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
Amphinema dinema
(Péron and Lesueur, 1810)
Fig. 29
A, B
See Schuchert (2007) for a complete synonymy.
FIGURE 29.
Amphinema dinema
:
A
, portion of a hydroid colony with medusa bud;
B
, medusa (A, B same scale bar) (drawn by C.G. Di Camillo). Scale bar: A. B, 4.0 mm
Material examined.
HCUS-S 0 34 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula)—polyp stage.
Description
(based on our own observations;
Rees & Russell 1937
;
Russell 1953
; Schuchert 2007, 2012):
Hydroid.
Hydrorhiza as creeping stolons; colony stolonal; hydrocaulus longer than hydranth, unbranched, covered by thin perisarc, often covered by detritus, extending to the base of the hydranth, distal perisarc margin indistinct, basal perisarc with or without annulations; hydranths fusiform, hypostome rounded-conical; with 8–14 amphicoronate filiform tentacles in one whorl; medusa buds ovoid to pyriform, enclosed in thin perisarc membrane, borne singly on short pedicel arising from hydrorhiza. Colour: hydranth bright orange-red.
Habitat
type
.
Posidonia
, depth range 0.5–
20 m
(
Boero 1981a
,
b
;
Boero & Fresi 1986
), and on several substrates.
Substrate.
Eudendrium glomeratum
(Hydrozoa)
,
Sertularella crassicaulis
(Hydrozoa)
,
Cellaria fistulosa
(Bryozoa)
and dead colonies of Bryozoa, gorgonians,
Posidonia
rhizomes, algae, sponges, barnacles.
Seasonality.
In the Mediterranean Sea from January to December (
Boero & Fresi 1986; this study
).
Reproductive period.
In the Tyrrhenian Sea (
Brinckmann-Voss 1987
), fertile colonies occur from May to August.
Medusa.
Adult. Bell slightly higher than wide, up to
4 mm
wide and
6 mm
high, mesoglea of uniform thickness besides top, with a large, conical, solid, apical projection; manubrium flask-shaped, cross-like in section, almost as long as bell cavity, emerald green in colour; mouth cruciform with 4 prominent, recurved lips; without mesenteries; 8 gonads in adradial pads with smooth surface; 2 large elongated conical basal bulbs, each with a very long tapering opposed marginal tentacle, violet, their proximal part intensively purple; 12–24 small marginal warts, without tentaculae; without ocelli.
Developmental stages. Newly liberated medusa spherical, no apical projection present, scattered nematocysts on exumbrella; manubrium cylindrical, about 1/3 of height of bell cavity, reddish orange; two opposite tentacular marginal bulbs, same in colour as manubrium, each with a long tentacle, at place of other tentacles only small marginal warts.
Cnidome.
Microbasic euryteles, desmonemes (hydroid); only microbasic euryteles (medusa).
Distribution.
Atlantic, Indo-Pacific, Mediterranean (
Motz-Kossowska 1905
;
Neppi & Stiasny 1913
;
Russell 1953
;
Vannucci 1957
;
Kramp 1961
;
Patriti 1970
;
Goy
et al
. 1991
;
Medel & López-González 1996
;
Schuchert 1996
, 2007;
Gravili
et al.
2008a
; Puce
et al
. 2009;
Touzri
et al
. 2010
).
Records in Salento.
Rare at: Porto Cesareo, S.ta Caterina, Otranto (Ionian and Adriatic Apulian coast) (
Denitto 1996
;
Miglietta
et al
. 2000
; this study).
Remarks.
The life cycle of
A. dinema
has been investigated by Rittenhouse (1910),
Rees & Russell (1937)
,
Schuchert (1996)
, and in this study.
References.
Schneider (1898)
,
Motz-Kossowska (1905)
,
Rees & Russell (1937)
,
Russell (1953)
,
Trégouboff & Rose (1957)
,
Picard (1958a)
,
Kramp (1959)
,
Rossi (1961)
,
Balduzzi
et al
. (1980)
,
Boero (1981a
,
b
),
Boero & Fresi (1986)
,
Medel & López-González (1996)
,
Schuchert (1996)
,
Miglietta
et al.
(2000)
, Bouillon
et al.
(2004),
Benović
et al.
(2005)
, Gravili (2006), Schuchert (2007, 2012),
Gravili
et al.
(2008a)
, Puce
et al.
(2009),
Touzri
et al
. (2010)
.