Chone quebecensis, Tovar-Hernández, 2007

Tovar-Hernández, María Ana, 2007, Revision of Chone Krøyer, 1856 (Polychaeta: Sabellidae) from North America and descriptions of four new species, Journal of Natural History 41 (9 - 12), pp. 511-566: 548-553

publication ID

http://doi.org/ 10.1080/00222930701250912

persistent identifier

http://treatment.plazi.org/id/03B1879F-3006-5C62-FE31-E236C5B6FA92

treatment provided by

Felipe

scientific name

Chone quebecensis
status

n. sp.

Chone quebecensis   n. sp.

( Figures 13–15 View Figure 13 View Figure 14 View Figure 15 , 19C View Figure 19 )

Material examined

Type material. Quebec [ CMN 1989-0394 View Materials ], holotype   , 13 paratypes; [ ECOSUR 0074 View Materials ]   , four paratypes (two covered in gold for SEM): Saint Lawrence estuary, off Point Mitis, Sta. B 610-7IL-152D, 37 m, coll. Rafat MASSAD, 9 July 1971. Topotypes [ CMN 1989-0384 View Materials ], off Trois Pistols, Sta. B 130-70F-11D, 33 m, coll. Rafat MASSAD, 22 June 1970 (6). [ CMN 1989-0391 View Materials ], off Grandes Beyoeromes, Sta. B 94-15, 70L, 274 m, coll. Rafat MASSAD, 30 July 1970 (6). [ CMN 1989-0386 View Materials ], off Trois Pistols, Sta. B 167-70P-86D, 165 m, coll. Rafat MASSAD, 21 August 1970 (30). [ CMN 1989- 0390 View Materials ], off Point au Pire, Sta. B 527-71H-57D, 220 m, coll. Rafat MASSAD, 17 June 1971 (12). [ CMN 1989-0393 View Materials ], off St. Simon, Sta. B 247 71I-81D, 282 m, coll. Rafat MASSAD, 22 June 1971 (3). [ CMN 1989-0392 View Materials ], off Grandes Beyoeromes, Sta. B 92-7, 71I-83D, 357 m, coll. Rafat MASSAD, 23 June 1971 (2). [ CMN 1989-0385 View Materials , 10 View Materials ], off Trois Pistols, Sta. BI 63-7IL-121D, 115 m, coll. Rafat MASSAD, 6 July 1971 (10). [ CMN 1989-0387 View Materials ], off Point au Pire , Sta. B 504-71L-164B, 15 m, coll. Rafat MASSAD, 9 July 1971 (2)   .

Non-type material. Labrador Sea [ ZMUC-POL-1758], ‘‘ Ingolf’ ’, Sta. 38., 59 ° 129N, 51 ° 059W, 3521 m, 30 July 1895 (1)   material cited by Wessenberg-Lund (1950) as C. infundibuliformis   . Nova Scotia [ CMN 1983-0165 View Materials ], Cape Breton, Bras d’Or Lake , St. Andrews Channel , Sta. CBNID, 60–120 m, 46 ° 38.59N, 60 ° 38.59W, coll. NMNS 121 View Materials Expedition, 1 July 1981 (22) GoogleMaps   . [ CMN 1983-01 View Materials ], Bras d’Or Lake, Saint Andrews Channel, Sta. CBNID, 60–120 m, 46 ° 359N, 60 ° 38.59W, coll. NMNS 121 View Materials Expedition, 1 July 1981   (1).

Additional material. Chone bimaculata Banse and Nichols, 1968   [USNM 36280, paratypes; 36281, paratype]. Chone ecaudata ( Moore, 1923)   [USNM 17319, holotype, 58970, paratype]. Chone letterstedti ( Kinberg, 1867)   [SMNH 576, holotype]. Chone perkinsi   Tovar- Hernández, 2005 [FSBC I 66735 View Materials , holotype].

Description (in parentheses variation observed in paratypes)

Colour, body shape, and size. Body and base of the branchial crown cream coloured. Trunk cylindrical ( Figure 13B, C View Figure 13 ), posterior abdomen depressed latero-ventrally ( Figure 13G View Figure 13 ). Body length 14 mm (4.1–16), width 1.3 mm (0.3–1.2). Tubes unknown.

Branchial lobes and branchial crown. Insertion of the branchial lobes (bl) exposed beyond collar ( Figure 13A, B View Figure 13 ). Branchial crown length 7 mm (6–7). Radioles: 10 pairs (8–13). Radioles with median pinnules three times longer than more proximal pinnules. Radiolar tips long ( Figure 13E View Figure 13 ). The palmate membrane extends to three-quarters the length of branchial crown. Lateral flanges broad ( Figure 13E View Figure 13 ). Dorsal lips three times longer than wide, erect, without mid-rib. Dorsal pinnular appendages: one to three short pairs, united by a palmate membrane. Ventral lips rounded, as long as wide, about one-quarter the length of dorsal lips. Ventral radiolar appendages: one to three pairs, the inner one as long as three-quarters the length of branchial crown, the remainder about one-quarter the length of branchial crown.

Peristomium   . Anterior peristomial ring lobe exposed beyond collar ( Figure 13B–D View Figure 13 ), distally bilobed ( Figure 13D, F View Figure 13 ). Posterior peristomial ring collar: antero-dorsal margin deeply incised, forming two well-developed dorsal pockets ( Figure 13A View Figure 13 ), two dorsal, oval glandular shields (ogs) ( Figure 13A, B View Figure 13 ), entire length of mid-dorsal collar margins forms a narrow gap ( Figure 13A View Figure 13 ); lateral and ventral margins entire ( Figure 13C, D View Figure 13 ); ventral margin slightly higher than dorsal ( Figure 13B, C View Figure 13 ). Ventral shield of collar swollen, horseshoe-shaped, two times wider than long ( Figure 13D View Figure 13 ). Ratio of posterior peristomial ring collar length versus chaetiger 2 length, in lateral view: 2:1.

Thorax. Chaetiger 1: two groups of four to six elongate, narrowly hooded chaetae. Chaetigers 2–8: notopodia—two irregular rows of four to five elongate, narrowly hooded chaetae; one anterior row with four to five bayonet chaetae ( Figures 13I View Figure 13 , 14D, F View Figure 14 ); two posterior rows with five symmetrical, paleate chaetae with long mucro ( Figures 13J–L View Figure 13 , 14D, E View Figure 14 ); neuropodia—one row of 8–13 acicular uncini per torus, main fang surmounted by four rows of teeth equal in size, occupying half the length of main fang ( Figures 13H View Figure 13 , 14A View Figure 14 ). Pre- and post-chaetal lobes well developed. Broad glandular, columnar epithelium (gce), swollen in ventral thoracic segments ( Figure 19C View Figure 19 ). Broad glandular ridge on chaetiger 2, occupying half of the epithelium in longitudinal section ( Figure 19C View Figure 19 ).

Abdomen. Abdominal segments: 46 (42–46). Anterior segments: two transverse rows of five to six elongate, narrowly hooded chaetae ( Figure 13M, V View Figure 13 ), chaetae from upper row half as long as chaetae in lower row ( Figure 14G View Figure 14 ); 10–12 uncini per torus, older (dorsalmost) and younger uncini (ventralmost) with the main fang surmounted by six regular rows of teeth in frontal view, equal in size, occupying three-quarters the length of main fang ( Figure 14B View Figure 14 ), main fang not extending beyond breast ( Figure 14O View Figure 14 ), breast rectangular. Posterior segments: one or two very elongate, narrowly hooded chaetae, 25% longer than in anterior segments ( Figure 14H View Figure 14 ), making a small angle with the shaft at the base of the hood ( Figure 13N, U View Figure 13 ); five to eight modified uncini per torus with the main fang surmounted by six to seven regular vertical rows of teeth equal in size ( Figure 14C View Figure 14 ), occupying threequarters the length of main fang, older (dorsalmost) uncini smaller than younger uncini (ventralmost), main fang not extending beyond breast, breast rectangular. Ventral, glandular, whitish band on posterior abdomen (gb) ( Figure 13G View Figure 13 ). Pygidium with triangular posterior margin ( Figure 13G View Figure 13 ).

Gametes. Females with oocytes polyhedron-shaped in thorax and abdomen ( Figure 15B View Figure 15 ), diameter 37.5–56.25 mm. Sperm in posterior abdominal chaetigers, spermatozoa rectangular nucleus (two times longer than wide), acrosome sucking-shaped (occupying one-quarter the length of nucleus) and two small, rounded mitochondria.

Methyl green staining. Anterior end of the ventral shield of collar not coloured, posterior end dark. Dorsally, there is no colour in collar, chaetigers 1 and 2; then each segment is divided into four dark rectangles by the presence of the faecal groove, inter-segmental and intra-notochaetal and neurochaetal grooves. Ventrally, each segment has a median, longitudinal dark band; lateral sides are coloured uniformly. Laterally, the collar has two large, rectangular spots ( Figure 13C View Figure 13 ). Pygidium stays darker for several days.

Histology. The ventral, posterior abdominal glandular band (gb) in Chone quebecensis   n. sp. is a complete whitish band in preserved material ( Figure 13G View Figure 13 ), pink with haematoxylin–eosin ( Figure 15A View Figure 15 ). This structure is located in a mid-ventral transition zone on the columnar epithelium ( Figure 15A, C, E, F View Figure 15 ), and composed of strongly differentiated acidophil glandular cells (ag), tubular-shaped with granulose secretions ( Figure 15F View Figure 15 ). The glandular columnar epithelium (gce) has large, rectangular cells, covered by cuticle (cu) ( Figure 15E View Figure 15 ). Abdomen is composed of two ventral (vplm) and two dorsal packages of longitudinal muscle (dplm) ( Figure 15A, D View Figure 15 ); the coelom is filled with oocytes (oo) and yolk (y) ( Figure 15B View Figure 15 ).

Remarks

Chone quebecensis   n. sp. is unique among Chone species   in having (1) the ventral margin of anterior peristomial ring lobe distally bilobed; (2) two peristomial, dorsal glandular shields; (3) a ventral, longitudinal glandular band on the posterior part of abdomen; and (4) spermatozoa with rectangular nucleus (two times longer than wide), head suckershaped and two small, rounded mitochondria. The bilobed condition of the anterior peristomial ring lobe in Chone quebecensis   n. sp. is common in species of Amphicorina Claparède, 1864   (in which it could be minutely bilobed or trilobed), and also in C. bimaculata   and C. sp. 3 Fitzhugh, 2002 (bilobed in both). However, C. quebecensis   n. sp. is easily distinguished from C. bimaculata   and C. sp. 3 by having two peristomial, dorsal glandular shields and a ventral, longitudinal glandular band on the posterior part of abdomen.

Chone quebecensis   n. sp., C. albocincta   , and C. perkinsi   have the glandular ridge on chaetiger 2 broad on one side: broad ventrally in C. quebecensis   n. sp. and C. albocincta   , and broad dorsally in C. perkinsi   . Paleate chaetae with long mucro in C. quebecensis   sp. nov. and C. perkinsi   , with medium-sized mucro in C. albocincta   . C. perkinsi   has radioles with five to six dark brown bands, each band constituted by a variable number of bright, brownish spots surrounding the cells of the branchial skeleton; these bands are absent in C. quebecensis   n. sp. Branchial lobes are exposed beyond the collar in C. quebecensis   n. sp., and not exposed in C. perkinsi   .

Chone quebecensis   n. sp. and C. letterstedti   have the antero-dorsal margin of the posterior peristomial ring collar deeply incised. Chone quebecensis   n. sp. has long radiolar tips (short in C. letterstedti   ); narrow flanges (broad in C. letterstedti   ); posterior abdominal uncini modified (not modified in C. letterstedti   ); and a posterior dorso-ventral abdominal depression (absent in C. letterstedti   ).

Etymology

The specific epithet refers to the collecting and distribution zone.

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Order

Sabellida

Family

Sabellidae

Genus

Chone

Loc

Chone quebecensis

Tovar-Hernández, María Ana 2007
2007
Loc

Chone quebecensis

Tovar-Hernández 2007
2007
Loc

Chone quebecensis

Tovar-Hernández 2007
2007
Loc

C. quebecensis

Tovar-Hernández 2007
2007
Loc

Chone quebecensis

Tovar-Hernández 2007
2007
Loc

C. quebecensis

Tovar-Hernández 2007
2007
Loc

C. quebecensis

Tovar-Hernández 2007
2007
Loc

C. quebecensis

Tovar-Hernández 2007
2007
Loc

C. quebecensis

Tovar-Hernández 2007
2007
Loc

C. perkinsi

Tovar-Hernandez 2005
2005
Loc

C. perkinsi

Tovar-Hernandez 2005
2005
Loc

C. perkinsi

Tovar-Hernandez 2005
2005
Loc

C. perkinsi

Tovar-Hernandez 2005
2005
Loc

C. perkinsi

Tovar-Hernandez 2005
2005
Loc

C. albocincta

Banse 1972
1972
Loc

C. albocincta

Banse 1972
1972
Loc

C. albocincta

Banse 1972
1972
Loc

C. bimaculata

Banse and Nichols 1968
1968
Loc

C. bimaculata

Banse and Nichols 1968
1968
Loc

Amphicorina Claparède, 1864

Claparede 1864
1864