Correcting sponge names: nomenclatural update of lower taxa level Porifera Author Van Soest, Rob W. M. text Zootaxa 2024 2024-01-09 5398 1 1 122 http://dx.doi.org/10.11646/zootaxa.5398.1.1 journal article 10.11646/zootaxa.5398.1.1 1175-5334 10494167 E233F731-D5FA-4032-B3A4-CEFE5A809C49 Petrosia truncata var. aruensis Hentschel, 1912 ( Fig. 4H ) Petrosia truncata var. aruensis Hentschel, 1912: 402 , pl. XXI fig. 51. Xestospongia truncata aruensis ; De Voogd & Van Soest 2002: 203 (listed only). Petrosia aff. aruensis ; Lim et al. 2016: 112 , listed only citing unpublished thesis of Putchakarn 2006. The variety was described by Hentschel from the Aru Islands, Stats. 12–14, approximate coordinates 6.2946 – 6.2985 ° S 134.3249– 134.7609°E , depth 15–18 m ( 14 syntype specimens , SMF 1061–1064). Although Hentschel did not indicate any differences of his variety with the the typical variety of Ridley & Dendy (1886: 327 , collected in the Eastern Philippines (Challenger Exped. Stat. 208, 11.6167°N 123.5167°E , depth 33 m , holotype BMNH 1887.5.2.208), it may be deduced from the two descriptions that strongyles in the present variety exceed those of the typical variety in length, 192–280 µm vs. 170 µm in Ridley & Dendy’s material, but Hentschel described also smaller strongyles 64–136 µm long, and he admitted that perhaps intermediate sizes between the larger and smaller strongyles were present. Hentschel’s material was extensive, whereas Ridley & Dendy only had one small fragment, which may explain the more limited spicule size they gave. The differences seem insufficient to justify recognizing a separate taxon for the present species and accordingly I propose to merge the variety into a single, somewhat variable species to be named Petrosia (Petrosia) truncata ( Ridley & Dendy, 1886 ) .