Galathearcturus antoniae, Poore, 2013

Poore, Gary C. B., 2013, Rectarcturidae Poore, 2001 rediagnosed with descriptions of new Australian genera and species (Isopoda: Valvifera), Memoirs of Museum Victoria 70, pp. 17-36 : 19-21

Galathearcturus antoniae sp. nov.

Zoobank LSID. http://zoobank.org/ urn:lsid:zoobank.org:act:

C2E736F0-6E2D-4680-A446-C2DD94E8FA2D

Figures 2 , 3

Material examined. Holotype. Australia, Qld , off Maroochydore (26°33'S, 153°31'E), 86 m, 5 Nov 1951 ( Galathea stn 539), ZMUC (ovigerous female, 6.3 mm).

Description. Ovigerous female. Pereonites 2–4 swollen, taller and broader than more anterior and posterior segments, smooth between major sculptures, 2.6 times as long as greatest width. Pleotelson 0.3 times total body length.

Head with pair of submedian tubercles on anterior margin, pair of submedian, erect, obliquely transverse blades, followed by pair of submedian, sharp, erect ridges converging posteriorly and divided along their lengths by a shallow, dorsal notch; maxillipedal segment indistinguishable from cephalon; ventrolateral margin smooth, with deep fissure between head and pereonite 1. Pereonite 1 without sculpture; pereonite 2 with obsolete submedian and sublateral bosses; pereonites 3 and 4 with obsolete submedian bosses and prominent sublateral conical tubercles; pereonites 5–7 with sublateral rounded tubercles. Submedian and sublateral tubercles on pereonites 1 and 2 simple; submedian processes on pereonite 3 obsolete. Pereonites 1–7 + maxillipedal segment with supracoxal, rounded-triangular, slightly excavate plates on 2–4, weaker on 5–7. Pereonites without supplementary ridges. Pleonites 1–2 with pair of obsolete submedian ridges; pleonite 3 barely distinguished from pleonite 2; posterior pleotelson with broad sublateral domes, with rounded lateral wings; pleotelson tapering evenly to sharply rounded apex, tapered section 0.5 times as long as wide.

Antennule flagellum with 1 pair plus 1 aesthetascs, article 2 without aesthetascs. Antenna, fused articles (1 + 2) short, stout, with ventrolateral flange; article 5 2.4 times length of article 4; flagellum of 3 articles, 0.7 times length of peduncle article 5.

Pereopod 1 propodus twice as long as wide. Pereopod 2 tuberculate only along flexor margins; dactylus unguis as long as dactylus body. Pereopod 4 with triangular lobe on extensor margin of basis; dactylus body 1.5 times as long as propodus, dactylus unguis setiform, 0.3 times length of dactylus body. Pereopods 5–7 with 2 small tubercles on extensor margins of ischium–carpus. Pereopod 7 dactylus body 0.75 times as long as propodus, unguis stout, 0.3 times length of dactylus body.

Oostegites 1–4 supported by oval coxal plates; oostegites 5 a pair of adjacent oval discs.

Uropodal exopod 0.8 times length of endopod.

Etymology. For my granddaughter, Antonia Salter.

Distribution. Southern Qld, Australia, 26°S, 86 m depth.

Remarks. For similarities see notes for the genus. The only specimen is an ovigerous female; the male is unknown.

Figures

Figure 2. Galathearcturus antoniae sp. nov. Female holotype, ZMUC: habitus; a1, a2, antennule, antenna; ur, uropodal rami; P3–P5, oostegites and coxal plates of pereonites 3–5.

Figure 3. Galathearcturus antoniae sp. nov. Female holotype, ZMUC: p1, p2, p4, p7, pereopods 1, 2, 4 and 7, with details of distal articles.