New taxa and taxonomic revisions to the Poraniidae (Valvatacea; Asteroidea) with Comments on Feeding Biology
Author
Mah, Christopher L.
Author
Foltz, David W.
text
Zootaxa
2014
3795
3
327
372
journal article
45800
10.11646/zootaxa.3795.3.7
f0614c34-e456-4231-a5c0-281479168dac
1175-5326
252134
77AB3EAA-DA13-4C8D-885D-EB9F5F14DE34
Clavaporania fitchorum
nov. sp.
Figure 3
A–F
Etymology.
The species epithet is named for Mason and Lisa Fitch, for their support of academic endeavors.
Taxonomic notes.
This species is only the second recognized poraniid from the
Macquarie Island
region and the first from such the upper bathyal zone.
O’Hara (1999)
recognized
“
Porania
”
antarctica
from
13–105 m
depth.
“P.”
antarctica
lacks the covering of spinelets on the body surface, the well-developed spines on the abactinal and marginal surface and the strongly stellate body.
Clavaporania
shares a reticulate abactinal skeleton with
Bathyporania
, “
P. antarctica
, and
Poraniopsis
. Large primary spines are present in all known species of
Bathyporania
and
Poraniopsis
but not in all species of
“P.”
antarctica
.
Given the more distant phylogenetic position of
Poraniopsis
, it is unclear if the skeleton and spines are shared plesiomorphies or derived characters in
Clavaporania
.
Occurrence.
South of
Macquarie Island
,
1574–1693 m
.
Description.
Body shape, strongly stellate (R/r=5.4), Arms round in cross-section, disk small (
Fig. 3
A). Pedicellariae not observed.
Abactinal skeleton densely reticulate, embedded in a thick, fleshy skin. Skeleton composed of larger, reticulate ossicles and smaller, secondary ossicles distributed throughout. Single papular pores. Open papular meshes absent. Abactinal and marginal spines are strongly clavate, almost mace-like, with blunt, but finely notched to irregular tips (
Figs. 3
D, F). Some spine tips with one to three short, thorny tips (
Figs. 3
F). Spines sit on strongly convex bosses present along reticulated network. Abactinal and lateral surface with a dense covering of spinelets, these completely cover the abactinal and lateral surfaces. Individual spinelets with one or two points; approximately five spinelets per mm. Surfaces around spine bases lacking spinelets. Fifteen short spines surrounding anal periphery. Madreporite on strongly convex plate, surrounded by short spinelets. Sulci relatively simple.
Marginal plates with one-to-one correspondence proximally, becoming offset distally. Marginal plate surface, as on the abactinal surface, covered by dense spinelets. Marginal series strongly swollen (
Fig. 3
C), superomarginals and inferomarginals each with prominent spine-bearing clavate/mace-like and/or two pronged thorny tip, one or two per plate, (
Fig. 3
C, D, E) identical to those on abactinal plates forming distinct periphery around actinolateral edge. Some marginal spines with a broad spearhead-like shape. Intermarginal region with single papular pore (
Fig. 3
C). Marginal plates form distinct, closely articulated series separate from the abactinal reticulation.
Actinal surface composed of three plate series (
Fig. 3
B). Series with largest sized plates distalmost, near contact with inferomarginal plates. Actinal plates smaller, more proximally. Plates are quadrate with rounded edges becoming smaller and more round. Actinal surface lacking large spines, but covered by widely spaced, tiny spinelets similar to those on abactinal surface (
Fig. 3
B, E). Actinal and oral plates covered by skin.
Furrow spines number one or two, with a single, larger subambulacral spine, all in a transverse row with flattened and squarish to pointed tips (
Fig. 3
E). Furrow spines are about half the thickness of the subambulacral spine, but all spines similar in length. Adambulacral plates rectangular in outline. Two blunt, pointed spines per oral plate directed into mouth (
Fig. 3
E). Oral plate furrow spines three to four. Large blunt spine with wide, flat tip on oral plate surface.
Color in life unknown.
FIGURE 3.
Clavaporania fitchorum
nov. gen, nov. sp. A.
Holotype. USNM 1232816. Abactinal surface, (R=4.9)
B.
Actinal surface.
C.
Marginal plate series.
D.
Marginal plates.
E.
Actinal surface, close up.
F.
Mace-like abactinal spines and spinelets covering abactinal surface.
FIGURE 4.
Marginaster pectinatus
& size comparisons
.
A.
USNM
E30130
Marginaster pectinatus
Abactinal
surface. (R=0.9).
B.
M. pectinatus
actinal surface.
C.
USNM Paralectotype 18496, abactinal surface
Porania pulvillus
. (R= 0.9)
D.
USNM 1136790
Glabraster antarctica
abactinal surface (R=1.2)
Material examined.
Holotype
,
USNM
1232816, South of
Macquarie island
,
56º21’S
,
158º28’E
,
1574–1693 m
, Coll. USC R/V
Eltanin
(1 dry spec. R=4.9, r=0.9)