The non-Siphonophoran Hydrozoa (Cnidaria) of Salento, Italy with notes on their life-cycles: an illustrated guide
Author
Gravili, Cinzia
Author
Vito, Doris De
Author
Camillo, Cristina Gioia Di
Author
Martell, Luis
Author
Piraino, Stefano
Author
Boero, Ferdinando
text
Zootaxa
2015
3908
1
1
187
journal article
42365
10.11646/zootaxa.3908.1.1
6f1d1977-6b97-4789-828c-76ed250cf1ae
1175-5326
242729
D6AD2B49-170B-4D9C-84AA-DBE0FEEAD8BE
Hebella scandens
(Bale, 1888)
Fig. 75
A–C
See
Boero
et al.
(1997a)
for a complete synonymy.
FIGURE 75.
Hebella scandens
:
A
, straight hydrotheca and twisted one;
B
, portion of fertile colony growing on a sertulariid;
C
, juvenile medusa (modified after Boero
et al.
1997a). Scale bars: A, B, 0.5 mm; C, 1.0 mm.
Material examined.
HCUS-S 0 82 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula)—polyp stage.
Description
(based on our own observations;
Boero
et al.
1997a
):
Hydroid.
Colonies stolonal; hydranths with 12–16 tentacles; hydrothecae asymmetrical, with perisarcal diaphragm, with smooth to slightly corrugated walls, flared margin, mostly oblique but bent 90° when growing over host hydrothecae, pedicels short, smooth or annulated. Gonothecae asymmetrical, with undulated walls, truncated distally, tapering toward base, operculum with 4 opercular flaps, bigger than hydrothecae, on short pedicels, containing up to 4 medusa buds.
Habitat
type
and substrate.
Littoral and shelf species found from the tidal level to
120 m
depth (García
Carrascosa 1981
;
Templado
et al
. 1986
).
Substrate.
Algae, epizootic on other hydroids, especially
Sertulariidae
, sponges, bryozoans, other organisms.
Seasonality.
May, September (
Llobet i Nadal 1987
) in the Western Mediterranean; January, February, April–July, November–December (for a review see Bouillon
et al
. 2004); just March (De Vito 2006; this study) in Salento waters.
Reproductive period.
No references of fertile material from the Mediterranean.
Medusa.
Newly released medusa. Bell deep-campanulate, mesoglea thicker at apex, exumbrella evenly covered by nematocysts; manubrium short; mouth with 4 small lips; 4 radial canals; 2 big tentacular bulbs and 6 smaller atentaculate bulbs, 2 perradial and 4 interradial ones; with an adaxial ocellus on each marginal bulb.
Cnidome.
Microbasic mastigophores.
Distribution.
Atlantic, Indo-Pacific, Mediterranean (
Medel & López-González 1996
;
Boero
et al.
1997a
; Bouillon
et al.
2004;
Gravili
et al.
2008a
).
Records in Salento.
Rare at Otranto (De Vito 2006; Gravili 2006;
Gravili
et al.
2008a
; this study).
Remarks.
The hydrothecae can be almost symmetrical, or sharply asymmetrical, according to their position on the sertulariid hosts (for more details see
Boero
et al.
1997a
). Gonothecae and medusae not seen in the present study.
References.
Picard (1951a
,
1958a
), Millard (1957),
Vervoort (1959)
,
Rossi (1961
,
1971
),
Millard & Bouillon (1973)
,
Schmidt (1973)
,
Sarà
et al.
(1978)
,
Marinopoulos (1979
,
1983
), García
Carrascosa (1981)
,
Isasi (1985)
, Gili (1986),
Roca (1986)
,
Llobet i Nadal (1987)
,
Calder (1991)
,
Llobet
et al
. (1991)
,
Vervoort (1993)
, Altuna (1994),
Medel & López-González (1996)
as
Hebellopsis
;
Migotto (1996)
, Altuna (1996),
Boero
et al.
(1997a)
,
Peña Cantero & García Carrascosa (2002)
, Bouillon
et al.
(2004), De Vito (2006), Gravili (2006),
Gravili
et al.
(2008a)
.