Pereionotus dieteri, Coleman, Oliver & Lowry, James K., 2012

Coleman, Oliver & Lowry, James K., 2012, The genus Pereionotus (Crustacea, Amphipoda, Phliantidae) from Australia, Zootaxa 3486, pp. 63-88 : 69-83

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.

Figures

FIGURE 4 a – j: Pereionotus dieteri sp. nov., holotype male, 3.8 mm, AM P. 88037. a) dorsal keel, left aspect; b) habitus; c) antenna 1; d) antenna 2 and eye; e) maxilla 1; f) maxilla 2; g) upper lip; h) left mandible; i) right mandible. Scale bars: b) 1 mm; d – i) 100 µm; c) 200 µm.

FIGURE 5 a – d: Pereionotus dieteri sp. nov., holotype male, 3.8 mm, AM P. 88037. a) maxilliped; b) coxa of pereopod 1; c) basis to dactylus of pereopod 1; d) pereopod 2. Scale bars: a-c) 100 µm; d) 200 µm.

FIGURE 6 a – c: Pereionotus dieteri sp. nov., holotype male, 3.8 mm, AM P. 88037. a) pereopod 3; b) pereopod 4; c) pereopod 5. Scale bars: a – c) 200 µm.

FIGURE 7 a – c: Pereionotus dieteri sp. nov., holotype male, 3.8 mm, AM P. 88037. a) pereopod 6; b) pereopod 7; c) pleopod 3. Scale bars: a – c) 200 µm.

FIGURE 8 a – f: Pereionotus dieteri sp. nov., holotype male, 3.8 mm AM P. 88037 and paratype female AM P. 81988: a) urosome. Paratype female: b) urosome; c) pleopod 1; d) pleopod 3; e) uropods 3 and telson, ventral aspect; f) pleopod 2. Scale bars: a) 200 µm; b – f) 100 µm.

FIGURE 9 a – i: Pereionotus hartmuti sp. nov., holotype female, 3 mm, AM P. 81931. a) habitus; b) antenna 1; c) antenna 2; d) right mandible; e) left mandible; f) upper lip; g) maxilla 1; h) lower lip; i) maxilla 2. Scale bars: a) 500 µm. b, c) 200 µm. d – i) 100 µm.

FIGURE 10 a – c: Pereionotus hartmuti sp. nov., holotype female, 3 mm, AM P. 81931. a) maxilliped with detail of inner plates; b) pereopod 1; c) pereopod 2. Scale bars: a) 100 µm: b, c) 200 µm.

FIGURE 11 a – c: Pereionotus hartmuti sp. nov., holotype female, 3 mm, AM P. 81931. a) pereopod 2; b) pereopod 4; c) pereopod 5. Scale bars: a – c) 200 µm.

FIGURE 12 a – e: Pereionotus hartmuti sp. nov., holotype female, 3 mm, AM P. 81931. a) pereopod 6; b) pereopod 7; c) pleopod 1; d) pleopod 2; e) uropods 3 and telson, ventral aspect. Scale bars: a – e) 200 µm.

FIGURE 13 a – b: Pereionotus hartmuti sp. nov., holotype female, 3 mm, AM P. 81931. a) urosome; b) pleopod 3. Scale bars: a, b) 200 µm.