Reef sponges of the genus Agelas (Porifera: Demospongiae) from the Greater Caribbean
Author
Parra-Velandia, Fernando J.
Author
Zea, Sven
Author
Van Soest, Rob W. M.
text
Zootaxa
2014
3794
3
301
343
journal article
45859
10.11646/zootaxa.3794.3.1
8f255bd6-4072-4dfc-ab35-d233e0766ff3
1175-5326
285997
51852298-F299-4392-9C89-A6FD14D3E1D0
Agelas wiedenmayeri
Alcolado, 1984
Figs. 4
,
15
F
The species was named to honour Felix Wiedenmayer, palaeontology curator at the Basel Museum.
Agelas wiedenmayeri
Alcolado, 1984
: 11
,
Figs. 7
B–C, 8B; 2002: 62;
Humann 1992
: 22
, Fig. pag. 23;
Gammill 1997
: 86
, Fig. 86;
Assmann
et al
. 1999
: 455
Assman 2000
: 39
, pl. 5, Fig. A;
Mothes
et al.
2007
: 87
;
Díaz 2007
: 56
;
Alcolado & Busutil 2002
: 69
; Zea
et al
. 2009.
Agelas schmidti
;
Wiedenmayer 1977
: 130
, Fig. 137, pl. 27
Fig. 1
(with further synonymy),
Zea 1987
: 210
, Fig. 76, pl. 12
Fig. 9
(with further synonymy);
Gammill 1997
: 43
, Fig. 42, 74;
Erpenbeck
et al.
2007
: 1564
;
Muricy
et al
. 2008
: 84
, figs.; Rützler
et al
. 2009: 302.
?
Agelas schmidti
;
Wintermann-Kilian & Kilian 1984
: 132
;
Muricy
et al
. 2011
: 39
.
[Non:
Agelas schmidti
Wilson, 1902
: 398
(a valid species)].
Material and distribution.
Holotype
not examined, but see remarks below; deposited at the Instituto de Oceanología—Cuba, IdO–409, collected in Barlovento (La Habana), depth
13 m
.
There is a schizoholotype at the National Museum of Natural History (
USMN
39229). The material reviewed here includes (but is not restricted to) specimens from
Belize
(INV–
POR
952), Rosario Islands (INV–
POR
965),
Bahamas
(INV–
POR
923), San Andres Island (INV–
POR
978) and Santa
Marta
(INV–
POR
987
)
.
There are also reports from
the Bahamas
(
Gammill 1997
; Zea
et al
. 2009), Florida Keys (
Gammill 1997
;
Assmann
et al
. 1999
;
Assmann 2000
; Rützler
et al
. 2009; Zea
et al
. 2009),
Dominican Republic
(
Weil 2006
),
Guadeloupe
(
Alcolado & Busutil 2012
), Guajira in northern
Colombia
(
Díaz 2007
), Los Roques (
Venezuela
, observed by S. Zea) and Northern
Brazil
(
Mothes
et al.
2007
;
Muricy
et al
. 2008
). From the above, we consider
A. wiedenmayeri
a tropical northwestern Atlantic species, despite its apparent absence in
Jamaica
,
Barbados
and
Curaçao
.
Wiedenmayer (1977)
collected his specimens between
37 to 42 m
in
the Bahamas
.
Zea (1987)
collected his specimens between 6 to 35 meters in Rosario Islands and Santa
Marta
, and
Díaz (2007)
from
50 m
in northern
Colombia
. Our specimens were found from
10 m
to
35 m
in depth, abundant between
21–
22 m
.
Description.
This species usually forms clusters of cylindrical short tubes (
4–15 cm
,
Fig. 4
), wider at their bases than their ends. Sometimes it is possible to find long (
10–20 cm
) solitary tubes slightly compressed, which maintain the diameter along all their length. The tubes have
1–3 cm
of external diameter, and
0.5–2 cm
of inner diameter. The walls are
2–5 mm
thick. The tube clusters form a hollow, basal small body, which can be buried in rubble or filling spaces between ramose or foliose corals; solitary or branched tubes creep under rocks or corals, exposing only their apices. The ectosome colour in exposed areas is similar to
A. dispar
, dark brown, shaded areas and internal tissues are cream. Dry specimens maintain the color but it becomes reddish; older alcohol samples lose their colour, but the distinction of ectosome from choanosome is still possible. The pinacoderm, smooth and even, is similar to
A. dispar
.
There are two
types
of openings; the apical ones (
Fig. 4
A), circular or slightly elongated
0.5–2.5 cm
wide, keyhole-like (see remarks); and circular oscules
1–4 mm
wide, regularly scattered along the tubes, conspicuous in shaded areas, where they are sometimes occluded by a white “eardrum-like” membrane. Its consistency is spongy in life, harder when dry. The choanosome of the tube walls is not cavernous apart from some narrow (<
4 mm
) channels connected with the small oscules.
The primary fibres are more or less straight with 60–105 µm in diameter; they are echinated and cored by 1–6 spicules. Interconnecting secondary fibres are less echinated, 40–80 µm in diameter; tertiary fibres not present. The main fibres are oblique to the surface, radiating and ascending from the inner surface of the tubes to the external surface. The acanthostyles are curved but is not unusual to find some of them straight; the whorls, with 3–9 spines, more or less regularly spined and spaced at most geographical areas, are irregular at Santa
Marta
; length 72–288 (136±37.2) µm, width 4–15 (9±3) µm and 7–21 (12±2.6) whorls per spicule. Detailed lengths, widths and average number of whorls are shown in
Table 2
.
Remarks.
Dr. P.M. Alcolado kindly checked several photographs, spicule/skeleton measurements and descriptions of our material and agreed with our identification. Dr. P.M. Alcolado also provided us with a small fragment in order to compare our material with his.
Wiedenmayer (1977)
description of
A. schmidti
does not match the
holotype
and original description of
Wilson (1902)
, but match the
holotype
and description of
A. wiedenmayeri
(see also
Alcolado 1984
). We examined a spicule mount and several old and recent photographs of the
holotype
of
A. schmidti
and it is definitely a different species.
Zea (1987)
followed Wiedenmayer’s lead, as apparently did
Muricy
et al
. (2008
;
2011
) and Rützler
et al
. (2009).
FIGURE 4.
Photographs of
Agelas wiedenmayeri
. A) Two tubes from the Bahamas; note the tube bud on the left tube. B) Five tubes from Belize, note two tiny tube buds at the common base. C) One tube from San Andres Island, Colombia. D) Keyholed tube covered by cianobacteria at Rosario Islands, Colombia.
In
Belize
and
the Bahamas
this species appears as erect tube clusters (
Fig. 4
A, B), but in Rosario Islands (
Colombia
) it occurs mainly as creeping solitary or sparsely branched tubes (
Fig. 4
D). In Santa
Marta
it forms clusters of tubes, but the tubes are long (
15–20 cm
), thin (
1 cm
), and the basal body is strongly reduced or absent. Only one solitary tube was found in San Andres Island (
Fig. 4
C). This species lives in low to medium waveexposed sites, usually in foliose coral or rubble habitat, or in crevices or under foliose corals in reef slopes. In
Belize
, it is common to find specimens with short tubes in remarkable similarity with
A. dispar
(see remarks above); however the absent or reduced short hollow body formed by coalescent tubes distinguish them.
Gammill (1997)
distinguished two morphotypes of this species (using
A. schmidti
as its name), that often coexist, one with the tops of tubes flattened and another with more rounded tube tops, with the characteristic keyholelike oscules. Although we observed flat-topped tubes, we were not aware of consistent differences with rounded ones; Gammill’s (1997) hypothesis of these being separate species should be tested. Based on the results of our work and photographs, we believe the specimens under the name
A. schmidti
used in
Erpenbeck
et al.
(2007)
really correspond to
A. wiedenmayeri
.
The initial confusion with
A. schmidti
probably arose from a small note at the end of Wilson’s description (1902): “Schmidt (loc. cit) divides his
Chalinopsis
species into two groups, the one including solid forms (
Pachychalinopsis
), the other tubular forms (
Siphochalinopsis
). Of the latter group he had but a single specimen, which he mentions was
9 cm
high, with a wall
3 mm
thick, and with spicules like those of
Chalinopsis
(
Agelas
)
. Schmidt thought it unnecessary to found [sic] a species name on such slight material. Schmidt’s specimen in the Museum of Comparative Zoology is essentially identical with mine, although the wall is thicker, color is dark brown, and the whorls of spines on the spicules are somewhat more distinct, the number in a whorl usually, exceeding four (6 to 8, about).” (Underlined is ours.)
Our hypothesis is that part of the Schmidt’s material to which Wilson referred is actually
A. wiedenmayeri
. But the real identity of those specimens at the Museum of Comparative Zoology still needs to be assessed.
Wintermann-Kilian & Kilian (1984)
material from Santa
Marta
(
Colombia
) needs to be checked, as these authors did not mention colour, and it could belong to
A. wiedenmayeri
or it could be
A. schmidti
. The compilation of Brazilian records for
A. schmidti
by
Muricy
et al
. (2011)
needs to be revised as at least
Muricy
et al
. (2008)
probably belongs to
A. wiedenmayeri
on account of its brown color.