Thecacineta calix ( Schroder, 1907 )

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 : 426

Thecacineta calix ( Schroder, 1907)

( Fig 2 A–B )

= Acineta calix Schroder, 1907

= Paracineta moebiusi Kahl, 1934

= Thecacineta desmodorae Schulz, 1931

= Thecacineta donsi Allgén, 1935

= Thecacineta subantarctica Allgén, 1949

= Thecacineta paradesmodorae Allgén, 1949

= Thecaineta oblonga Allgén, 1955

= Thecacineta laophontis Jankowski, 1981

Material examined: One individual found as epibiont on nematode host belongs to the family Desmodoridae Filipjev, 1922 collected from stn MUC-16, at sediment depth 0–2 cm, water depth 3463 m, Arabian Sea , Indian Ocean .

Diagnosis: Marine loricate suctorian. Cell body entirely fills the lorica and attach to its base. Lorica ribbed with a series of transverse annular ridges that become progressively closer toward the base. Apical part of the body protrudes beyond lorica aperture. Up to 30 clavate tentacles from the apical surface of the body. Stalk with various length, from one fourth to the same length as lorica. Macronucleus ovoid, located in the basal region of the cell body. Large contractile vacuole located in basal region of the body usually near macronucleus.

Measurements from present find (based on one individual, in µm): Lorica length 55, maximal lorica width 24, body length 45, maximal body width 15, stalk length 45, stalk diameter 3, length of tentacles 11–16.

Host and substrate specificity: Thecacineta calix has been reported as an epibiont on nematodes, crustacean copepods, halacarid mites and algae ( Chatterjee et al. 2019c). As epibiont of nematodes T. calix has been reported on Croconema cinctum Cobb,1920 , Croconema sphaerica (Kreis, 1928) (= Desmodora sphaerica ); Croconema stateni (= Desmodora stateni Allgen, 1928 ), Desmodora communis (Butschli, 1874) , Desmodora sp , Desmodorella schulzi (Gerlach, 1950) (= Desmodora schulzi Gerlach, 1950 ), Desmodorella tenuispiculum Allgén, 1928 , Paradesmodora sp. , etc. ( Schroder 1907; Schulz 1931; Steiner 1931; Allgén 1935, 1949, 1955; Susetiono 2006; Ingole et al. 2010; Panigrahi et al. 2015; Ansari et al. 2017; Chatterjee et al. 2019c). In present communication, this is reported as epibiont on nematode host belongs to the family Desmodoridae .

Distribution: Atlantic, Pacific, Antarctic and Indian Oceans, from the intertidal region to the deep sea (for detail see Chatterjee et al. 2019c); Arabian Sea, 3463 m depth (present report).

Remarks: Earlier this species was reported as epibiont on nematode species Croconema sphaerica (Kreis, 1928) (= Desmodora sphaerica ) (reported as Desmodora sphaerica ) and D. pontica (Filipjev, 1922) (invalid species name), Andaman Sea, Indian Ocean at a water depth of 1301 m ( Ingole et al. 2010).

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.