Iophon hesperidesi Rios, Cristobo & Urgorri 2004

Iophon hesperidesi Rios, Cristobo & Urgorri, 2004

(Figure 4)

Specimens. BELUM. Mc 2015.584 Port Circumcision, Pieterman Island (65°10.471’S, 64° 08.070’W), depth 5–9 m; collected by C. Goodwin and E. Priestley, 15/02/2015.

BELUM.Mc2015.653 The Minnows, Prospect Point (66°01.642’S, 65° 21.323’W), depth 6–18 m; collected by C. Goodwin and E. Priestley, 17/02/2015.

External morphology. In situ appearance (Figure 4A): Both specimens were a beige crust. One was on an algal holdfast, the other over a bivalve shell.

Preserved appearance. Soft, brown, easily broken crust.

Skeleton (Figure 4B): Reticulation of bundles of 3–4 oxea. Ectosomal pallisade of tylotes.

Spicules: Styles (Figure 4C): Heads spined with a few large spines (Figure 4D). BELUM.Mc2015.653 426(452)478 by 12(16) 20 µm; BELUM.Mc2015.584 349(370)404/11(16) 20 µm.

Tylotes (Figure 4E): With rounded, densely spined ends (Figure 4F). BELUM.Mc2015.653 272(289)304 by 7(10) 12 µm; BELUM.Mc2015.584 248(266)283/8(9) 11 µm.

Chelae (Figure 4G): With a prominent spine on the base: BELUM.Mc2015.653 14(17) 19 µm; BELUM. Mc2015.584 17(20) 23 µm.

Bipocilla (Figure 4H): BELUM.Mc2015.653 8(10) 11 µm; BELUM.Mc2015.584 8(9) 12 µm.

Remarks. The type location for this species is Livingstone Island, South Shetland Islands between 21– 30m. The encrusting form, skeleton and spicule dimensions correspond well to those of the holotype and paratype (Styles 370–410 by 5–20 µm; Tylotes 208–285 by 4–10 µm; Bipocilla 9–11 µm and chelae 19–35 µm). We did not note thin acanthostyles but these were very rare in the type specimens.

Distribution. There are currently no other records in the scientific literature. These records extend the range of I. hesperidesi considerably further south along the Antarctic Peninsula.