Craniella polyura

(Figure 13 (a – h))

Tetilla polyura Schmidt 1870, p. 66; pl. VI, fig. 8; Vosmaer 1885, p. 9 – 10; pl. I, figs 1 – 3; pl. II, fig. 16; pl. V, figs 3 – 7; Breitfuss 1911, p. 213; Rezvoi 1928, p. 76; Van Soest 2016, p. 322, fig. 5a – g

Description

(Figure 13 (a)). Sponge egg shaped, up to 4 cm in height and 2.5 cm in width. Surface even, slightly setose. The consistency is rather soft and elastic. Single conical osculum slightly displaced to the side from the summit. Comparatively long spicules protrude from the lower end of the body, forming a felt-like mass. Colour light brown. Two specimens examined.

Skeleton

Skeleton of radially spiral structure. Cortex absent.

Spicules

(Figure 13 (a – h)). Large oxea, usually with unequal ends, dimensions: 1532.6 – 2904.5 – 4375.3 (n = 20) × 11.7 – 28 – 42.3 (n = 20) µm. Small oxea, slightly fusiform, with equal ends, dimensions: 556.5 – 776 – 1117.9 (n = 30) × 6.2 – 17.6 – 29.4 (n = 25) µm. Anatriaenes, rhabdome length up to 5 cm and thickness 4 – 4.5 – 5.2 (n = 10) µm; cladome length: 64 – 74.7 – 86.3 (n = 10) µm. Sagittal protriaenes, rhabdome length: 1073 – 1637.9 – 2575 (n = 15) × 2.6 – 3.66 – 5.6 (n = 15) µm; length of paired cladomes: 20.2 – 33.3 – 69.4 (n = 15) µm; unpaired cladome length: 66.7 – 106.5 – 179.7 (n = 15) µm. Normal protriaenes, rhabdome length: 510 – 617.8 – 931.7 (n = 10) × 4.7 – 5.8 – 6.9 (n = 10) µm; cladome length: 22 – 27.8 – 33.2 (n = 10) µm. Raphides, dimensions: 192 – 347.7 – 473 (n = 10) × 1 – 2 µm. Sigmas centrotylote, spined, dimensions: 9 – 12.7 – 16 (n = 25) µm.

Distribution

Iceland. Barents, Kara, Laptev (st. A-102, L-12) and East Siberian seas (st. A-31). Depth range: 33 – 313 m.