Chone magna ( Moore, 1923 )

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: 536-539

publication ID

http://doi.org/ 10.1080/00222930701250912

persistent identifier

http://treatment.plazi.org/id/03B1879F-303A-5C54-FE17-E053C260FC4F

treatment provided by

Felipe

scientific name

Chone magna ( Moore, 1923 )
status

 

Chone magna ( Moore, 1923)  

( Figure 9 View Figure 9 )

Euchone magna Moore 1923, p 245   , Plate 18, Figures 45, 46; Hartman 1961, p 42.

Chone magna: Hartman 1969, p 669   ; Banse 1972, p 472 –474, Figure 5 View Figure 5 . Material examined

Type material. California [ USNM 17281 View Materials (holotype), ANSP AD 3297 View Materials (one paratype), ANSP 1-22 View Materials , 1-23 View Materials (one paratype mounted in slides), San Miguel Island, off Harris, R / V Albatross , Sta. 4436, 271 m, 15 April 1904]   .

Non-type material. Washington [ USNM 43636 View Materials ], South of Orcas Island, W of Blakeley Island, 48 ° 34.99N, 122 ° 50.89W, 13 August 1964 (1). [ FHL 293], Lopez Island , San Juan Archipelago, Upright Head, coll. R GoogleMaps   . P. Dales and G. John, 2 August 1960 (1). [ LACM- AHF], Point Loma, Westec, LA 5, 430– 480 m, 30 March 1983 (1). [ LACM-AHF], BLM 2296, BFI   (1).

Additional material. Chone aurantiaca ( Johnson, 1901)   [ MCZ 1933, holotype]. Chone farringtonae Tovar-Hernández, 2005   [ FSBC I 66733 View Materials , holotype]. Chone mollis   (Bush in Moore, 1904) [ YPM 2793, holotype]. Chone picta ( Verrill, 1885)   [ YPM 30000 View Materials , topotype].

Description (based on holotype, number in parentheses correspond to paratypes and non-type material)

Colour, body shape, and size. Body cream coloured, covered by an iridescent layer of epicuticle. Trunk cylindrical ( Figure 9C, E, F View Figure 9 ). Holotype fragmented in three parts (without branchial crown, posterior abdomen damaged as well as a few chaetigers). Body length 8.2 mm (54–71), width 3 mm (2.5–6). Tubes unknown.

Branchial lobes and branchial crown. Insertion of the branchial lobes not exposed beyond collar (exposed only when anterior margins of collar are reflexed). Branchial crown length (16–18 mm). Radioles: (29) pairs. Radioles with median pinnules two times longer than basal ones. Radiolar tips long (3.5 mm) ( Figure 9D, P View Figure 9 ). The palmate membrane extends to three-quarters the length of branchial crown. Lateral flanges narrow ( Figure 9P View Figure 9 ). Dorsal lips (dl) broadly rounded, longer than wide, without mid-rib ( Figure 9I, M View Figure 9 ). Dorsal pinnular appendages (dpa): (five to six short and median pairs). Ventral lips small, rounded, as long as wide, about one-half length of dorsal lips. Ventral radiolar appendages: one to three pairs, the inner one about three-quarters the length of branchial crown, the remainder about one-quarter the length of branchial crown.

Peristomium   . Anterior peristomial ring lobe not exposed above collar, distally entire, triangular. Posterior peristomial ring collar: antero-dorsal margin entire, entire length of mid-dorsal margins forms a broad gap ( Figure 9A, E View Figure 9 ), deep faecal groove, dorsal pockets well developed; lateral and ventral margins entire ( Figure 9E, F View Figure 9 ); ventral margin higher than dorsal ( Figure 9B, C, F View Figure 9 ). Ventral shield of collar swollen, rounded ( Figure 9B View Figure 9 ). Ratio of posterior peristomial ring collar length versus chaetiger 2 length, in lateral view: 3:1.

Thorax. Chaetiger 1: two groups of 10 elongate, narrowly hooded chaetae. Chaetigers 2–8: notopodia—two rows of 8–10 elongate, narrowly hooded chaetae ( Figure 9J View Figure 9 ); one anterior row with eight to nine bayonet chaetae; two posterior rows with 11 symmetrical, paleate chaetae without mucro (a very short hair-like mucro in additional material) ( Figure 9K View Figure 9 ); neuropodia—two irregular rows of 26–46 acicular uncini per torus ( Figure 9G View Figure 9 ), facing in the same direction, the oldest upper parts of the tori have only one row (one-quarter the length of tori), main fang surmounted by four rows of teeth, second tooth enlarged, located in the midline, dentition occupying a quarter the length of main fang ( Figure 9L View Figure 9 ). Pre- and post-chaetal lobes well developed. Glandular ridge on chaetiger 2: narrow.

Abdomen. Abdominal segments: 42 (62–72). Anterior segments: two rows of 6–10 elongate, narrowly hooded chaetae, chaetae from upper row half as long as chaetae in lower row; 10–12 uncini per torus with the main fang surmounted by three rows of teeth, occupying half the length of main fang, older (dorsalmost) uncini smaller than younger uncini (ventralmost), main fang not extending beyond breast, breast rectangular with a triangular anterior tip ( Figure 9N View Figure 9 ). Posterior segments: one or two very elongate, narrowly hooded chaetae, 50% longer than in anterior segments; five to eight uncini per torus, similar to those in anterior segments, but smaller ( Figure 9O View Figure 9 ). Pygidium with rounded posterior margin ( Figure 9H View Figure 9 ).

Gametes. Holotype male with sperm in posterior abdomen, spermatozoa nucleus barrelshaped (1.5 times longer than wide), acrosome sub-triangular and two large, rounded mitochondria.

Methyl green staining. Anterior end of the ventral shield of collar not coloured, posterior end dark. Collar coloured only in the basal half. Body coloured uniformly dorsal and ventrally.

Remarks

Euchone magna   was transferred to Chone   by Hartman (1969), see details in Banse (1972, p 473). Chone magna   is included in the Group I (species with anterior and posterior abdominal uncini with similar shape; Table III). Chone magna   and C. picta   have a long posterior peristomial ring collar, three times longer than second chaetiger; but C. magna   has long radiolar tips (short in C. picta   ) and narrow radiolar flanges (broad in C. picta   ).

ANSP

Academy of Natural Sciences of Philadelphia

R

Departamento de Geologia, Universidad de Chile

V

Royal British Columbia Museum - Herbarium

AHF

Allan Hancock Foundation, University of Southern California

MCZ

Museum of Comparative Zoology

YPM

Peabody Museum of Natural History

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Order

Sabellida

Family

Sabellidae

Genus

Chone

Loc

Chone magna ( Moore, 1923 )

Tovar-Hernández, María Ana 2007
2007
Loc

Chone magna: Hartman 1969 , p 669

Banse K 1972: 472
Hartman O 1969: 669
1969
Loc

Euchone magna

Hartman O 1961: 42
Moore JP 1923: 245
1923