Lycopodina cupressiformis ( Carter, 1874 )

Morozov, Grigori, Sabirov, Rushan & Zimina, Olga, 2019, Sponge fauna of the New Siberian Shoal: biodiversity and some features of formation, Journal of Natural History 52 (47), pp. 2961-2992 : 2961-2992

Lycopodina cupressiformis ( Carter, 1874)

( Figure 5 (a – f1))

Esperia cupressiformis Carter 1874, p. 215 – 217; pl. XIV, figs 16a – f, 17, 18; pl. XV, fig. 37 Esperella cupressiformis var. robusta: Levinsen 1887, p. 364 – 365; pl. XXIX, figs 10 – 11; pl.

XXXI, figs 7 – 14, 16a – c cladorhiza cupressiformis: Fristedt 1887, p. 457 – 458; pl. 25, figs 66 – 69; pl. 31, fig. 27 Esperella fristedtii: Lambe 1900, p. 21 – 22; pl. I, fig. 2a – h Asbestopluma cupressiformis: Lundbeck 1905, p. 58 – 62; pl. II, figs 11 – 14; pl. XI, figs 4a – f, 5;

Koltun 1959, p. 77 – 78, fig. 32; pl. VII, figs 3 – 4; Hentschel 1929, p. 934 Lycopodina robusta: van Soest 2016, p. 328 – 329, fig. 11a – e Lycopodina cupressiformis: Hestetun 2017, p. 38 – 43, figs 32 – 33, table 6

Description

( Figure 5 (b)) Leaf-shaped, slightly flattened body provided with thin cylindrical peduncle, with a slightly expanded base of attachment. From the main body, numerous small conical appendages (up to 2 mm in length) protrude. The consistency is soft and elastic. Colour beige. Two specimens examined.

Skeleton

( Figure 5 (a)) Skeleton composed of stout spicule axis, surrounded by diffuse network of spicules. Surface appendages also possess a spicule axis at their base but do not connect with the main axis.

Spicules

( Figure 5 (c – f1)) Cylindrical, slightly fusiform, straight (sometimes sinuous) styles (or tylostyles) of the main body, dimensions: 564.8 – 700.7 – 835.5 (n = 30) × 10.6 – 13.58 – 15.5 (n = 20) µm; styles (or ylostyles) of the peduncle (similar to previous in shape), dimensions: 375 – 616.7 – 769 (n = 20) × 8.4 – 12.19 – 15.4 (n = 20) µm; palmate anisochelae, dimensions: 20 – 24 – 25.4 µm (n = 30); forceps centrotylote, with slightly diverging legs, terminating in swellings, often rarely found, up to 40 µm in length.

Distribution

The Davis Strait, Baffin Bay, Hudson Bay. The East Greenland Shelf, between Iceland and Faroe, northern slope of the Wyville-Thomson Ridge, the Rockall Bank (?). The Barents, Kara and Laptev seas (st. O-20), north of the New Siberian Islands (st. А-70). Depth range: 41 – 1000 m.

Remarks

Lycopodina cupressiformis and L. lycopodium ( Levinsen 1887) are fairly eurybathic Arctic species frequently found in the Nordic seas, where their habitat is confined by the bathyal zone. In the western Arctic seas (the Barents, Kara and Laptev seas) they are often recorded in shallow-water areas as well. These distributional peculiarities are reviewed in the Discussion section.

Both species exhibit remarkable intraspecific variation, and are supposedly represented by complexes of morphologically close species ( Hestetun et al. 2017). It is particularly interesting to note some morphological differences between species populations inhabiting the areas to the north and south of the Greenland-Iceland-Faroe Ridge, which almost completely excludes the exchange of deep water masses of the Nordic seas and Atlantic Ocean. Therefore, it is quite doubtful that gene flow occurs between them.

Figures

Figure 5. Lycopodina cupressiformis: (a) cross section; (b) habitus; (c–f1) scanning electron microscope(SEM) images of spicules; (c) large style; (d) microstyle (associated with embryos); (e) forceps; (f, f1) palmate anisochelae.