Cirrophorus branchiatus Ehlers, 1908

Erdoğan-Dereli, Deniz, Çinar, Melih Ertan & Dağli, Ertan, 2017, Cirrophorus species (Annelida: Polychaeta: Paraonidae) in the Sea of Marmara, with description of a new species, Zootaxa 4347 (1), pp. 137-150 : 147-149

Cirrophorus branchiatus Ehlers, 1908

( Figure 8 )

Cirrophorus branchiatus Ehlers, 1908: 124 –126, Fig. (Tafel.17) 5–9; Day, 1963:419, 423–424 Fig.9 l–o; Glémarec, 1966: 1049 –1051, Fig. 1A ; Day, 1967: 563 –564, Fig. 24.3.a–e; Laubier, 1971: 261, Fig 1.d–f ; Strelzov, 1973: 127 –131, Fig. 46; Laubier and Ramos, 1974:1138; Katzmann and Laubier, 1975: 584; Campoy, 1982: 644, 653–654, Fig 33A, B; Blake, 1996: 38 –39, Fig. 2.4; Aguirrezabalaga, 2012: 231 –235, Fig. 100–101.

Material examined. ESFM-POL / 2013-62, Sea of Marmara, Turkey, 0 6 June 2013, Y2, 40°06'59''N, 26°22'04''E, 50 m, muddy sand, 1 specimen; ESFM-POL / 2013-81, 0 6 June 2013, Y4, 40°17'49''N, 26°35'44''E, 25 m, mud, 1 specimen; ESFM-POL /2013-1048, 14 June 2013, Y31, 41°01'25’'N, 28°26'23''E, 25 m, maerl bed, 8 specimens; ESFM-POL /2013-1134, 0 7 June 2013, Y7, 40°24'28''N, 26°51'24''E, 25 m, maerl bed, 23 specimens; ESFM-POL / 2013-1261, 0 6 June 2013, Y3, 40°12'15''N, 26°26'12''E, 25 m, mud, 1 specimen; ESFM-POL /2013-1262, 0 6 June 2013, Y3, 40°13'10''N, 26°25'45''E, 50 m, sand, 3 specimens; ESFM-POL /2013-1264, 0 7 June 2013, Y4, 40°18'09''N, 26°35'15''E, 50 m, sand, 1 specimen; ESFM-POL /2013-1265, 0 7 June 2013, Y5, 40°20'55''N, 26°40'38''E, 25 m, mud, 1 specimen.

Description. Largest specimen (ESFM/POL-2013-1048) complete, 14.6 mm long, 0.27 mm wide with 93 chaetigers. Color in alcohol opaque white. Body long, thick. Anterior part of prostomium rounded; prostomium much longer than wide ( Fig. 8A ). Posterior buccal lips extending to anterior part of first chaetiger. Nuchal organs starting at middle part of posterior region of prostomium, extending to end of prostomium. Eyes absent. Antenna cirriform, located at middle part of prostomium, extending to end of prostomium. Peristomium fused with prostomium, visible on ventro-lateral side ( Fig. 8C ). Proboscis simple, cylindrical and without lobes ( Fig. 8C ). Parapodia biramous. Notopodial postchaetal lobes starting from chaetiger 1, cirriform, increasing in length after chaetiger 3; getting shorter after chaetiger 14; becoming longer and filiform in shape in posterior region, and almost inconspicuous in pre-anal region. Neuropodial postchaetal lobes absent. Branchiae cylindro-conical with rounded tip, 11–15 pairs, beginning on chaetiger 5 ( Figs. 8A–B ). First and last pair of branchiae shorter (length/ width mostly 4.5; maximum length: 28 µm). Short ciliary bands on middle line of branchiae. Neuro- and notocapillary chaetae slender, long, not hirsute; maximally 387 µm long in anterior parapodia; 400 µm long in middle parapodia; 441 µm long in posterior parapodia. Capillary chaetae numbering 33 (notopodium), 26 (neuropodium) in anterior parapodia; 10 (notopodium), 8 (neuropodium) in middle parapodia; 2 (notopodium), 16 (neuropodium) in posterior parapodia. Modified notochaeta first appearing on chaetiger 6 as a lyrate chaeta and, transforming into acicular chaeta on chaetiger 9. Lyrate chaeta numbering one or two in chaetigers 6–9, with unequal branches; longer branch three or four times longer than smaller one; width of branches unequal; teeth discernible. Acicular chaeta yellow, thick, with rounded tip, bearing long, slender lateral filament; base of filament with discernible teeth ( Fig. 8E ). Pygidium rounded, much wider than long, bearing 3 anal cirri ( Fig. 8D ); mid-dorsal one thick and rounded; two latero-dorsal cirri thin and long.

Reproduction. Some specimens of C. branchiatus collected in June have sperm packed in the coelomic cavities of the middle and posterior segments (after chaetiger 30). Specimens with 4– 6 eggs per segment, starting in the middle region (after chaetiger 23); egg diameter: 130–190 µm.

Remarks. The specimens of Cirrophorus branchiatus from the Sea of Marmara differ from the original description of C. branchiatus . According to Ehlers (1908), the notopodial postchaetal lobes are well developed on the anterior segments (width of segment / length of notopodial postchaetal lobe: 3) and the body bears 22 pairs of branchiae, but in our specimens, the notopodial postchaetal lobes are not well developed (width/ notopodial postchaetal lobes: 5.4) and the body bears only 14 pairs of branchiae. According to Laubier (1965), the specimens of Cirrophorus branchiatus from the Mediterranean have an ovoid or very weakly cirriform antenna; rounded eyes; acicular chaeta starting from the chaetiger 6; and 14–17 pairs of branchiae. However, the specimens of C. branchiatus from the Sea of Marmara have cirriform antenna; no eyes; acicular chaeta starting from the chaetiger 9; and 11– 15 pairs of branchiae. However, Laubier (1965) postulated that specimens with or without eyes, and the acicular chaetae on chaetigers might vary based on size. Strelzov (1973, 1979) also pointed out that the number of branchiae on specimens changes according to the width of the specimens ( Strelzov, 1979, see Table 8).

Distribution. Western and eastern Mediterranean.

Figures

FIGURE 1. The map of sampling area (Sea of Marmara, Turkey) with stations where specimens of Cirrophorus species were found (K: Coastal Stations, Y: Soft Substrata Stations).

FIGURE 8. Cirrophorus branchiatus. A, overview (ESFM / POL- 2013 - 1048); B, anterior end, lateral view (ESFM / POL- 2013 - 1048); C, prostomium and proboscis, ventro-lateral view (ESFM / POL- 2013 - 62); D, pygidium (ESFM / POL- 2013 - 1048); E, acicular chaeta (ESFM / POL- 2013 - 1048). Scale bar: A = 660 µm, B = 444 µm, C = 192 µm, D = 83 µm, E = 21 µm.