Evoplosoma sp. 1

Mah, Christopher L., 2022, New Genera, Species and Occurrences of Deep-Sea Asteroidea (Valvatacea, Forcipulatacea, Echinodermata) collected from the North Pacific Ocean by the CAPSTONE Expedition, Zootaxa 5164 (1), pp. 1-75 : 49

Evoplosoma sp. 1

FIGURE 16A, B

The observations reported herein show further feeding of species in the genus Evoplosoma but identification to known species was not possible.

This includes two observations of Evoplosoma species from Wake Island feeding on primnoid octocorals, which was an unusual departure from the more common Isididae observed as prey. Figure 16A shows what appears to be a fully extended pyloric stomach over a bare primnoid stalk. This species appears to show some variation in feeding relative to Hippasteria capstonei n. sp. ( Fig. 17B ) which was observed feeding on primnoid corals but only on the internal polyps. Evoplosoma appears to entirely devour all of the soft-coral tissue suggesting different strategies or perhaps different stages of feeding for these different corallivorous species.

Images Examined feeding on Primnoidae Wake Island region, 25.16108084, -161.6456548, 1705 m EX1606 _IMG_20160802 T225315 Z_ ROVHD _COR_ ASR.jpg

feeding on gold stalk-Primnoidae?. West Wake Atoll, Wake Island region, 17.30782363, 165.9618851, 1941 m EX1606 _IMG_20160809 T023948 Z_ ROVHD _ ASR _ AUD _HL.jpg

no feeding. No Name Guyot , Wake Island region, 20.44506063, 163.7179445, 1859 m. EX1606 _IMG_20160803 T010704 Z_ ROVHD _ ASR.jpg

Figures

FIGURE 16. Evoplosoma spp. Feeding observations. Evoplosoma sp,. Wake Island. A. Feeding on Primnoidae. 1704 m. B. Feeding on likely Primnoidae, Wake Island Atoll, 1940 m. C. Hawaiian Islands region, North Maro Seamount, Hawaiian Islands, 1613 m.

FIGURE 17. Hippasteria capstonei n. sp. USNM 1457387. A. Abactinal view. Scale bar=5.0 mm. Inset showing pedicellariae and surface details. Pedicellariae=1.5 mm length. B. In situ observation of holotype feeding on primnoid coral, Johnston Atoll, 1982 m. C. Actinal view. Scale bar=5.0 mm. D. Abactinal-lateral view showing pedicellariae and spination. Scale bar=2.0 mm. E. Lateral view showing spines and other accessories. Scale bar=2.0 mm. F. Actinal close up, showing spination, etc. Scale bar=2.5 mm. G. Adambulacral spination, including furrow and subambulacral spines. Scale bar=1.0 mm.