A taxonomic revision of Anthothela (Octocorallia: Scleraxonia: Anthothelidae) and related genera, with the addition of new taxa, using morphological and molecular data
Author
Moore, Kirrily M.
Author
Alderslade, Philip
Author
Miller, Karen J.
text
Zootaxa
2017
4304
1
1
212
journal article
32506
10.11646/zootaxa.4304.1.1
3b9bd2c4-7dee-46a3-a36d-80077b88a78b
1175-5326
842289
3D557C94-0783-4C39-80C3-9C321DA94800
Lateothela
gen. nov.
Moore, Alderslade & Miller
http://zoobank.org/45E8D773-D627-45BC-A604-F6FCD829309B
Diagnosis:
Monomorphic scleraxonians which form bulky, complex colonies; often with an extensive membranous or encrusting growth, from which multiple, upright, robust branches may emanate; some secondary branching can occur along with anastomoses; medulla without well-defined coelenteric canals; ring of boundary canals encircling medulla, clearly defining the cortex; distinct, robust calyces with a smooth mat-like surface; sclerites include tuberculate sticks and spindles, rodlets and spiky clubs; preponderance of short, stout warty rodlets in calyces and surface; longitudinally arranged tuberculate sticks and spindles and spiky clubs in the tentacle rachis; thorny
josephinae
clubs crowded and longitudinally arranged in the pinnules.
Type species:
Parerythropodium grandiflorum
Tixier-Durivault & d'Hondt, 1974
by designation and monotypy.
=
Lateothela grandiflora
new combination
Remarks:
Morphologically comparable genera include
Anthothela
,
Victorgorgia
and
Briareopsis
Bayer, 1993
. Specimens of
Lateothela
n. gen.
have been mistakenly identified as
Anthothela grandiflora
for over 150 years. Superficially the colonies are similar with a complex construction of both encrusting and branched forms, similar colour and habitat and comparable appearance of calyces and polyps.
The main features of
Lateothela
n. gen.
which differ from those of
Anthothela
are: preponderance of short, stout, warty rodlets in the cortex and calyx (
Anthothela
specimens chiefly have tuberculate sticks and spindles); many thorny
josephinae
clubs in pinnules and tentacle rachis, few or no flat spatulate clubs (
Anthothela
specimens have many spatulate clubs and few or no
josephinae
clubs); crowded mixed sclerite forms on the polyp neck and tentacle rachis that include spiky clubs (
Anthothela
specimens have only sparse tuberculate sticks and spindles on the polyp neck and tentacle rachis).; colony robust, with a tendency for multiple branches to grow roughly perpendicular from a membrane with only minor secondary branching or anastomosing (
Anthothela
specimens have many narrow, tangled, commonly anastomosing branches growing without any discernable organisation). The main features of
Lateothela
n. gen.
which differ from those of
Victorgorgia
are: thorny
josephinae
clubs in the tentacles (
Victorgorgia
has
josephinae
clubs which lack thorns and have only small, rounded tubercles); no central coelenteric canals in the medulla (
Victorgorgia
has clearly defined central coelenteric canals in the medulla); growth form not aborescent (
Victorgorgia
has arborescent colonies); sclerites present in the pharynx (
Victorgorgia
species lack pharynx sclerites).
Lateothela
n. gen.
could be compared to
Briareopsis
due to a similarity of sclerites but
Briareopsis
has a distinct single main stem which then branches dichotomously, the cortex is divided into two layers (the inner layer is very spongy), the medulla and cortex are only poorly differentiated by boundary canals and the calyces are very low (
Bayer 1993
).
Lateothela
n. gen.
actually appears to be relatively common in the
northern eastern Atlantic
, especially around
Norway
and in the
north western Atlantic
along the
North American
continental shelf (Scott
France
, pers. comm.), and can form large and extensive colonies, however its true identity has remained overlooked due to the erroneous assumption it was
Anthothela grandiflora
.
The
type
species of
Lateothela
n. gen.
,
Parerythropodium grandiflorum
Tixier-Durivault & d'Hondt, 1974
(currently known as
Alcyonium grandiflorum
) was described as a membranous colony, and more recently other membranous colonies were identified by
Stokvis
&
Ofwegen
(2006)
as
Alcyonium grandiflorum
.
There
is a possibility that many specimens from
Lateothela
n. gen.
have been collected as membranous colonies only, presumably prior to the formation of branches with a medulla, and thus not associated with the
scleraxonia
.
In
fact,
Stokvis
&
van Ofwegen
(2006) describe a number of
Alcyonium
species which are all membranous and have similar sclerites to
Lateothela
n. gen.
.
In
particular, some of the specimens have thorny
josephinae
clubs in the pinnules and tentacles as well as the short, stout, tuberculate rods and short clubs in the calyx and cortex.
Both
morphological and molecular characters of
Lateothela
n. gen.
appear to be very similar to that of some nominal
Alcyonium
species, and these intricately entwined relationships are worthy of further investigation.
The genus is placed tentatively in the family
Anthothelidae
with the knowledge that the family as currently recognised (
Williams & Cairns 2015
) is polyphyletic (
Cairns & Wirshing 2015
), and the phylogenetic position of
Lateothela
n. gen.
is entwined with some nominal
Alcyonium
(Alcyoniidae)
species. It is possible that
Lateothela
n. gen.
and some of these nominal
Alcyonium
species form a family separate from
Anthothelidae
and
Alcyoniidae
but this decision requires a revision of both families. Given that
L. grandiflora
n. comb.
differs significantly, morphologically and genetically, from the
type
species of
Alcyonium
(
A. digitatum
Linnaeus
) it was thought that it is unlikely to be considered a true
Alcyoniidae
and for the species to be placed in
Alcyoniidae
would require a significant broadening of the diagnosis of the family. The gross morphological characterisitics, chiefly the scleraxonian axis and colony formation place the genus within the current definition of
Anthothelidae
.
Etymology:
The new generic name is derived from the Latin,
lateo
(to lurk, lie hidden or escape notice) and
thela
in recognition that the genus has long been mistaken for specimens of
Anthothela
.