Chone oculata Annenkova 1952, new status

Chone oculata Annenkova, 1952 new status

Figure 12

Chone murmanica oculata Annenkova, 1952: 153 –154.

Material examined. Type material. Laptev Sea [ZIRAS 47434, syntype], RV Sadko, Sta. 9, 77°25.5’ N, 115° 45.2’ E, 62 m, sandy mud, Coll. G. P. Gorbunov.

Additional material. Chone murmanica Lukasch, 1910 [ZIRAS 38178, Franz-Joseph Land].

Diagnosis. Tube organic, transparent, more or less incrusted by sand and mud. Anterior peristomial ring (apr) exposed beyond collar dorsally (Fig. 12 A). Ventral margin of collar higher than dorsal (Fig. 12 B). Lateral margin of collar with a median depression (Fig. 12 B). Anterior peristomial ring lobe not exposed beyond collar. Peristomial eyespots present. Glandular ridge on chaetiger 2 narrow. Thoracic segments biannulate. Ventral thoracic shields well developed (Fig. 12 B).

Remarks. According to Annenkova (1952), Chone murmanica oculata and C. murmanica have similar shape of the collar, branchiae, chaetae and tube, but they differ because C. m. oculata has eyespots on peristomium and despite being bigger, it has less chaetigers. However, C. murmanica has peristomial eyes (see diagnosis of C. murmanica above), and re-examination of type material of C. m. oculata shows additional differences: C. m. oculata has the lateral margin of collar with a median depression (absent in C. murmanica); the anterior peristomail ring is exposed dorsally (not exposed in C. murmanica); anterior peristomial ring lobe not exposed beyond collar (bilobed, exposed beyond collar in C. murmanica); and the entire length of middorsal collar margins forms a narrow gap (very prominent margins and broad gap in C. murmanica). Thus, C. m. oculata deserves specific status although examination of more materials from the type locality is necessary in order to describe characters from chaetae and uncini, and branchial crown appendages.