Tetilla sibirica Fristedt 1887

• Main Authors: Dinn, Curtis, Edinger, Evan, Leys, Sally P.
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2019
• Subjects: Biodiversity; Taxonomy; Animalia; Porifera; Demospongiae; Tetractinellida; Tetillidae; Tetilla; Tetilla sibirica; Antarc*; Frobisher Bay
• Online Access: https://doi.org/10.5281/zenodo.5189302; http://treatment.plazi.org/id/03E3F074535D3808C6C7F930F3B11BE8

Tetilla sibirica Fristedt, 1887 Figure 6; Table 6 Synonymy: Tethya sibirica Fristedt, 1887: 436 –437 pl. 28, fig. 17. Tetilla sibirica : Koltun 1966: 61 –62, fig. 32–33. Morozov et al. 2019: 21 –22, fig. 12. Dinn & Leys 2018: 86. Material examined. CMNI 2018-0165, specimen in 95% ethanol, collected by Philippe Archambault by ROV hydraulic manipulator; 25 October 2015, 65 m depth, (63° 38.5745’N, 68° 36.5265’W). CMNI 2018-0183, specimen in 95% ethanol, collected by Curtis Dinn by Agassiz trawl; July 15, 2017, 141 m depth, (63° 38.390’N, 68° 37.642’W). All operations performed from the CCGS Amundsen near Hill Island in Frobisher Bay. Description. Two specimens of different sizes were collected in the inner bay near Hill Island. CMNI 2018- 0 165 (Fig. 6B) is a large spherical sponge about 20 cm in diameter in situ (Fig. 6A), and the root is nearly 13 cm long after collection, and CMNI 2018-0183(Fig. 6D) is less spherical and more club shaped, about 2 cm in width, 3.5 cm in height with a root length of 2.5 cm. The surface of both specimens is hispid due to protruding spicules. The sponges are firm and incompressible, are covered in sediment in situ, and appear light brown or grey immediately after collection. (Fig. 6B, D). The spicules from CMNI 2018-0183 consist of large oxeas 2811 (1784– 4080) x 37 (28–54) µm; short oxeas 1026 (754–1290) x 40 (26–52) µm; anatriaenes 3030 (1992–4378) x 21 (9–35) µm; protriaenes, sometimes with one whip-like clad 2219 (1150–3452) x 21 (6–29) µm, clads are 57 (29–83) µm, whip-like clads, when present are 91 (64–113) µm; and sigmaspires 17 (11–20) µm in length (Fig. 6 E–K). Genetic data. 28S rDNA sequences suggest this specimen groups with Cinachyra and Antarctotetilla specimens based on the D3–D5 domain sequence (GenBank accession MH394249). This species and the sympatric C. polyura appear to be closely related based 28S sequences. Taxonomic Remarks. The original description by Fristedt (1887) is of a firm sponge that is ovoid or subspherical with numerous roots. Koltun (1966) ...