Iophon piceum Arctic 1882

Iophon piceum (Vosmaer, 1882)

Figure 4, Table 4

Synonymy:

Alebion piceum Vosmaer, 1882: 42 –44 pl. I, fig 19, pl. III, fig. 75–78, 81–82.

Esperia pattersoni; sensu Fristedt, 1887: 448 –449.

Iophon piceum: Lundbeck 1905: 175 –180, pl. VI, fig. 1–2, pl. XVII, fig. 3a–b. Brunel et al. 1998: 62–63, Dinn & Leys 2018: 32.

Material examined. CMNI 2018-0177, specimen in 95% ethanol, collected by Curtis Dinn by BX 650 MK III box core; July 14, 2017, 507m depth (62° 49.126’ N, 66°56.354’ W) operated from the CCGS Amundsen, Frobisher Bay, Canada.

Description. Large fragments of a cup shaped specimen were collected (Fig. 4A). The whole specimen is thought to have been 10–20 cm in diameter, but the growth form was not obvious as the sponge was collected in pieces. The spongin fibres and spicules form a lattice. The sponge is rough to the touch, fragile and dark black in colour. The black pigment leeches out of preserved specimens and will transfer the colour to ethanol. The spicules (Fig. 4 B–F) consist of acanthostyles 320 (275–349) x 16 (12–19) µm; tylotes with spined heads 260 (237–278) x 12 (9–16) µm; spurred anisochelae 18.5 (13–32) µm; and bipocilli with unequal alae, both with fine teeth 11.8 (8.7–16.5) µm.

Taxonomic Remarks. The spicule measurements agree with those in the original description by Vosmaer (1882) and in subsequent descriptions by Lundbeck (1905) and Arndt (1935) (Table 4). Two slight variations in spicule size were noted in this specimen: tylote thickness reaches a maximum of 16 µm whereas the thickest tylotes described by Lundbeck (1905) are 11 µm. The acanthostyles in this specimen do not exceed 350 µm, whereas Lundbeck states that acanthostyles can reach 450 µm. Vosmaer (1882) described this species as being of a “pitchy colour” and having a cup-shape. Lundbeck (1905) describes the sponge as leaf shaped and erect with an attachment to the seafloor at the base. The overall spicule complement in the present specimen is very similar to Lundbeck’s (1905) description. The bipocilli in the present specimen are rounded, with numerous fine teeth, similar to those described in Lundbeck (1905). However, Lundbeck (1905) also describes some bipocilli that attain “monstrous forms” where the alae split from the shaft, but these types of spicules were not seen in the present specimen. Despite minor variations in spicule size, the present specimen agrees with previous descriptions, especially in growth form and colour.

1 from Van Soest et al. (2000)

Discussion. Iophon c.f. piceum was previously identified by Murillo et al. (2018) from eighteen specimens collected in the eastern Canadian Arctic. The assignment of these specimens to species is not assured as spicule measurements and photos were not presented, and the author suggests that more than one species may be represented (J. Murillo personal communication, Nov. 2018). The cup-shaped growth form, thick acanthostyles, bipocilli with fine teeth, and pitch-black colouration are clear identifiers of this species, thus the difficulty of the authors to identify their specimens to the species level suggest congeneric species are present in their samples. Previous records show collections near SW Iceland and in the Barents Sea and White Sea (Lundbeck 1905). The species was also collected from a depth of 719 m on the western Greenland shelf by Lundbeck (1905) during the Danish Ingolf-Expedition. Vosmaer found this species at 350 m in the Barents Sea. Brunel et al. (1998) note that de Laubenfels thought that Lambe’s (1900) records of I. cheliferum were actually I. nigricans, and Lévi suggested that the specimens were actually I. piceum. Since there is much confusion about the identity of Iophon specimens in the region, a revision of the genus is recommended. This sponge was not seen in ROV video from the site near Hill Island, which supports reports that it is primarily a deep-water, rocky bottom species. The species was only found in the deep water near the mouth of Frobisher Bay and not in the sandy and shallow inner regions of the bay.