Preliminary account on the bryozoans of the Alboran platform (Western Mediterranean), with description of two new species
Author
Ramalho, Laís V.
0000-0003-1459-3954
Museu Nacional, Universidade Federal do Rio de Janeiro, Quinta da Boa Vista s / n, São Cristóvão, Rio de Janeiro, RJ, Brazil. 20940 - 040. & Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain. 29071.
laisvr10@yahoo.com
Author
Rodríguez-Aporta, Raquel
0000-0001-5081-5003
Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain. 29071.
rodriguezaporta10@gmail.com
Author
Gofas, Serge
0000-0002-3141-3700
Departamento de Biología Animal, Facultad de Ciencias, Universidad de Málaga, Málaga, Spain. 29071.
sgofas@uma.es
text
Zootaxa
2022
2022-02-02
5094
1
53
91
journal article
10.11646/zootaxa.5094.1.2
fbcfcfa4-103d-4190-84f2-79ebe38ac1e9
1175-5326
5964865
EBF67241-D93F-48CD-9548-463F0B0A9D47
Escharella similis
n. sp.
(
Fig. 9
)
urn:lsid:zoobank.org:act:
2DED7AC0-2358-459D-8627-A498F5309300
Escharella
sp.
Ramalho
et al
., 2020a: 106
, table 2.
FIGURE 8.
Adeonellopsis
aff.
multiporosa
Aristegui, 1985
(MNCN 25.03/4298). A. General view of a colony fragment showing the bifurcation. B. Detail of the branch showing zooids arranged in longitudinal series and the curved distal peristome. C. Close-up of some zooids showing the suboral avicularium and spiraminal pores. D. Detail of a zooid showing the beaded convex proximal margin of the orifice, spiraminal pores, as well as some areolar pores. Scale bars: A, 800 µm; B, 300 µm; C, 200 µm; D, 100 µm.
Material examined.
Holotype
:
MNCN
25.03/4302
: BV12,
112–120 m
; coll.
UMA
;
one living
colony encrusting the bryozoan
Adeonellopsis distoma
.
Paratypes
:
MNCN
25.03/4303
: BV12, 112–
120 m
; coll.
UMA
;
three living colonies
encrusting the bryozoan
A. distoma
and a polychaete tube;
MNCN
25.03/4304
: BV13,
95–99 m
; coll.
UMA
;
nine living colonies
encrusting a cyclostome bryozoan and
A. distoma
, a polychaete tube and algae;
MNCN
25.03/4305
: BV14,
96–100 m
; coll.
UMA
;
two living colonies
encrusting a shell;
MNCN
25.03/4306
: BV15,
96 m
; coll.
UMA
;
two living colonies
encrusting shell fragments.
Etymology.
From the Latin
similis
, -
e
, meaning similar and referring to the similarities of this species with other
Escharella
species
(e.g.
E. praealta
).
FIGURE 9.
Escharella similis
n. sp.
(Holotype: MNCN 25.03/4302). A. General view of a colony growing on a shell fragment. B. Detail of some fertile zooids showing the eight persistent oral spines, small suboral umbo and ovicells with independent aperture (arrow shows the kenozooidal ovicell). C. Detail of an ancestrula with 8 + 5 spines and subsequent zooids with 8 oral spines. D. Basal view of the aperture of a zooid showing the lyrula (lower level) and suboral umbo (higher level), condyles absent. Scale bars: A, 1 mm; B, 300 µm; C, 200 µm; D, 80 µm.
Diagnosis.
Colony encrusting, unilaminar. Primary orifice bearing eight oral spines (in both autozooids and ovicellate zooids) and small lyrula not visible frontally; proximally to the orifice a small, triangular umbo. Ovicell kenozooidal, spherical, with ooecial surface texture similar to that of the zooidal frontal shield. Ancestrula with 13 spines and an extensive cryptocyst.
Description.
Colony encrusting, unilaminar (
Fig. 9A
). Zooids elongate, hexagonal [L 584–714–855 (N 13, SD 73), W 378–435–506 μm (N 13, SD 34)], separated from each other by deep grooves; frontal wall very convex, finely granular, with a row of small, circular areolar pores (
Fig. 9B
). Primary orifice hidden by a well-developed peristome, bearing eight oral spines (persisting in the fertile zooids), and a small, triangular proximal umbo (
Fig. 9B, C
). Lyrula not easily visible due to the peristome, but small and triangular in shape (
Fig. 9D
). Ovicell of kenozooidal origin; ooecium spherical, wider than long [L 182–196–216 (N 10, SD 11), W 243–262–279 μm (N 10, SD 12)], not closed by the maternal operculum; ooecial surface similar to zooidal frontal shield (
Fig. 9A, B
). Ancestrula tatiform, smaller than a zooid [L 380, W 307 μm (N 1)], with almost circular opesia and eight oral spines placed disto-laterally; cryptocyst a flat extensive shelf, surface granular, extensive gymnocyst bearing five mural spines (
Fig. 9C
).
Remarks.
Escharella
is a very species-rich genus with approximately 70 species (
Bock 2021
). Only two species have eight oral spines:
E. octodentata
(
Hincks, 1880
)
and
E. lopezfei
Souto
et al
., 2016
. The former species is characterized by fertile zooids normally having six oral spines, occasionally eight (consistently eight in the new species), orifice with a broad, anvil-shaped lyrula and pointed condyles, and smaller autozooids (420–600 μm in
Hayward & Ryland 1979
).
Escharella lopezfei
described from the
Galicia
Bank (off NW Spain) has fertile zooids with 8–9 spines but differs in having an orifice with thick, short, blunt condyles and lyrula visible in frontal view, no proximal umbo, and an ancestrula with 12 spines (
13 in
the new species). Moreover, in the two above-mentioned species the ovicell is produced by the distal zooid, whereas in the Alboran colonies it is of kenozooidal origin. All three species share an ancestrula with an extensive cryptocyst.
Another very similar species is
E. praealta
(
Calvet, 1907
)
, recorded from the Gulf of Cadiz (
type
locality), the Canary Islands, and the Strait of
Gibraltar
(
López de la Cuadra & García-Gómez 1988
,
1993
). It has a similar appearance (triangular suboral umbo, lyrula hidden by the peristome and absence of condyles), but has six oral spines in both ovicellate and non-ovicelllate zooids, a better developed umbo, an acutely-triangular lyrula, the ovicell has an umbo proximally near the aperture, and the ancestrula has six oral spines and another five mural spines around the cryptocyst. Thus, we identified the specimens from the Alboran platform as a new species.
Ramalho
et al
. (2020a)
found some colonies of
Escharella similis
n. sp.
(mentioned as
Escharella
sp.
) in samples collected on the Chella Bank (also known as Seco de los Olivos, Alboran Sea) at
95 m
.
Considering both sites (Chella Bank and the Alboran platform), the known depth range of this new species is
95–
120 m
.