Sponge epizoism in the Caribbean and the discovery of new Plakortis and Haliclona species, and polymorphism of Xestospongia deweerdtae (Porifera)
Author
Vicente, Jan
Author
Zea, Sven
Author
Hill, Russell T.
text
Zootaxa
2016
4178
2
209
233
journal article
10.11646/zootaxa.4178.2.3
ef8d5717-31b6-4e69-a0ec-6e313588ecda
1175-5326
255301
7A957617-C37C-41C8-9A8C-D7BB9178638C
Xestospongia deweerdtae
Lehnert & Van
Soest 1999
(
Figs. 6
,
7
;
Table 3
)
Xestospongia deweerdtae
Lehnert & Van
Soest, 1999
: 163
, Figs. 44–47; Van Soest & De
Weerdt 2001
: 114
,
Fig. 4
C–D, 5C–D;
Rützler
et al
. 2014
: 91
; Zea
et al
. 2014 (“-associated” and “-free living” forms);
Vicente
et al
. 2014
,
Figs. 3
a–f, 5, 6, 7a–d (ecology and symbiosis with
Plakortis
spp.).
Xestospongia
sp.2;
Zea 2001
:
Table 1
(appendix).
Xestospongia
sp.-thin pink sheet over
Plakortis
;
Zea
et al
. 2009
.
Diagnosis.
Thinly to thickly encrusting, pink, red and white mottled sponge. Surface smooth. Consistency hard but easily broken and only slightly compressible. Ectosome is a dense tangential reticulation of strongyles bound by spongin. Choanosome is an isotropic reticulation of single spicules with some paucispicular tracts (Lehnert & Van
Soest 1999
).
Material
examined.
Holotype
: ZMAPOR13584,
Discovery Bay
,
Jamaica
,
82 m
depth, coll.
Helmut Lehnert
,
June
26, 1996
;
USNM
1254644
,
Punta Caracol
,
Bocas del Toro
,
Panama
(
9.3777° N
,
82.1265° W
)
8 m
, coll.
Jan Vicente
and
Micah J.
Marty,
June 13, 2015
;
USNM
1254645
,
Dolphin Rock
,
Bocas del Toro
,
Panama
(
9.35076° N
, -
82.1863° W
),
14 m
coll.
Jan Vicente
and
Arcadio Castillo
May
20, 2015
;
USNM
1254648
,
Yellow Reef
,
Desecheo Island
,
Puerto Rico
(
18.3918° N
-
67.4760° W
)
23 m
coll.
Jan Vicente
October
7, 2011
;
USNM
1254649
,
Old Bouy
,
La Parguera
,
Puerto Rico
(
17.8883° N
, -
66.9981° W
)
31 m
, coll.
Jan Vicente
and
Milton Carlo
August
8, 2012
;
USNM
1254647
,
San Salvador
,
Bahamas
, (
24.0406° N
, -
74.5314° W
)
33 m
coll.
Jan Vicente
and
Steven E.
McMurray
July 19
, 201
;
USNM
1254646
,
Plana Cays
,
Bahamas
(
22.6045° N
, -
73.5465° W
),
32 m
coll.
Jan Vicente
and
Steven E.
McMurray,
July 21, 2011
.
Description
(
Figs. 6
A–B,
Fig 7
A–B). External morphology is influenced by lifestyle (associated with
P. deweerdtaephila
sp. nov.
or
P. symbiotica
sp. nov.
or free-living) and by environmental factors. Free-living forms of
X. deweerdtae
in
the Bahamas
(
Fig. 6
A) and
Panama
(
Fig. 7
A) fit the original description of Lehnert & Van
Soest (1999)
and Van Soest & De
Weerdt (2001)
. They form volcano shaped elevations that can measure up to
5 cm
in length and with oscules on top, up to
0.7 cm
in diameter. Individuals are light to dark pink, purple (
Panama
), orange (
Bahamas
) and turn white when preserved in ethanol; color in the choanosome is the same. Surface smooth; consistency hard, slightly compressible. Although not mentioned in the original description, we noticed that freeliving sponges always exude a viscous slime when cut.
The external morphology of associated lifestyles does not fit the original description of
X. deweerdtae
. In
the Bahamas
, associated individuals can be a thin encrusting veneer of patchy tissue that overlays and burrows into the
Plakortis
spp. body (
Fig. 6
B) (
Fig. 6
A–C in
Vicente
et al.
2014
) with no visible oscula. In
Panama
, associated individuals are thickly encrusting (
1 cm
) and completely overgrow the
P. deweerdtaephila
sp. nov.
body, forming
6–15 cm
diameter plates (
Fig. 7
B; small oscules (
1–3 mm
) are aligned probably due to the high wave energy environment of Dolphin Rock). Associated individuals are softer, slightly compressible and more brittle than freeliving individuals. Color is a light pink and even though we did not find free-living individuals with zoanthids, associated individuals in
Puerto Rico
were densely covered with red zoanthids (
Fig. 3
A).
Skeleton.
Despite the differences in external morphology from the different lifestyles, the ectosome of both associated and free-living morphologies regardless of location consist of a unispicular regular skeleton of strongyles with 6–7 spicules meeting at each node (
Fig. 6
C–D;
Fig. 7
C–D). Meshes of the ectosome are somewhat triangular. The choanosome for all lifestyles and regardless of location consist of an isotropic reticulation of strongyles with occasional paucispicular tracts, which conform to
X. deweerdtae
(Lehnert & Van
Soest 1999
)
(
Fig. 6
E–H;
Fig. 7
E–H).
Spicules:
Thick and sometimes thin strongyles, 151–423 µm long by 6.5–28.2 µm in width. Size and morphology of strongyles depends on the associated status of
X. deweerdtae
and geographical location. Across all geographical areas sampled (
Bahamas
,
Puerto Rico
,
Panama
), associated individuals have smaller and thinner spicules than free-living ones (see also discussion in
Vicente
et al
. 2014
); and between geographical areas, across lifestyles, individuals from island locations such as
Bahamas
,
Puerto Rico
and
Jamaica
have smaller and thinner spicules than those from
Panama
(
Table 3
).
TABLE 3.
Spicule measurements of strongyles (length and width) of
Xestospongia deweerdtae
associated and free living. Measurements are expressed as minimum–
mean
(±1 standard deviation)–maximum. N=30.
Specimen |
Location |
Life style |
Length (µm) |
Width (µm) |
ZMAPOR13584
*
|
DB, Jamaica |
Free-living |
288–
340.9
(± 16.9)–373
|
6.5–
12.1
(± 2.2)–17.5
|
USNM1254646 |
SS, Bahamas |
Free-living |
305–
336.6
(± 14.8)–362
|
6.7–
11.8
(± 2.3)–17.2
|
USNM1254647 |
SS, Bahamas |
Associated |
151–
203.0
(± 18.8)–243
|
6.3–
7.9
(± 1.1)–11.2
|
USNM1254644 |
BDT, Panama |
Free-living |
340–
376.8
(± 19.7)–424
|
15.5–
21.8
(± 3.6)–28.2
|
USNM1254645 |
BDT, Panama |
Associated |
229–
323.8
(± 22.0)–379
|
12.8–
18.6
(± 2.8)–23.9
|
USNM1254648 |
LP, Puerto Rico |
Free-living |
296–
324.3
(± 15.2)–355
|
9.3–
13.0
(± 2.1)–17.7
|
USNM1254649 |
LP, Puerto Rico |
Associated |
159–
223.8
(± 23.5)–274
|
7.3–
10.2
(± 1.7)–13.8
|
*Specimen ZMAPOR13584 is the
holotype
(Lehnert & Van
Soest 1999
)
Habitat and ecology.
X. deweerdtae
was originally described from deep (
82 m
) fore reef habitats and reef caves of Jamaica (Lehnert & Van
Soest 1999
) and then later found in reef caves (
10–12 m
) of Curaçao (Van Soest & De
Weerdt 2001
). In our study, we found
X. deweerdtae
growing beneath scleractinean corals and on the shaded side of
Agaricia
reefs in Panama at depths as shallow as
2 m
.
X. deweerdtae
and
Plakortis
spp. nov.
sponge pairs can be found on the shaded side of spur and groove reef formations (
14 m
) exposed to high wave energy environments in Panama. In the Bahamas and Puerto Rico sponge pairs are found deeper, below
30 m
in cryptic habitats growing on vertical walls, on the roof of overhangs and on the bottom of reef caves. Associated individuals of
X. deweerdtae
are more frequently observed than free-living ones when both lifestyles are present in a given area (
Vicente
et al.
, 2014
).
Distribution.
(FL=free-living,
AS
=associated)
Jamaica
(Discovery Bay-FL) (Lehnert & van
Soest, 1999
) Curaçao-FL (van Soest & de
Weerdt 2001
),
Mexico
(Cozumel-FL, Banco Chinchorro-FL) (
Vicente
et al.
, 2014
),
Bahamas
(Plana Cays-FL-AS, Mayaguana-FL, San Salvador-AS, Little San Salvador-AS, Little Inagua-FL-AS, Acklins-FL, Great Inagua-AS, Mira Por Voz-AS) (Also
Vicente
et al
. 2014
and Zea
et al
. 2014),
Puerto Rico
(Mona-AS, Desecheo-FL-AS, La Parguera-AS) (also
Vicente
et al.
2014
),
Panama
,
Bocas del Toro
(Fiugre 7A-FL, Punta Caracol,
Figure 7
B-AS, Dolphin Rock),
Colombia
(Serrana Bank-AS) (
Zea 2001
).
Taxonomic remarks.
The polymorphic nature of
X. deweerdtae
is revealed by lifestyle (associated and freeliving) and by environmental factors (high wave energy and high silica environments, the latter associated with geographical location). Associated individuals do not exhibit a massive morphology and long volcano shaped oscules mentioned in the original description are absent. Instead, associated sponges are thinly to thickly encrusting. In
Panama
oscules for associated cases are small but visible (
1–3 mm
) and colonies are more thickly (
0.5–1 cm
) encrusting than associated individuals from
Puerto Rico
and
the Bahamas
(
1 mm
). Oscules for associated individuals from
Puerto Rico
and
the Bahamas
were not visible. Significantly smaller strongyles are observed in associated (250 × 12.2 µm) sponges than free-living sponges (346 × 15.5 µm) in three different geographic areas resembling high and low silica concentrations. This was interpreted as a possible benefit for
X. deweerdtae
in terms of a lower investment in skeleton synthesis for support (see discussion in
Vicente
et al.
2014
). Another possible explanation is that nutrients may be limiting for both sponges and one species might be depriving the other of silica. On the other hand, in the high silica environments in
Panama
(see D’Croz
et al.
2005) longer and thicker spicules were present in both free-living and associated sponges when compared with both associated and free-living individuals of
Puerto Rico
and
the Bahamas
(
Table 3
). Free-living individuals from
Panama
also produced not only thicker and longer strongyles, but also had sharply bent terminals that bend either opposite (sshaped) or in the same direction (bracket-shaped) (
Fig.
7
I) probably due to hypersilicification (
Zea, 1987
; Zea
et al.
, 2014). One other important character from free-living sponges, missing in the original description, is the release of viscous mucus by sponges when cut. Associated sponges however, produce very little mucous when cut. The conspecificity of associated and free-living individuals was confirmed with phylogenetic analysis from partial sequences of the 18S, 28S rRNA and
cox1
genes (see below and
Vicente
et al
. 2014
).
FIGURE 6.
Xestospongia deweerdtae
from the Bahamas, comparing free living (A, C, E, G, I) and associated (B, D, F, J) life styles. (A, B) in situ underwater images (A, USNM1254646; B, USNM1254647 (pink) with
Plakortis symbiotica
sp. nov.
(brown); (C, D) tangential section of the ectosome (LM); (E, F) perpendicular section through the ectosome and choanosome (LM); (G, H) close-up of a perpendicular section through the choanosome (LM); (I, J) strongyles (SEM).
FIGURE 7.
Xestospongia deweerdtae
from Bocas del Toro Province in Panama, comparing free living (A, C, E, G, I) and associated (B, D, F, J) lifestyles. (A, B) In situ underwater images (A, USNM1254644; B, USNM1254645 completely overgrowing
Plakortis deweerdtaephila
; (C, D) tangential section of the ectosome (LM); (E, F) perpendicular section through the ectosome and choanosome (LM); (G, H) close-up of a section through the choanosome (LM); (I, J) Strongyles (SEM).
Phylogenetic analysis.
To confirm the identity of
Haliclona plakophila
sp. nov.
as a new species and reconfirm the conspecificity of associated and free-living morphotypes of
Xestospongia deweerdtae
we partially sequenced the 18S, 28S rRNA and
cox1
genes of
holotype
and
paratype
specimens. We conducted a maximum likelihood analysis from sequences of species belonging to
Haplosclerida
that were closely related to
Haliclona
spp. and
Xestospongia
spp. deposited in GenBank. The maximum likelihood analysis of the 18S rRNA gene sequence placed
H. plakophila
distant from any of the monophyletic clades (A–E) previously reported by
Redmond
et al.
(2013)
(
Fig. 8
A). Members of clade C (
Redmond
et al.
, 2013
) were not included in the phylogenetic analysis, because sequences from
H. plakophila
were highly dissimilar to species in this clade. Sequences from associated and free-living individuals of
X. deweerdtae
were all>99% homologous to each other and to the
holotype
of
X. deweerdtae
(ZMAPOR13584), confirming that all specimens of both life styles are conspecific. Conspecificity of all
X. deweerdtae
lifestyles, including the
holotype
specimen, had a>99% sequence homology for the 28S rRNA and
cox1
genes (
Fig. 8
B–C).
We were unable to retrieve enough sequence data from the
holotype
specimen of
X. deweerdtae
to produce a phylogenetic tree of the
cox1
with strong bootstrap values, encompassing all closely related
Haplosclerida
species. However, we had enough sequence data from our material and proceeded to do a maximum likelihood analysis of the
cox1
including members of the
Haplosclerida
that form monophyletic clades A and B from
Redmond
et al.
(2011)
(
Fig. 9
). The clade of all
X. deweerdtae
conspecifics did not fall into either monophyletic clade. Like
X. deweerdtae
,
H. plakophila
sp. nov.
also did not fall into either clade A or B (
Fig. 9
).