Ushanaia fervens gen. et sp. nov.

urn:lsid:zoobank.org:act: D8AA094B-80EA-4BAE-A4A7-C93F44708100

Figs 1D–E, 2J, M, 11D, 28B, 31–33, 34A

Alcyonium aurantiacum – Benham 1928 in part: 71–75, figs 6–11. — McFadden et al. 2006b: 517, 521, 523, figs 1, 3.

? Alcyonium aurantiacum – Grange et al. 1981: 211–212, 214, 216, 224, figs 2, 4. — Westerskov & Probert 1981 in part: 111, pl. 28. — Goldberg et al. 1990: 99, fig. 4. — Grange et al. 2010 in part: 148.

Diagnosis

Colonies encrusting, red to orange with white polyps. Collaret and points bright orange and composed of slender, often flattened, warty to spiny spindles and thorny clubs. Tentacles contain irregular, warty, scale-like sclerites. Polyp neck contains warty rod- and spindle-like sclerites. Polyp mounds contain similar warty rod-like and spindle-like sclerites, which grade into clubs and irregularly branched forms. Surface contains warty radiates and spindle-like forms. The interior contains similar sclerites.

Etymology

The species name is the Latin ‘ fervens ’, meaning ‘red-hot’ or ‘burning’ and referring to the flame-like red and orange colour combination of the examined specimens.

Material examined

Holotype NEW ZEALAND • Fiordland, Te Puaitaha / Breaksea Sound, Sunday Cove; 45.5952° S, 166.7422° E; depth 4 m; 16 Jan. 2018; R. Kinsey leg.; stn Z17956; NIWA 156311.

Paratypes NEW ZEALAND • 3 specimens; Fiordland, Milford Sound / Piopiotahi; 44.6183° S, 167.8588° E; depth 25 m; 30 Mar. 1981; New Zealand Oceanographic Institute exped.; stn M773; NIWA 3970 • 4 specimens; same collection data as for holotype; NIWA 126412 .

Additional material

NEW ZEALAND – Wellington • 1 specimen; Sorrento Bay, on wharf piles; 41.2547° S, 174.9012° E; 20 Jul. 2020; NIWA exped.; stn WLG31205-SF; NIWA MITS 75304. – Fiordland • 1 specimen; Milford Sound / Piopiotahi; 44.5833° S, 167.7833° E (estimated); depth 20 m; 2 Sep. 1996; stn Z10091; NIWA 154128 • 4 specimens (and several small fragments); Milford Sound / Piopiotahi; 44.6033° S, 167.8288° E; depth 27 m; 29 Mar. 1981; New Zealand Oceanographic Institute exped.; stn M763; NIWA 142996 • 3 specimens; Milford Sound / Piopiotahi, Harrison Cove, Underwater Observatory; depth 13 m; 16 Jun. 2003; K. Gowlett-Holmes leg.; MAGNT C014322 • 3 specimens (and several small fragments); Taitetimu / Caswell Sound; 45.0033° S, 167.1567° E; depth 30 m; 18 Apr. 1991; Chris N. Battershill and National Cancer Institute leg.; stn Q66C/Z7552; NIWA 17099 • 1 specimen; Doubtful Sound, Deep Cove; depth 12–14 m; 19 Jun. 2003; K. Gowlett-Holmes leg.; MAGNT C014323 • 1 specimen; Te Puaitaha / Breaksea Sound, Vancouver Arm; 45.5250° S, 166.9250° E; 21 Nov. 1999; M.S. Roy leg.; MAGNT C014989 • 1 specimen; Wet Jacket Arm / Moana Uta; 45.6667° S, 166.7333° E; 21 Nov. 1999; M.S. Roy leg.; MAGNT C014988 .

Description (holotype, NIWA 156311)

Colony form

The holotype consists of a colony that measures ~ 4 cm by ~ 3 cm and up to ~ 3 mm thick, and encrusts a sponge fragment (Figs 28B, 31). The holotype (ethanol-preserved) is dark red, fading to lighter shades of red or orange towards its edges or at thinner sections. Polyps are irregularly spaced, tending to concentrate towards the thicker, fleshier parts of the colony but also occasionally emerge from very thin sections. Polyps are white and 0.75 mm to 2 mm tall when expanded. Larger polyps tend to occur on thicker sections of the colony. The collaret and point sclerites are bright orange, contrasting against the white flesh of the polyps and the sometimes darker red or orange colour of the rest of the colony (Figs 2J, M, 29, 31B–C).

Sclerites

Points are composed of slender, warty to spiny spindles (~ 0.2–0.3 mm long), many of which are flattened, and thorny clubs are present distally (~ 0.12–0.32 mm long) (Fig. 32A–B). Proximally, the spindles become larger and more crescentic (~ 0.12–0.28 mm long), transitioning into a transverse orientation and merging with the collaret, which is seven to ten rows deep (~ 0.2–0.55 mm long) (Figs 2J, M, 32A, 34A). The tentacles contain irregular, warty, scale-like forms, often slightly crescentic (~ 0.1–0.3 mm long) (Fig. 32C). The polyp neck contains warty rod- and spindle-like sclerites (~ 0.1–0.22 mm long) (Fig. 32D). Close to the polyp neck, polyp mounds also contain abundant warty rod-like and spindlelike forms (~ 0.08–0.16 mm long), which grade into clubs and a few irregularly branched forms (~ 0.08– 0.18 mm long) further away from the polyp (Fig. 33A). The surface between polyp mounds is dominated by warty radiates and spindle-like forms (~ 0.08–0.2 mm long) (Fig. 33B). Similar radiates and spindlelike forms are found in the interior of the thick, fleshy areas of the colony, although here they tend to be smaller (~ 0.06–0.16 mm long), less variable in shape and more sparsely ornamented (Fig. 33C).

Variability

Preserved specimens of Ushanaia fervens gen. et sp. nov. are somewhat variable in overall colony colour, ranging from the dark red seen in the holotype and NIWA MITS 75304, to lighter red and orange in the other specimens (Fig. 28B). All specimens are otherwise similar in growth form. All eleven lots are also very uniform in their sclerite compositions, with slight variations in size ranges representing the only appreciable difference between some individual colonies, but these always fall within the ranges described for the holotype (Figs 32–33).

Comparisons

Differences to Ushanaia ferruginea gen. et sp. nov. are discussed under that species. Much like Ushanaia ferruginea gen. et sp. nov., U. fervens gen. et sp. nov. clearly differs from U. solida gen. et sp. nov. in not forming fleshy lobes to the same extent as that species and in possessing polyps of around twice the size (up to 2 mm vs up to 1 mm; Fig. 34). Ushanaia fervens also lacks the distinctive, broad, flattened collaret and point sclerites found in U. solida (compare Figs 32A and 35A). Conversely, U. solida lacks the conspicuous, bright collaret and points colouration which is characteristic of U. fervens specimens.

Habitat and distribution

All specimens were collected in Fiordland, except NIWA MITS 75304, which was collected in Wellington Harbour, and all specimens (for which a depth was recorded) were collected at shallow depths of ≤ 30 m (Fig. 1D–E). MAGNT C014323 was collected on a rock wall and MAGNT C014988 and MAGNT C014989 are recorded as encrusting black coral. NIWA MITS 75304 was collected from a wharf pile.

Remarks

Having been collected in Fiordland, the encrusting specimen described by Benham (1928) was most likely a member of Ushanaia fervens gen. et sp. nov. Similarly, the “ A. aurantiacum ” recorded by Grange et al. (1981) at depths of 4–20 m in Fiordland probably refers to this species, although it is unclear whether encrusting or upright-growing colonies were observed, and it may be that representatives of Kotatea gen. nov. also inhabit this area. The A. aurantiacum illustrated by Westerskov & Probert (1981) likely also represents U. fervens .

Notably, Goldberg et al. (1990) documented the formation of long, thread-like, defensive sweeper tentacles on black corals in Fiordland in response to encrusting epibionts identified as “ A. aurantiacum ”. These observations can probably be attributed to Ushanaia fervans due to their encrusting habit.

As noted by Grange et al. (1981, 2010), a white octocoral also encrusts black corals in Fiordland, but since no specimens matching this description were available for examination it remains unclear whether these observations represent a form of Ushanaia fervens gen. et sp. nov. or a separate species.

The sequence identified as Alcyonium aurantiacum in McFadden et al. (2006b), belongs to U. fervens gen. et sp. nov. (MAGNT C014988).