The genera and species of Comatulidae (Comatulida: Crinoidea): taxonomic revisions and a molecular and morphological guide
Author
Summers, Mindi M.
Author
Messing, Charles G.
Author
Rouse, Greg W.
text
Zootaxa
2017
4268
2
151
190
journal article
33045
10.11646/zootaxa.4268.2.1
e114acb7-3683-4094-a53f-c9bc7ed84353
1175-5326
580173
0742D287-B82C-4014-A6AC-C357F259D5D7
Phanogenia
Lovén, 1866
Table 1
,
Fig. 7
Type species.
Phanogenia typica
Lovén, 1866
.
Other included taxa (7).
Alecto Novae Guineae
Müller, 1841
;
Actinometra distincta
Carpenter, 1888
;
Actinometra gracilis
Hartlaub, 1893
;
Actinometra multibrachiata
Carpenter, 1888
;
Comaster fruticosus
AH
Clark, 1911b
;
Comaster schönovi
AH
Clark, 1918a
;
Comatula serrata
AH
Clark, 1907b
;
Comaster sibogae
AH
Clark, 1912a
.
Diagnosis.
Mouth central in fully developed individuals; up to 170 arms; cirri absent or present; IBr2 series united by cryptosynarthry or synarthry; first syzygy at 3+4 on arms arising from IBr, at 1+2 on arms arising from subsequent brachitaxes; IIBr and subsequent brachitaxes 2(1+2) or 4(3+4); distal intersyzygial interval 3–4; pinnule combs at intervals to near arm tip; comb teeth tall, triangular to spade-shaped, confluent with outer edge of pinnule; proximal tooth saucer-like and transverse.
Distribution.
Tropical Indo-western Pacific from northern
Australia
(Jurien Bay, WA, to Lady Elliott I., QLD), west to
Madagascar
and the Red Sea, east to
Fiji
and
Kwajalein Atoll
, and north to Sagami Bay,
Japan
(
Chen
et al.
1988
; AH
Clark 1931
; AM
Clark 1972
;
Kogo & Fujita 2014
;
Rowe & Gates 1995
;
Zmarzly 1985
). Depth range:
0–210 m
; only
P. distincta
and
P. serrata
occur regularly at depths greater than
100 m
; a few records from greater depths are likely errors.
Molecular
results.
Molecular
results for this genus are congruent with results in
Owen
et al.
2009
(
Fig. 7
).
Clade A
of
Owen
et al.
(2009)
is herein referred to as
Phanogenia typica
based on a new specimen collected near the
type
locality,
New Harbor
,
Singapore
;
Clade B
is designated as
Phanogenia gracilis
type
A; and
Clade C
is designated
Phanogenia gracilis
type
B.
Phanogenia gracilis
type
A and
type
B had greater than 5.5% pairwise divergence in uncorrected
COI
(
intra
specific divergences of less than 2.5% for both).
Both
were at least 3.3% and 4.0% divergent relative to
P. typica
and
P. multibrachiata
, respectively
.
No
morphological characters have been found that distinguish among
P. gracilis
type
A,
P. gracilis
type
B, and
P. typica
(e.g.,
Owen
et al.
2009
, and below). Also, current data does not allow determining to which clade the name
gracilis
should apply. The
type
locality for
P. gracilis
is Edam
Island
,
Java
Sea,
Indonesia
(Göttingen Museum), from which we lack specimens.
Phanogenia typica
alone returned up to 8.6%
intra
specific divergence, in comparison with only 0.5% for
P. multibrachiata
, suggesting that the former may include additional cryptic species.
Remarks.
Three taxa in
Phanogenia
are reported as reef-dwellers:
P. gracilis
,
P. typica
, and
P. multibrachiata
(
Messing 1998a, and references therein
). The first two have a reduced centrodorsal with at most a few rudimentary cirri in small specimens. The second has a well-developed centrodorsal with numerous cirri.
Messing (1998a)
distinguished the
holotype
of
P. typica
, from
Singapore
, on the basis of its longer pinnule combs relative to those of
P. gracilis
from elsewhere, in specimens of similar size: 24–29 teeth on P1, and rarely fewer than 10 teeth on brachial pinnules, versus P1 with only 10–12 teeth and almost always fewer than 10 teeth on subsequent pinnules, respectively. He therefore treated all acirrate
Phanogenia
from Indo-western Pacific reefs except the
P. typica
holotype
as
P. gracilis
sensu lato
. However, new material from the
Singapore
type
locality includes specimens with long “
P. typica
” combs as well as other specimens, otherwise indistinguishable (including the same color pattern) and from the same habitat, with short “
P. gracilis
” combs (
Messing & Tay 2016
). Similarly, comb form varies among specimens in all three molecular clades discussed above. The
P. typica
clade was so named because it includes a long-combed specimen from the
Singapore
type
locality.
The remaining taxa resemble
P. multibrachiata
in having a well-developed centrodorsal with numerous cirri. They differ chiefly on the basis of characters that vary with size, i.e., arm number and number and proportion of cirrals, with smaller taxa generally recorded from greater depths, e.g.,
P. multibrachiata
(to 160 arms; ~
20–50 m
),
P. fruticosa
(37–63 arms;
35–106 m
),
P. sibogae
(60 arms;
88 m
),
P. distincta
(30–50 arms; 15–290 [chiefly ~70– 110] m), and
P. serrata
(13–30 arms;
100–174 m
) (AH
Clark 1931
; AM
Clark 1972
;
Kirkendale & Messing 2003
;
Kogo 1998
; Messing, unpublished observations). Some or all may prove to be synonyms.
Chen
et al
.’s (1988)
report of a small
P. distincta
from reef crevices in
12–25 m
off
China
may be a juvenile
P. multibrachiata
. Messing (1998) noted that the
holotype
of
P. novaeguineae
(60 arms; no depth recorded), currently treated as accepted (Messing 2001), appeared intermediate between
P. fruticosa
and
P. multibrachiata
and that the three might prove developmental stages of a single species.