Pereionotus dieteri Coleman & Lowry, 2012, sp. nov.

Pereionotus dieteri sp. nov.

(Figs 4–8)

Palinnotus thomsoni.— J.L. Barnard, 1972: 295, pl. 176–179

Material examined. Holotype, male, 3.8 mm, AM P.88037, south side of New Year Island, Northern Territory, Australia (10°54'S 133°2'), on the brown alga, Padina sp., J.K. Lowry, 14 October 1982, NT 2. Paratypes, + 30 specimens, AM P.81988, same data as holotype.

Type locality. South side of New Year Island, Northern Territory, Australia (10°54'S 133°2').

Additional material studied. Western Australia: 1 specimen, AM P.81941, beach at north end of Bundegi Reef, Exmouth Gulf, Western Australia, Australia (21°49'S 114°11'E), encrusting compound ascidian, 1 m depth, H.E. Stoddart, 4 January 1984, WA-394; 1 specimen, AM P.81933, near Point Murat, Bundegi Reef, Exmouth Gulf, Western Australia, Australia (21°49'S 113°11'E), coral rubble washings, 9 m depth, J.K. Lowry, 4 January 1984, WA-410; 5 specimens, AM P.82010, southern side of pass, Ningaloo Reef, Western Australia (21°54'43"S 113°57'6"E), coarse coral rubble, 2 m depth, N.L. Bruce, 8 June 2008, NIN1D, Creefs No. 3031; 4 specimens, AM P.82002, Tantabiddy Creek, Ningaloo Reef, Western Australia, Australia (21°54'46"S 113°58'43"E), coarse coral rubble N.L. Bruce, 8 June 2008, NIN1B, Creefs No. 3001; 1 female with juveniles, AM P.82009, southern side of pass, Ningaloo Reef, Western Australia (21°55'6"S 113°57'37"E), coarse coral rubble, 3 m depth, 10 June 2008, NIN8A, Creefs No. 3071; 7 specimens, AM P.81934, inshore limestone reef off Neds Camp, Cape Range National Park, Western Australia, Australia (21°59'S 113°59'E), green alga, Caulerpa sp. and basal rubble, 1.5 m, J.K. Lowry, 2 January 1984, WA-374; 1 juvenile, AM P.81935, inshore limestone reef off Neds Camp, Cape Range National Park, Western Australia, Australia (21°59'S 113°59'E), "crinkly" brown alga, 1.5 m depth, R.T. Springthorpe, 2 January 1984, WA-379; 8 specimens, AM P.81943, inshore limestone reef off Neds Camp, Cape Range National Park, Western Australia, Australia (21°59'S 113°59'E), 2 January 1984, green alga, Caulerpa and basal rubble, 1.5 m depth, J.K. Lowry, WA-374; 2 specimens, AM P.81942, inshore limestone reef off South Neds Camp, Cape Range National Park, Western Australia, Australia (22°S 113°55'E), sea grass with rhizomes/bases, 2 m depth; R.T. Springthorpe, 31 December 1983, WA-327; 10+ specimens, AM P.81993, inshore limestone reef off South Neds Camp, Cape Range National Park, Western Australia, Australia (22°S 113°55'E), sea grass with rhizomes/bases, 2 m depth, R.T. Springthorpe, 31 December 1983, WA-327. 2 specimens, AM P. 81937, 500 m offshore at Bush Bay, 30 km south of Carnarvon, Western Australia, Australia (25°10'S 113°39'E), airlift from extensive shallow branching sea grass beds, 0.5 m depth, J.K. Lowry & R.T. Springthorpe, 6 January 1984, WA- 426; 2 specimens, AM P.81994, exposed intertidal rock shelf, The Blow Holes, Point Quobba, Western Australia, Australia (24°39'S 113°25'E), broad-leaved brown alga, J.K. Lowry, 7 January 1984, WA-441; 3 specimens, AM P.81946, Thompsons Bay, Rottnest Island, Western Australia, Australia (32°S 115°33'E), seagrass, Posidonia bed, 3 m depth, J.K. Lowry & R.T. Springthorpe, 20 December 1983, WA-221+222; 4 specimens, AM P.81938, Cathedral Rocks, Rottnest Island, Western Australia, Australia (32°1'30"S 115°27'E), coralline algae, red algae, sponge, 3 m depth, J.K. Lowry, 21 December 1983, WA-248; AM P.81944, 1 specimen, off jetty at Green Island, Rottnest Island, Western Australia, Australia (32°1'S 115°30'E), mixed algal turf on rock, 1 m depth, R.T. Springthorpe, 21 December 1983, WA-268; 1 specimen, AM P.81939, near Mistaken Island, Vancouver Peninsula, King George Sound, Western Australia, Australia (35°4'S 117°56'E), algae-covered sponge, 2 m depth, R.T. Springthorpe, 13 December 1983, WA-119; 2 specimens, AM P.81936, near Mistaken Island, Vancouver Peninsula, King George Sound, Western Australia, Australia (35°4'S 117°56'E), grey sponge and crinoids, 2 m depth, R.T. Springthorpe, 13 December 1983, WA-114; 1 specimen, AM P.81945, near Mistaken Island, Vancouver Peninsula, King George Sound, Western Australia, Australia (35°4'S 117°56'E), seagrass bases with detritus, 3 m depth, J.K. Lowry, 13 December 1983, WA-112; 1 specimen, AM P.81940, near Mistaken Island, Vancouver Peninsula, King George Sound, Western Australia, Australia (35°4'S 117°56'E), stalked ascidian, 3 m depth, J.K. Lowry, 13 December 1983, WA-109; 1 specimen, AM P.81932, near Mistaken Island, Vancouver Peninsula, King George Sound, Western Australia, Australia (35°4'S 117°56'E), grey sponge and crinoids, 2 m depth, R.T. Springthorpe, 13 December 1983, WA-114.

Northern Territory: 10+ specimens, AM P.81955, south side of New Year Island, Northern Territory, Australia (10°54'S 133°2'E), branching brown algae, 14 m depth, J.K. Lowry, 14 October 1982, NT-31; 5 specimens, AM P.81956, south side of New Year Island, Northern Territory, Australia (10°54'S 133°2'E), red algae, 14 m depth, J.K. Lowry, 14 October 1982, NT-27; 2 specimens, AM P.81954, west end of Oxley Island, Northern Territory, Arafura Sea, Australia (11°S 132°49'E), muddy sand, 14 m depth, J.K. Lowry, 21 Oct 1982, NT-85; 1 specimen, AM P.81957, west end of East Point, north end of Fannie Bay, Darwin, Northern Territory, Australia (11°24'30"S 130°48'30"E), Echinogorgia sp., 8 m depth, J.K. Lowry, 26 October 1982, NT-93; 1 specimen, AM P.81953, west end of East Point, north end of Fannie Bay, Darwin, Northern Territory, Australia (11°24'30"S 130°48'30"E), sponges, green alga, Caulerpa sp., 8 m depth, J.K. Lowry, 26 October 1982, NT-89.

Queensland: 1 specimen, AM P.81989, Sunken Reef, north of Goodes Island, Torres Strait, Queensland, Australia (10°31'29"S 142°3'18"E), coral rubble, 12 m depth, J.K. Lowry & M. Capa, 29 September 2006, QLD 1867; 3 specimens, AM P.81950, west of Friday Island, Torres Strait, Queensland, Australia (10°6'47"S 142°6'38"E), L.E. Hughes & M. Capa, 3 October 2006, QLD 1929; 1 specimen, AM P.81952, Northwest Islet, Torres Strait, Queensland, (10°18'54"S 142°5'26"E), green alga, Halimeda sp., 4.7 m depth, L.E. Hughes& M. Capa, 1 October 2006, QLD 1914; 1 specimen, AM P.81947, sunken reef, north of Goodes Island, Torres Strait, Queensland, Australia (10°31'29"S 142°3'18"E), brown alga, Padina sp. on agglomerated coral rubble 12 m depth, J.K. Lowry & M. Capa, 29 September 2006, QLD 1859; 1 specimen, AM P.81948, reef between Hammond Island and Goodes Island, Torres Strait, Queensland, Australia (10°33'43"S 142°10'27"E), on the brown alga Padina sp. on rock, 9 m depth, M. Capa, 28 September 2006, QLD 1892; 3 specimens, AM P.81949, reef between Hammond Island and Goodes Island, Torres Strait, Queensland, Australia (10°33'43"S 142°10'27"E), brown alga, Dictyota sp., 7.9 m depth, L. Hughes & M. Capa, 28 September 2006, QLD 1855.

Etymology. Named for Mr. Dieter Kluge, the brother-in-law of the senior author.

Diagnosis. Dorsal keel consisting of subequal evenly rising dorsal humps on pereonites 2–7. Antenna 1 peduncular article 2 longer than wide. Sparse long setae on the distal margins of coxae 1–4. Propodi of pereopods 1–7 without additional robust setae half-way on posterior and anterior margins.

Description. Based on male holotype, 3.8 mm. Body (Fig. 4b) laterally not much expanded, coxae not much laterally splayed, pereonites hump-like produced laterally, with shallow dorsal keel (Fig. 4a), each carina on pereonites 2–7 wide and rising from anteriorly to posteriorly; on pereonite 1 a small rounded process anteriorly, posteriorly a somewhat longer, rounded protrusion. Carinae on pereonites 3–6 slightly drawn out posteriorly; on pereonite 7 wide and posteriorly truncate, that on pleonite 1 similar to that on pereonite 7, on pleonite 2 a rounded hump on the posterior half.

Head small, shorter than pereonite 1; eyes produced on rounded dorsal processes. Antenna 1 (Fig. 4c) peduncular article 1 with short lateral subapical lobe, longer than wide, twice as wide as article 2, peduncular articles 2 and 3 long and relatively slender; short uni-articulate flagellum with long terminal aesthetascs. Antenna 2 (Fig. 4d) slender, peduncular article 5 subequal or only slightly longer than article 4; article 4 2 x as long as article 3. Upper lip (Fig. 4g) apically truncate. Mandibles (Fig. 4h, i) with dentate incisors and narrow molar. Lower lip with truncate apical margin and short mandibular lobes. Maxilla 1 (Fig. 4e) outer lobe with 6 robust setae of differing width; uni-articulate, inconspicuous, flat palp, not reaching the apex of the outer plate. Maxilla 2 (Fig. 4f) plates separate only apically; inner plate about 2 x as wide as outer plate. Maxilliped (Fig. 5a) inner plate apically truncate with 3 nodular setae and some slender setae; outer plate long, distally rounded; palp 3-articulate, slender, subequal in length to outer plate.

Pereon. Coxae 1–4 with some long slender setae apically. Pereopod 1 (Fig. 5b, c) coxa subrectangular; basis slightly expanded distally; ischium longer than merus; merus distally oblique, about the length of carpus; propodus as long as merus and carpus combined, anterior margin convex, posterior margin straight, inner face of propodus with row of stout apically setulose setae; dactylus falcate with long unguis. Pereopod 2 (Fig. 5d) coxa wider than that of pereopod 1; basis distally expanded, both margins straight; ischium expanded distally; merus and carpus as for pereopod 1; propodus somewhat more slender and longer compared to pereopod 1 and without row of robust setae on inner face; dactylus as for pereopod 1. Pereopod 3 (Fig. 6a) coxa similar in shape to that of pereopod 2, but wider; basis subrectangular; ischium as in pereopod 2; merus with straight posterior margin and convex anterior margin, distal margin oblique; carpus slightly expanded distally, apical margin straight; propodus and dactylus subequal to that of pereopod 2. Pereopod 4 (Fig. 6b) coxa widest with angular short lobe posteromarginally; basis to dactylus as for pereopod 3. Pereopod 5 (Fig. 6c) coxa much wider than long, wider than the width of the basis, bilobed, posterior lobe slightly longer and wider than anterior one; basis anteromarginally straight, with wide rounded posterior lobe, expanded ventrally and partly covering the ischium, which is longer than wide; merus drawn out into rounded posterodistal lobe; carpus as long as merus, slightly expanded distally; propodus and carpus longer than in pereopod 4. Pereopod 6 (Fig. 7a) coxa wider than long, narrower than basis width; basis to dactylus subequal to that of pereopod 5. Pereopod 7 (Fig. 7b) coxa smallest; basis with small posteromarginal lobe, much narrower than basis of pereopod 6 and without posteroventral lobe; ischium subrectangular; merus with posterodistal lobe subequal to that of pereopod 6; carpus and propodus shorter than that of pereopod 6.

Pleon. Pleopod 1 (Fig. 8c: female) peduncle longer than wide, with 2 coupling hooks; outer ramus slightly shorter than inner. Pleopod 2 (8f: female) peduncle wider than long with 2 coupling hooks, rami widened proximally. Pleopod 3 (Figs 7c: male, 8d: female) peduncle wider than long with a tapering medial process ending in an apex with 2 coupling hooks, rami as for pleopod 2. Uropod 1 (Fig. 8 a) peduncle longer than rami in male, slightly expanded distally; outer ramus shorter than inner, with nodular seta on the tip. Uropod 2 peduncle longer than inner ramus, outer ramus somewhat longer than inner ramus, both rami apically with nodular setae. Uropod 3 without rami, hidden under the triangular telson (Fig. 8e).

Sexual dimorphism. Female body much wider than male habitus. Uropod 1 peduncle shorter than rami, outer ramus shorter than inner, both rami longer than in male and terminal nodular setae minute. Uropod 2 peduncle shorter and more slender than in male, ramus more slender, outer ramus lacking.

Remarks. For comparison of P. dieteri sp. nov. and the similar P. thomsoni see table 1 and for differences to similar species see discussion.

Distribution. Australia: Western Australia, Northern Territory, Torres Strait, Queensland.

Material examined. Holotype, female, 3 mm, AM P.81931, Queensland, Northwest Islet, Torres Strait, Australia (10° 18' 54" S, 142° 5' 26" E), 1 Oct 2006, Padina sp., 5.3 m depth, L. Hughes, QLD 1917.

Type locality. Northwest Islet, Torres Strait, (10° 18' 54" S, 142° 5' 26" E) 5.3 m depth.

Additional material examined. Papua New Guinea: 1 specimen, AM P.81990, coral reef east of Manunouha Island, Bootless Bay, Papua New Guinea, (9°32'S 147°16'30"E), coral rubble, J.K. Lowry & S. Arnam, 26 October 1980, PNG 15.

Western Australia: 1 specimen, AM P.81991 west side of Malus Island, Dampier Archipelago, Western Australia, Australia (26°30'36"S 116°38'55"E), brown alga, Sargassum sp. on sand, 2.6 m depth, R.A. Peart, 27 August 1999, WA 663.

Northern Territory: 15 specimens, AM P.81999, reef off East Point, Darwin Harbour, Northern Territory, Australia (12°24'36"S 130°39'57"E), brown alga, Sargassum sp., on reef flat, 0.5 m depth, R.A. Peart, 24 November 2000, NT 266. 3 specimens, AM P.82000, reef off East Point, Darwin Harbour, Northern Territory, Australia (12°24'36"S 130°39'57"E), brown alga, Sargassum sp., on reef flat, 0.5 m depth, R.A. Peart, 24 November 2000, NT 262.

Queensland: 5 specimens, AM P.81998, Sunken reef, north of Goodes Island, Torres Strait, Queensland, Australia (10°31'29"S 142°3'18"E), rocks with 15 cm tall Sargassum sp., 12 m depth, J.K. Lowry & M. Capa, 29 September 2006, QLD 1866;

Etymology. This species is named for Hartmut Coleman, the brother-in-law of the senior author.

Diagnosis. Dorsal keel humps on pereonites 3–4 shorter than humps on preceding pereonites. Antenna 1 peduncular article 2 longer than wide. Coxae 1–4 with dense fringe of long slender setae on the distal margins. Pereopods 1–7 propodi without additional robust setae half-way on posterior and anterior margins.

Description. Based on female holotype, 3 mm. Body (Fig. 9a) laterally not much expanded, coxae not much laterally splayed; with shallow dorsal keel consisting of a row of pointed processes, on pereonites 2–7 of a single rather narrow pointed peg, especially low on pereonites 3–4; on pereonite 1 a short pointed process anteriorly, followed by a much longer one. Carinae on pereonites 5–6 longer than those on pereonites 3–4; pereonite 7 and pleonite 1 with a rounded dorsal hump; pleonite 2 with only a short rounded protrusion.

Head small, shorter than pereonite 1; eyes produced on rounded lobes. Antenna 1 (Fig. 9b) peduncular article 1 narrow with a short rounded distolateral lobe, 1.5 x as long as wide, twice as wide as article 2, peduncular article 3 half the width of article 2; short uni-articulate flagellum with long terminal aesthetascs. Antenna 2 (Fig. 9c) slender, peduncular article 5 slightly longer than article 4; article 4 1.2 x as long as article 3. Upper lip (Fig. 9f) apically truncate. Mandibles (Fig. 9d, e) with dentate incisors and narrow molar. Lower lip (Fig. 9h) with rounded apical margin and short mandibular lobes. Maxilla 1 (Fig. 9g) outer lobe with 8? robust setae of differing size; small inconspicuous remnant of a palp mid-laterally. Maxilla 2 (Fig. 9i) plates separate only apically with only 3 robust setae apically; inner plate somewhat wider than outer plate. Maxilliped (Fig. 10a) inner plate apically truncate with 3 nodular setae and some stout setae; outer plate long, palp 3-articulate, somewhat longer than outer plate.

Pereon. Coxae of pereopods 1–4 with a fringe of long slender setae. Pereopod 1 (Fig. 10b) coxa subrectangular; basis expanded distally; ischium subrectangular, almost as wide as basis apex, twice as long as merus; merus triangular; carpus as long as ischium; propodus slightly longer than merus and carpus combined, anterior margin with proximal protrusion, posterior margin straight, inner face of propodus with row of stout apically setulose setae; dactylus falcate with long unguis. Pereopod 2 (Fig. 10c) coxa wider than that of pereopod 1, but of similar shape; basis only weakly expanded, anterior margin straight, posterior margin convex; ischium subrectangular, as wide as distal basis region; merus and carpus as for pereopod 1; propodus somewhat longer compared to pereopod 1 and without row of robust setae on inner face; dactylus as for pereopod 1. Pereopod 3 (Fig. 11 a) coxa similar in shape to that of pereopod 2, but wider; basis expanded posterodistally; ischium as in pereopod 2; merus with straight posterior margin and convex anterior margin, distal margin oblique; carpus slightly expanded distally, apical margin straight; propodus and dactylus subequal to those of pereopod 2. Pereopod 4 (Fig. 11b) coxa widest with drawn out narrow lobe posteromarginally; basis to dactylus as for pereopod 3. Pereopod 5 (Fig. 11c) coxa much wider than long, wider than the width of the basis, bilobed, anterior lobe longer and wider than posterior one; basis anteromarginally weakly convex, with wide rounded posterior lobe, expanded ventrally and partly covering the ischium, which is somewhat wider than long; merus drawn out into rounded posterodistal lobe; carpus shorter than merus, subrectangular; propodus and carpus as long as in pereopod 4. Pereopod 6 (Fig. 12a) coxa wider than long, narrower than basis width; basis to dactylus subequal to those of pereopod 5. Pereopod 7 (Fig. 12b) coxa not clearly separated from tergite; basis subrectangular, distal margin straight; ischium subrectangular, weakly narrower than basis; merus with posterodistal lobe slightly smaller than that of pereopod 6; carpus slightly longer than that of pereopod 6; propodus to dactylus as for pereopod 6.

Pleon. Pleopod 1 (Fig. 12c) with subrectangular peduncle, with 2 coupling hooks; outer ramus slightly longer than inner. Pleopod 2 (Fig. 12d) peduncle wider than long, with 2 coupling hooks, rami subequal in length. Pleopod 3 (Fig. 12b) wider than long with a tapering medial process ending in an apex with 2 coupling hooks, outer ramus slightly shortened. Uropod 1 (Fig. 13a) peduncle as long as outer ramus (in female), slightly expanded distally; outer ramus slightly shorter than inner, with some small setae on the tip. Uropod 2 (Fig. 13a) peduncle slightly longer than ramus, apically without nodular seta. Uropod 3 (Fig. 12e) hidden under the triangular telson.

Sexual dimorphism. The male body is more slender than that of the female. Uropod 1 peduncle as long as inner ramus, slightly expanded distally; outer ramus slightly shorter than inner, with nodular seta on the tip. Uropod 2 peduncle longer and wider than rami, outer ramus slightly shorter than inner, with an apical nodular seta each.

Remarks. See general discussion.

Distribution. Papua New Guinea; Australia: Western Australia, Northern Territory, Queensland.