On a collection of hydroids (Cnidaria, Hydrozoa) from the southwest coast of Florida, USA
Author
Calder, Dale R.
text
Zootaxa
2019
2019-10-25
4689
1
1
141
journal article
25128
10.11646/zootaxa.4689.1.1
a63613b4-e611-42e8-89cd-2d3aae126759
1175-5326
3519047
41BFBBDF-41AD-4329-B6B9-CF38D64815A6
Lytocarpia tridentata
(
Versluys, 1899
)
Fig. 22d
Aglaophenia tridentata
Versluys, 1899: 47
, figs. 16–18.
Aglaophenia contorta
Nutting, 1900: 96
, pl. 20, figs. 5–7.—
Wallace, 1909: 137
.
Type
locality.
Venezuela
:
Los Testigos Islands
,
11 m
(
Versluys 1899: 49
, as
Aglaophenia tridentata
)
.
Material examined.
Florida
Keys,
Bahia
Honda Channel
,
24°39.489’N
,
81°17.198’W
,
6 m
,
16 June 2008
, on limestone, three colony fragments, up to
14.5 cm
high, with gonophores,
ROMIZ
B3806
.—
Fort Myers Beach
, stranded intertidally on detached octocoral,
16 February 2013
, one colony,
2.9 cm
high, without gonophores, coll.
D. Calder
,
ROMIZ
B4403
.
Remarks.
Versluys (1899)
provided the first account of this species, as
Aglaophenia tridentata
, based on sterile colonies from the Archipiélago de Los Testigos in the southeastern Caribbean Sea. It was described again by
Nutting (1900)
, as
A. contorta
, from fertile specimens taken near Key West, Florida. On recognizing that hydroids in the two accounts were conspecific,
Stechow (1923b)
followed the Principle of Priority and adopted the senior name for the species.
Totton (1926)
assigned it to
Thecocarpus
Nutting, 1900
based on the morphology of corbulae from material collected in
Brazil
. With
Thecocarpus
now held to be a junior synonym of
Lytocarpia
Kirchenpauer, 1872
, the valid name of the species is
Lytocarpia tridentata
.
Lytocarpia tridentata
is most readily distinguished by the morphology of its saddle-shaped hydrothecae. These consist of a somewhat bulbous base having an adcauline intrathecal ridge and supporting a large and projecting median inferior nematotheca, a somewhat constricted mid-region, an expanded distal end flanked by a pair of hornshaped lateral nematothecae, and a margin with three cusps, one well-developed median and two blunt laterals. Colonies are erect, with a monosiphonic and unbranched hydrocaulus reaching as much as
18 cm
high (
Migotto 1996
). Hydrocladia, occurring in a distal plume on larger colonies, are alternate and unbranched.
Detailed accounts of the taxonomy of this species include those of
Vervoort (1968
, as
Aglaophenia tridentata
), and
Migotto (1996
, as
Lytocarpia tridentata
), with the latter study based on material from
Brazil
. Records of
L. tridentata
in the tropical northwest Atlantic have been fewer in number than those to the south in
Brazil
(
Oliveira
et al
. 2016
). As noted by
Vervoort (1968)
and confirmed by the collection data of
Migotto (1996)
and others, this hydroid is predominantly a species of shallow waters. Its known bathymetric range extends from the intertidal zone (
Migotto 1996
) to
70 m
(
Grohmann
et al
. 2003
;
Posada
et al
. 2010
), with most reports at depths of less than
20 m
.
Reported distribution.
Gulf coast of Florida.
Off Key West, 5½ ftm (
10 m
) (
Nutting 1900: 96
, as
Aglaophenia contorta
).—Off Marco Island, 2 ftm (
4 m
) (
Nutting 1900: 96
, as
Aglaophenia contorta
).—Dry
Tortugas
(
Wallace 1909: 137
, as
Aglaophenia contorta
).
Elsewhere in western North Atlantic.
Venezuela
: Los Testigos Islands,
11 m
(
Versluys 1899: 49
, as
Aglaophenia tridentata
).—
Virgin Islands
of the
United States
: St. Thomas, Sound + Savannah Passage (
Vervoort 1968: 76
, as
Aglaophenia tridentata
).—
Costa Rica
: off
Limón
,
10°01’10”N
,
83°04’45”W
(
Kelmo & Vargas 2002: 616
).—
Colombia
: Golfo de Salamanca,
70 m
(
Posada
et al
. 2010: 79
, as
Aglaophenia tridentata
).—Caribbean Sea (
Wedler 2017b: 148
, fig. 177).