Ircinia lowi, Kelly & Thacker, 2021

Kelly, Joseph B. & Thacker, Robert W., 2021, New shallow water species of Caribbean Ircinia Nardo, 1833 (Porifera: Irciniidae), Zootaxa 5072 (4), pp. 301-323 : 304-305

Ircinia lowi sp. nov.

Figures 2 , 3 ; Tables 1 , 2 .

urn:lsid:zoobank.org:act:78177724-A5A5-4396-B78D-F6A8181ACB82

Holotype: USNM 1582268 (P16x42; 9.37767, -82.3032; appx. 0.5 m depth; coll. J.B.K.; 22 July 2016).

Paratypes: USNM 1582267 (P16x41; 9.37767, -82.3032; appx. 0.5 m depth; coll. J.B.K.; 22 July 2016) , USNM 1582269 (P16x43; 9.37767, -82.3032; appx. 0.5 m depth; coll. J.B.K.; 22 July 2016) , USNM 1582270 (P16x44; 9.37767, -82.3032; appx. 0.5 m depth; coll. J.B.K.; 22 July 2016) , USNM 1582278 (P16x52; 9.37767, -82.3032; appx. 0.4 m depth; coll. J.B.K.; 23 July 2016) .

Type locality: Bocas del Toro, Panama.

External morphology. Ircinia with a thickly encrusting growth habit and a forest green external surface color. Sometimes possesses lobate, short branches departing from base ( Figure 2 ). Conules small (1.5–2 mm in height), sometimes of lighter color than the rest of the body. The body is dotted with black oscula that are uniform in size (0.4–0.5 cm diameter) and are either slightly elevated or flushed to the surface.

Interior morphology. Primary fascicular fibers 80–200 µm wide, cored. Interconnecting fibers 20–60 um wide, nearly uncored to completely uncored ( Figure 3 ). Irciniid filaments 1–4 µm wide, terminating in spherical knobs 6–10 µm in diameter.

Ecology. All specimens were collected from shallow depths (0.4–0.5 m) on patch reefs that occur in association with small seagrass beds.

Etymology. This species is named for the immunologist Jun Siong Low for his methodological advances in identifying pan-coronavirus antibodies.

Remarks. Tissue takes on a slightly crisper consistency when preserved in ethanol for several days. Referred to as the ‘Encrusting’ growth form in Kelly et al. (2021).

Figures

FIGURE 2. Ircinia lowi sp. nov. A: USNM 1582268 (holotype), B: USNM 1582267 (paratype), C: USNM 1582269 (paratype), D: USNM 1582270 (paratype). Note the wide points of attachment to hard substrate and coral rubble.

FIGURE 3. Histological sections of Ircinia lowi sp. nov., specimen voucher USNM 1582268 (holotype). Abbreviations: 1°: primary fibers, 2°: fibers, Sp: spicules, Se: sediment grains, Met: symbiotic metazoan, i: irciniid filaments. A: Bands of parallel irciniid filaments are visible throughout the mesohyl, with one plane of bands annotated by the bracket in the upper right-hand quadrant. Large, foreign spicule fragments are highlighted in the bottom right quadrant and at center bottom-left. B: Three primary fibers are joined by secondary fibers. Note the sand grains and spicule fragments in the primary fibers and their near absence from secondary fibers.