Submarine cave sponges of the genus Rhabderemia (Demospongiae, Biemnida, Rhabderemiidae) from the Ryukyu Islands, southwestern Japan: rediscovery of R. forcipula and description of a new species Author Ise, Yuji Kuroshio Biological Research Foundation, 560 Nishidomari, Otsuki, Hata, Kochi 788 - 0333, Japan. Author Tajiri, Rie Tajiri Thin Section Laboratory, 3 - 1 - 11 Sannose, Higashiosaka, Osaka, 577 - 0849, Japan. Author Mizuyama, Masaru 0000-0002-1671-4046 m.mizuyama@meio-u.ac.jp Author Fujita, Yoshihisa Okinawa Prefectural University of Arts, 1 - 4 Shuri-Tounokura, Naha, Okinawa 903 - 8692, Japan. text Zootaxa 2025 2025-01-14 5569 2 365 382 https://doi.org/10.11646/zootaxa.5569.2.8 journal article 307860 10.11646/zootaxa.5569.2.8 9d0fdb20-aab1-4012-8017-8f04063ab5b6 1175-5326 14734120 3F421A77-321A-4E3F-999E-3EEFDF5908DD

TABLE 2. Measurements of spicules of Rhabderemia forcipula type specimens and submarine cave specimens. Numbers indicate minimum– mean –maximum. All spicule measurements are in µm.

	holotype		paratype	NSMT-Po-2503	NSMT-Po-2504	NSMT-Po-2505	NSMT-Po-2506	NSMT-Po-2507
Rhabdostyle length shaft width	270.4– 325.1 –371.6 7.3– 15.4 –19.6	275–375 10–22	230– 307.2 –381 10– 17.1 –21	154.2– 304.9 –408.5 8.3– 14.4 –19.3	151.0– 277.2 –380.8 5.2– 13.8 –18.9	186.6– 274.0 –341.8 3.2– 12.6 –17.4	170.0– 288.6 –366.8 3.2– 10.9 –14.9	143.1– 292.1 –361.3 5.5– 12.4 –17.1
Rugose microstyle length base width shaft width	143.7– 166.1 –178.0 1.5– 2.3 –3.0 1.2– 1.8 –2.4	150–180 not measured 1–2	150– 162.5 –171 not measured 1– 1.25 –2	124.0– 134.5 –144.2 1.2– 1.8 –2.3 1.2– 1.4 –1.6	143.7– 151.7 –159.3 1.0–2.0 1.0–1.4	137.3– 145.4 –152.4 1.6– 1.8 –2.0 1.0– 1.4 –1.6	145.7– 158.4 –174.5 1.6– 1.8 –2.6 1.0– 1.4 –1.5	130.1– 148.9 –162.5 1.0–2.0 1.0–1.5
Larger spirosigma/Thraustosigma
total length shaft width	26.0– 29.6 –37.0 2.3– 3.1 –4.3	25–30 2	25– 27.0 –30 not measured	20.0– 23.3 –26.8 1.9– 2.2 –2.7	22.4– 24.0 –26.5 1.9– 2.1 –2.3	23.5– 26.7 –30.1 1.9– 2.2 –2.8	19.6– 22.4 –26.2 1.6– 2.2 –2.6	23.6– 27.4 –30.5 1.9– 2.3 –2.7
Smaller spirosigma total length shaft width	12.9– 16.1 –21.9 0.8– 1.3 –2.0	10–18 not measured	12– 14.8 –18 not measured	15.5– 17.7 –19.6 ca. 1	16.0– 17.3 –19.4 ca. 1	14.3– 16.8 –18.6 ca. 1	15.1– 18.1 –22.1 ca. 1	15.7– 18.0 –21.4 ca. 1
reference	this study	Lévi & Lévi (1989)	Van Soest & Hooper (1993)	this study	this study	this study	this study	this study