Tasmarcturus erinae, 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 : 27-30

Tasmarcturus erinae sp. nov.

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

2792F44A-A83F-42A3-AFFA-1D5E6DBABC8C

Figures 1b , 7 , 8

Material examined. Holotype. Australia, Tas., E of Maria I (42°36'S, 148°10'E), 75 m, 23 Apr 1985 (stn TAS-30), NMV J16686 (male, 6.3 mm).

Paratypes. Collected with holotype, NMV J62082 (ovigerous female, 7.1 mm); NMV J8766 (2 mancas, 2.6 mm; ovigerous female, 7.0 mm).

Tasmania, 5 km NE of Mistaken Cape (42°37.0'S, 148°12.3'E), 100 m, 23 Apr 1985 (stn TAS-31), NMV J16685 (2 males) . 15 km E of Maria I (42°37'S, 148°20'E), 102 m, 9 Oct 1984 (stn BSS-221), NMV J16681 (manca); NMV J23446 (2 mancas, 5 males, 1 ovigerous female). Eastern Bass Strait , 100 km NE of North Point, Flinders I (38°52.36'S, 148°25.12'E), 140 m, 15 Nov 1981 (stn BSS-170), NMV J23447 (12 mancas, 7 males, 1 female) .

Description. Ovigerous female. Pereonites 2–4 swollen, taller and broader than more anterior and posterior segments, with highly spinulose transverse ridges and numerous spinules besides, 3.1 times as long as greatest width. Pleotelson 0.3 times total body length.

Head ornamentation prominently square anteriorly in lateral view, comprising high suprantennal forehead, frontal margin ornamented with pair of transverse ridge-like tubercles, with pair of oblique–transverse ridges separated by medial V-shaped notch, followed by pair of less prominent submedian oblique–longitudinal blade-like ridges, all microtuberculate; maxillipedal segment with double transverse ridge with 2 or 3 pairs of spinules front and back; ventrolateral margin with anterior triangular lobe in front of eye, and deep fissure between head and pereonite 1. Pereonite 1 with transverse ridge (doubled laterally) bearing pairs of anterior and posterior spinules ranging from submedian to sublateral; pereonite 2 with pair of submedian blunt, hatchet-like projections, with transverse ridge (doubled laterally) bearing pairs of anterior and posterior spinules concentrated on sublateral swellings, plus submedian posterior tubercles; pereonites 3 and 4 similar to pereonite 2, pereonite 3 with the most prominent ornamentation, a ridge ending laterally as a sharp projection; pereonites 5–7 each with double transverse ridge bearing 4 pairs of anterior spines and 2 pairs of posterior spines. Submedian and sublateral tubercles on pereonites 1 and 2 secondarily pustulose; submedian processes on pereonite 3 longitudinally flattened. Pereonites 1–7 + maxillipedal segment with supracoxal rounded plates, larger on 3 and 4, weaker on 5–7, all spinulose especially on dorsal surfaces, arranged such that a deep lateral groove exists between end of lateral ridge and supracoxal plate. Pereonites 2–4 each with transverse row of tubercles in front of main ridge, most complex on 3. Pleonites 1 and 2 with 4 pairs of tubercles, the submedian pair larger; pleonite 3 with submedian pair of tubercles, more prominent than on pleonites 1 and 2, and triangular lateral lobes; posterior pleotelson with anterior pair of submedian ridges and a posterior medial ridge, plus sublateral wing-like projections, with 2 pairs of lateral wings, anterior blade-like, posterior triangular; pleotelson tapering evenly to sharply rounded apex, tapered section 0.5 times as long as wide.

Antennule flagellum article 1 with 4 pairs of aesthetascs, article 2 with 2 aesthetascs. Antenna, fused articles (1 + 2) short, stout, with ventrolateral flange; article 5 2.3 times as long as article 4; flagellum of 3 articles, 0.7 times length of peduncle article 5.

Pereopod 1 propodus 2.2 times as long as wide. Pereopod 2 tuberculate, especially basis and flexor margin of carpus; dactylus unguis as long as dactylus body. Pereopod 4 dactylus body 1.5 times as long as propodus, unguis setiform, 0.4 times length of dactylus body. Pereopods 5–7 with 2 to several tubercles on extensor margin of basis and ischium, 1 each on carpus and propodus. Pereopod 7 dactylus body 0.6 times as long as propodus, unguis stout, 0.4 times length of dactylus body.

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

Uropodal exopod 0.6 times length of endopod.

Male. Of even dimensions throughout length, with highly spinulose transverse ridges and numerous spinules besides. Head ornamentation prominently square anteriorly in lateral view, comprising frontal pair of submedian tubercles, followed by pair of prominent, erect, conical sublateral tubercles sitting over eyes but not obscuring in dorsal view, then pair of sublateral stellate tubercles; maxillipedal segment with 3 pairs of tubercles, all microtuberculate and together forming submedian ridges diverging and sloping upwards anteriorly; ventrolateral margin with anterior triangular lobe in front of eye, and deep fissure between head and pereonite 1. Pereonite 1 with transverse ridge (doubled laterally) bearing 1 medial and 4 pairs of spinules anteriorly and posteriorly, ranging from submedian to sublateral; pereonites 2–4 similar to pereonite 1 except medial spinules absent; pereonites 5–7 each with a single transverse ridge bearing 4 pairs of anterior spines and 2 pairs of posterior spines. Submedian and sublateral tubercles on pereonites 1 and 2 secondarily pustulose. Pereonites 1–7 + maxillipedal segment with supracoxal rounded plates, larger on 3 and 4, weaker on 5–7, all spinulose, especially on dorsal surfaces, arranged such that a deep lateral groove exists between end of lateral ridge and supracoxal plate. Pereonites 3 and 4 each with pair of submedian tubercles anterior to main ridge (larger on 4). Pleonites 1 and 2 with pair of obsolete submedian ridges; pleonite 3 similar to pleonite 2; posterior pleotelson with oblique–conical sublateral projections at midlength, with marginal boss posterior to this, with triangular lateral wings; pleotelson tapering evenly to sharply rounded apex, tapered section 0.6 times as long as wide.

Male pleopod 1 exopod little more than 3 times basal width; exopod posterior face without erect lobes along groove; lateral margin bearing row of 6 multifid setae proximally, 9 stout setae distally; distomesial seta-bearing lamina well separated from apex by deep triangular notch and equalling it in length.

Etymology. For my granddaughter, Erin Poore.

Distribution. Southeastern Australia, 39– 42.5°S, 75–102 m depth.

Remarks. Tasmarcturus erinae and T. lewisi are similar but differentiated most easily on the lateral profile of the head; the head has a pair of prominent anterodorsal projections in T. erinae . Neither species has the conical tubercles evident in T. simplicissimus .

Figures

Figure 1. Dorsal and lateral views of four species of Rectarcturidae, males on top, females below. (a) Nowrarcturus jamesi sp. nov. (with ventral view of oostegites 3–5), male, NMV J19187; female, NMV J23734. (b) Tasmarcturus erinae sp. nov., male, NMV J16686; female, NMV J62082. (c) Tasmarcturus lewisi sp. nov., male and female, NMV J23743. (d) Tasmarcturus simplicissimus (Whitelegge, 1904), male and female, NMV J8758. Scale bars = 1 mm.

Figure 7. Tasmarcturus erinae sp. nov. Female paratype, NMV J62082: habitus; a1, antennule; a2, antenna; ur, uropodal rami.

Figure 8. Tasmarcturus erinae sp. nov. Male holotype, NMV J16686: p1, p2, p4, p7, pereopods 1, 2, 4 and 7; pl1, pleopod 1 with detail of lateral margin; pl2, pleopod 2.