Higginsia johannae, Sim-Smith & Hickman & Kelly, 2021

Sim-Smith, Carina, Hickman, Cleveland & Kelly, Michelle, 2021, New shallow-water sponges (Porifera) from the Galápagos Islands, Zootaxa 5012 (1), pp. 1-71: 32-34

publication ID

https://doi.org/10.11646/zootaxa.5012.1.1

publication LSID

lsid:zoobank.org:pub:56C6852D-AAE0-4B6B-AB57-919CD62DAEC1

persistent identifier

http://treatment.plazi.org/id/D3075148-FFC4-FFDA-FF67-8A6DB32ACE21

treatment provided by

Plazi

scientific name

Higginsia johannae
status

sp. nov.

Higginsia johannae   sp. nov.

( Fig. 14 View FIGURE 14 , Table 5)

Material examined. Holotype — MCCDRS9415, Tagus Cove , Isabela Island, 0.265 ° S, 91.373° W, depth unknown, 17 Jan 2003 GoogleMaps   . Paratypes — MCCDRS9416, Tagus Cove , Isabela Island, 0.265 °S, 91.373° W, 13 m, 16 Nov 2003; MC- CDRS9414 View Materials GoogleMaps   , Las Marielas , Isabela Island, 0.597° S, 91.092° W, 5 m, 2 Dec 2004 GoogleMaps   . Other material— MCCDRS9413, Las Marielas , Isabela Island, 3 m, 2 Dec 2004   .

Type locality. Tagus Cove , Isabela Island   .

Habitat and distribution. Only collected from type locality; 3–13 m, but commonly observed around Isabela Island. Grows on rock substrate and often encrusted by zoanthids ( Parazoanthus sp.   ).

Description. Thickly encrusting sponge, with a rugose to deeply dissected surface ( Fig. 14A–C View FIGURE 14 ). Holotype is 50 mm wide × 25 mm thick. Texture is firm, slightly compressible. Colour in life is deep orange, colour in ethanol is tan.

Skeleton. The choanosomal skeleton is formed by bundles of styles I, pointed end uppermost, which form plumose tracts ascending through the centre of the sponge, and protruding slightly beyond the surface of the sponge. Bundles of thinner styles II and very thin oxeas line the periphery of the extra-axial skeleton, orientated tangential to the surface. Acanthose microxeas form a dense, paratangential band, around the periphery of the lower portion of the sponge and lining the spaces in the basal region of the choanosome. Microxeas are also sparsely scattered throughout the choanosome ( Fig. 14D View FIGURE 14 ).

Spicules. Megascleres— Styles I (choanosomal, Fig. 14E View FIGURE 14 ), short and stout, usually with a pronounced curve; 561 (401–715) × 26 (12–45) µm (n = 90). Styles II (extra-axial, Fig. 14G View FIGURE 14 ), long and thin, often curved or slightly sinuous; 1164 (810–1702) × 15 (4–27) µm (n = 76). Oxeas (extra-axial, Fig. 3I View FIGURE 3 ), very thin and hair-like; 775 (438– 1377) × 7 (2–13) µm (n = 90). Microscleres— microxeas ( Fig. 14F View FIGURE 14 ), spined and angulate; 101 (55–161) × 5 (2–10) µm (n = 90).

Etymology. Named for Johannah E. Barry, founder and first president of the Galápagos Conservancy, a USbased non-profit organisation created in 1991 to support Galápagos conservation, research, and education. Johannah was also instrumental in encouraging the creation of similar organisations in Canada, Europe, and Japan dedicated to conservation in the islands.

Remarks. This is the first record of the genus Higginsia   from the Galápagos Islands. MCCDRS9413 has slightly longer spicules than the other three specimens ( Table 5), but this difference is likely to be due to natural variability.

Only one other species of Higginsia   is recorded from the eastern Pacific— Higginsia higginissima Dickinson, 1945   from California and west Mexico, which has oxeas (600 × 12 µm) as the main choanosomal megasclere.

Higginsia   is closely related to the genus Halicnema   , with one species, Halicnemia diazae Desqueyroux-Faúndez & Van Soest, 1997   , described from the Galápagos Islands. Higginsia johannae   sp. nov. has a similar suite of spicules to H. diazae   with both species possessing, two sizes of styles, oxeas and angulate acanthoxeas. However, H. diazae   possesses a distinct ectosome that consists of a felted mass of tangential acanthoxeas and bouquets of oxeas, whereas H. johannae   sp. nov. lacks a distinct ectosome. Furthermore, H. diazae   has shorter styles II (800 (720–1300 µm), oxeas (375–520 µm), and acanthoxeas (65–115 µm) than H. johannae   sp. nov.

Order Bubarida Morrow & Cárdenas