Loxosomella unicornis Borisanova & Krylova, 2014, sp. nov.

• Main Authors: Borisanova, Anastasiya O., Krylova, Elena M.
• Format: Other/Unknown Material
• Language: unknown
• Published: 2014
• Subjects: Biodiversity; Taxonomy; Animalia; Kamptozoa; Entoprocta; Coloniales; Loxosomatidae; Loxosomella; Loxosomella unicornis; White Sea; Kandalaksha; Krylova
• Online Access: https://zenodo.org/record/5631969; https://doi.org/10.5281/zenodo.5631969

Loxosomella unicornis sp. nov. (Figs 2, 3) Material examined. Holotype: ZMMU No. Uk- 5 (an adult), from Kandalaksha Bay, White Sea (66 ° 34 ' N, 33 °08' E), 24 m, 26 June 2013, on the bryozoan Cribrilina sp. living as an epibiont on a shell of Mytilus edulis Linnaeus, 1758. Paratypes: ZMMU No. Uk- 6 (7 paratypes, all adults), from the same locality as holotype. Additional material examined: the same locality, 5 m, 27 August 1983, on the bryozoan Electra sp., 20 adult specimens. Etymology. Greek unicornis, horn, alluding to the horn-shaped appendage on the top part of the calyx. Diagnosis. Adults: Medium-sized species, total length of body from end of foot to base of tentacles 300–350 µm (up to 650 µm) (Table 2). Calyx length 130–215 µm, width 120–230 µm. Calyx compressed in anteroposterior axis, about twice as wide as thick. Stalk length varies from 90 to 320 µm, stalk width about 70–105 µm. There is pair of thin, transparent lateral wings on sides of calyx making it rounded in frontal view. Calyx with 8 rather short tentacles, directed forward; 2 pigmented semicircular strips located on lateral margins around tentacle crown. Top part of back side of calyx above tentacle ring bearing a conspicuous horn-shaped appendage about 50–60 µm in length. Two pairs of ciliated lateral papillae are located on each side of calyx. Stomach about twice as wide as high, with lateral lobes. Stalk with prominent longitudinal muscles. Foot reduced. Reproduction: Buds emerge from paired laterofrontal areas at lower level of stomach, one bud on each side. Some specimens have 1–2 developing larvae in brood chamber. Larva with well-developed frontal and apical organs, prototroch diameter about 85 µm and episphere height about 110 µm. Specimen 1 2 3 4 5 6 * * Total length 296 250 289 370 398 355 377 515 Loxosomella unicornis sp. nov. differs from all described loxosomatid species in having a large horn-shaped appendage on top of the calyx. It is known that some loxosomatids have conspicuous appendages on their calyces (Table 3), but ...