Taxonomy of intertidal cheilostome Bryozoa of Maceió, northeastern Brazil. Part 1: Suborders Inovicellina, Malacostegina and Thalamoporellina
Author
Vieira, Leandro M.
Author
Almeida, Ana C. S.
Author
Winston, Judith E.
text
Zootaxa
2016
4097
1
59
83
journal article
10.11646/zootaxa.4097.1.3
4d26544d-be4b-4440-a33e-26dee7d14b5e
1175-5326
271017
8274E4B9-A01E-4395-AE22-0579D8E47BC7
Arbocuspis ramosa
(
Osburn, 1940
)
n. comb.
(
Figs. 28–31
)
Electra bellula
:
Marcus, 1937
: 37
(in part), pl. 6, figs. 14A, E–F [not pl. 6, figs. 14B–D]. [
Brazil
: São Paulo] Non
Membranipora bellula
Hincks, 1881
: 149
. [
Australia
]
Electra bellula
var.
ramosa
:
Osburn, 1940
: 355
, pl. 2, figs. 20–21. [
Puerto Rico
]
Electra bellula
:
Marcus, 1941
: 16
(in part), fig. 6 (in part). [
Brazil
: Paraná]
Electra bellula
:
Vieira
et al.
, 2008
: 12
(in part). [
Brazil
: São Paulo and Paraná]
Material examined.
Syntypes
:
USNM
11826,
USNM
11881,
Electra bellula
var.
ramosa
, balsam slide with erect and encrusting colony, R. Osburn collection, Piles of Guayanilla,
Puerto Rico
, Station 2632.
Additional specimens
:
UFPE
0 37, Sobral sewer outfall, Maceió, Alagoas State,
Brazil
,
9º40'45" S
,
35º45'01" W
, intertidal, on algae, coll.
27 April 2006
by L.M. Vieira and M.D. Correia;
UFPE
0 38,
UFPE
0 78, coll.
18 January 2007
by L.M. Vieira and M.D. Correia.
Description.
Colony primarily encrusting, multiserial, forming yellowish-white unilaminar to bilaminar plates; erect phases branching, jointed at the base. Encrusting phase with elongate zooids,
0.296–0.445 mm
(0.382 ± 0.044) long and
0.148–0.222 mm
(0.181 ± 0.018) wide; a distal oval opesia,
0.124–0.235 mm
(0.174 ± 0.029) long, is surrounded by a crenulated rim of gymnocyst that occupies one-third to two-thirds of the zooid length,
0.086–0.296 mm
(0.213 ± 0.06) long; cryptocyst occurs as a proximal narrower shelf on inner margin of gymnocyst; a pair of curving pointed spines occurs at the distal end of the opesia on either side of the operculum; usually a large median spine, curved, unbranched, is placed very close to the proximal rim of the opesia; one or two smaller lateral spines may occur close to the rim of the opesia. Erect phase branched, formed by two zooids placed back to back, usually followed by four in the next series, forming narrow 4-sided branches; zooids pyriform, with the distal oval opesia and proximal gymnocyst occupying about half of the zooid length; cryptocyst narrow. A pair of pointed spines occurs at the distal end of the opesia on either side of the operculum (but belongs to the distal zooids); a long pointed median spine, unbranched, is placed very close to the proximal rim of the opesia, forming an angle of 60 degrees in relation to the frontal surface; two smaller lateral spines, usually forming a right angle, are placed very close to the proximal rim of the opesia. Colonies develop from a single ancestrula.
Remarks.
Despite the absence of branched spines,
Electra bellula
var.
ramosa
Osburn, 1940
is here assigned to
Arbocuspis
owing to the presence of smooth gymnocyst, narrow cryptocyst, and spines slightly bending across the opesia.
Arbocuspis ramosa
is characterized by a two-phased colony; encrusting and erect colonies have one to three unbranched spines placed at the proximal end of the gymnocyst very close to the opesia and a crenulated opesia rim. It is distinguished from other species of the genus in having only unbranched spines.
Distribution.
Arbocuspis ramosa
is found in the Western Atlantic, from
Puerto Rico
to southern
Brazil
. This is the first record of the species in Alagoas.