Bryozoa on disarticulated bivalve shells from Todos os Santos Bay, northeastern Brazil, with the description of two new species
Author
Almeida, Ana C. S.
Author
Souza, Facelucia B. C.
Author
Farias, Jamile
Author
Alves, Orane F. S.
Author
Vieira, Leandro M.
text
Zootaxa
2018
2018-06-18
4434
3
401
428
journal article
29876
10.11646/zootaxa.4434.3.1
5cb7d5d0-e5da-4227-ad4c-f7435f09336d
1175-5326
1292019
4E6E9F71-801E-4657-91DA-51F0B06807F6
Rhynchozoon phrynoglossum
Marcus, 1937a
(
Fig. 9A–D
;
Table 11
)
Rhynchozoon phrynoglossum
MARCUS, 1937
A: P. 115, PL. 23, fIg. 61A, PL. 22, fIg. 61B, C.
Rhynchozoon phrynoglossum
:
MARCUS, 1955
: P. 304.
Rhynchozoon phrynoglossum
:
VIEIRA
et al
., 2008
: P. 33.
Rhynchozoon phrynoglossum
: ALMEIDA
et al.
, 2015A: P. 5.
Material examined
.
UFBA
1650,
UFBA
3388, on
valve
of
Dallocardia muricata
.
Redescription.
Colony encrusting, uni- to multilaminar. Zooids subrectangular at the growing edge (
Fig. 9A
),
arranged in linear horizontal rows, separated by slightly raised lateral walls; with increasing calcification, becoming somewhat oblong and irregularly organized, with zooidal boundaries indistinct. Frontal wall smooth, with 6–12 marginal pores. Primary orifice (
Fig. 9B
) small relative to zooidal length, almost obscured by secondary orifice; distal edge with 12–16 rounded denticles; proximal edge with broad, shallow median sinus; condyles small, rectangular, located at proximal corners of orifice. No oral spines. Secondary orifice well developed, formed by 1– 3 tubercles (two lateral and one median); median tubercle commonly with acute tip. Suboral avicularium (
Fig. 9B
) single, located lateral to median orificial tubercle, oblique and directed distolaterally; rostrum subtriangular, with hooked tip and complete crossbar; foramen triangular. Frontal avicularia small, 1 or 2 per autozooid, similar in outline to suboral avicularium but without hooked tip, located near zooidal margins, variable in orientation. Large vicarious avicularia (
Fig. 9C
) occur, smaller than autozooids, rostrum nearly rectangular, narrower in proximal third, proximal edge rounded and distal edge nearly straight; foramen nearly oval; calcified palate occupying about half the rostrum length. Ovicell (
Fig. 9A, D
) prominent, becoming immersed with increasing calcification; ooecia semicircular and frontally flat; ectooecium non-calcified frontally, leaving a large, semicircular tabula of completely calcified entooecium.
Remarks.
This is the first description of
R. phrynoglossum
based on SEM images since the original description by Marcus (1937a). The species differs from congeners in having 1–3 tubercles around the primary orifice, with a large suboral avicularium, frontal avicularia similar to the suboral avicularium, large subrectangular avicularia and semicircular ooecia.
Rhynchozoon phrynoglossum
is found on hard substrata, commonly encrusting shells (Marcus 1937a, 1955).
Distribution.
Western
Atlantic:
Brazil
(Rocas Atoll,
Bahia
,
Espírito Santo
and
São Paulo
) (
Vieira
et al
. 2008
; Almeida
et al
. 2015a).