Asterocheres tenerus Hansen 1923

• Main Authors: Bandera, Eugenia, Conradi, Mercedes
• Format: Other/Unknown Material
• Language: unknown
• Published: Zenodo 2009
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Maxillopoda; Siphonostomatoida; Asterocheridae; Asterocheres; Asterocheres tenerus; Davis Strait
• Online Access: https://doi.org/10.5281/zenodo.6221578; http://treatment.plazi.org/id/03AEF308FFEE6110FF4D19B06E588204

Asterocheres tenerus (Hansen, 1923) (Figs 2–4) Ascomyzon tenerum Hansen 1923: 7. Asterocheres tenerus : Stock 1966b: 152; Johnsson 1998: 92. Material examined . Holotype Ψ and 8 paratypes (5 Ψ and 3 ɗ) (ZMUC. CRU-8357) collected during the “Danish Ingolf Expedition” in Davis Strait, Station 25 (63º30΄N, 54º25΄W), at 582 fathoms depth (ca. 1.06 km). Redescription of adult female : Body (Fig. 2 A) cyclopiform, with oval cephalothorax and cylindrical urosome. Total length 904 µm (n = 1); maximum width 452 µm. Ratio of length to width of prosome 1.5:1. Ratio of length of prosome to urosome 2.6:1. Prosome comprising cephalothorax fully incorporating first pedigerous somite and 3 free pedigerous somites. Pedigerous somite 4 much smaller and narrower than preceding somites. Dorsal cephalothoracic shield and free pedigerous somites ornamented with integumental pores and sensillae (these features not shown in Fig. 2 A). Urosome (Fig. 2 B) 4-segmented, comprising pedigerous somite 5, genital double-somite and 2 free abdominal somites. Genital double-somite and following somites furnished with large spinules. Pedigerous somite 5 narrow, largely concealed under tergite of pedigerous somite 4, with spinular row on each side of dorsal midline. Genital double-somite about as long as wide, with separate genital apertures, each comprising ventrolateral copulatory pore and dorsolateral gonopore (oviduct opening); lateral margins with rows of setules posterior to genital apertures. Caudal rami longer than wide, armed with 6 setae (seta I absent); setae III–VI arranged along posterior margin; setae II and VII inserted subapically on dorsal surface. Antennule (Fig. 2 C) 21-segmented, 544 µm long. Segmental homologies (expressed segment given first followed by ancestral segment(s) in brackets) and setation pattern as follows: 1(I)-2, 2(II)-2, 3(III)-2, 4(IV)-2, 5(V)-2, 6(VI)-2, 7(VII)-2, 8(VIII)-2, 9(IX–XII)-7, 10(XIII)-2, 11(XIV)-1+spine, 12(XV)-2, 13(XVI)-2, 14(XVII)-2, 15(XVIII)-2, 16(XIX)-2, 17(XX)-2, 18(XXI)-2+ae, ...