Systematics of interstitial encrusting bryozoans from southeastern Brazil
Author
Winston, Judith E.
Author
Vieira, Leandro M.
text
Zootaxa
2013
3710
2
101
146
journal article
10.11646/zootaxa.3710.2.1
867ca84b-ed17-40e4-a603-b2efd0e6fef3
1175-5326
248125
6E42B926-DAA9-4BAE-B995-8BDB19B93268
Ammatophora arenacea
sp. nov.
(
Fig. 5
;
Table 3
)
TABLE 3.
Measurements (in mm) of
Ammatophora arenacea
sp. nov.
.
Lz
|
Wz
|
Lop
|
Wop
|
Lov
|
Wov
|
N |
18 |
18 |
18 |
18 |
8 |
8 |
Mean |
0.469 |
0.262 |
0.223 |
0.140 |
0.146 |
0.263 |
SD |
0.056 |
0.025 |
0.292 |
0.018 |
0.018 |
0.033 |
Min |
0.360 |
0.198 |
0.108 |
0.108 |
0.126 |
0.216 |
Max |
0.576 |
0.306 |
1.386 |
0.162 |
0.180 |
0.306 |
Material examined.
Holotype
: MZUSP 713 (
Fig. 5
A–C,), measured specimen #1, BIOTA Stn 205.
Paratypes
: MZUSP 685, specimen #14, near BIOTA Stn 205, 15 m; MZUSP 686, #15 [4 colonies], near BIOTA Stn 205, 15 m; MZUSP 715 (
Fig. 5
D), BIOTA Stn 205; MZUSP 716, measured specimen #2, BIOTA Stn 211; VMNH 70007, measured specimen #3, BIOTA Stn 205; VMNH 70008, BIOTA Stn 211.
Additional material
: MZUSP 708, BIOTA Stn 205.
Supplementary video.
http://cifonauta.cebimar.usp.br/taxon/ammatophora-arenacea/
Etymology.
From Latin
arenaceus
, of sand, for its habit of encrusting small substrata in sand-bottom areas.
Diagnosis.
Characterized by small zooid size, large tubercles at proximal edges of zooids, broad ooecia, and closely connected zooids with tubules between them.
Description.
Colony encrusting, unilaminar. Zooids oval in outline, closely connected by tubules, which are sometimes hidden by gymnocystal development. Inside lateral rim of zooids is a beaded cryptocyst. Cryptocyst extending over proximal half of zooid and around the lateral edges of the triangular to bell-shaped opesia which occupies most of the distal half of the zooid. Irregularly shaped calcified tubercles develop at the proximal ends of zooids. Ooecia imperforate, with a convex proximal rim, endooecium not exposed; short in length, but equal to or greater than zooids in width. Polypides with 11 tentacles. Ancestrula similar to later zooids, the proximal margin crenulated.
Remarks.
Ammatophora arenacea
sp. nov.
was found encrusting shell grains and larger pieces of broken mollusk shells in interstitial habitats. The encrusting unilaminar colonies of small zooids with a depressed cryptocyst and large nodular kenozooids, as well as the flattened imperforate ooecium seem to place this species in the genus
Ammatophora
, along with
Ammatophora nodulosa
, an Eastern Atlantic species which, according to Hayward & Ryland (1998, p. 200), occupies a similar habitat on offshore shell gravels “where it forms part of a characteristic community of cheilostomate bryozoans adapted for living on the smallest shell substrata.”
The short, often hidden tubules connecting the zooids might indicate a relationship with
Mollia
. However, unlike
Mollia
species, the zooids are not attached to the substratum by rhizoids, but are directly attached by the basal wall (although holes, like those for rhizoids are present in the basal wall and can be seen in the broken zooids in
Fig. 5
B).
Only one morphologically similar species has been recorded from
Brazil
(Vieira
et al.
2008).
Mollia elongata
was described by Canu & Bassler (1928b) from deeper-water stations. It has much larger zooids and more voluminous ooecia immersed in the zooid (see Marcus 1949, fig. 18), distinct from other
Mollia
species. Souto
et al.
(2010) also noted confusion between some characters of specimens assigned to
Mollia
and to other
Calloporidae
, suggesting the need for reexamination of
Mollia elongata
, which may be more closely related to
Ammatophora arenacea
.
Distribution.
São Paulo state,
Brazil
.