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
Clytia paulensis
(Vanhöffen, 1910)
Fig. 105
A–E
See
Peña Cantero & García Carrascosa (2002)
for a complete synonymy.
Material examined.
HCUS-S 112p and HCUS-S
112m
(Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula)—polyp and medusa stages.
Description
(based on our own observations;
Stechow 1923
; Ramil & Vervoort 1992;
Cornelius 1995
):
Hydroid.
Hydrorhiza thin, as creeping stolon system; colony stolonal; pedicels arising at irregular intervals, erect and delicate, ringed basally and below hydrothecae (sometimes also centrally), usually unbranched, each supporting one hydrotheca; hydranth provided with 16–22 tentacles; hydrotheca cylindrical, deep, with a thin diaphragm at base, rim with 7–11 cusps usually bicuspidate and rounded. Gonothecae cylindrical, tapering gradually below and slightly above, smooth, borne on stolon on short and ringed pedicels.
Habitat
type
.
Littoral and shelf species found from the tidal level to
250 m
depth (
Stechow 1923
;
Marinopoulos 1981
;
Boero & Fresi 1986
).
Substrate.
Several other hydroid species, some bryozoans, shells of various invertebrates, stones, algae, rhizomes and leaves of
Posidonia oceanica
.
Seasonality.
September–April (
Boero and Fresi, 1986
), and February–June, August–December (De Vito 2006; Puce
et al.
2009; this study) in several localities of the Mediterranean.
Reproductive period
April (Gili 1986; C. Gravili unpublished observations), May (
Stechow 1923; C. Gravili unpublished observations
), and July, August (
Peña Cantero & García Carrascosa 2002
; C. Gravili unpublished observations) in the Mediterranean Sea.
Medusa.
Adult. Fourteen-day-old medusa with umbrella flat, diameter about
4 mm
, mesoglea fairly thin; manubrium quadrate, with small base, as long as the subumbrellar cavity; gonads oval on each radial canal, near manubrium; 24 marginal bulbs and tentacles; 1–2 statocysts between two adjacent bulbs. Colours: manubrium, gonads and marginal bulbs transparent.
Developmental stages. Newly released medusa with umbrella almost spherical, diameter about
1 mm
, mesoglea thin; manubrium quadrate, ½ of length of subumbrellar cavity; mouth with 4 simple lips; 4 radial canals; 8 marginal bulbs (four reduced); 4 tentacles; 8 statocysts (C. Gravili unpublished observations). Nine-day-old medusa with umbrella hemispherical (diameter about
2 mm
); mesoglea thin; manubrium quadrate, ½ of length of subumbrellar cavity; mouth with 4 simple lips; 4 radial canals; 4 small gonads on each radial canal near manubrium; 16 bulbs (8 tentaculated); 1–2 statocysts between two adjacent bulbs.
Cnidome.
Microbasic mastigophores.
Distribution.
Cosmopolitan (
Millard 1975
; Ramil & Vervoort 1992;
Cornelius 1995
; Medel & López- González 1996; Bouillon
et al.
2004;
Gravili
et al
. 2008a
;
Soto Ãngel & Peña Cantero 2013
).
Records in Salento.
Rare at: Grotta del Ciolo (Denitto
et al
. 2007;
Moscatello & Belmonte 2007
); Otranto (De Vito 2006; Gravili 2006;
Gravili
et al
. 2008a
;
Ventura 2011
;
Piraino
et al.
2013
; this study); Il Chiapparo (C. Gravili unpublished observations).
Remarks.
The whole life cycle is described for the first time in the present study.
References.
Stechow (1919
,
1923
),
Leloup (1934)
,
Picard (1951a
,
1955
,
1958
a),
Riedl (1959)
,
Fey (1970)
,
Marinopoulos (1979)
,
Boero (1981a
,
b
, 1985), García
Carrascosa (1981)
, Boero
et al.
(1985),
Isasi (1985)
,
Boero & Fresi (1986)
, Gili (1986),
Ramil (1988)
, Ramil & Vervoort (1992), Altuna (1994),
Medel & López-González (1996)
,
Piraino
et al.
(1999)
,
Medel & Vervoort (2000)
,
Peña Cantero & García Carrascosa (2002)
, Bouillon
et al.
(2004), De Vito (2006), Gravili (2006), Denitto
et al.
(2007),
Moscatello & Belmonte (2007)
,
Gravili
et al.
(2008a)
, Puce
et al.
(2009),
Ventura (2011)
,
Piraino
et al.
(2013)
.