Alien bryozoans in the eastern Mediterranean Sea — new records from the coast of Lebanon
Author
Harmelin, Jean-Georges
text
Zootaxa
2014
2014-12-09
3893
3
301
338
journal article
10.11646/zootaxa.3893.3.1
8d8dd34e-6ba4-4c54-99ff-b34de0978996
1175-5326
250297
015E59F7-6450-40E4-81C8-B09024D4C7BA
Rhynchozoon larreyi
(
Audouin, 1826
)
(
Fig. 15
A–D;
Table 13
)
Cellepora
(?)
larreyi
Audouin, 1826
: 239
[
Savigny 1817: pl. 8, fig. 5.
].
“
Cellepora
”
lareyi
(
sic
):
Balavoine 1959
: 277
, pl. 6, figs 3–4.
Rhynchozoon larreyi
:
Harmer 1957
: 1074
(part), pl. 70, figs 12, 16–20;?
Powell 1969b
: 361
;
Dumont 1981
: 636
(list); d’Hondt 1988: 194 (list); d’Hondt 2006: 33.
Rhynchozoon lareyi
(
sic
): Ünsal & d’Hondt 1978: 624.
Rhynchozoon globosum
:
Powell 1967a
(
fide
Powell 1969b
). Non
Rhynchozoon globosum
Harmer, 1957
: 1072
.
Non
Rhynchozoon larreyi
:
Ristedt & Schuhmacher 1985
: 167
, figs 1–3;
Gordon 1989
: 74
, pl. 43B–D;
Gordon & Mawatari 1992
: 35
, pls 3B, 10C.
Material examined.
Specimens from
Lebanon
: 1) Stn 2A, 2 colonies; 2) Stn 3A, 1 colony on biogenic concretion; 3) Stn 4A, 1 colony; 4) Stn 5A, 1 colony on
Phyllangia mouchezi
; 5) Stn 5B, 2 colonies on
Spondylus spinosus
shell; 6) Stn 5D, 1 colony; 7) Stn 11A, 2 colonies on dead
Reteporella
sp. and
Spondylus
shell; 8) Stn 16An 3 colonies on
Spondylus
shell.
Other material examined
: 1)
MNHN
, specimens recorded as
Cellepora lareyi
(
sic
) by
Balavoine (1959)
, Dollfus coll., Al Sayad survey in Gulf of Suez: No. 7836, Stn XI,
8 December 1928
; No. 7849, Stn XII,
28 December 1928
, on scleractinian (colony figured by
Balavoine 1959
, pl. 6, fig. 3–4); 2) SEM photos of
Rhynchozoon
NSP03, northern Bay of Safaga, Red Sea, posted by Ostrovsky
et
al. (2011).
Description
. Colony encrusting, unilamellar, well calcified. Autozooids disposed in files, frontal shield distinctly nodular, 4–6 large areolae on each side, separated by ridges. Primary orifice frontally exposed in newly formed zooids at growing edge, deeply immersed in older zooids, around 10% wider than long; anter denticulate with 10–14 small, widely spaced beads; condyles medium-sized, step-shaped; proximal sinus broad, shallow, rounded. Peristome lacking pseudosinus, typically with raised median process, variably sized, conical when short, cylindrical when long, with tapered tip or sometimes a little inflated with a granular surface, often flanked by shorter, irregularly shaped and sized mucros. Two oral spines occasionally present in young zooids. Large suboral avicularium visible frontally in zooids near growing edge, in raised, swollen chamber replacing median umbo; mandible long, triangular; rostrum hooked, raised obliquely and directed laterally; crossbar complete. In older zooids, suboral avicularium immersed in inner side of peristome, not visible frontally. Frontal avicularium occasionally present, smaller than suboral avicularium, with narrow triangular rostrum directed proximally. Ooecium with thick, nodular rim of ectooecium and large, semicircular frontal exposure of smooth endooecium.
TABLE 13.
Rhynchozoon larreyi
, measurement of the primary orifice in six colonies from Stns 2A, 5A, 5D, 11A and 16A.
R. larreyi
|
X |
SD |
Range |
X |
Or L |
110 |
6 |
100–125 |
22 |
Or W |
121 |
5 |
115–135 |
22 |
Remarks
.
Cellepora
(?)
larreyi
was introduced without description by
Audouin (1826)
for Savigny’s (1817) beautiful drawing of a colony of which the origin, Red Sea or Mediterranean, is unknown. As Savigny’s collection is lost (d’Hondt 2006), the only morphological traits offering a basis for defining this species are those provided by Savigny’s figure. This colony is unilaminar, small (<100 zooids), with recumbent zooids arranged in staggered files, presenting a frontal wall that nodular or seemingly costate; the orifices near the colony edge are rounded, but are hidden by a peristome with 2–4 conical or digitate processes in older zooids; ooecia are numerous and appear early in astogeny, many of them being either incompletely formed or partially broken; avicularia and oral spines are apparently absent. These features revealed by Savigny’s picture are insufficient for modern discrimination of
Rhynchozoon
species. In this genus, species may present large morphologic variations that may overlap those occurring between closely related species (
Dick & Mawatari 2005
). However, the general appearance of the colony pictured by Savigny, particularly the shape of the peristome, recalls both the specimens from the Gulf of Suez reported as '
Cellepora
'
lareyi
(sic) by
Balavoine (1959)
and those from
Lebanon
presented here. Therefore, the decision to ascribe the Lebanese specimens to
R. larreyi
is in part arbitrary.
The Lebanese material of
R. larreyi
shows a broad range of morphological variation within- and between colonies. Features that appear to be diagnostic and relatively constant are supplied by the primary orifice, peristome, suboral avicularium (when present) and ooecium, particularly its endooecial frontal area. The two orificial spines in newly formed zooids are also a diagnostic feature, but they are rarely observed.
FIGURE 15.
Rhynchozoon larreyi
(Audouin, 1826)
, Lebanon; A from Stn 16A; B–C from Stn 5A:
A,
part of colony showing ovicelled zooids with raised granular processes;
B
, ovicelled zooids, one bearing a large, hooked, suboral avicularium;
C
, primary orifice with beaded anter. Scale bars: A, B, 200 µm; C, D, 100 µm.
The occurrence of
R. larreyi
in the SE Mediterranean (
Turkey
:
Ünsal & d’Hondt 1979
;
Çinar
et al.
2011
;
Lebanon
: present records) results most probably from a Lessepsian migration. Several common features suggest that
R. larreyi
and
Rhynchozoon
sp. 1
Hayward (1974)
from Chios (see also
Zabala & Maluquer 1988
) may be closely related. The migratory capacity of
R. larreyi
had been suggested by its presence in
New Zealand
according to
Powell (1967b)
, who had encountered it in a Gulf of Suez sample (
Powell 1969b
). Accepting Powell’s identification,
Gordon & Mawatari (1992)
reported it from
New Zealand
ports, but according to
Gordon (2009)
,
New Zealand
records of
R. larreyi
correspond to
R. zealandicum
Gordon, 2009
, a widespread shelf and coastal species, and it is likely that most figures of
R. larreyi
given by
Harmer (1957)
also do not illustrate this species. It occurs in natural habitats of the Egyptian coast of the Red Sea as proven by SEM photos of specimens collected in the Northern Bay of Safaga and reported as
Rhynchozoon
NSP03 by A. Ostrovsky and J. P. Cáceres-Chamizo (http/ /palse2.pal.univie.ac.at/Bryozoa/Safaga_Bay/Safaga_Bay.html; pers. comm.). In contrast, the large pink colonies from Eilat recorded as
R. larreyi
by
Ristedt & Schuhmacher (1985)
belong to another species, which differs in the shape of the primary and secondary orifices and the suboral avicularium (J.P. Cáceres-Chamizo, pers. comm., based on SEM examination of Ristedt’s material). Obviously, records of
Rhynchozoon
need the support of a whole range of detailed images for adequate interpretation (
Dick & Mawatari 2005
). A thorough revision of
Rhynchozoon
species from the whole of the Mediterranean and the Red Sea is obviously required. At several Lebanese stations,
R. larreyi
co-occurred with native
Rhynchozoon pseudodigitatum
Zabala & Maluquer, 1984
and
Rhynchozoon neapolitanum
Gautier, 1962
.