Table Of ContentRevue suisse de Zoologie (September 2015) 122(2): 213-246 ISSN 0035-418
Notes on some hydroids (Cnidaria) from Martinique,
with descriptions of five new species
Horia R. Galea1-4 & Romain Ferry2,3
' Hydrozoan Research Laboratory, 405 Chemin des Gatiers, F-83170 Tourves, France
2 Département Scientifique Interfaciiltaire, EA929-AIHP-GEODE (BIOSPHERES), Université des Antilles et de la
Guyane, Campus de Schoelcher, B.P. 7209, F-97275 Schoelcher cedex, Martinique, France
3 Association Océanvironnement, Résidence Madiana Plage, App. B21, F-97233 Schoelcher, Martinique, France
4 E-mail: [email protected]
Abstract: The present report supplements a series of earlier accounts on the hydrozoan fauna of the French Lesser
Antilles, and discusses 16 species of hydroids from Martinique. Of these, five are new to science: Hydractinia promiscua,
Halecium plicatum, Dynamena bimorpha. An tenne I la quaterna and Monostaechas bertoti. The medusoid gonophores
of Ralpharia gorgoniae Petersen, 1990 are described in detail. The female gonothecae of Halecium labiatum Billard,
1933, recorded for the second time, are redescribed. Characters of the trophosome and the cnidome composition allowed
a reliable identification of Halecium lightbourni Calder, 1991, a species whose previously unknown gonothecae are here
described for the first time. A reexamination of the type of Dynamena tropica Stechow, 1926 proved that it is conspecific
with D. crisioides Lamouroux, 1824. Sertularia notabilis Fraser, 1947 is included in the synonymy of S. hattorii Leloup,
1940, and arguments for doing so are provided. The so called variety pusilla Ritchie, 1910, associated for a long time with
Hincksella cylindrica (Bale, 1888), is raised to species, as H. pusilla (Ritchie, 1910), and their distinguishing characters
are emphasized. Clytia edentula Gibbons & Ryland, 1991 is found for the second time, extending its known range of
distribution.
Keywords: Hydrozoa - Lesser Antilles - French West Indies - Caribbean.
INTRODUCTION MATERIAL AND METHODS
The hydrozoan fauna of the French Lesser Antilles, never Sampling was done either by scuba diving or snorkeling.
investigated in the past, has received increasing attention Hydroid colonies were carefully removed from their
during the last few years, with a number of taxonomical substrate using haemostatic forceps, so as to preserve
studies that provided the first comprehensive accounts the integrity of the adjacent fauna. Although some
on the species composition of two overseas departments, observations were done on living specimens shortly after
Guadeloupe and Martinique (Galea, 2008; 2010a; 2013; collection, most of them were carried out on formalin-
Galea et al., 2012; Galea & Ferry, 2013). preserved material, using the methods described in
Additional samples from Martinique were gathered Galea (2007, 2008, 2010a). Samples were deposited
during a recent survey undertaken in January and in collections of the Muséum d’Histoire Naturelle of
February 2014. New stations have been explored, and Geneva, Switzerland, and registration codes are indicated
some of those inspected in 2012 (see Galea, 2013) were by MFING-INVE- followed by numbers. Occasionally,
visited again. references are made to samples either hosted in the
The present study deals with those species that have private collection of the senior author of this study (these
not been the subject of earlier accounts, as well as with are indicated by HRG- followed by a four-digit number)
those for which new data became available, such as the or belonging to the British Antarctic Survey (BAS).
finding of fertile specimens, allowing reliable taxonomic
determination to be made for materials identified
previously to genus only.
Manuscript accepted 22.02.2015
DOI: 10.528 l/zenodo.29998
214 H. R. Galea & R. Ferry
TAXONOMY AND RESULTS elongate and slender, as well as ovoid haplonemes (Fig.
3E4'6).
Order Anthoathecata Cornelius, 1992
Family Hydractiniidae L. Agassiz, 1862 Dimensions: Gastrozooids up to 3 mm high;
Genus Hydractinia Van Beneden, 1844 gonozooids up to 1 mm high (preserved material,
though not differing much from live material). Unspent
Hydractinia promiscua Galea & Ferry, sp. nov. gonophore ca. 890 pm long and 745 pm wide; spent
Figs IA, B; 3A-E; Table 1 gonophore ca. 915 pm long and 760 pm wide. Des¬
monemes (6.3-6.8)x(3.4-3.7) pm; small microbasic
Holotype material: MHNG-INVE-91108; sample
euryteles (7.4-7.7)x(2.6-2.8) pm; large microbasic eury¬
#M280; France, Martinique, Le Prêcheur, Babody,
teles (9.7-10.6)x(3.1-3.4) pm; egg-shaped haplonemes
14.78632° -61.21765°, 20 m; 25.01.2014; male colony
ca. 5.1x3.1 pm; elongate and slender haplonemes
encrusting the outside of a worm tube and adjacent
(9.4-10.3)x(2.3-2.6) pm; ovoid haplonemes (10.0-
sponge.
10.3)x(4.0-4.3) pm.
Paratype material: MHNG-INVE-91124; sample
Distribution: Known only from Martinique (present
#M335; France, Martinique, Le Prêcheur, Babody,
study).
14.78632° -61.21765°, 15-20 m; 25.06.2014; male
colony on ascidian. Type locality: France, Martinique, Le Prêcheur,
Babody.
Diagnosis: Hydractiniid growing on various substrates,
with gastro-, gono-, and tentaculozooids. Gonophore a Remarks: Notoriously difficult to identify, the
non-liberated medusoid with four radial canals and eight hydractiniid hydroids - especially those producing
tentacle stumps. Nematocysts comprising desmonemes, medusoids - offer few exploitable distinguishing
two size classes of microbasic euryteles, and three size morphological features. In addition, several structures,
classes of haplonemes. such as the spines and/or the dactylozooids, occur in
certain conditions and, as a consequence, they do not
Etymology: From the Latin promiscua, meaning
offer enough features to the species that produce them
indiscriminately, for its unselective substrate affinity.
in order to establish reliable comparisons with other
Description: Colony stolonal, with creeping, scarcely congeners.
branching and anastomosing hydrorhiza. Pensare To compare the present hydroid with its relatives, only the
thin, smooth to irregularly wrinkled, ending at base non-calcareous species producing medusoid gonophores
of polyps; spines absent; no naked coenosarc. Polyps with radial canals were considered (see Table 1).
of three types: gastro-, gono-, and tentaculozooids. Since the genera Schuchertinia and Bouillonactinia
Gastrozooids creamy-white in color, davate, con¬ (both introduced by Miglietta et al., 2010) are not well
tractile; 12-20 filiform tentacles, amphicoronate in characterized, all nominal species discussed herein are
life; hypostome dome shaped, with a wide belt of referred to the widely speciose genus Hydractinia Van
nematocysts between mouth and insertion of tentacles Beneden, 1844.
(Fig. 3A). Gonozooids smaller than their feeding A considerable impediment concerns the species for
counterparts, with 8-11 filiform tentacles, and a belt of which only limited descriptions are available and/or
nematocysts around hypostome (Fig. 3B). Gonophores no data on the cnidome composition exist (e.g. Clarke,
1-2 per gonozooid, given off laterally from proximal 1882; Sigerfoos, 1899; Broch, 1914; Wedler & Larson,
halves of polyps; only males present. Ripe gonophores 1986; Hirohito, 1988).
nearly spherical, width slightly exceeding height For example, the relationships between H. arge (Clarke,
(Fig. 3B2); four radial canals and a barely visible 1882) and H. hooperii (Sigerfoos, 1899) are unsettled yet.
circular canal (Fig. 3B1); manubrium surrounded by According to Calder (1988), their types are reportedly
apparently four compact, interradial masses of sperm lost, thus preventing a comparison of their cnidomes.
cells; no signs of rudimentary tentacle knobs at this Calder (1971) provided arguments in favor of their
stage (Fig. 3B1). More advanced medusoids (Fig. 3C), specific separation, whereas he united them in a later
whose gametes had been expelled, are still attached study (Calder, 1988). The Bermudian specimens assigned
to their corresponding gonozooids; their shape had to H. arge in his latter account may not belong to Clarke’s
changed from spherical to oval, their length being taxon, owing to: 1) their smaller size; 2) their exclusive
greater than the diameter; 8 rudimentary tentacles (four occurrence on gastropod shells instead of being mainly
perradial and four interradial), as well as a velum, are epiphytic [an occurrence of H. arge on the gastropod
present. Tentaculozooids filiform (Fig. 3D), sparsely and Bittium sp. was noted by Calder (1971)]; 3) the lack of
irregularly scattered amongst the other zooids; of varied gastrozooid autotomization, as described by both Clarke
length, sometimes exceeding the size of gastrozooids. (1882) and Calder (1971) [note that Bavestrello et al.
Cnidome: 1) desmonemes (Fig. 3E1); 2, 3) small and (2000) showed that water movement induced transverse
large microbasic euryteles (Fig. 3E2,3); 4-6) egg-shaped. fission in the zooids of H. pruvoti (Motz-Kossowska,
Notes on some hydroids (Cnidaria) from Martinique 215
Fig. 1. A, B: Hydractinia promiscua sp. nov. (A) Portion of colony growing on worm tube. (B) Detail of a gonozooid carrying a male
medusoid. (C-G): Ectopleura sp. (C) Whole colony. (D) Hydranth. (E) Detail of the neck region showing belt of nematocysts.
(F, G) Cross sections through two stems, showing endodermal ridges. Scale bars: 100 pm (F, G), 200 pm (E).
1905), suggesting that the autotomization observed in 1975) on Hydractinia altispina and H. multitentaculata,
H. arge may not be an intrinsic feature of this species, respectively. We agree with Schuchert (P. Schuchert,
depending instead on environmental factors]. pers. comm.) that some of these rare capsules, as well as
It is obvious that, for reliable comparisons, the cnidome the so called size classes observed in certain categories
composition should be emphasized, though it is obvious of nematocysts, might be no more than early and
that this approach has its limits too, due to some variation intermediate stages, respectively, in the formation of
in size of the capsules from one sample to another, and fully-functional capsules. In order to use them reliably
their assignment to a given type. The following examples as taxonomic discriminators, their occurrence should be
are edifying: 1 ) Namikawa (2000) found differences in the documented carefully in multiple hydroid populations of
size of nematocysts of H. misakiensis from two localities; a given species.
2) similar data also emerge from the accounts of Millard Owing to the taxonomical impediments discussed above,
(1975) and Vervoort (2006) on H. multitentaculata, it is likely that molecular techniques may prove to be the
unless they dealt with different species; 3) one of the size only truly reliable method of separating these difficult
classes of microbasic euryteles reported by Namikawa hydroid species.
(1991) in his H. maltigranosi is said to belong to the Although the available data on all species of medusoid-
haplonemes in a later study (Namikawa, 2000). producing hydractiniids are summarized in Table 1,
In addition, the small size and/or the rare occurrence the present hydroid is compared in more detail to its
of some nematocysts could easily lead the examiner to congeners from the temperate to tropical western North
overlook them. It is also likely that capsules of the same Atlantic. Indeed, due to their mostly epizootic habit,
type, but belonging to different size classes, were lumped these hydroids are not expected to occur outside their
together, as illustrated by the accounts of Millard (1955, known geographical areas.
216 H. R. Galea & R. Ferry
E n
D o
ous isorhizas), hat no informati HsQ©o *B©zSN33j £bo. S H ec2 48N2
basitrich gnifies t ¥38
BI ( A. si a c
hizas), es); N. X< X< C _<o x<% X<8 tf
or ul
atrichous is ntified caps £ X — .-Saa> TX<eC3L3)
d are as follows: AI ( ophores), UC (unide i3s 5g 1uc23 TIO>N3v O*1=) X-XÈON2>5. -SC*puOa/5 . *133 os X(oioo£15B TOc0cC©b^3) >> •X-Hw2oa<IoÖSD3 P -IQ>2v* I£O« 3£33 c2 «£“C oc§E3
The abbreviations use M (nricrobasic mastig ¥"cOSsO93 --XJoS«a3 -f°Iet 1 a a53 •I©oCSOXS/35 I.1x5I8320 m"ÜëCa5XC/35 X1lë“oa3x l>«2C a3 ag. aiSs 2 ü53 -O2 3J1a$SL -Q2
s. B
ucing allie yteles), 111 v¥4O (4N O x <• • t— (N uCEQ Cj
oid-prod basic eur ^¥ WCQ üDÎ5 T_ £—4W<. 4nD¥j'*. I°*?TrSi)) 4t—r) ¥ C£—sQ "§O r;i ®m°£?
v. and its medus s), mBE (micro *u3E©£©§ OWn 'r~TEC t4WQ" —4PIJ mwQ£®C“2 >3&ccno WüC4cGXOQ >C2~.EQ 5. 2< £2 ÇwQ£ (S-N <2 <nCr—WQ•nN Oo• . O^*^CüXgQNn <2 2< cWQ>«XEnnn
no me
p. ne
miscua s E (hetero '<5 *g5 < JoS ioc2 ^2£ DcOC £¥<5 Uoeg. CD</3S
ro H
p
a ),
ni es
ydracti plonem Ox'»/NnI,- oC©^tN; o0o0 rON- oONo X«y OO>nv'
ween H HA (ha p—Sp 2wr~> Xu« 2u2C3 2 j¥a3 Co©oo —Xo tO2~-' —CoQ rOC-~'. 2 2 JO5 —2 f-"
bet s),
Table 1. Comparison (desmonemeis available. T.c§33• trëi £g<3o X0UC—w<«£QC0DS- 1wo0O2—cCÖ3N0oS3,l S<o—sS£53o3!?' <Jcu<c3gy^3i ^°-w° ~¥aË•1£gSa:; ^2 '*CqOOSQ3! "OOrqNN- "Xs^Coqs rIn- fa••sa>as lv§o aT£3: 2
Notes on some hydroids (Cnidaria) from Martinique 217
s
°© ’+CO/3 soO zooid
H<©8ag. =B©©5«3 -'£E§N53L 353cg© x< X< £G x< z< Tentaculo
© o
0E0C OÛ/3Û X< X<) X< 5C§£/3 j7s§n C£/3 X< *CGH/5D —C/3 i0OÛ o©©S3 present Smooth
T3
© G ©
1o O g xw SC/3
© © £o cd ^ g ed
£«G© £© ¥IQä8GC£3 £©1°© ’<a—3¥13i§©S2^SG3 , ^©O©CO©c^O<3L3> « ¥| 0-3! •C£o©a3O -—U®r §u -Ia f-J5CO3aid IcO©y 03 iZU—5o25> *2©IaC2 ä%oobM -z^oÖapo*^ a —X©©©, gGo ccÆËI_2*«conV“P5o!3 I^—©ga©©©8>88> -a©Ga Network of perisarc coverstolons
¥5 cks,
o
•xs 2© © o XXC/3 es (r
a aaC0©/33 X-©o aa©C0/33 oiM©as i <©cOdD ©cOGg^D. aaMOc0^3M OÌM©M iaMoM i.tgs a¥I§s IË- TaìOao3 -aIoSa©a—< TaaäOao3 -o Inert substrat laminarians)
< < < < 3WWmvMVu•Tx—E•*- nTl " -IrrO_—xTx5oai3 ' < üeUD s4 < v<WssOrÓrSx.°pó Ont7. (O^-<0—rC2xN§3nN0^'i ^n«s^o'o«<TXXfos Ocr((r^wcw^XNN£•~n-oN 1.-- o S—y—0^r-xw^o OG.o0 j•„’-' 0 ^^—coXO3o—"a?Oos,-3s rnoo òrSSWwSs7—E.n 3'T r^ C ¥A0~m^_o«oWE>?0ci;•. ,, G©cuuNr/J3l HeWCrrnCT~ £.Ónn NQi- ' VNi<rr—T«Y«nNr-3-ri ^^°WA»O°n. txc(xXX00N£n2ì2 8.6-11.2)x(2.8-4.0)] and [( 11.2-6.0)x(3.8-4.8)] E: (8-9)x4; mBE: 12x(3-4)
z Z Z Z Q oo z D iri Z G Q 2 « Q x: Q [( 1 D
Japan Japan ¥.>S°a ¥zÏ%S 5at©o©©3: s©©©§f§c! CEX<©©3/5 •aC<©3©3S/3 *o0©C©n3Û *•<S -UIC©aa3 British Is. toAlboran Sea
OOOÄJ£©©Nni .Ofo0s2pbfo0Ni Tm2?0M©323< 0OxZ_N0- C3 4P j"Oä j-3s «OON 2=sw¥~Ju •X0OZ52t£30S'? ^OC_§£0N3 M21CG£is3 2‘o^On .iI1> i2i £ £o Yamada (1959),Kubota (1991) Schuchert (2008)
E§&a >§§ .52I«P --S>•o©ok§og§o . ^8§_53S3 0c~eg0? J—<R n T1Ic33 "J1•S*RRO23 X X•-C2©u0R©50*§O23»33 2 £..«>0s5R0§O3§330 ^S *¥Z#gORSr55»0. 2^—XC^d ~'5Ss»SaGS> ^•EÜ2v~o) >‘|"-as^^S28s8 (eNo jU£©oz 32) (Hincks,proboscidea 68)
s:2 ü - a: : 5:22^ 5: 22 ü s 5; 2 mj 2c^d 19 H. *^
218 H. R. Galea & R. Ferry
T3 O S X
8 OoN z £ '«S ’Es S a o O
COO O _3O2 « ^ ^ O5 E3 ®m 2E ^3 A
s. Zfi 5fi
H °s H J e2 È*
«
11.a
•S Ig* J1 Jä gh r<d ¥§h
>. § fi "S g a«â
g I fi 2 Sel ß
.«2 +s-r X*£* o -fi
oO cwo §S ¥2¥?¥ !s fi -fSi Z-fi' fi
O O. en a. o n? e
.2
-fi
-o £ O —
§ 3
-c °o? oÒ o ^ o ^ <
-C>* o .esn o o z
-o
o
tfi
e
2 g £ O
s « Zo«U .Su2O —? n^UaCOOi £C:3C-L Ûo x§ T£D aSs Æa© fi”
Z'
©x ©
jo CO .Se2 B»S ¥ëoS—I X£fi) ¥f56i- 1ffii —©;
» j1? "--Co3 X’<Su 1S- Js. OCCLl Z<L> 1fit 1© CgU J3
-fkCfOaii .3go 3aoS3 ¥3Ia Zfffiii- c ;¿> 0E1
en O < O 3 O 2'S -1s 2g
E g S < < < <
ZV fi «s Z z Z Z
¥2 °,
rjj r- x O W oo
03 CQ On ' . «2 *-
£., “-a E•¥ •• 2 4vd fi =© £ £o.
Pm —§ : ^ S^S" ¥soU- H1 1e <2 3
tÎ- oo 1 (N t-L — c 2 ?
rÌnT <nNo ^ :rH^ ^ iH ^ON ^ B
0v0o cXi f? T <r-N* (XNT ' (’Nt o o— r-
m r- ö 4 s4 .esn V —
r- x 5 oo' X,
< <
ON o Ü S H
Z Z Q S-
<
O
g 5.2 Z
t M .5"
'"aB> 1o3 ’c do
U 4* 00
s "f3i J
H 5 ©£
c
o
fi nS
g a a
c —1 c2 3
-üc «Jaa c? <$* G H e
J -2
T3 00 T3 00
U OS ’fi O ON <y E
^ ~ a ^ C- a •en- wE —* m
O
=3 s fi3 00 00
.5us0> Ì*2¥ Z^2 oO«rni '%|Oü SSD SS- o0o0 §n3 IgQ) C'SQq0 2 -"<O£L> IU—-—(U- Ö ' Oo2—fNoi
1g li ^S oC •.5S" O~N S s£?> U3
Si. § £ ~ o 5 S « C
a: ai g *^--2 U73 ai Hj - ^ - &5 a:
Notes on some hydroids (Cnidaria) from Martinique 219
o w
¥3 I
O«® a3S ^^>©—) °CroN <Z or0s <z 10-20 21-32
'1SSS“ 1.'IS5SJ5 S?aa 0wS£*023 -£2coo ^ao. ¥<O Z< 8 “indication”of tentacles
S3
=3 1
& 4J —-O_
CL c8 0- G 4 4
i SUS 0 0
a. o — 50 40
.C«a/3 <z -OUTS 'X——). Oofnn C-——H•-. Z< N.A. 550x($) ;450x
O1§ 2a" V — ^ — NVO raCsj 4-8 N.A.
2a© G2 Dgc_. 2*c©<“L*> L—L8o-« .. cGO . cGo. DQC ,. uoo.. Middle of body Upperthird
S1 S
2 S3 S
a b «Ç nt
Zi« SI23 Æa>> Z<: Z< Z< z< <Z Z< <Z <Z Z< Prese N.A.
68 -Ö
rH1o» sEa CGN" us — o—ó oË us O"T' 6-16 5-12
'§ I
N S
© w
O®e .GaaÆ* — o <Z <z <z z< <z 0.5-1 1.1
W E
3 T3 2
68 8 g nt
«E g£ gS. < < < < < < ese A.
Z 8 £ z z z z z z Pr N.
0 6«
a « I < <
- z z
2 2
«
68 Æ — CN NO 2
Ha<y E3s <z C2C uos V 12-2 8-15
« E <
u C•Za) we z 2-3 2
^ c
So°|_2_o02i3- ï ^^I«9£ 5't_®S§02r '_£"3co<Q2oU ot-v- -_1S"gGaa £¥as •ao3 K2aca .C£OP .c2l/3ìP :"^>O (Allman,mis Millard,aria
SÈQj ?WGì OVOOO' <2 Üao 2a sSu uto"vs a§: ¥£2 ^g*> 2«00 ¥^s2g2: ai H. iner1872) H. kaff1955
220 H. R. Galea & R. Ferry
fj
fl >* ? < c A.
Dc Z e2 N.
1 S 3
G G
Sa "£3 £G < o+ _<»c o-4c* o—o J<SO N.A.
=«3 1 CO>Ur JJeC2« ' Presum-ably 4
OF
E
SL
<Z (OuN-1 OO— OOr- Q *=o N.A.
t2
^i- OF 3
1-
g| eCOO . 1a
OSX OO
c~ N -a
..©SS« <fe5c«u» DaD. . â~S° BSS <> D D8a.. Daa. 2Diaa-. c¥Ep>°/5 .üI5(<Ju DOQ- . <> Upperhalf
>u>- se
3« -so 3x
|§a < < < < A.
Z «j -fi z Z Z -<O Z N.
15 OF
S s — oo X (N — c*~i — 8
NC 00 —- 5.
< < ö < A.
Z Z V Z N.
< < < A.
Z Z J<C Z N.
2
î &} 6*5 ©
111 ¥Jü —A Ca>Z>) (N — —' 1
^ u
« =s
BU S3 13
H s 9-
« s
•¥jHî -g5 - iÖ/y *(—N< 2-3
t/ë3, 5; .2 â5'O5S :22 5OsQI:: oO—1ENn ^.§5^& ^-g>Se UBo „^a*SQg£3>:N oN2^1S.SoO2 •SgdS3 a*2ON§g°2i- - >oOSSdÿ/N¥> =JCas(„«§6-Joti 94. oNj2—1geoO .5a•¥•Sbo§S«SC2ii-- O2ó0~O=0ò' a“Qi> . //. sp. (as sp.)Styactis
Notes on some hydroids (Cnidaria) from Martinique 221
Like H. arge, the present hydroid possesses gonophores Material examined: MHNG-INVE-91110; sample
with 4 radial canals and 8 tentacle rudiments, but its #M294; France, Martinique, Saint Pierre, Tombant de la
gastro- and gonozooids are comparatively smaller, and Galère, 14.75144° -61.18236°, 3 m; 01.02.2014; colony
do not show any tendency to autotomize. The Bermudan up to 5 cm high with incipient gonophores. - MHNG-
material assigned by Calder (1988) to the same taxon INVE-91121; sample #M332; France, Martinique, Saint
comes close to our specimens regarding the size of its Pierre, Tombant de la Galère, 14.75144° -61.18236°,
zooids, the number of their tentacles, and the structure of 2-4 m; 04.03.2014; colony up to 7 cm high with
its medusoid, but its cnidome seems to possess only one incipient gonophores.
type of haplonemes, whilst two additional ones occur in
Description: Stems sparsely branched (no auto¬
the Martinican hydroid.
epizootic growth), rarely simple, arising in dense
The Puerto Rican material identified as Stylactis arge by
clusters from tortuous, tangled mass of stolonal fibers
Wedler & Larson ( 1986) possesses taller zooids with more
attached to sand grains (Fig. 1C). Pensare irregularly
numerous tentacles, and its medusoids are apparently
annulated, with smooth areas between corrugated
devoid of tentacle stumps (possibly immature?). The
patches, thinning out distally. Coenosarc with two
rather brief description, combined with the absence of
longitudinal, endodennal ridges which may meet in
data on the cnidome, prevents any further comparison
the centre. Neck region conspicuously swollen, flexible
from being established with our material.
and contractile, covered basally with filmy perisarc;
Hydractinia hooperii, as described originally, has similar
a narrow, but distinct, transversal band of nematocysts
medusoids, but its zooids are much taller and possess
(isorhizas) in middle. Hydranths vasiform; aboral
comparatively more tentacles, thus differing from our
tentacles long, 17-21 (commonly 18) in number,
material.
monilifiliform, oval in cross section, especially basally.
The gonozooids of H. sandrae (Wedler & Larson, 1986)
Oral tentacles short, 14-18 in number, not adnate basally
are said to exhibit a red pigmentary belt between the
to hypostome, semimoniliform, circular in cross section.
whorl of tentacles and the insertion of gonophores, but
About 10-14, short, lobed blastostyles arise slightly
this was not apparent in our material examined alive
above the aboral row of tentacles. Gonophores incipient,
(see PI. 1B). No data on the cnidome of H. sandrae were
their type could not be ascertained. Cnidome: large
provided by the authors, making impossible any further
stenoteles (Fig. 31') in oral tentacles; small and rounded
comparison with our hydroid.
The medusoid-producing Hydractinia sp. from Mar¬ stenoteles (Fig. 3I2) in both oral and aboral tentacles;
tinique, described earlier by one of us (Galea, 2013), has small and ovoid stenoteles (Fig. 3I3) in both oral and
a different cnidome and, consequently, is not conspecific aboral tentacles; microbasic basitrichous isorhizas (Fig.
with the present species. 314) in both oral and aboral tentacles; O-isorhizas (Fig.
Last, the as yet unidentified species of Hydractinia from 315) in both oral and aboral tentacles; desmonemes (Fig.
Puerto Rico [see Wedler & Larson ( 1986), p. 95, fig. 10E, 316) in aboral tentacles.
as Stylactis sp.] is incompletely described, and data on its
Dimensions: Stems up to 7 cm high. Hydranths ca.
cnidome is lacking.
2.5 mm high, and 7 mm wide between tips of opposite
In spite of the rather scanty data available, it seems that
tentacles. Large stenoteles (10.0-10.3)x(8.3-8.6) pm;
our material differs morphologically from each of the
small and rounded stenoteles (6.6-7.4)x(5.7-6.6) pm;
three nominal species mentioned above, particularly
small and ovoid stenoteles (5.7-6.3)x ca. 4.8 pm;
with respect to their original descriptions (subsequent
microbasic basitrichous isorhizas (8.3-9.1 )x ca. 3.4 pm;
assignments are taken with reserve). According to
O-isorhizas (8.0-8.6)x(7.4-8.0) pm; desmonemes (4.3-
Schuchert (P. Schuchert, pers. comm.), the present species
4.8)x(3.1-3.7) pm.
is indistinguishable macroscopically from H. aculeata
(Wagner, 1833) [see Schuchert (2014)] but, owing to Remarks: In the absence of fully formed gonophores,
its different substrate selection, remote geographical the present material could not be identified reliably to
distribution, and different cnidome composition, it should species. According to Petersen (1990), six species of
be kept separate. In addition, none of the remaining Ectopleura with a known hydroid stage occur along
species listed in Table 1 is expected to occur in our study the Atlantic coast of North America, viz. E. americana
area, on the account of their limited dispersal ability due Petersen, 1990, E. crocea (L. Agassiz, 1862),
to their characteristic epizoic or epiphytic habit. E. dumortierii (Van Beneden, 1844), E. grandis Fraser,
1944, E. larynx (Ellis & Solander, 1786), and E. mayeri
Petersen, 1990. A seventh species, E. obypa Migotto &
Family Tubulariidae Fleming, 1828 Marques, 1999, was described from Brazil.
Genus Ectopleura L. Agassiz, 1862 Ectopleura americana could be excluded on account of
several distinct features: 1 ) its aboral tentacles are circular
Ectopleura sp. throughout in cross-section; 2) the neck region is finely
Figs 1C-G; 3F-I and longitudinally striated; 3) the cauli are unbranched;
222 H. R. Galea & R. Ferry
4) the 14-24 blastostyles are long, stout, dichotomously Remarks: The complex structure of the blastostyle,
branched, and arranged in up to three whorls (Petersen, with the gonophores inserted proximally and clusters of
1990). nematophores occurring distally (Fig. 2A), is common
According to various authors (Deevey, 1950; Defenbaugh to three species of the genus, viz. R. neira Petersen,
& Hopkins, 1973; Petersen, 1990), the reduced number 1990, R. rosetta Watson, 1999, and R. sanctisebastiani
of tentacles (never exceeding 16) even in mature, fertile (da Silveira & Migotto, 1984). Nothing is known about
individuals, is diagnostic for E. grandis. Our specimens, the blastostyles of R. parasitica (Korotneff, 1887), nor
provided with up to 18 tentacles in the oral whorl, and about its gonophores.
up to 21 around the hypostome, would not fit the above The gonophores of R. gorgoniae were illustrated for
diagnosis. However, we believe that the tentacle number the first time by Wedler & Larson (1986, as Tubularia
alone should not be regarded as a reliable character. parasitica), while a short account is available in Petersen
Unfortunately, no data are available on the cnidome of (1990). In the present material, the gonophores were
E. grandis. This species is said to reproduce through liberated from their corresponding polyps within less
medusae, though fully mature specimens have never than an hour, corresponding to the time elapsed between
been seen. the sampling and their examination in the laboratory.
The sympatric E. may eri is equally excluded on the They apparently belong to both sexes, as suggested
account of the characteristic yellow fluorescent tinge of by differences in their size and color (Fig. 2B). Their
its living hydranths, and the occurrence of microbasic anatomy, as described below, shows that we are dealing
mastigophores in its cnidome (Galea, 2013). with eumedusoids. In both sexes, the umbrella is bell
The cnidome of the present species shows affinities with shaped, slightly longer than wide. The mesoglea is rather
those of E. crocea [see Schuchert (1996)], E. dumortierii thin (Fig. 2C) and the endoderm is provided with closely-
[see Schuchert (2010)], E. larynx [see Östman et set circular muscle fibers (Fig. 2H). In contrast with the
al. (1995)], and E. obypa [see Migotto & Marques statement by Petersen (1990), who reported only 4 radial
(1999)], though additional data are necessary to clarify canals in his material, each medusoid in the present
the precise identity of some of the capsules involved. collection has generally 4-5 (rarely 3 or 6) radial canals,
While E. larynx is a temperate to cold water species, not some of which may give off one or two additional,
expected to occur in tropical environments, our material secondary branches, most often a short distance after
comes closest to E. crocea (P. Schuchert, pers. comm.), their origin from the manubrium, but also more distally,
a species with considerable spreading capabilities due on the sides of the umbrella. The bell margin is provided
to anthropic activities. Ectoplenra obypa is different in with a raised, internal, thickened collar (Fig. 2C, D),
forming exclusively unbranched cauli, and in having a composed of large, polygonal cells (Fig. 2G). No tentacle
higher number of tentacles. bulbs or rudimentary tentacles exist. A cross section
through the bell margin reveals that the circular canal,
of ovoid shape, passes in the middle of the raised collar
Genus Ralpharia Watson, 1980 (Fig. 2F). There is a well-developed velum (Fig. 2D)
which, according to the observations made by Wedler
Ralpharia gorgottiae Petersen, 1990 & Larson (1986), helps the medusoid swim actively
Fig. 2 in the plankton. The manubrium is globular to ovoid,
not surpassing half of the subumbrellar cavity, and is
Ralpharia gorgoniae - Galea, 2013: 10, pi. 1L-O, fig. 2R.
devoid of a mouth (fig. 2E). The gonads could not be
Material examined: MHNG-INVE-91114; sample
distinctly seen around the manubrium, especially in
#M320; France, Martinique, Case-Pilote, 14.63753°
formalin-fixed specimens, though in some gonophores
-61.13974°, 3 m; 20.02.2014; 5 fertile polyps, 10 female
which appear to be female, either several flattened eggs
and 20 male medusoids set free.
or developing larvae could be seen (it is also likely that
Description: See the original account by Petersen the gonophores were partly spent prior to the specimen
(1990) and the additional data provided by Galea examination). The bell margin, the radial canals, as well
(2013). as the gonads in living specimens are bright orange in
females and yellow-orange in males (Fig. 2B), due to
Dimensions: Male medusoids 890-1060 pm (951±49
pigment granules disseminated in their tissues. The
pm, n=10) long and 755-900 pm (865±41 pm, n=10)
whole gonophore is entirely devoid of nematocysts.
wide; female medusoids 1110-1245 pm (1181±43 pm,
Gonophores provided with a similar raised, internal collar
n= 10) long and 1000-1100 pm (1090±41 pm, n=10)
around the bell margin are also known in R. magnifica
wide.
Watson, 1980, R. neira, and R. sanctisebastiani, but
Distribution: Possibly endemic to the Caribbean Sea. they are absent in R. coccinea Watson, 1984, and
Scattered records from some countries bordering the - apparently - in R. rosetta. Four rudimentary tentacle
basin are summarized by Galea (2013), but the species knobs, as well as nematocysts, are present in the
is certainly widely-spread within the whole area. medusoids of R. magnifica and R. coccinea.
