Fiche d'espèce de Copépode
Calanoida ( Ordre )
    Clausocalanoidea ( Superfamille )
        Scolecitrichidae ( Famille )
            Xantharus ( Genre )
Xantharus siedleckii  Schulz & Kwasniewski, 2004   (F)
Ref.:
Schulz & Kwasniewski, 2004 (p.151, figs.F, Rem: p.156-158); Bradford-Grieve, 2005 (p.947, tab.1: morphological remarks)
Espèce Xantharus siedleckii - Planche 1 de figures morphologiquesissued from : K. Schulz & S. Kwasniewski in Sarsia, 2004, 89. [p.153, Fig.6].
Female (from Spitzbergen): A, habitus (lateral left side); B, idem (dorsal); C, forehead (lateral); D, rostrum (anteroventral view); E, urosome (lateral left side); F, genital segment (double somite) (ventral); G, caudal rami (ventral); H, A2; I, Mx2.
Scale lines 0.05 mm.

Nota :
Rostrum strong , directed ventrally, bearing pair of slender filaments.
- A2 : exopod slightly longer than endopod. Coxa with patch of long spinules along outer margin and 1 long inner seta ; basis with 2 unequal inner setae ; endopod 2-segmented ; exopod indistinctly 8-segmented, setal formula 0, 1, 1, 1, 1, 1, 1, 3.
- Mx2 : proximal praecoxal endite with 4 setae ; distal praecoxal and both coxal endites each with 3 setae, one of them shorter ; basal endite carrying 1 stout spine, 1 strong curved seta plus 2 selender setae. Endopod indistinctly 3-segmented, armed with 5 subequal brush-like sensory setae having small compact heads, and 3 long worm-like sensory setae.
- 1st pedigerous somite integrated into cephalosome ; 4th and 5th pedigerous somites separate except ventrolaterally.
- Sensillae distributed on prosomal somites as figured.
- Urosome 4-segmented.
- Genital double-somite symmetrical (in dorsal aspect), weakly roduced ventrally ; seminal receptacles comparatively large, bean-shaped.
- Urosomal somites 1-3 with dentate hyaline frill on posterior margin ; somite 3 longer than 2 ; anal somite very short, about 10% length of preceding somite and completely concealed beneath its hyaline frill.
- Caudal rami symmetrical, longer than wide ; armature consisting of 6 setae ; seta II reduced, implanted on lateral edge ; setae III-VI strong, implanted distally ; seta VII reduced, displaced ventrally.


Espèce Xantharus siedleckii - Planche 2 de figures morphologiquesissued from : K. Schulz & S. Kwasniewski in Sarsia, 2004, 89. [p.154, Fig.7].
Female: A, A1 (segments I-XIII), idem (segments XIV-XXVIII); C, Md; D, Mxp; E, P1.
Scale lines 0.05 mm.
Nota :
A1 symmetrical, short, 24-segmented ; compound segments involving ancestral segments II-IV, X-XI and XXVII-XXVIII


Espèce Xantharus siedleckii - Planche 3 de figures morphologiquesissued from : K. Schulz & S. Kwasniewski in Sarsia, 2004, 89. [p.155, Fig.8].
Female: A, Mx1; B, P2; C, P3; D, P4; E, P5.
Scale lines 0.05 mm.

Nota :
Mx1 : praecoxal arthrite with 9 marginal and 3 posterior setae ; coxal epipodite with row of 9 setae ; coxal endite with 2 setae ; basal endites with 4 setae each ; exopod with 8 marginal setae ; endopod uncegmented, armed with 3 + 2 + 5 setae. Praecoxal arthrite, basis and exopod ornamented with denticles as figured.
P5 : uniramous, symmetrical, 3-segmented, with proximal segment separate from intercoxal sclerite ; distal segment mostly fused to second, bearing 2 short spine-like projections distally and 1 short inner spine subdistally, all covered with denticles ; length of segments increasing from 1st to 3rd, and ornamented with denticles ; inner margin of 2nd segment bearing long spinules.


Espèce Xantharus siedleckii - Planche 4 de figures morphologiquesissued from : K. Schulz & S. Kwasniewski in Sarsia, 2004, 89. [p.157, Fig.9].
Male: A, habitus (lateral left side); B, idem (dorsal); C-F, A1; G, P5 (posterior).
Scale lines 0.05 mm.

Nota :
A1 slightly asymmetrical, extending to end of 2nd pedigerous somite. Segmentation pattern as in female except for right A1, 23-segmented due to fusion of ancestral segments XXII-XXIII ; armature differing from female especially in the presence of a higher number of aesthetascs, with double aesthetascs located on segments III, V, VII, IX, and XI.
P5 asymmetrical, uniramous ; left longer than right. Coxa of right leg fused with intercoxal sclerite ; left ramus indistinctly 5-segmented ; coxa larger than right counterpart, with sparsely set long spinules distally ; basis with lobe-like protrusion distally on inner margin (interpreted as remnant of endopod) ; exopod slender, 1st segment armed with small inner and slightly larger spine distolaterally ; 2nd segment having short inner row of spinules distally ; 3rd segment tapering distally, about half length of preceding segment and incompletely separated from it, with a row of spinules on inner margin. Right ramus 5-segmented, coxa and basis of about equal size, coxa ornamented with distolateral spinules ; basis unarmed, with distomedial outgrowth (probably remnant of endopod) ; exopod shorter than left counterpart, 1st segment with small spine on distolateral edge and spinules as figured ; 2nd segment having a row of spinules on inner face ; terminal segment more slender, spine-like, tapering distally and armed with small, spine-like projection on outer half.
Urosome 5-segmented. Genital somite asymmetrical, slightly produced posteriorly on left side ; gonopore opening posterolaterally on left side.
Anal somite extremely short.

Ref. compl.:
Hop & al., 2006 (p.182, Table 4);
NZ: 1

Carte de distribution de Xantharus siedleckii par zones géographiques
Loc:
Arctic: Spitsbergen (Kongsfjorden)
N: 2
Lg.:
(886) F: 1,2-1,54; {F: 1,20-1,54}
Rem.: Fonds: 360-330 m.
Voir aussi les remarques en anglais
Dernière mise à jour : 28/03/2016

 Toute utilisation de ce site pour une publication sera mentionnée avec la référence suivante :

Razouls C., Desreumaux N., Kouwenberg J. et de Bovée F., 2005-2024. - Biodiversité des Copépodes planctoniques marins (morphologie, répartition géographique et données biologiques). Sorbonne Université, CNRS. Disponible sur http://copepodes.obs-banyuls.fr [Accédé le 19 avril 2024]

© copyright 2005-2024 Sorbonne Université, CNRS

Webmaster
Mentions légales et informations nominatives
CNRS   Observatoire Océanologique de Banyuls sur Mer - Laboratoire Arago
Sorbonne Université

 

Version française
English version

 

Rechercher

Sur le WEB du CNRS

 


Copépodes planctoniques marins

Copépodes planctoniques marins

 

Imprimer Contact Accueil Plan du site Accès restreint Retour Une du Labo Imprimer Contact Plan du site Crédits Téléchargez les Plug-Ins