Aricidea (Allia) Strelzov, 1973
Aricidea (Allia) cf. ramosa Annenkova, 1934*
Voucher specimen. Sea Lion: Station 54MFB
Diagnosis. Voucher incomplete specimen with around 60 segments (body is posteriorly coiled and segments are impossible to count and exact measurement difficult to obtain), around 10mm long, 0.4 mm wide; colour in alcohol white; body dorsoventrally flattened anteriorly, cylindrical posteriorly, posterior part of the body coiled.
Prostomium weakly pear-shaped, narrowing anteriorly, nuchal grooves oblique, directed anteriorly. Antenna short, wide base with 5 branches, each branch simple (not branched); eyes absent. Posterior lip of mouth on ventrum of chaetiger 1 and partially on chaetiger 2. Branchiae from chaetiger 4, 17 pairs in voucher specimen, anterior branchiae (1-4 pairs) very wide, just meeting at middline with their tips, pairs 5- 9 getting longer with produced tips, posterior branchiae (pairs 10-12) longest, more slender, with very pronounced elongated tips, the most posterior branchiae slender, reducing in size with the last pair only slightly longer and thicker than corresponding notopodial postchaetal lobe.
Notopodial postchaetal lobes of chaetigers 1-2 small, becoming larger, cirriform with slightly inflated base from chaetiger 3 through branchial region, thereafter long, thin, cirriform. Neuropodial postsetal lobes inconspicuous.
Notochaetae capillaries, most dense with thick, curved capillary setae in branchial region; neurosetae thicker than notosetae; postbranchial notosetae thinner and straighter; neurosetae of same segments about as thick as in branchial region but shorter, becoming transformed into modified setae in the region of chaetigers 30-40 (impossible to determine exactly due to some damage and coiling of the body); modified setae straight or curved, bearing elongated terminal spine; 4 per fascicle in posterior part of the body; several thin capillaries accompany modified setae. Pygidium not observed.
Remarks. Aricidea ramosa can be readily distinguished by the presence of branched antenna. However given its cosmopolitan distribution, it is possible that more species lumped under this name are present. For example Strelzov (1973) described some branches of prostomial antenna being distally dichotomous not entire. Types of Annenkova have been lost according to Strelzov (1973). Until careful morphological examination of specimens form type locality accompanied by molecular studies is possible, we prefer to assign FI specimens to Aricidea (Allia) cf. ramosa.