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
Halecium
sp.
Figs. 19e, f
Material examined.
Southwest Florida Shelf, middle shelf west of Gasparilla Island,
26°45.86’N
,
83°21.44’W
,
50 m
,
18 July 1981
, triangle dredge, one colony fragment,
3.9 cm
high, without gonophores, coll. Continental Shelf Associates,
ROMIZ
B1594.—
Sanibel Island
, beach at
Lighthouse Point
,
26°26’58”N
,
82°01’04.5”W
, detached and stranded on beach,
21 March 2018
, 22° C, 34.5‰, one colony,
7 cm
high, with male gonophores, coll.
D. Calder
,
ROMIZ
B4381
.
Remarks.
These hydroids resemble the trophosomes of several species of
Halecium
Oken, 1815
that have been reported from the Gulf of
Mexico
(
Calder & Cairns 2009
), including
H. halecinum
(
Linnaeus, 1758
)
,
H. beanii
(
Johnston, 1838
)
,
H. sessile
Norman, 1867
,
H. macrocephalum
Allman, 1877
, and
H. bermudense
Congdon, 1907
. In lacking female gonophores, the specimens cannot be reliably identified to species. Colonies were strongly polysiphonic, with alternate and predominantly pinnate side branches; hydranths bore 20+ tentacles and the cnidome comprised both pseudostenoteles (10.2–12.0 long x 5.4
–
7.0 μm wide) and microbasic mastigophores (ca. 6.0 long x 1.8 μm wide).