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
Parasmittina loxoides
Winston,
Vieira & Woollacott, 2014
(
Fig. 5A–F
;
Table 6
)
Parasmittina loxoides
WINSTON, VIEIRA & WOOLLACOTT, 2014
: P. 202, fIg. 40 (CUM SYN.).
Parasmittina loxa
: ALMEIDA
et al
., 2015A: P. 4.
NOT
Smittina trispinosa
VAR.
loxa
: MARCUS, 1937B: P. 225, fIgS 23C, 24.
Material examined.
UFBA
1619,
UFBA
3323–3325, on
valve
of
Plicatula gibbosa
.
UFBA
1621,
UFBA
1622,
UFBA
1627,
UFBA
1628,
UFBA
1652,
UFBA
1654,
UFBA
1661,
UFBA
3326–3353, on
valves
of
Pinctada imbricata
.
Redescription.
Colony encrusting (
Fig. 5A
), uni- to multilaminar. Autozooids (
Fig. 5B
) subrectangular to polygonal, surrounded by 18–28 large marginal pores. Frontal wall centrally imperforate, rough. Primary orifice (
Fig. 5C
) longer than wide, distal margin smooth, not beaded; 1–2 oral spines; lyrula short, relatively narrow, truncate (non-alate), occupying about one-sixth or less of orifice length; two downward-directed condyles with serrated tips.
Secondary orifice low
,
developed
as
two lateral flanges
. Avicularia of three types. Avicularia type 1 (
Fig. 5D
, arrow) small, triangular, varying in orientation, frequently single, occasionally paired, distolateral or proximolateral to peristome, sometimes along autozooid margin on one side. Avicularia type 2 (
Fig. 5D
, circle) small, obovate to truncate, frequently single, occasionally paired, marginal, commonly replacing an areolar pore. Avicularia type 3 (
Fig. 5B, E
) large, spatulate, with orientation depending on location, commonly lateral (straight or with rostrum arched up) and distally directed, sometimes oblique to orifice, with subtriangular foramen and calcified palate occupying about half rostrum length, becoming longer with age. Ovicell (
Fig. 5E, F
) prominent, peripherally covered by secondary calcification from surrounding zooids; becoming submersed with increasing calcification; ectooecium perforated by 21–26 small pseudopores that sometimes coalesce with each other.
Remarks.
Winston
et al.
(2014)
recently described
P. loxoides
based on specimens from
Rio de Janeiro
, and also reassigned to this species specimens from
São Paulo
previously reported
as
Parasmittina loxa
(
Marcus, 1937b
)
. The
holotype
of
P. loxa
from
Santa Helena
, a volcanic
island
in the tropical South Atlantic Ocean, has been destroyed, thus preventing comparison with the Brazilian species (
Winston
et al
. 2014
).
Since
P. loxoides
was originally described from a single colony fragment mounted on a SEM stub (
Winston
et al
. 2014
), some morphological characters were not evident (i.e. presence and number of oral spines, ornamentation of condyles, frequency and types of avicularia). Since the taxonomy of
Parasmittina
Osburn, 1952
is mainly based on the morphology of primary orifice (i.e. distal margin, condyles and lyrula), avicularia and ovicell (
Soule & Soule 1973
,
2002
;
Winston
et al
. 2014
),
P. loxoides
is here redescribed.
The following combination of characters distinguishes
P. loxoides
from congeners: autozooids subrectangular to polygonal, with large marginal pores; 1 or 2 oral spines; lyrula short, relatively narrow, truncate (non-alate); condyles with serrate tips; three types of avicularia (small, triangular; small, obovate; large, spatulate); ectooecium of ovicell with 21–26 small pseudopores. Also, among the eight species of
Parasmittina
known from Brazil (Vieira
et al
. 2018),
P. loxoides
is unique in having large avicularia (type 3) distally directed.
Distribution.
Western
Atlantic:
Brazil
(
Bahia
,
Rio de Janeiro
and
São Paulo
) (Almeida
et al.
2015a;
Winston
et al
. 2014
).