Taxonomic revision of some lepraliomorph cheilostome bryozoans (Bryozoa: Lepraliomorpha) from Rio de Janeiro State, Brazil
Author
Ramalho, Laís V.
Author
Muricy, Guilherme
Author
Taylor, Paul D.
text
Journal of Natural History
2011
2011-03-28
45
13 - 14
767
798
http://dx.doi.org/10.1080/00222933.2010.535917
journal article
10.1080/00222933.2010.535917
1464-5262
5203413
Reteporella antennata
sp. nov.
(
Figure 9
)
Material examined
Holotype
: MNRJ-175.
Paratypes
: MNRJ-236, MNRJ-237. REVIZEE
Station
2 (
23
◦
47.629
′
S
,
041
◦
42.514
′
W
), all collected by
D.C. Savi
from the naval ship
Diadorim
,
20 July 2004
, using a trap, depth
341 m
.
Reteporella beaniana
: NHM
1963.3.30.248,
Lervik
,
Hardanger Fiord
,
Norway
,
Harmer Collection
.
Etymology
The name
antennata
refers to the antenna shape of the distal spines.
Diagnosis
Colony fenestrate, chalice-like; frontal walls smooth, containing few marginal areolar pores; oral spines antenniform, six in number; ovicell with indistinct fissure and short and wide labellum; frontal avicularia monomorphic, oval with rounded mandible, proximally directed; dorsal avicularia of two kinds, one the same as the frontal avicularia, the second a giant avicularium with rounded mandible, attached below the fenestrae or on internal borders.
Figure 9.
Reteporella antennata
sp. nov.
(A,B) Views of the cup-shaped colony; (C) distal branch showing autozooidal arrangement, antenna-like spines and labial pore; (D) autozooidal arrangement at bifurcation region; (E) ovicellate autozooids and frontal avicularia. F. Avicularia. Scale bars: A,B: 0.5 cm; C–E: 200 µm; F: 50 µm. MNRJ-175.
Description
Colony erect, fenestrate, large (
20 mm
high by
30 mm
diameter), four to five branches originating from a narrow base, bifurcating and anastomosing to form a circular, chalice-shaped net; white in colour (
Figure 9A,B
).
Autozooids longer than wide (635 µm long, range 588–735 µm, by 257 µm wide, range 206–294 µm), convex, narrower distally, arranged in two series alternately on frontal side of branches; frontal wall smooth with a few marginal pores; secondary calcification present (
Figure 9B,C
). Peristome variably developed, hiding the primary orifice; a long fissure partially closed forming the labial pore which is large and round (
Figure 9D
). Six long peristomial spines (three external and three internal), articulated, antenniform; thicker base, narrowing towards the tip; complete in the distal zooids and often broken in other zooids (
Figure 9B,C
). Ovicell almost globose, hyperstomial, imperforate, wider than long, 196 µm long by 235 µm wide (range 216–255 µm), sometimes embedded in autozooidal calcification; labellum short and wide; fissures normally indistinct; secondary calcification present, usually not covering the entire frontal region (
Figure 9D
).
Frontal avicularia small (94 µm long, range 78–118 µm, by 57 µm wide, range 49–69 µm), oval with short mandible rounded at the tip, cross-bar weak; located below zooid midline, directed proximally; one to two avicularia on frontal wall; avicularium chamber sometimes slightly elevated forming projection on frontal wall (
Figure 9B–E
). Dorsal avicularia of two kinds: one similar to frontal avicularium, small, with a mandible rounded at tip (
Figure 9F
); the other larger (245 µm long, range 216–274 µm, by 122 µm wide, range 98–147 µm), very rare, with mandible rounded at the tip, located immediately below fenestrae or between the dorsal and frontal sides near bifurcations.
Habitat
Found on rock and coralline substrates in deep water (
341 m
).
Geographical distribution
REVIZEE station 2 (
23
◦
47.629
′
S
,
041
◦
42.514
′
W
),
Rio de Janeiro State
,
Brazil
.
Remarks
In the presence of antenniform spines and an oval frontal avicularium, this new species is similar to
R. flabellata
Busk, 1884
. However,
R. flabellata
has a dichotomously branched colony which is not fenestrate, dorsal avicularia are absent, and branches are formed by one to three series of zooids.
Hitherto, no species of
Reteporella
has been recorded from
Brazil
.
Hayward (1993
, 1995) mentioned nine
Reteporella
species
in the Antarctic region, but all of these have large to giant avicularia and oral spines are absent or less frequent than in the new species.
Gordon (1989)
described three new species of
Reteporella
from
New Zealand
, but most of these are not fenestrate and differ in other characters from the Brazilian species.
Hayward and Ryland (1996)
described five
Reteporella
species
from North Atlantic waters. These species differ from the new Brazilian species principally in having fewer spines, avicularia lateral or proximal of the orifice, and triangular avicularian mandibles.
Gordon and d’Hondt (1997)
described five species from
New Caledonia
which also differ from the new Brazilian species as giant avicularia and oral spines are absent.