Aricidea (Acmira) catherinae Laubier, 1967

Erdoğan-Dereli, Deniz & Çinar, Melih Ertan, 2020, The diversity of the genus Aricidea (Polychaeta: Paraonidae) from the Sea of Marmara, with descriptions of two new species and two new records for the Mediterranean fauna, Zootaxa 4844 (1), pp. 1-73 : 13-15

Aricidea (Acmira) catherinae Laubier, 1967

( Figures 7–9 )

Aricidea catherinae Laubier 1967: 112–118 , figs. 4, 5 A–D.

Aricidea (Acesta) catherinae: Strelzov 1979: 105–108 , fig. 38.

Aricidea (Acmira) catherinae: Blake 1996: 56–57 , fig. 2.14; Lovell 2002: 42–44, fig. 5; Aguirrezabalaga 2012: 169–172, figs. 59–60.

Material examined. ESFM-POL/2013-41 , 06 June 2013, station Y1, 40°00’27’’N, 26°13’24’’E, 10 m, mud, 91 specimens ; ESFM-POL/2013-76 , 06 June 2013, station Y3, 40°13’10’’N, 26°25’45’’E, 50 m, sand, 4 specimens ; ESFM-POL/2013-1268 , 07 June 2013, station Y4, 40°18’09’’N, 26°35’15’’E, 50 m, sand, 2 specimens ; ESFM-POL/2013-1059, 07 June 2013, station Y6, 40°26’10’’N, 26°41’51’’E, 10 m, mud, 6 specimens; ESFM-POL/2013- 1061 , 07 June 2013, station Y7, 40°24’28’’N, 26°51’24’’E, 25 m, maerl bed, 6 specimens ; ESFM-POL/2013- 1063 , 08 June 2013, station Y9, 40°26’25’’N, 27°11’29’’E, 25 m, mud, 4 specimens ; ESFM-POL/2013-1064 , 07 June 2013, station Y10, 40°31’28’’N, 26°54’12’’E, 10 m, sand, 5 specimens ; ESFM-POL/2013-1066 , 07 June 2013, station Y10, 40°30’38’’N, 26°54’58’’E, 25 m, maerl bed, 4 specimens ; ESFM-POL/2013-51 , 08 June 2013, station Y12, 40°40’38’’N, 27°16’25’’E, 10 m, 2 specimens ; ESFM-POL/2013-65 , 10 June 2013, station Y13, 40°44’59’’N, 27°20’16’’E, 10 m, muddy sand with shell fragments, 1 specimen ; ESFM-POL/2013-1067 , 10 June 2013, station Y13, 40°45’00’’N, 27°20’29’’E, 25 m, maerl bed, 1 specimen ; ESFM-POL/2013-1424 , 10 June 2013, Y13, 40°45’15’’N, 27°20’49’’E, 50 m, maerl bed, 2 specimens ; ESFM-POL/2013-94 , 10 June 2013, station Y13, 40°45’27’’N, 27°21’24’’E, 100 m, mud, 15 specimens ; ESFM-POL/2013-1070 , 09 June 2013, station Y17, 40°39’16’’N, 27°41’14’’E, 25 m, fine sand, 5 specimens ; ESFM-POL/2013-1068 , 09 June 2013, station Y17, 40°39’58’’N, 27°41’08’’E, 50 m, mud, 55 specimens ; ESFM-POL/2013-102 , 12 June 2013, station Y19, 40°56’10’’N, 27°44’16’’E, 100 m, sandy mud with shell fragments, 2 specimens ; ESFM-POL/2013-1071 , 12 June 2013, station Y20, 40°57’09’’N, 27°54’46’’E, 50 m, mud with shell fragments, 2 specimens ; ESFM-POL/2013-1072 , 16 June 2013, station Y23, 40°23’55’’N, 28°09’49’’E, 10 m, mud with shell fragments, 3 specimens ; ESFM-POL/2013-1073 , 16 June 2013, station Y23, 40°27’20’’N, 28°10’19’’E, 50 m, maerl bed, 3 specimens ; ESFM-POL/2013-105 , 16 June 2013, station Y25, 40°24’28’’N, 28°20’84’’E, 10 m, sand, 9 specimens ; ESFM-POL/2013-1074 , 16 June 2013, station Y26, 40°22’06’’N, 28°39’55’’E, 10 m, sand with mudy shell fragments, 2 specimens ; ESFM-POL/2013- 1075 , 16 June 2013, station Y26, 40°22’36’’N, 28°39’41’’E, 25 m, sand with mudy shell fragments, 14 specimens ; ESFM-POL/2013-951 , 17 June 2013, station Y29, 40°32’34’’N, 28°46’53’’E, 25 m, maerl bed, 18 specimens ; ESFM-POL/2013-952 , 17 June 2013, station Y30, 40°36’37’’N, 28°56’19’’E, 50 m, mud, 9 specimens ; ESFM-POL/2013-1118, 23 June 2013, station Y32, 41°00’28’’N, 28°34’27’’E, 10 m, mud, 1 specimen; ESFM-POL/2013- 955 , 23 June 2013, station Y 33, 10 m, 40°58’21’’N, 28°45’14’’E, sandy mud with shell fragments, 7 specimens ; ESFM-POL/2013-956 , 22 June 2013, station Y36, 40°57’57’’N, 29°01’14’’E, 10 m, mud, 94 specimens ; ESFM-POL/2013-960, 19 June 2013, station Y39, 40°39’36’’N, 29°09’18’’E, 10 m, sandy mud station, 57 specimens; ESFM-POL/2013-961 , 20 June 2013, station Y41, 40°41’46’’N, 29°24’58’’E, 10 m, mud with shell fragments, 4 specimens ; ESFM-POL/2013-1076 , 20 June 2013, station Y43, 40°41’29’’N, 29°35’33’’E, 10 m, mud with sandy shell fragments, 39 specimens ; ESFM-POL/2013-1077 , 20 June 2013, station Y43, 40°41’32’’N, 29°35’34’’E, 25 m, mud, 26 specimens ; ESFM-POL/2013-966 , 26 June 2013, station Y48, 41°07’29’’N, 29°05’35’’E, 10 m, mud, 16 specimens ; ESFM-POL/2013-1079 , 26 June 2013, station Y48, 41°07’36’’N, 29°05’29’’E, 25 m, sand with mudy shell fragmnets, 59 specimens ; ESFM-POL/2013-968 , 26 June 2013, station Y49, 41°09’15’’N, 29°02’20’’E, 10 m, sandy mud with shell fragments, 3 specimens ; ESFM-POL/2013-972 , 26 June 2013, station Y49, 41°09’08’’N, 29°02’40’’E, 25 m, sandy mud with shell fragments, 6 specimens ; ESFM-POL/2013-1081 , 26 June 2013, station Y50, 41°12’16’’N, 29°07’25’’E, 10 m, sand, 11 specimens .

Description. Largest specimen complete, 12.03 mm, 0.38 mm wide at chaetiger 10, with 156 chaetigers. Color in alcohol usually light yellow; red speckles present near notopodium of gamete bearing specimens. Body thick, cylindrical and long; dorsal side slightly swollen in prebranchial region; widths of prebranchial and branchial regions nearly same; posterior part of body thick and gradually becoming thinner towards pre-anal region ( Fig. 7A ).

Prostomium triangular, longer than wide (ratio length / width: 0.5); anterior margin of prostomium rounded, one pair of eyes located dorso-laterally on midline of prostomium. A crown-like ciliary band (clcb) present, connecting nuchal organs ventrally ( Fig. 8C ). A pair of ciliary slits located near antenna ( Fig. 8C ). Antenna long, digitiform, with swelling near proximal part (antenna length / prostomium length: 1.2), reaching to chaetiger 2 ( Figs 7A ; 8C ; 9D ). A pair of nuchal organs as deep, short slits placed on dorso-lateral sides of posterior prostomium, more or less convex in shape; without pigmentation ( Fig. 8A ). Mouth with three buccal lips; two placed anteriorly, one posteriorly and extending to anterior margin of chaetiger 1 with eight longitudinal folds.

A dense dorsal ciliary band (dcb) present on mid-dorsal transversal line of prebranchial and branchial chaetigers. A pair of small transverse dorsal ciliary bands (sdcb) posterior to base of each branchia ( Fig. 8 A–B). Ciliary bands absent on ventral side of body.

Branchiae numbering 16 pairs, starting on chaetiger 4, somewhat flattened and weakly foliaceous, with a rounded tip in anterior region; branchiae becoming longer and with an elongated tip towards posterior region ( Fig. 7A ); 215 μm long in anterior region, 333 μm in middle region and 344 μm in posterior region.

Interramal lobes absent ( Figs 8 B–C; 9A, D). Notopodial papillae from mid-branchial to posterior-most branchial chaetgiers ( Figs 7 B–C; 8A–B).

Notopodial postchaetal lobes thick, short and digitiform in first two chaetigers; subsequently becoming thicker and longer with weakly asymmetrical basal swelling; thin, long and filiform in posterior chaetigers ( Figs 8 A–C; 9A–D). Neuropodial postchaetal lobes present only in chaetigers 1–9, short and tuberculated ( Fig. 8B ). Ventral lobes absent.

Lateral sense organs present all along body, located posterior to notopodial postchaetal lobes in each chaetiger; with flexible cilia distinctly protruding from opening or embedded into pore; elliptical with irregularly clustered pores in prebranchial and branchial regions; straight line-shaped with regularly clustered pores in postbranchial region ( Figs 8C ; 9 A–C); with 15–20 pores in prebranchial region (long axis of lateral organ: 11–12 μm); with 25–32 pores (long axis: 7–8 μm) in anterior and middle chaetigers of branchial region; with 45–50 pores (long axis: 17–18 μm) in posterior part of branchial region; with 45–50 pores (long axis: 19–20 μm) in posterior part of body.

Three main types of chaetae present in chaetigers: limbate, capillary and modified neurochaeta. Limbate chaetae of two types; first type present only in notopodia of chaetigers 1–13, numbering 15–18, arranged in three rows, 171– 244 µm long, thin and straight with fibrils along edge (hirsute), on to dorsal side, light rose colored; second type present only in neuropodia of chaetigers 1–13, numbering 25–30, arranged in four rows, 146–183 µm long, slightly wider and sigmoid with fibrils along edge (hirsute), on to ventral side, light rose colored ( Figs 8 B–C; 9A, C–D).

Capillary chaetae starting in noto- and neuropodia from chaetiger 14 and present in all subsequent chaetigers; in middle notopodia numbering 8–19, arranged in two rows, ca. 142 μm long; in posterior notopodia numbering 4–7, arranged in one row, ca. 199 μm long; in middle neuropodia numbering 8–11, arranged in 2–3 rows, 273 μm long; in posterior neuropodia numbering 2–3, arranged in one row, 207 μm long.

Modified neurochaeta from chaetiger 25 to 35 and present on all subsequent chaetigers, numbering 5–7, arranged in one row. Length of modified chaetae (about 82 μm) almost identical in body regions, slightly curved subterminally, with a rounded tip; pubescence on convex side of distal region; with small, weak “hood” on concave side of subterminal region; with a long arista at tip ( Fig. 7 D–F).

Pygidium antero-ventrally flattened, cylindrical with three cirri: two latero-ventral cirri (82 μm long) and one mid-ventral cirri (19 μm long) ( Fig. 7A, G ).

Reproduction. Some specimens of this species from the Sea of Marmara had eggs in their coelomic cavities from chaetiger 28 to the end of the body; each chaetiger had four eggs. The egg diameter varied between 130 and 182 μm. The gamete bearing specimens have red speckles near notopodia along the body. Sexually mature specimens were previously reported in June and July ( O’Connor et al. 1984; Aguirrezabalaga 2012), and the egg diameter was estimated between 100 and 170 μm ( O’Connor et al. 1984)

Parasites. The branchiae (on chaetigers 15 to 18) of some specimens of A. catherinae from the Sea of Marmara were parasitised by an unidentified copepod species ( Fig. 7H ). Laubier & Carton (1973) reported that the branchiae of specimens of Aricidea (Strelzovia) mediterranea ( Laubier & Ramos, 1974) from the western Mediterranean were parasitised by the copepod Vectoriella ramosae Laubier & Carton 1973 . A further detailed study is needed to clarify if the same parasite also infected the A. catherinae specimens.

Remarks. The specimens of Aricidea catherinae from the Sea of Marmara differ from the original description by Laubier (1967) in their larger body size, in bearing more branchiae and in possessing notopodial papillae and neuropodial postchaetal lobes. However, the Sea of Marmara’s specimens are similar to the original description in terms of the shapes of the antenna (with a swelling near proximal part) and of the shape of the notopodial postchaetal lobes, the branchiae and the modified neurochaetae. Weakly asymmetrical basal swellings in the notopodial postchaetal lobes were not mentioned in the original description, but subsequently illustrated by Strelzov (1979). The neuropodial postchaetal lobe was not mentioned by Laubier (1967), but Gil & Sarda (1999), Blake (1996) and Aguirrezabalaga (2012) reported it on the specimens from the Mediterranean, Atlantic Ocean and Pacific Ocean.

Lovell (2002) was the first to report the notopodial papillae (as papillary protuberance) for this species. Aguirrezabalaga (2012) also photographed (in Figure 60A) but did not describe it. It seems that this character, which only occurs in chaetigers 7–8 in the branchial region, might have been overlooked because of the difficulty in discriminating it. The notopodial papillae were previously described in Aricidea finitima Strelzov, 1973 ( Strelzov 1979) and A. rubra Blake, 1996 ( Blake 1996) .

In the previous descriptions of this species, the short dorsal ciliary bands (sdcb), which were placed just posterior to the bases of branchiae, were not mentioned, but they were apparent in the SEM photograph (in Figure 60C) taken by Aguirrezabalaga (2012). It seems that they were some kind of sensory organs, but their real function should be investigated in detail.

Habitat and Distribution. The specimens of Aricidea catherinae were found in soft substrata at depths ranging from 10 to 100 m in the Sea of Marmara. It was previously reported from the same habitats between 0 and 494 m depths in the Pacific Ocean ( Blake 1996; Montiel et al. 2002; Aguado & López 2003), Indian Ocean ( Lovell 2002), Arctic Ocean ( Strelzov 1979), Atlantic Ocean ( Campoy 1982; Gil & Sarda 1999; Aguirrezabalaga 2012), and eastern ( Çinar et al. 2014) and western ( Laubier & Ramos 1974) Mediterranean.

Figures

FIGURE 7. Aricidea (Acmira) catherinae. A, General view of body (ESFM-POL/2013-1076); B, Lateral view of chaetigers 12,13 and 14, with notopodial papillae (ESFM-POL/2013-1079); C, Lateral view of branchial chaetigers (ESFM-POL/2013- 960); D, Modified neurochaetae of chaetiger 94 (ESFM-POL/2013-960); E, Modified neurochaeta of chaetiger 42 (ESFM- POL/2013-960); F, Modified neurochaeta with arista of chaetiger 50 (ESFM-POL/2013-960); G, Lateral view of pygidium (ESFM-POL/2013-1076); H, A copepod parasite on chaetiger 15 (ESFM-POL/2013-1076). Abbreviations: ntp, notopodial papil; ntpcl, notopodial postchaetal lobe; rds, red speckles. Scale bar: A, 783 µm; B, 41 µm; C, 101 µm; D, 32 µm; E, 22 µm; F, 24 µm; G, 150 µm; H, 643 µm.

FIGURE 8. Aricidea (Acmira) catherinae. A, Antero-dorsal view of body (ESFM-POL/2013-1077); B, Lateral view of posterior part of branchial region with notopodial papillae (ESFM-POL/2013-1077); C, Antero-lateral view of prostomium (ESFM- POL/2013-1077). Abbreviations: bran, branchia; clcb, crown-like ciliary band; cs, ciliary slits; dcb, dorsal ciliary band; lso, lateral sense organ; neupcl, neuropodial postchaetal lobe; ntp, notopodial papil; ntpcl, notopodial postchaetal lobe; sdcb, short dorsal ciliary band. Scale bar: A, 121 µm; B, 88 µm; C, 78 µm.

FIGURE9. Aricidea(Acmira) catherinae.A, Lateralsenseorgan on a parapodiuminanteriorbranchial region(ESFM-POL/2013- 956); B, Lateral sense organ on a parapodium in posterior branchial region (ESFM-POL/2013-956); C,A notopodium of posterior chaetiger (ESFM-POL/2013-956); D, Dorso-lateral view of anterior end, short dorsal ciliary bands (ESFM-POL/2013-1077). Abbreviations: bran, branchia; lso, lateral sense organ; neupcl, neuropodial postchaetal lobe; ntpcl, notopodial postchaetal lobe; sdcb, short dorsal ciliary band. Scale bar: A, 26 µm; B, 18 µm; C, 27 µm; D, 118 µm.