Acinetopsis lynni Baldrighi et al., 2020

Chatterjee, Tapas, Sautya, Sabyasachi, Dovgal, Igor & Gaikwad, Santosh, 2022, Report of suctorian ciliates (Ciliophora, Suctorea) as epibionts on meiobenthic nematodes in an oxygen minimum zone of the Arabian Sea, Indian Ocean, Zootaxa 5138 (4), pp. 492-500 : 496-497

Acinetopsis lynni Baldrighi et al., 2020

( Fig. 3A–F )

Material examined: Twenty ciliate specimens were found attached with eight female Desmodora sp. and sixty ciliate specimens were found attached with nine males of the same species from 202 m depth of the Arabian Sea.

Brief Description: Marine suctorian ciliate enclosed in stalked lorica. The cellbody is attached to the bottom of lorica, which fills about two thirds or three fours of it. The apical surface of the cell is somewhat concave down. Lorica elongate, slightly flattened, smooth. Stalk, short, straight, some extended upward, very weakly longitudinally striated, with the adhesive disc. There are 6–7 extremely contractive, long, agile tentacles (in investigating individuals all tentacles were contracted). Macronucleus ovoid, positioned near foot of the body. Reproduction by endogenous budding with the formation of a single protomite.

Measurements from present find (in µm, based on four individuals): Lorica length 53–77; lorica width 17–24; body length 47–58; body width 16–22; stalk length 5–8; macronucleus length 7–11; macronucleus width 4–6; length of the contracted tentacles 4–7.

Remarks: In the present observation total of 80 Acinetopsis lynni specimens are found attached to 17 individuals of the host ( Table 2 ). The place of attachment was shown in Pie diagram ( Fig. 4 ) giving information on the percentage of infestation at anterior, middle and posterior body parts of the nematode host. It was found that 11% ciliates were attached on the anterior part of the body while, attachment on middle and posterior parts was 54% and 34%, respectively. Baldrighi et al. (2020) reported the attachment of this species on the host body at the middle part and tail region of the body.

This species was earlier reported as epibiont on Desmodora sp. found attached to the middle part and tail region from the Gulf of Naples-shallow vent area ( Baldrighi et al. 2020).

This is the first report of this species from the Arabian Sea and the Indian Ocean.

Figures

FIGURE 3A, B. Acinetopsis lynni Baldrighi et al., 2020 attached on nematode hosts, C–F. Manified views of Acinetopsis lynni.

FIGURE 4. Pie diagram showing percentage of Acinetopsis lynni infestation at anterior, middle and posterior body parts of nematode hosts.