Solaster E.Forbes 1839

Solaster sp. 1

Figure 18E

This species was stellate (R/r=~2.1–2.4) possessed a thick disk with nine relatively short, tapering arms. Abactinal paxillae weakly developed, but widely spaced on the surface. Each arm with approximately 20–30 evenly spaced paxillae, per side (40 to 60 from arm tip to arm tip) each with approximately three to six spinelets forming the actinolateral boundary. Color varied from orange to bright magenta-red.

Crab Associate & Ecological Notes

This red species was observed on a flat, muddy plain populated by what appeared to be ophiuroids with elongate arms possibly Ophiomusa lymani. Jangoux (1982) have indicated ophiuroids as a prey items for Solaster endeca, which is similar in appearance. This species hunting for ophiuroids would be consistent with the fact that while most asteroid observations are solitary, two individuals of this species are present within 60 cm of one another.

The orange colored Solaster sp. 1 individual showed a small lithodid crab present on the abactinal surface of one arm. This area was significantly discolored and was a distinct white color as opposed to the darker orange on the remainder of the body. Its unclear if the crab had been feeding upon the surface tissue of the star or if the discoloration could have originated as a result of constant movement by the crab on that specific region of the arm.Although no accounts of deep-sea lithodid predation on asteroids were located, the shallow-water lithodid crab Paralithodes camtschatica has been observed to attack and feed on the asteroid Pycnopodia helianthoides (Feder, 1980).

Occurrence: Pamlico Canyon Ridge, 1587–1673 m.

Images Examined

brittle star field. Pamlico Canyon Ridge, North Atlantic 34.77461, -75.3424, 1673 m EX1806_IMG_20180625T141433Z_ROVHD.jpg

EX1806_IMG_20180625T141541Z_ROVHD.jpg

with crab. Pamlico Canyon Ridge, North Atlantic 34.77497, -75.34556, 1587 m EX1806_IMG_20180625T165230Z_ROVHD.jpg