Two new species of cheilostome bryozoans from the South Atlantic Ocean
Author
Almeida, Ana Carolina S.
Author
Souza, Facelucia B. C.
text
Zootaxa
2014
3753
3
283
290
journal article
46736
10.11646/zootaxa.3753.3.7
41b6c19b-b2fc-4b4e-bbf5-f6c9b74590f0
1175-5326
226369
3C6C55EB-ADBE-4E11-9418-C358B2C8A292
Hippotrema fissurata
n. sp.
(
Figs 6–9
,
Table 2
)
Material examined.
Holotype
:
UFBA
336, Praia de Guarajuba, Camaçari, Bahia State,
Brazil
(
12º50' S
,
38º10' W
),
28 m
, sand, collected
March 2002
by W. Andrade.
Paratypes
:
UFBA
339,
Ilha
de Trindade, Espírito Santo State,
Brazil
(
20º30' S
,
37º18' W
),
93 m
, collected
April 1996
by REVIZEE Expedition,
93 m
;
UFBA
477, Camamu, Bahia State,
Brazil
(
13º45' S
,
38º45' W
),
47 m
, collected
December 2006
by W. Andrade;
UFBA
499, Camamu, Bahia State,
Brazil
(
13º45' S
,
38º50' W
), collected
August 2004
by W. Andrade;
UFBA
500, Itacaré, Camamu, Bahia State,
Brazil
(
14°02' S
,
38°52' W
), collected
August 2004
by W. Andrade.
Additional material
:
UFBA
333, Praia de Guarajuba, Camaçari, Bahia State,
Brazil
(
12º50' S
,
38º09' W
),
37 m
, gravel, collected
March 2002
by W. Andrade;
UFBA
337, Praia de Arembepe, Camaçari, Bahia State,
Brazil
(
12º44' S
,
38º04' W
),
28 m
, gravel, collected
March 2002
by W. Andrade;
UFBA
496; Praia de Guarajuba, Camaçari, Bahia State,
Brazil
(
12º50' S
,
38º11' W
),
23 m
, gravel, collected
September 2002
by W. Andrade;
UFBA
502, Praia de Guarajuba, Camaçari, Bahia State,
Brazil
(
12º50' S
,
38º09' W
),
23 m
, gravel, collected
September 2002
by W. Andrade;
UFBA
507, Camamu, Bahia State,
Brazil
(
13º47' S
,
38º52' W
), 23,5 m, gravel, collected
December 2006
;
UFBA
515, Praia de Arembepe, Camaçari, Bahia State,
Brazil
(
12º45' S
,
38º07' W
),
22 m
, gravel, collected
March 2005
by W. Andrade;
UFBA
525, Praia de Guarajuba, Camaçari, Bahia State,
Brazil
(
12º52' S
,
38º10' W
),
45 m
, sand, collected
February 2006
by W. Andrade;
UFBA
526, Camamu, Bahia State,
Brazil
(
13º46' S
,
38º52' W
), 24,7 m, gravel, collected
December 2006
;
UFBA
585 Praia de Guarajuba, Camaçari, Bahia State,
Brazil
(
12º51' S
,
38º12' W
),
23 m
, gravel, collected
September 2007
by W. Andrade.
Diagnosis.
Colony white, vitreous, multilaminar, encrusting varied substrata. Zooids convex, orifice hoofshaped with a pair of lateral condyles and a broad shallow poster. Ooecium with large frontal slit.
Etymology
. Latim
fissura
, slit, alluding to the frontal surface of the ooecium.
TABLE 2.
Morphological measurements (N = 15; in millimeters) of
Hippotrema fissurata
n. sp.
Lz lz Lo lo Lav lav Lov lov MIN. 0.366 0.272 0.103 0.103 0.055 0.044 0.134 0.162 MAX. 0.501 0.465 0.145 0.152 0.090 0.065 0.198 0.255 MEAN 0.420 0.367 0.130 0.123 0.076 0.054 0.168 0.215 STD DEV. 0.035 0.055 0.015 0.014 0.009 0.005 0.019 0.026
Description.
Colony white, vitreous, encrusting nodules, shells, and dead bryozoan colonies on a substratum of sand to gravel. Uni- to multilaminar, forming small nodules to large colonies obscuring the substratum. First layer with zooids regularly orientated, subsequent layers with irregular orientation. Zooids convex, rhomboidal, hexagonal, with small marginal pores. Frontal shield thickly calcified, sometimes with small frontal pores. Orifice large, hoof-shaped with a pair of lateral condyles slightly down-curved, poster broad and shallow. Acute triangular avicularium often present, with complete cross-bar frequently laterally directed; sometimes absent in entire colonies. Ooecium hyperstomial, globose, not closed by operculum, with large frontal slit.
Remarks
. Although
Winston (2005)
pointed out that additional species could be placed in
Hippotrema
, the only species recognized so far is the
type
species.
Hippotrema fissurata
n. sp.
differs from
H. janthina
mainly in having a fissured ooecium;
H. janthina
merely has a less-calcified frontal area (
Cheetham & Sandberg 1964
;
Winston 2005
). Additionally, Besides,
H. fissurata
n. sp.
is white, vitreous and exclusively encrusting whereas
H. janthina
is deep purple or blue-black (
Osburn 1914
) and can become branching (
Winston 2005
). The two species also differ in the autozooidal and avicularian metrics—the zooid is broader in
H. fissurata
than in
H. janthina
(
0.272–0.465 mm
vs
0.28–0.30 mm
), while the avicularium is broader in
H. janthina
(0.06–
0.06 mm
vs
0.044– 0.065 mm
). The avicularium is common in
H. janthina
(
Winston 2005
)
but in
H. fissurata
it can be lacking in entire colonies.
Characodoma rotundorum
(
Norman, 1909
)
possibly belongs to
Hippotrema
(
Winston 2005
)
, but differs from
H. fissurata
in having a heavily calcified frontal wall and ooecium with a large uncalcified frontal area (
Cook 1985
).
Winston (2005)
also suggested that
Characodoma latisinuatum
Harmer, 1957
might also belong to
Hippotrema
. It differs from
H. fissurata
in its erect growth and densely pseudoporous and minutely tubercular frontal shield (
Harmer 1957
;
Cook & Bock 1996
). Both
Characodoma latisinuatum
and
Hippotrema fissurata
n. sp.
have a large frontal ooecial fissure but the ooecia may be obscured by secondary calcification in
C. latisinuatum
(
Cook & Bock 1996
)
.
Distribution.
Brazil
: States of Bahia and Espírito Santo,
22–93 m
depth.