Euchone analis ( KrØyer, 1856 )
|
publication ID |
https://doi.org/ 10.1080/00222930600901458 |
|
persistent identifier |
https://treatment.plazi.org/id/03C2878E-1F38-FFB6-FE56-F029FC6AFE2F |
|
treatment provided by |
Felipe |
|
scientific name |
Euchone analis ( KrØyer, 1856 ) |
| status |
|
Euchone analis ( KrØyer, 1856) View in CoL
( Figure 1 View Figure 1 )
Examined material
One specimen USNM 333, Greenland (locality unknown, leg. H. KrØyer), material kindly furnished by Maria Ana Tovar-Hernández, El Colegio de la Frontera Sur, Chetumal, Quintana Roo, México.
Addition to description
The staining pattern shows a quite homogeneous coloration of the ventral shields in the thorax ( Figure 1A View Figure 1 ) less evident in the abdomen ( Figure 1E View Figure 1 ). The first chaetiger seems not separated from the preceding and following segments by non-staining lines, nor is the intrasegmental furrow distinct. Dorsally the thorax and the anterior chaetigers of the abdomen are essentially free of stain-accepting cells. Dorsal lips extending from the inner, dorsal margin of the branchial lobes and terminating just dorsal to mouth, slightly elongate with radiolar mid-rib ( Figure 1C View Figure 1 ). Ventral lips rounded as long as wide, up to eight ventral radiolar appendages about the same length as the branchial crown ( Figure 1C View Figure 1 ). Radioles with radiolar flanges as distal continuation of the palmate membrane until a small free distal ends ( Figure 1D View Figure 1 ). Abdominal uncini of predepression and depression chaetigers quite similar ( Figure 1G, H View Figure 1 ).
Remarks
Chaetiger and radiolar number, shape of the collar and posterior abdominal depression ( Figure 1B, F View Figure 1 ) all correspond well to the original description by KrØyer (1856), as well as the description reported by Banse (1972) for material from Alaska, and Bick and Randel (2005) for material from Spitzbergen.
The examination of internal structures of the branchial crown seems to confirm the presence of dorsal radiolar appendages in the genus Euchone , even though extension of radiolar skeleton was not detected. However, dorsal radiolar appendage assessment produced a lot of misinterpretation both in Euchone and Chone . Histological analysis seems to indicate the presence of radiolar appendages and skeleton in E. analis ( Bick and Randel 2005) , by contrast Cochrane (2003), in her cladistic analysis, considers Euchone lacking this structure. Recently Tovar-Hernández (2005), redescribing the type material of Chone infundibuliformis , stated the absence of mid rib or dorsal radiolar appendages in the dorsal lips for the genus Chone by the absence of radiolar skeleton support. In this scenario, Fitzhugh (2002) detached the presence of radiolar appendages from the presence of branchial skeleton extension, stating that ‘‘the only gross morphological criteria, other than general shape, that can be used to identify radiolar appendages is the presence of the radiolar skeleton when present, or the combined presence of supporting sheath tissue, a blood vessel and the coelom’’. He considers Chone without radiolar appendages, and Euchone with radiolar appendages, but without branchial skeleton extension.
Lastly, the presence of some peristomial structures observed by Tovar-Hernández (personal communication), and referred to as ‘‘glandular tubular organs’’ must be noticed. These circular cameras situated dorsally in each side of the peristomium have already been detected in Chone princei (5 Jasmineira ) ( McIntosh, 1916), and in the genus Fabrisabella ( Fitzhugh, 1989) . However, in most specimens they are not easily discernible. In hereexamined specimen of E. analis , for example, they were not detected.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
|
Kingdom |
|
|
Phylum |
|
|
Class |
|
|
Order |
|
|
Family |
|
|
Genus |