uniserial colony (NHMUK 1899.7.1.2145, paratype of
Alysidota alderi
Busk, 1856
).
Table 2.
Measurements (in mm) of
Escherina alderi
(
Busk, 1856
)
(lectotype and paralectotypes of
Schizoporella ovum
Jullien, 1882
). SD = standard deviation; N = number of measurements.
Mean |
SD |
Minimum |
Maximum |
N |
Autozooid length |
0.640 |
0.0634 |
0.546 |
0.751 |
10 |
Autozooid width |
0.442 |
0.0673 |
0.331 |
0.528 |
10 |
Orifice length |
0.118 |
0.0083 |
0.106 |
0.130 |
10 |
Orifice width |
0.119 |
0.0086 |
0.106 |
0.133 |
10 |
Ooecium length |
0.260 |
0.0138 |
0.239 |
0.268 |
4 |
Ooecium width |
0.297 |
0.0209 |
0.266 |
0.310 |
4 |
Remarks
Busk (1856)
described
Alysidota alderi
, a species with zooids in linear series, imperforate ovicells and rare adventitious avicularia. Some years later, he described
Lepralia barleei
for a single multiserial colony encrusting a shell collected in
Shetland
, with ovicells with peripheral pores and lacking avicularia (
Busk 1860
).
Norman (1869)
was the first author who considered these two species to be synonymous while reporting
A. alderi
from
Shetland
at depths between 50 and 170 fathoms (
90–310 m
). He also stated that the
type
specimens of both species were in his collection.
Hincks (1880)
assumed this synonymy to be correct and transferred the species to the genus
Schizoporella
. Finally,
Marcus (1940)
transferred
Schizoporella alderi
to the genus
Escharina
.
Type
and other material labeled as
A. alderi
is conserved at the NHMUK, but no original material of
L. barleei
seems to exist. Although the sample NHMUK 1911.10.1.1197 is labeled as the
type
of ‘
Escharina alderi
var.
barleei
’, it contains two colonies on stones, so they do not match the original description of the species. As no original material of
L. barleei
is preserved and the original description is very vague, it is not possible at present to confirm or reject the proposed synonymy.
Schizoporella ovum
was described by
Jullien (1882)
for an undeterminate number of dead multiserial specimens, with ovicells with peripheral pores and lacking avicularia, collected off the NW Iberian Peninsula at a depth of
392 m
.
Three type specimens are now kept at NHMUK and MNHN; the one at NHMUK is here designated as the
lectotype
.
Calvet (1907)
reviewed the original record by Jullien, stating that the original material consisted of “
trois échantillons sur coquilles
”. This author also reported two further colonies, also on shells, collected by the
Talisman 1883
cruise from an unrecorded locality at a depth of
340 m
; this material (MNHN 3770), although belonging to the same species, is not part of the type series.
Schizoporella ovum
does not seem to have been rediscovered since then, but it was transferred to the genus
Schizomavella
by
Reverter-Gil & Fernández-Pulpeiro (2001)
following their revision of the type material at Paris.
The type material of
Schizoporella ovum
is identical to the sample NHMUK 1911.10.1.1197 (‘
Escharina alderi
var.
barleei
’), so they belong to the same species. Furthermore,
S. ovum
may be somewhat similar to
Lepralia barleei
as originally described. On the other hand, the autozooids of
S. ovum
are identical to the autozooids of
E. alderi
(see
Figs 4–5
), as was stated by
Hincks (1880: 244)
for uniserial and multiserial colonies of
S. alderi
. Differences between these two species do not appear to be significant.
Schizoporella ovum
(and
L. barleei
) develop multiserial colonies, whereas
Escharina alderi
forms uniserial chains of zooids. According to
Norman (1869)
, both forms of growth may even share the same substrate. In
S. ovum
(as in
L. barleei
) avicularia have not been reported, and in
E. alderi
they are rare. Therefore, their presence is perhaps related to the uniserial mode of growth, but in any case, their presence or absence should not be used to differentiate species. In
E. alderi
the development of a sporadic umbo in the ovicell and in the autozooids has been reported, while it is absent in the material of
S. ovum
. Its presence may be related to a different degree of calcification, with no phylogenetic significance. Finally, the ovicell was described as imperforate in
E. alderi
, while in
S. ovum
(and
L. barleei
) it has a series of septular pores around the basal periphery. However, SEM images of the
type
material of
E. alderi
demonstrate that the ovicell really has several basal pores (
Fig. 4E
), similar to those present in the
types
of
S. ovum
(
Fig. 5D
). It should be stated that in the genus
Escharina
, as in all members of the family
Escharinidae
, the ovicell has been described as imperforate (see
Hayward & Ryland 1999
;
Tilbrook 2006
), but the pores in the ovicell of
E. alderi
, as well as in other species of the family (see
Bock 2014
), indicate that the diagnosis of the family should be amended.
Fig. 5.
Schizoporella ovum
Jullien, 1882
.
A
. Entire colony (NHMUK 1899.7.1.2348, lectotype).
B
. Same, primary orifice.
C
. Same, a broken ovicell showing the marginal pores.
D
. Ovicellate and nonovicellate zooids (MNHN 2347, paralectotype).
E
. Dietella (MNHN 1025, paralectotype).
Table 3.
Measurements (in mm) of
Escharella guernei
(
Jullien & Calvet, 1903
)
comb. nov.
(lectotype). SD = standard deviation; N = number of measurements.
Mean |
SD |
Minimum |
Maximum |
N |
Autozooid length |
0.499 |
0.0262 |
0.457 |
0.549 |
24 |
Autozooid width |
0.361 |
0.0288 |
0.317 |
0.427 |
24 |
Orifice length |
0.109 |
0.0046 |
0.096 |
0.117 |
24 |
Orifice width |
0.098 |
0.0050 |
0.088 |
0.107 |
24 |
Ooecium length |
0.242 |
0.0057 |
0.238 |
0.246 |
2 |
Ooecium width |
0.275 |
0.0014 |
0.274 |
0.276 |
2 |
In conclusion, we propose here that
Schizoporella ovum
(and probably also
Lepralia barleei
) are junior synonyms of
Escharina alderi
, differing mainly in their mode of growth.