Chone sp.

Giangrande, Adriana & Licciano, Margherita, 2006, The genus Euchone (Polychaeta, Sabellidae) in the Mediterranean Sea, addition of two new species and discussion on some closely related taxa, Journal of Natural History 40 (21 - 22), pp. 1301-1330: 1316-1319

publication ID

http://doi.org/ 10.1080/00222930600901458

persistent identifier

http://treatment.plazi.org/id/03C2878E-1F2B-FFA0-FDCB-F76FFE4EFA0A

treatment provided by

Felipe

scientific name

Chone sp.
status

 

Chone sp.  

( Figures 8 View Figure 8 , 9 View Figure 9 )

as Oriopsis armandi   in Castelli (1982).

Material examined

Twenty specimens from Follonica (Tyrrhenian sea), 6 m depth on sand bottom, 1981, PCZL; eight specimens   , Ligurian Sea (Zoagli), 10 m depth on sand bottom, 1990, PCZL; two specimens   , Adriatic Sea (Brindisi), 0.5 m depth, 1989, on detritic hard bottom, PCZL; two specimens   Fiumicino (Tyrrhenian sea), 25 m depth, 1991 on muddy sand, PCZL   .

Description

Small worm with eight thoracic and 10 abdominal chaetigers ( Figure 8A View Figure 8 ). Total branchial crown length 1 mm. Total thorax–abdomen length 2.5 mm, maximum width 0.4 mm at chaetiger 7. Branchial lobe each with four fully developed radioles; feather-duster structure with numerous paired pinnules. Palmate membrane present for about half of the radiolar length ( Figure 8E View Figure 8 ). Outer surface of radioles slightly rounded. Radiolar flanges present. Sub-distal ends of radioles long filiform ( Figure 8E View Figure 8 ). Radiolar eyes absent. Dorsal lips pointed, longer than wide ( Figure 8D View Figure 8 ), dorsal radiolar appendages not detected. Ventral lip not detected. Ventral margin of anterior peristomial ring as triangular lobe ( Figure 8B View Figure 8 ), extending slightly beyond the collar. Peristomial collar membranous, well developed with narrow dorsal gap ( Figure 8B View Figure 8 ), ventral margin slightly higher than dorsal ( Figure 8C View Figure 8 ). Collar margin entire. Notopodial fascicles with six elongate narrowly hooded chaetae in chaetiger 1. Chaetigers 2–8 with superior elongate narrowly hooded chaetae, three to four per fascicle ( Figure 8H View Figure 8 ); inferior notochaetae arranged as four bayonet-type anteriorly and four to five posterior short and broadly hooded chaetae ( Figure 8I View Figure 8 , 9A View Figure 9 ); neuropodial acicular uncini in chaetigers 1–8 with a short and blunt main fang surmounted by a series of small teeth starting in profile very deeply ( Figures 8F View Figure 8 , 9B View Figure 9 ), eight uncini per torus. Abdominal neuropodia each with single transverse row of four narrowly hooded chaetae. Abdominal notopodia with uncini rasp-shaped, rectangular, and with teeth of equal size over a poorly developed main fang not extending beyond breast, last abdominal chaetigers with uncini showing a more developed dentate region ( Figure 8G View Figure 8 ), 13–15 uncini per torus showing intratorus variation ( Figure 9D View Figure 9 ). Pygidium rounded with long cirrus ( Figure 8A View Figure 8 ). Eggs in the thorax. Tube unknown.

Remarks

Chone sp.   is distinguished from all the other Chone species   in having thoracic uncini type 2 ( Figure 7B View Figure 7 ). In this feature it is more similar to Amphicorina   genus (type 4, Figure 7D View Figure 7 ), from which, however, it is distinguished for several other features such as the organization of the branchial crown (snowflakes in Amphicorina   ) and the presence of only two types of thoracic chaetae in Amphicorina   . As already stated, thoracic uncini type 2, very similar to those present in Chone sp.   , can be found in some small Euchone species   (Chiade sensu Cochrane), which are clearly distinguishable from Chone sp.   in having an Amphicorina   -like organization of the branchial crown (snowflake) and the presence of the anal depression.

All the other features of the here-described Mediterranean taxon are clearly typical of the genus Chone   , therefore, at present, it has been assigned to this genus.

After the first record in the North Tyrrhenian Sea (Gulf of Follonica), the same taxon was found at different sites along the Italian coasts. All the material agrees with the present description, except for that from Fiumicino, which has a higher number of abdominal uncini.

Habitat

Shallow sandy habitats.

Kingdom

Animalia

Phylum

Annelida

Class

Polychaeta

Order

Sabellida

Family

Sabellidae

Genus

Chone