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
Ectopleura wrighti
Petersen, 1979
Fig. 42
A, B
See Schuchert (2010) for a complete synonymy.
FIGURE 42.
Ectopleura wrighti
:
A
, hydroids without and with blastostyles;
B
, medusa (drawn by F. Boero). Scale bars: A, 2.0 mm; B, 0.25 mm.
Material examined.
HCUS-S 0 47 (Hydrozoa Collection, University of Salento—fauna of the Salento Peninsula)—polyp stage.
Description
(based on our own observations;
Brinckmann-Voss 1970
;
Petersen 1990
; Schuchert 2010, 2012):
Hydroid.
Hydrorhiza as creeping stolons not clearly demarcated from hydrocauli; colonies small; hydrocaulus slender, unbranched, of equal width throughout, inner lumen divided into two longitudinal canals by two endodermal ridges formed by highly vacuolated cells, perisarc flexible, thin and smooth, covering hydrocauli and stolons; hydranth vasiform, very slender, having long and slender neck region with low ring-shaped collar forming a groove secreting a thin outer perisarc; one oral whorl of 4–10 slightly capitate or moniliform tentacles which are not adnate to hypostome; one aboral whorl of 8–20 filiform tentacles. Gonophores released as free medusae, developing immediately distal to aboral whorl of tentacles on one circle of up to 8 short, branched or unbranched, blastostyles. Colours: whitish to colourless, transparent.
Habitat
type
.
The polyp occurs in the rocky littoral (depths of 0.5–
40 m
) on several hard substrata and organisms (
Brinckmann-Voss 1970
;
Boero & Fresi 1986
;
Peña Cantero & García Carrascosa 2002
).
Substrate.
Stylocidaris
(Echinodermata)
,
Posidonia
roots and pieces of rock, algae, sponges, hydroids, barnacles, concretions.
Seasonality.
In the western Mediterranean Sea,
Ectopleura wrighti
occurs from June to December (
Boero & Fresi 1986
), October (
Galea 2007
), January (Puce
et al.
2009); January, March, June, September (De Vito 2006; this study), and November (
Piraino
et al.
2013
) in Salento waters.
Reproductive period.
In the Ligurian Sea, fertile colonies occur in June (
Boero & Fresi 1986
); September (this study).
Medusa.
Adult. Umbrella nearly hemispherical; with four longitudinal meridian pairs of cnidocysts tracks; manubrium nearly as long as subumbrellar cavity; gonads completely encircling manubrium; with 4 perradial marginal bulbs; 2 opposite marginal perradial tentacles with a terminal knob of cnidocysts and distally 1 or 2 spherical cnidocysts knobs encircling tentacle, proximally one abaxial cnidocysts cluster.
Developmental stages. Newly released medusa spherical, exumbrella with 8 meridional lines of stenoteles; manubrium tubular, short; with 4 radial canals; gonads not developed; 4 equal bulbs of which only one opposite pair bears short tentacles, tentacles with one spherical terminal and one subterminal clasping nematocyst cluster. Colourless.
Cnidome.
Stenoteles of different size classes, desmonemes, almond-shaped microbasic mastigophores, discharged shaft sometimes slightly swollen and then approaching eurytele condition (polyp); stenoteles, desmonemes, and mastigophores (medusa).
Distribution.
Atlantic, Mediterranean (
Allman 1872
;
Stechow 1923
; Wright 1963;
Brinckmann-Voss 1970
;
Boero & Fresi 1986
; Bouillon
et al.
2004;
Gravili
et al.
2008a
; Schuchert 2010).
Records in Salento.
Rare at: La Strea, Porto Cesareo (
Presicce 1991
;
Faucci & Boero 2000
; this study); S.ta Caterina (
Miglietta
et al
. 2000
); Otranto (De Vito 2006; Gravili 2006;
Gravili
et al.
2008a
;
Piraino
et al.
2013
; this study).
Remarks.
The Mediterranean records of
Ectopleura minerva
(
Goy 1973
;
Goy
et al.
1991
) are most probably attributable to
E. wrighti
(see for details Schuchert 2010). Only the hydroid stage and the new born medusa were seen in the present study.
References.
Graeffe (1884)
,
Neppi & Stiasny (1913)
as
E. dumortieri
(see for details Schuchert 2010); Motz-
Kossowska (1905)
,
Stechow (1923)
,
Picard (1951a
,
1958a
) as
Acharadria larynx
;
Riedl (1959)
,
Brinckmann-Voss (1970
,
1987
) as
Tubularia larynx
;
Petersen (1979
,
1990
),
Boero (1981a)
,
Boero & Fresi (1986)
,
Franzen & Hündgen (1986)
,
Faucci & Boero (2000)
,
Miglietta
et al.
(2000)
,
Peña Cantero & García Carrascosa (2002)
, Bouillon
et al
. (2004), De Vito (2006) Gravili (2006),
Galea (2007)
,
Gravili
et al.
(2008a)
, Puce
et al.
(2009), Schuchert (2010, 2012),
Piraino
et al.
(2013)
as
E. larynx
.