The Chalinidae (Porifera) of Twin Cays, Belize, and adjacent waters

17 Pages·1991·7.3 MB·English

PROC. BIOL. SOC. WASH.
104(1), 1991, pp. 189-205
THE CHALINIDAE (PORIFERA) OF TWIN CAYS,
BELIZE, AND ADJACENT WATERS
Walentina H. de Weerdt, Klaus Riitzler, and Kathleen P. Smith
Abstract.—Eight species ofthe sponge family Chalinidae Gray (Haploscleri-
da, Demospongiae) are described from shallow-water habitats, primarily man-
groves, ofTwinCaysandGlover'sReef, Belize. Fourspeciesarenew:Haliclona
mucifibrosa, H. magnifica, H. twincayensis, and H. pseudomolitba. A key to
the species and illustrations are provided.
The Twin Cays mangrove islands
Materials and Methods
(16°49.4'N, 88°05.8'W) are situated about
3 km northwest ofCarrie Bow Cay (Belize) Most of the material has been collected
on the southern extent ofthe extensive Be- by K. Riitzler and K. Smith at Twin Cays
lizean barrierreefcomplex (Fig. 1) (Riitzler during 1984-1986, 1988 and 1989, and by
& Macintyre 1982). The islands harbor a W. H. de Weerdt in December 1988. This
rich sponge fauna, with a fair number of material is housed in the collection ofthe
species possibly new to science. From col- National Museum of Natural History
lecting and monitoring studies by two ofus (NMNH) and catalogued undernumbers of
(K. Riitzler«feK. Smith) during 1984-1989, the United States National Museum
it was determined that the sponge family (USNM). W. H. de Weerdt has had the op-
Chalinidae Gray (Haplosclerida: Demo- portunity to collect sponges from several
spongiae)isrepresentedbyeightspecies,four other Caribbean localities during cruises to
ofwhich are still undescribed. The goal of theLesserAntillesinMarch/AprilandJune/
the present paper is to describe these four July 1989 on the R/V SewardJohnson, and
new species andto elucidate the taxonomic during a field trip to the Florida Keys in
identity ofthe four species by comparison July 1989. This material is incorporated in
with type material. A key to the species is the sponge collections of NMNH and the
provided and based on characters ofliving Zoological MuseumAmsterdam (ZMA), the
and preserved specimens. One of the new Netherlands. A few specimens have also
species was never collected outside Belize. been collected by W. H. de Weerdt in Cu-
TheotherthreehavebeenfoundintheRor- rasao in December 1986 and are part ofthe
ida Keys; onealsoin Cura9ao, the Bahamas ZMAcollection. Typematerialhasbeenex-
andColombia; andonealsoinGuadeloupe. amined at the Peabody Museum ofNatural
It seems therefore reasonable to designate History, Yale University (YPM), New Ha-
paratypes from other localities than Twin ven, Connecticut, andatZMA. The present
Cays as well. The grouping of the species descriptions are based on external morpho-
follows the classification ofthe Chalinidae logicalcharactersandthearchitectureofthe
as proposed by de Weerdt (1989). The re- skeleton. Tostudyskeletonarchitectureand
newed use of the family name Chalinidae spicules, hand-cut tangential sections ofthe
instead ofHaliclonidae was justified by de ectosome and cross sections ofthe choano-
Weerdt (1986). some have been made. Spicule sizes are
3
190 PROCEEDINGSOFTHEBIOLOGICALSOCIETY OFWASHINGTON
o>
Fig. 1. MapofBelizedetailingstudysitesatTwin Cays.
based on measurements of 25 fully-devel- Haliclona mucifibrosa, new species
oped spicules in each specimen. Figs. 2a-c, 3b, 4a, b
— USNM
Typematerial. Holotype, 41517
Systematic Descriptions
(Belize, Twin Cays, Sponge Haven, 0.2 m,
Order Haplosclerida Topsent 26 Apr 1989, coll. K. Rutzler & K. Smith).
Family Chalinidae Gray Paratypes, USNM 41521 (=ZMA 7580)
Genus Haliclona Grant, 1835 (Belize, Twin Cays, SpongeHaven, NEcor-
Species ofthefistulosa Group Rneurt,zloenr &oysKt.erSmshietlhl)s;, U5 SJuNnM1948147,62col(lR.oKr.-
Architecturalplan (Fig. 2a, b).—Choano- ida, Florida Keys, ca. 1 km NW ofMenson
somal skeleton a rather dense, subisotropic Island, back reefflat, on sandy bottom, ca.
reticulation, usually intercepted by many 1 m, 13 Jul 1989, coll. W. H. de Weerdt &
choanosomal spaces. Ectosomal skeletonof S. Viada); ZMA FOR. 6403 (Curagao, en-
the same structure as the choanosome; ec- trance Fuikbaai, on sandy bottom, 3 m, 1
tosome usually very loosely overlaying the Jan 1987, coll. W. H. de Weerdt & P.
USNM
choanosome from which it is separated by Hoetjes). Additional material,
extensive subectosomal spaces. 41518 (Belize, TwinCays, BatfishPoint, on
VOLUME 104, NUMBER 1 191
a,b
400 ^m
c,d
100 *im
Fig. 2. Chalinidae ofthefistulosa Group: a, Choanosomal skeleton; b, Ectosomal skeleton; c, Spicules of
Haliclona mucifibrosa; d, SpiculesofH. magnifica.
mangrove roots and bank, 0-1 m, 28 Apr & S. Viada); Colombia, USNM 41832 (Co-
USNM
1986, coll. K. Smith «fe K. Riitzler); lombia, Bahia Portete, Guajira peninsula,
41519 (Belize, Twin Cays, Grouper Gar- 0.5 m, on lower parts ofMillepora on Tha-
dens, 0.5 m, 19 Apr 1986, coll. K. Riitzler lassia, 27 Jul 1987, coll. S. Zea).
& K. Smith); USNM 41520 (Belize, Twin Diagnosis.—S\yax>t'. Irregularly lumpy,
Cays, Sponge Haven, 21 Apr 1986, asso- massive base, typically about 10 cm in di-
ciatedwithXestospongia wiedenmayerivan ameter, from which arise short (2-3 cm),
Soest, coll. K. Rutzler & K. Smith); Baha- truncate, rather thick-walled oscular chim-
mas, USNM 33572 (Bahamas, Andros Is- neys. Oscules to 1 cm in diameter. Lateral
land, 30 m, 1982, coll. British Cave Diving expansions (fistules) 10-15 cm or more.
USNM
Expedition); Horida, 41761 (Ror- Color: Greyish purple to bluish gray in
ida, Biscayne Bay, Jul 1948, coll. M. W. de life (Fig. 3b).
Laubenfels; unpublished specimen, origi- Surface: Smooth, but occasionally with
nally identified by de Laubenfels as Hali- tuberculateareascausedbyshortfistule-like
USNM
clona); 41763 (Rorida, Florida projections.
Keys,underthebridgebetweenRamrodKey Consistency: Elastic compressible but
and Little Torch Key, pillars and muddy easily torn; pronounced mucus strands ap-
bottom, 1-3 m, 1 1 Jul 1989, coll. W. H. de pear when fragments are torn apart.
Weerdt&S.Viada);USNM41764(Florida, Choanosomalskeleton: Subisotropic, rig-
Florida Keys, unnamedmangroveislandca. idreticulation ofhigh spiculedensity, spon-
m
400 E of Big Torch Key, on mangrove gin inconspicuous (Figs. 2a, 4a).
roots, 12 Jul 1989, coll. W. H. de Weerdt Ectosomal skeleton: Tangential, sub-iso-
192 PROCEEDINGS OFTHE BIOLOGICALSOCIETY OFWASHINGTON
Fig. 3. PhotomicrographsofUveHaliclonaspecimensfrom Twin Cays mangroves: a, Halidona magnifica,
freshly dislocated from its peat substrate which is apparent at the upper left, xO.7; b, Haliclona mucifibrosa,
xO.9; c, Haliclona twincayensis, xO.8; d, Haliclona pseudomolitba, xO.8; e, Haliclona manglaris, xO.9; f,
Haliclonacuracaoensis, x0.9; g, Haliclona tubifera, xO.S;h, Haliclona implexiformis, xO.9
VOLUME 104, NUMBER 1 193
1"^'^1^'>^^7^v IT't^^
Y
^¥-s»^ >:
^1
'•^??3ip^<^.r'''.
1v'f»^ *t^
^0
i ^%^?*|^^
J<
<^
^^>v^''-
g
Fig. 4. Photomicrographs ofholotype tissue sections from all four new species ofHaliclona; choanosome
totheleft(a,c,e,g),ectosometotheright(b,d,f,h):a,b,H. mucifibrosa;c,d,H. magnifica;e,f,H. twincayensis;
g, h, H. pseudomolitba. (Scale on h applies to all photomicrographs.)
194 PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
Table 1.—Spicule sizes, length x width (Mm), offour specimens ofHalidona mucifibrosa (ranges, means,
standarddeviations, n= 25).
USNM 41517 214.6-237.1 (±9.2)-250.6 x 9.3-11.7 (±1.0)-13.7
41521 207.5-220.5 (±10.6)-237.5 x 7.0-10.7 (±2.2)-14.0
41762 188.6-208.2 (±8.0)-220.4 x 7.4- 9.1 (±0.5)-10.0
ZMA 6403 148.5-180.5 (±14.0)-204.2 x 4.9- 6.4 (±0.7)- 7.2
tropic spicule-rich reticulation, similar to pronounced mucus strands and its much
choanosomal network (Figs. 2b, 4b). more robust oxeas. A third Caribbean spe-
Fistule architecture: Same as ectosome cies belonging to thefistulosa group is H.
andchoanosome, no special reinforcement. albifragilisHechtel. This species stands out
Spongin: Distinct, at the nodes of the by its shape (thinly encrusting) and color
spicules. (white)andoccursincryptichabitats(under
Spicules: Oxeas, straightorslightly,even- coral rubble). Haliclona albifragilis has not
lycurved,robust,withlongandsharppoints; been found in Belize, but this may be due
occasionally the points are mucronate (Fig. to its cryptic and apparently also rare oc-
USNM
2c). Length x width (range of means for currence. Specimen 41832 (Colom-
four specimens measured. Table 1): 180.5- bia) stands out by the large size ofits oxeas
237.1 X 6.4-11.7 Aim. (mean length x width = 254.2 x 14.0 /im),
Ecology.—Habitats are mangrove roots, but this feature seems to be common in
peat banks, shallow sandy bays, and reef sponges from certain areas ofthe Atlantic
caves. The species is abundant on lower in- coast ofColombia (Zea 1987, and in litt).
tertidalpeatbanksofCudaCut, TwinCays,
where specimens can become fully air-ex-
Haliclona magnifica, new species
posed during low ebb tides.
Figs. 2a, b, d, 3a, 4c, d
Distribution. —Belize, Curagao, Baha-
mas, and Florida. Typematerial.—Holotype, USNM 41500
Etymology.—This specieswasnamed for (Belize, Twin Cays, Hidden Creek, 1 m, 9
heavy mucus strands that develop when May 1985, coll. K. Smith & K. Riitzler).
fragments are torn apart. Paratypes, USNM 41501 (Belize, Twin
Discussion.—Haliclona mucifibrosa is, to Cays, Batfish Point, 1 m, 19 Apr 1986, coll.
our knowledge, the only chalinid species of K. Rutzler & K. Smith); USNM 41502
the fistulosa group that develops mucus (Florida, FloridaKeys, unnamedmangrove
m
strands. So far, this feature has only been island 400 E of Big Torch Key, 13 Jul
observedinspeciesoftheaquaeductagroup 1989, coll. W. H. de Weerdt & S. Viada);
(de Weerdt 1989). Because of the mucus ZMA POR. 7579 (same site as USNM
strands, but also because ofthe color and 41502, 12 Jul 1989, coll. W. H. de Weerdt
growth form, H. mucifibrosa may be con- & S. Viada). Additional material, USNM
fused with H. tubifera (George & Wilson). 41514 (Belize, Twin Cays, Grouper Gar-
The latter species has smaller spicula (105- dens, peat bank, 0.2 m, 7 Dec 1988, coll.
155 X 4.0-7.5 fiva) andaverydelicate, uni- W. H. de Weerdt); USNM 41522 (Belize,
spicular, isotropic ectosomal and choano- Twin Cays, Hidden Creek, 29 Jun 1984,
somal skeleton. H. tubifera also has a more coll. K. Smith & K. Riitzler).
delicate shape and atendency to form long, Diagnosis.—Shape: Irregularly massive
thin proliferations. H. mucifibrosa differs base from which arise one to four thick-
fromH. magnifica, described below, by the walledtubes, to 15 cmhighand 5 cm thick.
VOLUME NUMBER
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Table2.—Spiculesizes,length x width(mhi),offourspecimensofHaliclonamagnifica(ranges,means,standard
deviations, n = 25).
USNM 41500 189.6-206.9 (±8.8)-220.6 x 3.8-5.5 (±0.5)-5.9
41501 181.2-198.5 (±9.6)-215.8 x 4.6-5.2 (±0.3>-5.8
41502 174.0-196.7 (±13.7)-220.4 x 5.1-6.0 (±0.5)-6.7
ZMA 7579 171.7-194.6 (±11.9)-218.1 x 4.9-5.6 (±0.6)-6.7
Each tube tapers towards an oscular chim- huggingdepressionsintheexposedpeatsur-
neyandosculumof1-2 cmdiameter. Char- face,withonlythewhitishoscularchimneys
acteristically, the choanosome, still present protruding. The species has a remarkable
in the basal parts ofthe tubes, disappears tolerance to sudden changes oftemperature
towards the osculum, so that the distal part and salinity that occur in the mangrove
ofthe tubes consists ofthe ectosomal skel- channels with changes oftidal flow.
eton only. In addition, several smaller fis- Distribution. —BqMzq, Florida, Puerto
tules, 2-5 cm thick and as much as 8 cm Rico.
high, may arise at irregular distances from Etymology.—The species is named Hali-
all parts ofthe sponges. clona magnifica because ofits magnificent
Color: Pink, to dull pink and drab, with color and shape.
white oscular fistules (Fig. 3a). Discussion.—Haliclona magnifica is a
Surface: Smooth. very characteristic species, not only for its
Consistency: Slightly crisp, very fragile, colorandgrowth form, butalso forits slen-
compressible,butnotelastic;mucuouswhen der, flexuous spicula, and confusion with
rubbed between fingers. otherlocal species is hardly possible. As far
Choanosomal skeleton: Regular, subiso- as Belizean chalinids are concerned, H.
tropic reticulation dominated by spicules magnifica is most closely related to H. mu-
(Figs. 2a, 4c). cifibrosa(seeabove). Itdiflersfromthisspe-
Ectosomal skeleton: Indistinguishable cies by its color and shape, the lack ofpro-
from choanosomal skeleton but easily de- nounced mucus strands, the much thinner
tached (Figs. 2b, 4d); in addition, the ec- oxeas and scarcer spongin. Haliclona mag-
tosomal skeleton is reinforced by longitu- nifica stands out among otherspecies ofthe
dinal spicula tracts towards the distal fistulosa group by its slender flexuous spic-
portions ofthe tubes where the choanoso- ula, which is a common feature in the ar-
mal skeleton is absent. enataandroseagroups(cf,deWeerdt 1989).
Fistule architecture: Subisotropic, rein- As far as North Atlantic species are con-
forced by loosely organized longitudinal cerned, the oxeas ofthefistulosa group are
spicule tracts that consist of 4-6 spicules consistently robust, straight"needles." Yet,
with overlapping points. by its subisotropic skeleton and extensive
Spongin: Scarce, confinedto the nodes of subectosomal spaces, H. magnifica clearly
the spicules. belongs to thefistulosa group.
Spicules: Oxeas, slender, fusiform, slight-
lyflexuous(Fig. 2d). Length x width (range
Species ofthe arenata Group
ofmeans for 6 specimens, including those
ofTable 2): 194.6-206.9 x 5.2-6.0 ^m. Architecturalplan (Fig. 5a, b).—Choano-
Ecology.—Typic2i\ habitats are peat un- somal skeleton a rather irregular reticula-
dercuts and banks in mangrove channels. tion with ill-defined paucispicular primary
The basal mass of specimens is typically lineswhichareirregularlyconnectedbyuni-
196 PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
a,b
400 ^m
c-f
100 ^m
Fig. 5. Chalinidae ofthe arenata Group: a, Choanosomal skeleton; b, Ectosomal skeleton; c, Spicules of
Haliclona twincayensis; d, Spicules ofH. pseudomolitba; e, Spicules ofH. manglaris; f, Spicules ofH. cura-
caoensis.
spicular secondary lines. There is a vague 1 May 1989, coll. K. Smith & K. Riitzler).
tendency towards rounded meshes. Ecto- Paratypes, USNM 41289 (Belize, Twin
somal skeleton, ifpresent, a discontinuous Cays,GrouperGardens,0.5 m, 10Jun 1983,
USNM
butcoherenttangentialreticulationofsingle coll. K. Rutzler); 41516 (Belize,
spicules. The tendency to form rounded Twin Cays, Hidden Creek, 1.5 m, 1 May
meshesismorepronouncedintheectosom- 1989, coll. K. Smith & K. Rutzler); USNM
al skeleton than in the choanosomal skele- 41770 (Florida, Florida Keys, under the
ton. Usually, the ectosomal membrane is bridge between Ramrod Key and Little
clearlyobservablewithclosely-packedpores Torch Key, on piles, 1-3 m, 11 Jul 1989,
in the open spaces between the spicules. col. W. H. de Weerdt & S. Viada); ZMA
Spongin is always present at the nodes of FOR. 7582 (same data as USNM 41515);
the spicules, but never abundant. Oxeas fu- USNM41771 (Guadeloupe, GrandCul-de-
siform, slender, usually curved or flexuous. Sac Marin, ca. 0.5 mi N ofPetit Canal, E
Microscleres sometimes present. side Bay, 16°23.5'N, 6r30.60'W, piling off
dock and old house, 0.2 m, 23 Jun 1989,
Haliclona twincayensis, new species coll. W. H. de Weerdt).
Figs. 3c, 4e, f, 5a-c Diagnosis.—Shape: Slender, solid, partly
Typematerial.—Holotype, USNM 41515 fused, erect whips or branches, 2-12 mm
(Belize, Twin Cays, Hidden Creek, 1.5 m. thick, 5-10 cm long, projecting without an
VOLUME NUMBER
104, 1 197
Table 3.—Spicule sizes, length x width iiJ.m), ofsix specimens ofHaliclona twincayensis (ranges, means,
standarddeviations, n= 25).
USNM 41515 146.2-155.4 (±6.2)-165.9 x 4.2-4.6 (±0.3)-5.3
41516 137.5-152.8 (±10.2)-167.5 x 3.7-4.9 (±l.l)-6.2
41289 142.5-151.7 (±9.4)-162.5 x 3.5-4.4 (±0.5)-5.5
41770 141.5-162.2 (±9.3)-176.3 x 5.1-6.1 (±0.6)-7.0
41771 111.4-120.3 (±4.4)-l27.6 X 4.4-4.8 (±0.3)-5.8
ZMA 7582 150.0-158.6 (±5.2)-167.5 x 3.7-4.5 (±0.5)-5.2
apparent base directly perpendicular from Discussion. —Haliclona twincayensis is
thesubstratum(mangroveroots, peatbanks, relatedtotheCaribbean speciesH. caerulea
piles). Osculainconspicuous,rare, ca. 1 mm, (Hechtel), H. manglaris Alcolado and H.
irregularly distributed along all sides ofthe curacaoensis(vanSoest).Thelattertwospe-
branches. cies occur also in Belize. H. caerulea is dis-
Color: Whitish gray to light tan in life, tinct by its bluish gray color and the pos-
light tan in spirit (Fig. 3c). sessionofsigmata.H. manglaris(seebelow)
Surface: Strongly punctate, with pro- is thinly encrusting, bright turquoise green,
nounced longitudinal subectosomal spaces, and has much smaller oxeas (75-108 x 2-
which are roofed by tangential ectosomal 4jum)thanH. twincayensis. H. curacaoensis
spicules. isdistinctbyitsshape(close-packedoscular
Consistency: Rather firm, only slightly mounds), sticky consistency, and smaller
compressible, but fragile. oxeas (93.5-135 x 2.3-5.7 ^m).
Choanosomal skeleton: Paucispicular
primary lines connectedby unispicular sec-
Haliclona pseudomolitba, new species
ondary lines, ill-defined and irregular (Figs
4e, 5a); many spicules, including numerous Figs. 3d, 4g, h, 5a, b, d
developmental forms, are placed in confu- Typematerial.—Holotype, USNM 41743
sion. (Belize, Twin Cays, Hidden Creek, 0.5 m,
Ectosomal skeleton: Unispicular, tangen- 1 May 1989, coll. K. Smith & K. Riitzler).
tial reticulation, irregular and discontinu- Paratypes, USNM 41503 (Belize, Twin
ous (Figs. 4f, 5b); with many open spaces Cays,HiddenCreek, 1 m, 10Dec 1988,coll.
between the spicules. W. H. de Weerdt); USNM 41797 (Marti-
Spongin: Scarce, confinedto the nodes of nique, Diamond Rock, 18 m, 3 Jul 1989);
the spicules. ZMA FOR. 7595 (same data as USNM
USNM
Spicules: Oxeas, slender, fusiform, slight- 41503). Other material, 41742 (Be-
ly flexuous (Fig. 5c). Length x width (range lize, HiddenCreek,0.5 m, 1 May 1989,coll.
ofmeansforsixspecimensmeasured,Table K. Smith & K. Riitzler).
3): 120.3-162.2 x 4.4-6.1 ixm. Diagnosis.—Shape: Erect, finger-shaped,
Ecology.—Habitats are stilt roots of red partly fused branches, to 15 cm high. Os-
mangrove, peat undercuts and bank, arti- culesnumerous, circular, flushwith surface,
mm
ficial wood piling fromjust below tide level 2-3 regularly distributed along the
m
to 3 depth. Fairly extreme and sudden branches.
temperature and salinity changes are tol- Color: Rich pink with yellowish cream
erated in mangrove channels during chang- tinges (Fig. 3d).
ing tides. Surface: Even, rather smooth.
Distribution. —Belize, Florida, Guade- Consistency: Extremely soft, limp, highly
loupe. compressible.
Etymology.—The species is named after Choanosomal skeleton: Paucispicular
its type locality, Twin Cays. primaries, unispicularsecondaries(Figs. 4g,
198 PROCEEDINGSOFTHEBIOLOGICALSOCIETYOFWASHINGTON
Table 4.—Spicule sizes, length x width (fim), offourspecimens ofHaliclonapseudomolitba(ranges, means,
standarddeviations, n= 25).
USNM 41503 107.0-115.3 (±5.1)-126.1 x 3.6^.5 (±0.5)-5.6
41742 110.0-115.7 (±5.6)-125.0 x 3.8^.3 (±0.3)-5.0
41743 110.0-125.1 (±5.5)-133.0 x 2.5^.0 (±1.0)-5.0
41797 111.4-124.5 (±8.6)-142.0 x 4.4-5.5 (±0.8)-7.0
5a),withmanyspiculesplacedinconfusion, Belize and Martinique prompted us to de-
commonly reinforced by loosely organized scribe the latter material as a new species.
spicule tracts of3 or more spicules. The skeleton ofH. pseudomolitba is closest
Ectosomal skeleton: Irregular, unispicu- to H. twincayensis, H. manglaris, and H.
lar tangential reticulation (Figs. 4h, 5b); no curacaoensisbecauseithasaratherirregular
particular specialization. reticulation with many spicules in confu-
Spongin: Scarce, confined to nodes of sion.
spicules.
Spicules: Oxeas, fusiform, straight or Haliclona manglaris Alcolado
evenly curved, occasionally the points are Fig. 3e, 5a, b, e
mucronate (Fig. 5d). Length x width(range
ofmeans forfour specimens measured. Ta- Haliclona manglarisAlcolado, 1984:4, figs.
IB, 2A.
ble 4): 115.3-125.1 X 4.0-5.5 Atm.
£'co/og>'.—Habitats are stilt roots ofred Material.-IJSNM 32960 (Belize, Twin
mangrove, peat undercuts and bank. Fairly Cays, Sponge Haven, associated with the
extreme and sudden temperature and salin- tunicateDistapliabermudensis, 25Feb 1984,
USNM
itychangesaretolerated in mangrove chan- coll. I Goodbody); 33581 (Belize,
nels during changing tides. Twin Cays, Lair Channel, associated with
Distribution.—Belize, Martinique. Distaplia sp., 26 Feb 1985, coll. L Good-
Etymology.—Thespeciesisnamedforits body); USNM 41737 (Belize, Twin Cays,
similarity ofhabit with Acervochalina mo- Grouper Gardens, 19 Apr 1986, coll. K.
litba. Rutzler&K. Smith); USNM41752 (Belize,
Discussion. —Haliclona pseudomolitba Twin Cays, The Lair, mangrove roots, 1 m,
appears at first to be very similar to Acer- 8 Dec 1988, coll. W. H. deWeerdt); USNM
vochalina molitba (de Laubenfels, 1949). 41757 (Belize, Twin Cays, Grouper Gar-
Botharepink, finger-like, softandlimp, but dens,onmangroveroots,0.3 m, 6Dec 1988,
the skeletons are distinctly different, H. coll. W. H. de Weerdt); USNM 41758 (Be-
pseudomolitba lacking any semblance of a lize, Twin Cays, Hidden Creek, on man-
spongin fiberskeleton. Weacknowledgethe grove roots, 0.5 m, 10 Dec 1988, coll. W.
markedvariationinspiculesizeandamount H. deWeerdt); USNM 41759 (Belize, Twin
ofspongininAcervochalinaspecies(cf., van Cays, GrouperGardens, onmangroveroots,
Soest 1980; de Weerdt 1986, 1989), but the 0.5 m, 12Dec 1988, coll. W. H.deWeerdt).
lack ofany intermediate form between the Diagnosis.—Shape: Laterally spreading,
spongin-dominated forms of^4. molitba as thinly encrusting base (1-5 cm diameter)
found in Bermuda (and described from with low volcano- or chimney-shaped os-
Bimini, Bahamas by de Laubenfels 1949, cularelevations, usuallynothigherthan 1.5
mm mm
and from Bermudaby de Laubenfels 1950) cm,and2-5 thick. Oscular0.5-2.5
andourspicule-dominatedspecimensfrom indiameter. Commonly,thin(2-3 mm)sto-