Iophon frigidus var. gracilis Hentschel 1929

• Main Author: Van Soest, Rob W. M.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2024
• Subjects: Biodiversity; Taxonomy; Animalia; Porifera; Demospongiae; Poecilosclerida; Acarnidae; Iophon; Iophon frigidus; Iophon frigidus var. gracilis hentschel; 1929; East Greenland; Greenland; Kara Sea; Ross Island; White Sea; Spitsbergen
• Online Access: https://doi.org/10.5281/zenodo.10568016; http://treatment.plazi.org/id/BF4E397FFFA331179786FCBEB9220028

Iophon frigidus var. gracilis Hentschel, 1929 Iophon frigidus var. gracilis Hentschel, 1929: 884 (no illustration). The variety described by Hentschel from North Spitsbergen, 1 mile N of Ross Island, 80.8°N 20.3833°E, depth 85 m (holotype in ZMH), and the White Sea, 66.6°N 41.3833°E, depth 54 m (collected by the ‘Deutschen Expedition in das N̂rdliche Eismeer im Jahre 1898’) was erected primarily on the basis of a single character: the possession of bipocillae, which were lacking in the typical variety described by Lundbeck (1905: 183) from the East Greenland shelf, 72.4167°N 19.55°W, depth 256 m, syntypes ZMUC DEM 18 and 26), and by Levinsen (1887: 360 as Esperella picea ) from the Kara Sea, and by Hentschel (1916: 10) from Spitsbergen. Further differences were more subtle: slightly smaller megascleres and anisochelae with a narrow upper half distinct from the broader shape in the typical variety. Burton (1932: 348) discussed the global diversity of species of Iophon and in a footnote he synonymized I. frigidus , (ignoring I.f. var. gracilis ), and I. dubius Hansen, 1885 with I. piceum (Vosmaer, 1885) citing observations of the variability in spiculation in species from the southern oceans [ I.radiatum Topsent, 1901 and I. proximum (Ridley, 1881)] as evidence for this conclusion. Koltun (1959: 151) largely followed Burton’s example but proposed a more differentiated widespread Arctic species Iophon piceum five ‘subspecies’. Of these, he confirmed that Iophon frigidus and the variety I. f. var. gracilis were synonymous with I. piceum dubium (Hansen, 1885) rather than with the typical subspecies. Remarkably, he proposed a subspecies Iophon piceum abipocillum , for a specimen which lacked bipocillae similar to I. frigidum . Koltun’s proposed diversity of largely sympatric ‘subspecies’ is not consistent with current hypotheses about subspecies. I am not convinced that Iophon piceum is the senior synonym of I. frigidum , as no comparative studies have been published. Burton’s and Koltun’s opinions are not ...