Ianiropsis alanmillari, Doti, Brenda Lía & Wilson, George D. F., 2010

Doti, Brenda Lía & Wilson, George D. F., 2010, The genera Carpias Richardson, Ianiropsis Sars and Janaira Moreira & Pires (Isopoda: Asellota: Janiridae) from Australia, with description of three new species, Zootaxa 2625, pp. 1-39 : 16-26

publication ID	https://doi.org/ 10.5281/zenodo.198196
DOI	https://doi.org/10.5281/zenodo.6196449
persistent identifier	https://treatment.plazi.org/id/8F5B152B-D056-8E6F-FF0A-F88AFC70FD91
treatment provided by	Plazi
scientific name	Ianiropsis alanmillari
status	sp. nov.

Treatment

Ianiropsis alanmillari View in CoL sp. nov.

( Figs 8–14 View FIGURE 8 View FIGURE 9 View FIGURE 10 View FIGURE 11 View FIGURE 12 View FIGURE 13 View FIGURE 14 )

Etymology. The species is named for Dr. Alan J. K. Millar (Royal Botanical Gardens, Sydney) in recognition for his contribution to collecting this species and the other Asellota described herein.

Type fixation. Holotype adult 3, 2.9 mm, P.81237, here designated.

Type locality. Australia, New South Wales, south of Batemans Bay, north of Burrewarra Point, Gutters, NSW 1996, 35º49.82'S, 150º14.08'E, 24 m, coll. by G. Wilson, A. Millar & N. Yee, 27 Oct 2002, among Pachymenia prostrata .

Paratypes. BƤ (2.5 mm) P.81238; BƤ (2.5 mm) dissected, P.81239; T3 #3 (2.9 mm) dissected, P.81242; A3 #2 (2.5 mm), dissected, P.81241; J3 #1 (2 mm), dissected, P.81240; Ƥ P.81228, SEM stub MI170; 3 P. 81229, SEM stub MI171; 24 inds (T3: 2.5–3.3 mm; non-T3: 2–2.5 mm; BƤƤ: 2–2.5 mm; juvs 1.3–1.5 mm) P.81243.

Other material. Montague Island, coll by A.J.K. Millar & party, 23–24 Mar 2001. Yakka Bay, 36º14.98'S, 150º13.37'E, 15 m: 33 inds, P.84021, NSW 1773, among Ecklonia radiata (alga holdfast); 1 juv, P.84022, NSW 1774, among mixed algae: Pterocladia capillacea , Cystophora sp., Plocamium microcladioides , Sargassum sp. (minor amount). 'Northwest Trench', 36º14.55'S, 150º13.45'E: Ƥ, 3 juvs, P.84023, NSW 1775, 33 m, among lacy bryozoan colonies; 51 inds, P.84024, NSW 1777, among Spyridia filamentosa & Zonaria diesingiana (red algae); 23 inds (2 BƤƤ, 9 ƤƤ, 9 3, 3 juvs), P.84025, NSW 1779, 33 m, among Heterosiphonia australis (alga); 317 inds, P.84026, NSW 1781, 33 m, among Lobophora variegata , Sargassum (alga); 21 inds (4 BƤƤ, 5 3, 3 ƤƤ, 9 JƤ), P.84027, NSW 1782, 30 m, among broad digitate orange sponge; 10 inds (1 BƤ, 2 ƤƤ, 2 3, 5 juvs), P.84028, NSW 1783, 30 m, among globose sponge.

'Twin Peaks', approx. 6 n. mi. from Tathra Wharf, coll by A.J.K. Millar & party, 26 Mar 2001: J3, P.84029, NSW 1793, 36º40.12'S, 150º1.06'E, 25 m, among white bushy hydroid tufts.

Batemans Bay Region, coll. by A.J.K. Millar & party, 25–28 Oct 2002. Burrewarra Point, East Wall, 35º50.02'S, 150º14.16'E: 5 inds (2 3, 1 BƤ, 2 ƤƤ), P.84030, NSW 1985, 25 m, among Peyssonelia nova - hollandiae (alga); 25 inds (3 BƤƤ, 10 ƤƤ, 9 3, and 3 juvs), P.84031, NSW 1986, among Curdiea crassa with small amount of Martensia australis (alga); 4 inds (1 BƤ, 2 ƤƤ, 1 3), P.84032, NSW 1987, among Corallina berteri (alga). Burrewarra Point, Gutters, 35º49.82'S, 150º14.08'E, 24 m: 4 inds (2 BƤƤ, 1 Ƥ, 1 3), P.84034, NSW 1993, among Pachymenia prostrata (alga); 41 inds, P.84035, NSW 1995, among branching hydroid; 1 Ƥ, P.84036, NSW 1998, Gutters, somewhat inshore, 35º49.87'S, 150º14.08'E, 23 m, among Caulerpa hodgkinsoniae (alga). Broulee Island: J3, P.84033, NSW 1989, 35º50.83'S, 150º11.09'E, 8 m, among branching coralline algae: Amphiora anceps & Jania natalensis . Tollgate Islands: 1 PƤ, P.84037, NSW 2005, 35º44.78'S, 150º15.47'E, 12 m, among Galaxuara marginata (alga).

Batemans Bay Region, coll. by A.J.K. Millar & party, 8–9 Feb 2003. Brush Island, 35º31.65'S, 150º24.96'E: 9 inds (3 BƤƤ, 2 ƤƤ, 2 3, 2 juvs), P.84038, NSW 2025, 12 m, among Pterocladiella capillacea (alga); 1 3, 1 Ƥ, P.81402, NSW 2026, 12 m, among Ecklonia radiata (alga); 3 inds (1 3, 1 BƤ, 1 Ƥ), P.81404, NSW 2029, 16.2 m, among Zonaria diesingiana (alga). Grasshopper Island, 35º38.02'S, 150º19.85'E: 1 3, P.81403, NSW 2034, 11 m, among Amphiroa anceps (alga).

Batemans Bay Region, coll. by P. Berents & party, 23–30 Mar 2004. Burrewarra Point, 35º49.81'S, 150º14.01'E: 11 inds (3 3, 5 ƤƤ, 3 juvs), P.84039, NSW 2498, 17 m, among gorgonacean; 2 ƤƤ, P.84040, NSW 2502, 20 m, among honeycomb sponge; 1 Ƥ, P.84041, NSW 2510, 17 m, among gorgonacean cf. Mopsella ; 5 inds (1 BƤ, 4 juvs), P.84042, NSW 2511, 17 m, among rock with Hydrodendron australe (hydroid) and other encrusting fauna; 1 Ƥ, P.84043, NSW 2513, 20.8 m, among bryozoan rubble. Burrewarra Point, 35º49.78'S, 150º13.96'E: 5 inds (2 3, 3 ƤƤ), P.84044, NSW 2525, 13.4 m, among dead bryozoan clumps attached to rocky reef; 1 juv, P.84045, NSW 2540, 15 m, among under stones, little sediment; 1 3, juv, P.84046, NSW 2542, 14.8 m, among Mopsella sp. (gorgonian); 22 inds (8 3, 3 BƤƤ, 10 ƤƤ, juv), P.84047, NSW 2543, 19.7 m, among cf. " Triphyllozoon " (bryozoan); (?) juv, P.84048, NSW 2544, 14 m, among small orange finger sponge; 16 inds (4 3, 1 BƤ, 3 ƤƤ, 5 juvs, 3 inds damaged), P.84049, NSW 2546, 14.1 m, among mixed bryozoan rubble. Three Islet Reef, 35º43.63'S, 150º16.01'E: 1 3, P.84050, NSW 2551, 10 m, among Capnella sp. (soft coral); 1 Ƥ, P.84051, NSW 2560, 12 m, among green sponge; 1 BƤ, P.84052, NSW 2561, 10 m, among Mopsella sp.? (gorgonian); 1 3, P.84053, NSW 2568, 11 m, among cf. Triphyllozoon sp. (bryozoan). Tollgate Islands, 35º45.2'S, 150º15.75'E: 17 inds, P.84054, NSW 2573, 10 m, among yellow sponge encrusting barnacles; 2 juvs, P.84055, NSW 2596, 17.5 m, among massive dark grey sponge. Burrewarra Point, 35º49.89'S, 150º14.11'E: 6 inds (2 BƤƤ, 4 juvs), P.84056, NSW 2597, 18 m, among bryozoan, hydroid and reef rock; (?) juv, P.84057, NSW 2598, 22 m, among coarse gravel, shell and bryozoan sediment. Burrewarra Point, 35º50.28'S, 150º14.09'E: 30 inds, P.84058, NSW 2618, 17 m, among brown lacy bryozoan cf. Membranipora ; 1 Ƥ, P.84059, NSW 2620, 18 m, among sponges; 26 inds, P.84060, NSW 2627, 18.5 m, among cf. " Triphyllozoon " (bryozoan); 13 inds (3 BƤƤ, 5 ƤƤ, 4 3, 1 juv), P.84061, NSW 2630, 18.3 m, among grey sponge from vertical rock face. Tollgate Islands, 35º44.83'S, 150º15.42'E: 1 Ƥ, P.84062, NSW 2643, 7 m, among Ecklonia radiata (alga) holdfasts; 1 Ƥ, 1 3, P.84063, NSW 2652, 8.2 m, among bryozoans under rock.

Twofold Bay, Munganno Point: 14 inds, P.35657, 37º06.2'S, 149º55.7'E, 4 m, 10 Oct 1984, coll. by J. van der Velde; 12 inds, P.35659, M4, 37º06.2'S, 149º55.7'E, 10 Oct 1984, coll. by J. van der Velde; 1 Ƥ, P.84130, M8, 37º06.2'S, 149º55.7'E, 19 Dec 1985, coll. by S.J. Keable & S.J. Perry; 22 inds (9 3, 13 ƤƤ), P.84131, M8, 9, 37º06.2'S, 149º55.7'E, 9 m, 0 9 Dec 1985, coll. by S.J. Keable & S.J. Perry; 103 inds (56 3, 47ƤƤ), P.84132, M6, 9, 37º06.2'S, 149º55.7'E, 19 Dec 1985, 9 m, coll. by S.J. Keable & S.J. Perry.

Twofold Bay, Murrumbulga Point: 2 inds, P.35658, Q2, 37º04.7'S, 149º53.1'E, 0 9 Oct 1984, coll. by S.J. Keable; 2 3, P.36152, Q7, 37º04.7'S, 149º53.1'E, 11 Dec 1984, coll. by S.J. Keable & E.A. Bamber; 3 ƤƤ, 1 3, P.84133, Q15, 37º04.75'S, 149º53.067'E, 17 Sep 1985, coll. by P.A. Hutchings & S.J. Keable. Port Jackson, Shark Bay, Steel Point: 24 inds, P.84139, NSW 1176, 33º51.05'S, 151º15.9'E, 2 m, 21 Dec 1995, coll. by K. Dempsey & J.K. Lowry.

Jervis Bay, 1 n. mi. south of Governor Head: 40 inds (7 3, 33 ƤƤ), P.84140, NSW 1226, 35º08.33'S, 150º45.72'E, 18 m, 28 Feb 1996, coll. by I. Takeuchi & R. Johnson.

Diagnosis. Head anterior margin in dorsal view linear; eyes dorsal, set back from lateral margin. Pereonites 2–4 laterally concave. Pleotelson lateral margin nearly circular arc, denticles absent. Antenna article 5 distinctly longer than articles 1–4. Mandible palp article 1 simple setae present. Maxilliped palp not projecting in front of head, article 3 in terminal male distomedial margin convex. Pereopod I coxa projecting anterolaterally, angular. Pereopod I of adult (terminal) male carpus with few short setae, robust setae in one row; propodus length 0.96 subequal to carpus length, distal width 0.9 proximal width, ventral margin without robust setae. Pleopod I of adult male distal margin concave. Pleopod II of adult male protopod distal margin setae absent. Uropods shorter than pleotelson; protopod elongate and rectangular.

Description. Pigmentation in preservative scattered brown pigment. Body length of male 2.5–3.3 mm (T3), female 2.0– 2.5 mm, length 2.3, 3.0 width (BƤ, T3, respectively), male widest at pereonites 3–4, female widest at pereonite 3.

Head ( Figs 8 View FIGURE 8 ; 12B, E; 13A, C). Width 1.73 length. Eyes with more than 10 ocelli, length 0.4 head medial length.

Pereonites ( Fig. 8 View FIGURE 8 A, C). Pereonites 1–7 medial length ratios relative to pereonite 2 (T3): 1.2, 1.0, 0.84 (>1.0 in BƤ), 0.76, 0.76, 0.73, 1.19, respectively.

Pleon ( Figs 8 View FIGURE 8 A, C; 12G; 13D). Pleotelson length 0.87 width. Pleotelson posterior margin broadly rounded, without posteromedial inflection (slight medial inflection visible in ethanol specimens).

Antennula and Antenna ( Figs 8 View FIGURE 8 ; 12E; 13A–C). Antennula of male length 1.24 head median length with 12–15 articles, female length 1.29 head median length with 12–14 articles; article 1 length 0.9 width, article 2 length 1.35 article 3 length. Antenna length 1.21 body length, articles 1–6 length 0.48 body length, article 5 distinctly longer than articles 1–4, article 5 length 0.94 article 6 length, flagellum with 40–50 articles.

Mouthparts ( Fig. 9 View FIGURE 9 ). Mandible left spine row with 5 spines; right spine row with 7 spines; molar distal margin with paired blade-like ridges. Mandible palp length 0.92 mandibular body length, article 1 with 1–2 simple setae (1 seta on left md and 2 on right). Maxillula lateral lobe distal margin with 13 robust denticulate setae. Maxilla lateral lobes with 4 curved denticulate setae. Maxilliped palp article 2 width 2.43 endite width, article 3 distally subrectangular, distomedial margin with distinct inflection, article 3 in terminal male distomedial margin convex; endite length 1.8 width, with 2 receptaculi, distal margin with 6 fan setae.

Pereopod I ( Fig. 13 View FIGURE 13 E). In adult female length 0.49 body length.

Pereopod I of adult (terminal) male ( Figs 10 View FIGURE 10 C; 12A–C). Length 1.1 body length; basis extremely elongate, longer than bases on posterior pereopods but projecting posteriorly well past pereonite 4, basis length 1.47 carpus length. Ischium elongate, distinctly longer than ischium on posterior pereopods, length 1.07 carpus length. Merus elongate, longer than merus on posterior pereopods, length 0.6 carpus length. Carpus width 0.28 length, proximal width near distal width, without differentiated palm region, with 1 robust seta (2–3 setae, thin but unequally bifid in subadult males, Fig. 10 View FIGURE 10 A, B). Carpus ventral margin proximal to palm approximately linear, slightly sinuous. Propodus subequal to carpus length, not tapering distally. Dactylus length 0.77 propodus distal width, well developed.

Pereopods II–VII ( Figs 8 View FIGURE 8 B, 11A–B; 12A; 13A–B). Pereopod II length 0.7 body length (in 3); coxa anterolateral margin rounded. Pereopod IV length 0.39 body length (2 ƤƤ). Pereopod VII length 0.59 body length.

Pleopods ( Figs 11 View FIGURE 11 C–E, G; 12H). Operculum of female length 0.98 width, distal margin concave with row of setae. Pleopod I of adult male distal width 0.75 proximal width; dorsal surface stylet guides lateral margin with row of denticles; medial lobe margin concave, width 0.77 pleopod (both sides) distal width, with 17 setae, of which 3–4 setae longer than others. Pleopod II of adult male protopod distal margin setae absent, endopod proximal article width near distal article maximum width, endopod stylet distal tip abruptly narrowed, length 0.49 protopod length. Pleopod III exopod length 1.2 endopod and protopod length, articulation between 2 articles present, distal margin broadly rounded, not tapering, with 2 simple setae.

Uropods ( Figs 11 View FIGURE 11 F; 12G; 13D). Shorter than pleotelson, length in adult male 0.84 pleotelson length, in adult female 0.83 pleotelson length. Protopod length 2.56 width. Endopod length 1.0 protopod length, 1.03 exopod length.

Distribution. Port Jackson to Twofold Bay, including Jervis Bay and Batemans Bay region (NSW, Australia), 7–33 m ( Fig. 14 View FIGURE 14 ).

Remarks. Ianiropsis alanmillari sp. nov. adds to the already considerable diversity in this genus. Several features distinguish I. alanmillari from the remaining species of the genus, viz., head, anterior margin linear; pleotelson, posterior margin broadly rounded without posterior inflection; an extremely enlarged pereopod I of terminal males, in which the basis extends posteriorly beyond the pereonite 4; and pleopod I, dorsal surface with a row of denticles along the lateral margin of the stylet guides. Of these features, I. alanmillari shares an anteriorly linear margin of the head with I. minuta Menzies, 1952 . The latter species, however, differs in the posterior margin of the pleotelson, which has the posterior inflection. On the other hand, I. alanmillari , I. serricaudis Gurjanova, 1936 and I. notoensis Nunomura, 1985 have the pleotelson posterior margin broadly rounded, but I. serricaudis can be distinguished by the pleotelson laterally denticulate, and I. notoensis by the extremely enlarged maxilliped palp in terminal males. I. alanmillari is the first species of the genus that shows denticles on the stylet guides on the dorsal surfaces of pleopod I. This character, however, may have been overlooked in the known species of the genus because descriptions often do not include details of this appendage.

In the SEM images ( Fig. 12 View FIGURE 12 H), the male pleopod I of Ianiropsis alanmillari sp. nov. appears to be unlike other Ianiropsis species in that the lateral lobes project posteriorly rather than posterolaterally. This condition is also seen in I. chiliensis Menzies, 1962 , where only half of the distal tip was illustrated, and in specimen described as " Ianiropsis sp." by Nunomura (1985). The illustrations of the microscope preparation of the limb ( Fig. 11 View FIGURE 11 C), however, show that it projects posterolaterally after the distal tip of the pleopod I is flattened on the slide for illustration.

In NSW, Ianiropsis alanmillari sp. nov. is one of the most frequently encountered isopods among both algal and non-algal substrates with no apparent preference for habitat.