Revision of the genus Phyrella (Holothuroidea: Dendrochirotida) with the description of a new species from Guam
Author
Michonneau, François
Author
Paulay, Gustav
text
Zootaxa
2014
2014-01-31
3760
2
101
140
journal article
5952
10.11646/zootaxa.3760.2.1
7ba5f9ac-4317-459f-9829-2975de0a42ff
1175-5326
4908324
C0E4CA6E-6D93-477E-99F6-14FFB652A2A7
Phyrella? ambigua
(
Cherbonnier, 1988
)
Fig. 23
Lipotrapeza ambigua
Cherbonnier, 1988: 236–237
, fig. 104 A–H;
Type
series: MNHN
EchHh
2767;
type
locality:
Madagascar
,
Tuléar
=
Phyllophorus (Phyllophorella) contractura
Cherbonnier, 1988: 226–228
, fig. A–L;
Holotype
: MNHN EcHh 3601; type locality:
Madagascar
, Tuléar
=
Thyonidiella oceana
Heding & Panning, 1954: 172–173
(in part)
Thyonidiella oceana
:
Cherbonnier, 1988: 229–232
, fig. 101 A–G
=
Thyonidiella cherbonnieri
Rowe & Richmond, 2004: 3306–3307
Material examined.
Madagascar
,
Tuléar
(all)
:
MNHN
EcHh
2767, (
syntypes
of
Lipotrapeza ambigua
)
.
MNHN
EcHh
3601 (
Holotype
of
Phyllophorus contractura
)
.
MNHN
EcHh
2918 (
Paratype
of
Phyllophorus contractura
),
September 12
th
1972
, coll.
Thomassin
,
1 specimen
.
MNHN
EcHh
2969,
August 17
th
, 1969
, coll.
Thomassin.
Paralectotypes
:
MNHN
EcHh
3863,
June 10
th
, 1972
, coll.
Thomassin
,
9 specimens
.
MNHN
EcHh
2223, 1972, coll.
Galénon
,
7 specimens
.
MNHN
EcHh
2913,
May 16
th
, 1972
, coll.
Thomassin
,
8 specimens
.
MNHN
EcHh
2921,
June 11
th
, 1972
, coll.
Thomassin
,
1 specimen
.
MNHN
EcHh
3794, 1975, coll.
Galénon
,
4 specimens
.
MNHN
EcHh
2905,
June 12
th
, 1972
,
1 specimen
.
MNHN
EcHh
2920,
May 29
th
, 1972
, coll.
Thomassin
,
1 specimen
.
Description based on
type
series of
P. ambigua
.
Two specimens partially dried up. One specimen is intact with introvert retracted; the other is dissected, with pharyngeal complex removed and in the jar. Body wall stiff, leathery, brown, covered with tube feet without any particular arrangement. Specimens about
1 cm
long and
5 mm
wide, light brown with relatively large, tubular podia covering the entire body wall; anal teeth present. Cherbonnier indicates that this species has 20 tentacles in 3 circles. The examination of the tentacles associated with the calcareous ring found in the jar reveals at least 16 tentacles (exact number difficult to assess given the state of preservation) in 2 circles. Cherbonnier indicates that radials and inter-radials are not fragmented, however his drawing (Fig. 104, H), which matches closely the calcareous ring found in the jar, shows that they are. Internal anatomy shows absence of intestine, respiratory trees shorter than in other
Phyrella
, gonads in two tufts formed by long, thin tubes, madreporite and stone canal apparently missing (Cherbonnier indicates that the stone canal is long and thin ending in a spherical madreporite), one globular Polian attached to the pharyngeal complex. Mid-dorsal body wall devoid of ossicles; podia with end plates and perforated plates. Cloacal region body wall with rosettes (Fig. 104, D in
Cherbonnier, 1988
) and irregular tables (Fig. 104, A, B in
Cherbonnier, 1988
), podia have end plates and perforated plates (Fig. 104, E in
Cherbonnier, 1988
).
Remarks.
We consider
Lipotrapeza ambigua
Cherbonnier, 1988
,
Phyllophorus contractura
Cherbonnier, 1988
, and
Thyonidiella cherbonnieri
Rowe & Richmond, 2004
to all represent the same species. As first revisers, we select
ambigua
as the valid name for this species, appropriate given the confusion surrounding this assemblage and the poor state of preservation of the specimens. It is notable that the
type
series of all three species were collected at the same locality.
In the description of
Lipotrapeza ambigua
, Cherbonnier
noted that the lot 2767 includes
12 specimens
(
holotype
and
paratypes
). However, this lot only includes
2 specimens
, and the
holotype
was not identified within the lot.
Synonymy and description of
Phyllophorus (Phyllophorella) contractura
.
The
holotype
(MNHN Hol 3601) is in poor condition. As indicated by Cherbonnier, it is about
9 mm
long,
4 mm
wide, light brown with relatively large, tubular podia covering the entire body. The body wall shows evidence of decomposition. All internal organs and the cloacal region are missing. The small calcareous ring has been opened, and some of its elements are not in their natural position, however one of the inter-radials is clearly fragmented and does not match Cherbonnier's drawing (Fig. 99, I). Furthermore, the body wall does not contain ossicles, and the podia have end plates and perforated plates. The general appearance of the
holotype
, in conjunction with the fragmented inter-radials, the ossicle assemblage, the presence of anal teeth (as reported by Cherbonnier), and the collection locality indicate that this specimen is indistinguishable from
Lipotrapeza ambigua
. Examination of the
paratype
indicates that it was used for illustrations, and is a different species, assignable to
Phyllophorus
sensu lato
.
Synonymy and description of
Thyonidiella cherbonnieri
.
This species was erected as a new name for Malagasy specimens incorrectly attributed to
Thyonidiella oceana
by
Cherbonnier (1988)
(see Remarks under
Phyrella
above). As noted by
Rowe & Richmond (2004)
this species resembles
T. oceana
except for the lack of tables and presence of plates in the body wall. Most of the specimens identified by Cherbonnier as
T. oceana
are fairly similar. Body wall soft, fairly thin and covered with tube feet (
Fig. 23
, MNHN EcHh 2969). Color light to dark brown in preservative; some specimens darker at the extremities. Small (
11–21 mm
long,
5–8 mm
wide), mostly cylindrical, with tapering posterior end and blunt anterior end when the introvert is retracted. Introvert retracted in all specimens examined,
1–2 mm
long, light gray to almost black. Tube feet relatively long (~
1 mm
), of the same color as the rest of the body, abundant, covering both radial and inter-radial area without particular arrangement. Fifteen small, dark brown tentacles (number of tentacles on each circle difficult to discern). Cloaca dark brown, surrounded by 5 small anal teeth. Polian vesicle single, light brown, with sparse small dark spots, about
1 mm
long. Stone canal lightly-calcified, embedded in membrane surrounding calcareous ring; madreporite single, small (<
1 mm
in diameter), spherical, partially embedded in membrane surrounding calcareous ring. When present, gonads in two tufts, composed of single, unbranched,
2–4 mm
tubes. Digestive tract relatively short, most specimens eviscerated. Mid-dorsal body wall without ossicles. Podia with end plate and perforated plates. Cloacal region body wall with rosettes and tables in some specimens (not reported by Cherbonnier), podia with end plate and perforated plates. Cherbonnier notes he examined
25 specimens
collected by Galénon, Thomassin in Tuléar
Madagascar
in 1975. MNHN holds
32 specimens
in 8 lots of this species, all collected by Galénon or Thomassin in Tuléar
Madagascar
, between 1969 and 1975;
four specimens
date from 1975. We consider these discrepancies to be likely
lapsus calami
, and consider all material listed above to correspond to the
syntype
series designated by
Rowe & Richmond (2004)
.
All specimens examined here are substantially smaller than other
Phyrella
species.
This species fits
Phyrella
except for the absence of tables in the body wall, that it is smaller, and the presence of “bâtonnets des podia” (which we did not observe in our preparations). The shape of the body; the propensity to eviscerate; the size, shape and distribution of tube feet on the body; the shape of the perforated plates; the fragmentation of the calcareous ring and the presence of posterior prolongations; the presence of anal teeth; the presence of rosettes in cloaca and introvert make this species closer to
Phyrella
than to any other phyllophorid genus with fragmented inter-radials.
Ecology & distribution.
Known from
Madagascar
, with specimens from
Mauritius
& Rodriquez, Mascarene Islands (not seen by us) also attributed to this species by
Rowe & Richmond (2004)
. Malagasy specimens were collected at low tide level under rocks set in sand on the Tuléar barrier reef. In Rodriquez, the species was found in a fore reef habitat under coral rock in
13–15m
, as well as in a coastal bay. The
Mauritius
specimens were collected at Cannoniers Point.