A review of Ancorina, Stryphnus, and Ecionemia (Demospongiae, Astrophorida, Ancorinidae), with descriptions of new species from New Zealand waters
Author
Kelly, Michelle
Author
Sim-Smith, Carina
text
Zootaxa
2012
3480
1
47
journal article
10.5281/zenodo.282353
675807a8-0007-438c-99e0-282827c51474
1175-5326
282353
Genus
Stellettinopsis
Carter
Stellettinopsis
Carter, 1879
: 348
.
Type
species
:
Stellettinopsis corticata
Carter, 1879
: 348
.
Diagnosis.
Massive, cushion-shaped, bulbous or thickly encrusting
Ancorinidae
, with oxeas packed obliquely or paratangentially in the choanosome. The ectosome is well developed and defined by bouquets of subdermal oxeas and triaenes, when present, emerging from the choanosome, in between which are large aquiferous canals. Euasters form a concentration below and throughout a crust of long microrhabds at the surface, and oxeas protrude through the surface, rendering it hispid and rough to the touch. Megascleres include medium-sized oxeas in 1 to 2 size categories with common stylote modifications, and relatively short triaenes of different
types
including dichotriaenes, plagiotriaenes, orthotriaenes, and rarely anatriaenes. Triaenes are frequently very rare. Microscleres include relatively long strongylote or hastate acanthomicrorhabds that form a crust at the surface of the sponge, under which is a concentration of small tylasters, chiasters, and oxyasters, and rarely anthasters in 1 to 2 size categories.
Remarks.
We are confident in this proposal to resurrect
Stellettinopsis
without recourse to examination of the relevant material because the published descriptions of species are clear and definitive, particularly those in the later contributions by van
Soest & Beglinger (2008)
and
Cárdenas
et al
. (2009)
(Table 3). The species conform to a general form of sponge that shares a unique combination of the characters seen in
Ecionemia
(possession of uniform ectosomal microrhabds),
Ancorina
(bouquets of megascleres in the ectosome, second category of oxyasters in choanosome), and
Stryphnus
(megascleres in paratangential arrangement in the choanosome, second category of choanosomal oxyasters, and variable presence of triaenes) in particular. Species considered to be valid include
Stellettinopsis corticata
(
type
species),
S
.
fenimorea
,
S
.
megastylifera
,
S
.
solida
,
S
.
cherbonnieri
, and
S
.
laviniensis
.
Stellettinopsis
(and
Stryphnus
) species that appear to lack triaenes because of their rarity, bear a superficial resemblance to
Melophlus
(see van
Soest & Beglinger 2008
) and
Asteropus
(see
Cárdenas
et al.
2009
on
Stryphnus
), genera which lack triaenes completely. However, species of
Melophlus
have a tangential layer of microrhabds in three size categories in the ectosome, and species of
Asteropus
have a tangential layer of large choanosomal oxeas.
It is interesting to briefly consider the biogeographic distribution of the genera
Ancorina
,
Ecionemia
,
Stryphnus
and
Stellettinopsis
(
Fig. 8
, see also Table 3). The greatest number of species (14) are found in the Western Indian Ocean, from the eastern coast of
South Africa
north to the Red Sea, with
Ecionemia
species extending east across the Indo-Pacific, down to warm temperate northern
New Zealand
, into the tropical west central Atlantic (
E
.
demera
) and across to West Africa (
E
.
nigra
). A further 14 species of
Stryphnus
and
Ancorina
are found in the cold southern waters off
New Zealand
. Five species of
Stryphnus
and
Ancorina
are found in the northeast Atlantic and Mediteranean, but only two species of
Stryphnus
are found in the tropical west central Atlantic with two species of
Stellettinopsis
. Thus,
Ecionemia
and
Stellettinopsis
are generally warm temperate–tropical species,
Ancorina
is a warm to cold temperate species, and
Stryphnus
is predominantly a cold to cool temperate water species.