Namalycastis abiuma (Grube, 1872)

Bharathidasan, Veeraiyan, Sarathy, Palanivel Partha, Murugesan, Perumal & Nogueira, João Miguel De Matos, 2021, New records for associations between peritrich protozoan ciliates (Ciliophora, Sessilida) and polychaete worms (Annelida) from off the southeastern coast of India, Zootaxa 5071 (4), pp. 492-504 : 498

2. Namalycastis abiuma (Annelida, Nereidiformia) and Epistylis sp.2 (Ciliophora, Sessillida)

The present is the first record of epibionts attached to Namalycastis abiuma polychaetes. Out of 20 specimens of N. abiuma examined, seven had individuals of Epistylis sp.2 attached to the parapodia, mostly on dorsal cirri, but also present on the ligules and ventral cirri. The ciliates are restricted to the parapodia, not occurring either on dorsal or ventral body surfaces of the worms, and may occur on both sides, anterior and posterior, of ligules and cirri. Partially contracted mature individuals of Epistylis sp.2 are 51.06 µm long, in average, and juveniles are 34.57 µm long, in average, in 30 individuals measured ( Fig. 3B, D ). Members of Epistylis sp.2 were found in both solitary and colonial forms ( Fig. 3B–D ), on average ~75 individuals per worm.

Figures

FIGURE 3. Specimens of Epistylis sp.2 on Namalycastis abiuma. (A). Entire worm, dorsal view; (B). Colony of Epistylis sp.2 on parapodial dorsal cirrus; (C). Solitary Epistylis sp.2 on parapodial dorsal cirrus; (D). Premature juvenile Epistylis sp. 2, on parapodial ventral cirrus; most specimens measured along longitudinal axis. White arrow points to folds of the posterior region of zooid; yellow arrow points to projecting tube formed by constriction of the peristomial lip, red arrow points to macronucleus.