Taxonomic revision of Leucascus Dendy, 1892 (Porifera: Calcarea) with revalidation of Ascoleucetta Dendy & Frederick, 1924 and description of three new species
Author
Cavalcanti, Fernanda F.
Author
Rapp, Hans Tore
Author
Klautau, Michelle
text
Zootaxa
2013
3619
3
275
314
journal article
10.11646/zootaxa.3619.3.3
2719c069-24fe-4cd6-967d-aea11f80e344
1175-5326
221852
92C07D63-F2F5-4898-A7FE-4937F4D5A043
Leucascus protogenes
(Haeckel, 1872)
comb. nov.
Diagnosis:
Cortical membrane with conspicuous inhalant apertures irregularly distributed on the surface. Only triactines are present.
Synonymies:
Ascetta primordialis
var.
protogenes
: Haeckel 1872: 17
;
Ascetta procumbens
: von Lendenfeld 1885: 1086;
Clathrina primordialis
: Carter 1886: 510
;
Leucosolenia protogenes
: Dendy 1891: 58
; Breitfuss 1897: 213; Dendy & Row 1913: 726; Dendy & Frederick 1924: 480; Brøndsted 1926 (?): 297; Breitfuss 1932: 243; Breitfuss 1935 (?): 13; Tanita 1943a (?): 371; Tanita 1943b: 24, 74; Burton 1963: 225.
Type
material:
Unknown
Type
locality:
near Port Phillip Heads (
Australia
)—
sensu
Dendy 1891
Analysed material:
BMNH 1925.11.1.29 (
Australia
; Dendy collection). This specimen is been suggested as a
neotype
.
Description:
The colour alive is unknown but after fixation it is beige (
Figure 9
A). The cormus is formed by thin and tightly anastomosed tubes, although some larger tubes are also present. The entire cormus is surrounded by an external membrane and another membrane covers the atrium. Several crustaceans are present inside the studied specimen.
The skeleton consists of two categories of triactines. The cortical skeleton is formed by triactines with thicker actines (
Figure 9
B), while the skeleton of the choanocyte tubes is formed by triactines with thinner actines (
Figure 9
C). As there are only triactines, the lumen of the tubes is smooth. The atrial skeleton is composed of triactines similar to those of the choanocyte tubes.
TABLE 6.
Spicules measurements (µm) of the proposed neotype of
Leucascus protogenes
(BMNH 1925.11.1.29).
Spicules
|
Length (µm)
|
Width (µm)
|
Min |
Mean SD |
Max |
Min |
Mean SD |
Max |
N |
Cortical triactine |
96.0 |
144.2 19.4 |
177.0 |
18.0 |
19.7 1.5 |
21.0 |
30 |
Choanosomal triactine |
84.0 |
123.7 14.8 |
144.0 |
13.5 |
14.3 0.7 |
15.0 |
30 |
Spicules
(
Table 6
):
(
i
) Cortical triactines (
Figure 9
D): Regular. Actines are conical, straight, with blunt tips; (
ii
) Triactines of the tubes and of the atrial skeleton (
Figure 9
D): Regular. They are similar to the cortical triactines, but their actines are thinner.
Remarks:
The original description of
Ascetta primordialis
and its four varieties is very incomplete. The variety
protogenes
, for example, was distinguished from the others only by the presence of triactines of one size forming a monolayer on the surface, while the others showed more than one layer or more than one size category of triactines. Moreover, Haeckel (1872) did not designate any
type
material and did not make any correlation between the varieties and the analysed specimens, which are probably lost (Burton 1963). He also did not mention any special distribution for
A. protogenes
, just making the comment that this variety was of a common form. For
Ascetta primordialis
as a whole he cited the following distribution: Mediterranean Sea, Adriatic Sea, Red Sea, Atlantic Ocean, Indian Ocean, and Pacific Ocean.
FIGURE 9.
Leucascus protogenes
(BMNH 1925.11.1.29, neotype). A, Fragment of the preserved specimen; B, Cortical membrane; C, Triactines in the wall of a choanocyte tube; D, Cortical (left) and choanosomal (right) triactines.
After Haeckel (1872),
Ascetta primordialis
var.
protogenes
was mentioned again only by Dendy (1891) when he was describing specimens from near Port Phillip Heads (
Australia
). Dendy (1891) elevated
protogenes
to the species rank, transferred it to the genus
Leucosolenia
and redefined it, as Haeckel had included specimens with different
types
of aquiferous system organization in this variety. Since then,
Leucosolenia protogenes
(Haeckel, 1872)
has been considered
sensu
Dendy (1891).
In the same work, Dendy synonymized
L. protogenes
with
Ascetta procumbens
Lendenfeld, 1885
, mentioning that the
type
specimen he analysed of
A. procumbens
represented
L. protogenes
. The
type
specimens of
A. procumbens
were later analysed by Klautau and Valentine (2003) that revalidated
A. procumbens
as
Clathrina procumbens
. Klautau and Valentine (2003) mentioned that one of the
type
specimens examined by Lendenfeld (and probably by Dendy; BMNH 1886.6.7.3) was indeed not
C. procumbens
, but
Leucosolenia
(
Ascaltis
)
protogenes
.
After analysing more and better preserved specimens, we concluded that this species is in fact
Leucascus protogenes
and we propose the specimen BMNH 1925.11.1.29 to be the
neotype
of this species. Up to date,
L. protogenes
is the only species of the genus with only triactines.
FIGURE 10.
Leucascus roseus
.
A, Specimen alive (photo. E. Hajdu); B–F, MNRJ 5827, holotype. B, Preserved specimen; C, Cortical membrane; D, Spicules in the wall of a choanocyte tube; E, Apical actine of a tetractine projected into the lumen of a tube (arrow); F, Atrial membrane.
Distribution:
Indian and Pacific Oceans: Near Port Phillip Heads, Abrolhos Islands, and Port Jackson—Australia (von Lendenfeld 1885; Carter 1886; Dendy 1891; Dendy & Frederick 1924); Moko Hinau Island and
Island
Bay—New Zealand (Brøndsted 1926). The occurrence of this species in
Japan
(Tanita 1943a, b) could not be confirmed as these descriptions of
L. protogenes
are very incomplete. Spalding
et al
. (2007) corresponding ecoregions: Bassian, Houtman, Manning-Kawkesbury, Northeastern
New Zealand
, and Central
New Zealand
.