Peltaster placenta

Peltaster placenta (Müller & Troschel, 1842)

Figure 14 A–C

Comments

Peltaster is a widely occurring goniasterid, containing two Pacific and one Atlantic species, all of which display widespread occurrence. Peltaster placenta for example has been documented on both sides of the Atlantic and across a broad bathymetric range, from 10 to over 1000 m depths. Although differentiated from Ceramaster and Sphaeriodiscus, the morphological boundaries between these two genera and Peltaster has been historically difficult to establish (e.g. see Mah 2018). All three genera demonstrate pentagonal body shape with relatively large marginal plates and granule-covered abactinal plates. Sphaeriodiscus and Peltaster show close morphological similarity and further understanding of variation and phylogenetic relationships might result in synonymy of the two genera.

Feeding Observation

This species was observed perched upon an unidentified demosponges present among dead, Lophelia rubble in two observations (Figs. 14A, B). Small soft corals were also present along the surface of the sponge, suggesting that Peltaster could also have been feeding on these as well as the sponge. Peltaster placenta was also observed on a hexactinellid (glass) sponge (Fig. 14C), displaying feeding behavior.

This species has also been reported feeding on antipatharians by Bo et al. (2018).Added discussion on Peltaster feeding is included in sponge feeding discussion below.

Occurrence: Western Atlantic: Cape Cod region, Massachusetts, New York, Florida, Georgia, Louisiana, Antigua and Barbados, Bahamas, Jamaica, Puerto Rico, Guadeloupe, Venezuela, Eastern Atlantic: Norway (near Trondheimsfjord) south to the equator, Iceland, Mediterranean, including Tunisia. 10–1007 m.

Images Observed

Bajo de Sico, Puerto Rico, 18.292659, -67.460653, 310 m

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Stetson Mesa “Seep”, 29.10912, -79.44749, 738 m

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27 June, Stetson Mesa “Seep”, 30.435198, -79.583484, 778 m EX1903L2_IMG_20190627T 170506 Z_ROVHD.jpg