Actinocyathula homari ( Sand, 1899 ) Curds, 1987

Chatterjee, Tapas, Sautya, Sabyasachi, Dovgal, Igor, Gaikwad, Santosh, Khokher, Sanofar H. & Choudhury, Amita, 2022, Report of deep-sea epibiont ciliates (Ciliophora) from more than 1000 m depth of the Arabian Sea, Indian Ocean, Zootaxa 5120 (3), pp. 423-434 : 427

Actinocyathula homari ( Sand, 1899) Curds, 1987

( Fig. 2 C–D )

= Acineta homari Sand, 1899

= Paracineta homari ( Sand, 1899) Collin, 1911

= Corynophrya homari ( Sand, 1899) Batisse, 1975

Material examined: One individual found as epibiont on nematode host belongs to the genus Tricoma collected from stn MUC-18, at sediment depth 0–2 cm, water depth 4119 m, Arabian Sea , Indian Ocean .

Diagnosis: Marine, loricate suctorian with ovoid body that protrudes from the apical region of the stylotheca. Cell body fills the upper half of lorica and attach to its aperture. Tentacles clavate, retractile, arranged at the anterior body surface. Stylotheca unflattened, smooth, triangular to bell-shaped, equipped with a robust rigid pseudostyle that length is the same or shorter that the rest of stylotheca. Contractile vacuole single, centrally or laterally located. Macronucleus spherical, located at posterior of body. Reproduction by semi-invaginative budding.

Measurements from present find (based on one individual, in µm): Stylotheca length 24, stylotheca width 18, body length 15, body width 15, macronucleus diameter 5, tentacle length 5–6.

Host and substrate specificity: The species firstly described from the setae of the telson and orbit of lobster ( Sand 1899), next found on the setae of pagurid Pagurus cuanensis Bell, 1845 ( Collin 1912) and was mentioned as epibiont of decapod crustaceans ( Curds 1987). However, Baldrighi et al. (2020) reported the species from nematode worms of genera Desmodora de Man, 1889 , Paradesmodora Schuurmans Stekhoven, 1950 and Pseudochromadora Daday, 1899 . This species is found as epibiont on nematode host belongs to the genus Tricoma (present report).

Distribution: Roscoff, France ( Sand 1899), Séte, France ( Collin 1912), NW Madagascar margin-deep sea pockmark, Gulf of Naples-shallow vent area, French Guiana-Mangrove forest ( Baldrighi et al. 2020); Arabian Sea, 4119 m depth (present report).

Figures

FIGURE 2. A–B. Thecacineta calix (Schroder, 1907) on nematode body; C–D. Actinocyathula homari (Sand, 1899) on nematode body; E–F. Loricophrya bosporica Sergeeva & Dovgal, 2016 on nematode body.