Loxosoma (Loxosomina) aripes Borisanova & Schepetov 2023, n. comb.

• Main Authors: Borisanova, Anastasia, Schepetov, Dimitry
• Format: Other/Unknown Material
• Language: unknown
• Published: 2023
• Subjects: Biodiversity; Taxonomy; Animalia; Kamptozoa; Entoprocta; Coloniales; Loxosomatidae; Loxosoma; Loxosoma aripes; White Sea; Kandalaksha; Sletten
• Online Access: https://zenodo.org/record/8243369; https://doi.org/10.5281/zenodo.8243369

Loxosoma (Loxosomina) aripes (Nielsen, 1964b) n. comb. (Figs 1–8, Table 3) Loxosomella aripes Nielsen, 1964b: 4, fig. 2. Original description. Small species, up to 470 µm. Lophophore has six very short, stout tentacles (one specimen with 4 tentacles). Atrium narrow. Stomach big and rounded. Peduncle longer than calyx. Peduncle slender, terminating in laterally compressed expansion, which on each side bears 3–4 transverse furrows. Youngest buds formed laterally at lower level of stomach, and older buds found above this reaching upper level of stomach; up to three buds at time. Embryos very big and quite deform the calyx; 1–3 embryos at time. Usually buds and embryos found only in one side of animal. Host: Laonice cirrata. Type locality: Raunefjorden, off Sletten (60°16.5′N, 5°12′E), depth 100– 120 m. The holotype is illustrated in Fig. 1. Material examined. Holotype (number 46395) (Fig. 1); No Uk-31 (ZMMU)— six specimens from the Kandalaksha Bay, White Sea (66°34′N, 33°08′E), 30–70 m; six specimens from the White Sea from a personal collection. Description of the material from the White Sea. Medium-sized species with average body length of 596 µm (Figs 2, 3) (measurements for 11 specimens are provided in Table 3 on page 11). Calyx is up to one and a half times shorter than stalk (average calyx length 228 µm). Calyx bears six short tentacles directed distally when embryos are not developed. When embryos are developing the calyx strongly swells on one side and the tentacles are shifted to the side and directed disto-laterally. The tentacles are unusually wide and the frontal surface is formed by nine rows of ciliated cells (Fig. 4a, b). The frontal groove is formed by three rows of frontal cells (Fig. 4a–c). The latero-frontal cells border the frontal groove (Fig. 4b–d), and the lateral cells form two rows on each side of the frontal surface of the tentacle (Fig. 4a, b, e). Digestive system includes esophagus, stomach, intestine and rectum (Fig. 5a). The esophagus is lined with cuboidal epithelium (Fig. 5b). The ...