Algal-tube Dwelling Amphipods in the Genus Cerapus from Australia and Papua New Guinea (Crustacea: Amphipoda: Ischyroceridae) Lowry, K. Berents, P. B. Records of the Australian Museum 2005 57 2 153 164 SJS3 Lowry & Berents, 2005 Lowry & Berents 2005 [975,1177,1763,1787] Malacostraca Ischyroceridae Cerapus Animalia Amphipoda 7 160 Arthropoda species volucola sp. nov.   Figs. 7–9   Type material.  HOLOTYPE, 3, 3.20 mm, AMP62408; 12  PARATYPES, AMP62407;  PARATYPE, 3, 2.84 mm, AMP62409;  PARATYPE, ♀, 3.92 mm, AMP62410; False Orford Ness, northeast of Cape York, Queensland, Australia, 11°23'S 142°52'E, rock, brown algae and sand,  4 m, D. Blake,  18 February 1979.  Fig. 6.  Cerapus murrayae n.sp., holotype male, 7.04 mm (P31037), Queenscliff Lagoon, New South Wales. Scales represent 0.1 mm.  Additional material. 13,  AMP62419; 2 specimens,  AMP62413, Padoz Natunreef, Madang Lagoon, Papua New Guinea, 5°09.60'S 145°48.77'E,  Halimeda& epiphytic algae on rubble consolidated by sponges,  8 m, D. Gochfeld,  15 December 1993; 1♀,  AMP62414, Padoz Natunreef, Madang Lagoon, Papua New Guinea, 5°09.60'S 145°48.77'E,  Halimeda& epiphytic algae on rubble consolidated by sponges,  8 m, D. Gochfeld,  2 January 1994. 3 specimens,  AMP62411, half way between Lizard Islandand Carter Reef, Queensland, Australia, 14°37'S 145°33'E,  38 m, J.Leis,  26 November 1981. 5 specimens,  AMP62417, Magnetic Island, Queensland, Australia, 19°8'S 146°50'E, among  Sargassum,  3 m, G. Edgar  13 August 1981. 1 ovigerous female,  AMP62415, north Wistari Reef, Capricorn Group, Great Barrier Reef, Queensland, Australia, 23°29'S 151°53'E, coral sand,  24 m, D. Fisk,  11 November 1978; 1♀,  AMP62416, northwest Wistari Reef, Great Barrier Reef, Queensland, Australia, 23°29'S 151°53'E, sand,  24 m, D. Fisk,  16 December 1978. 1♀,  AMP62418, Middle Reef, North Stradbroke Island, Queensland, Australia, 27°24.4'S 153°32'E,  Zonaria,  20 m, K.B. Attwoodand E.L.A. Ho,  4 June 1993.   Diagnosis. Head, rostrum long, apically acute; anteroventral corner rounded. Antenna 1 peduncular article 1 longer than article 3, swollen along posterior margin.Pereonite 2 without sternal keel. Pereopod 5 merus posterior lobe with 2 plumose setae.   Description. Based on holotypemale, 3.20 mm(P62408) and paratypefemale, 3.92 mm(P62410). With chocolatecoloured stripe around margin of head and dorsal surface of peduncle of antenna 1. Head, rostrum long, apically acute, length 0.3× head; lateral cephalic lobe with ventral corner rounded, subocular margin weakly recessed, anteroventral corner rounded, ventral margin horizontal, posterior margin vertical. Antenna 1long, length 0.5× body 162 Records of the Australian Museum (2005) Vol. 57 length; peduncular article 1 longer than (1.2×) peduncular article 3, not produced anterodistally and anteromedially, swollen along posterior margin, posterodistal corner not produced; flagellum 6-articulate; article 1 short. Antenna 2length 1× antenna 1; flagellum 6-articulate; article 1 short. Epistome and upper lipfused, straight. Mandiblewith palp article 2 long and slender, length 2.7× breadth, 1.1× article 3; palp article 3 slender, blade-like, long, 3.5× breadth.  Fig. 7.  Cerapus volucola n.sp., male, False Orford Ness, northeast of Cape York, Queensland: ( A), whole animal; ( B), tube; ( C), dorsal view of head.  Pereon. Pereonites 1 to 3without lateral or sternal keels. Pereonite 5length 1.6× depth.  Gnathopod 1coxa fused to pereonite 1, without anteroventral lobe; basis length 1.75× depth; carpus, length 1.25× depth with setose posterior lobe, broad; palm extremely acute, with barbed robust setae. Gnathopod 2carpochelate; coxa fused to pereonite 2, without anteroventral lobe or cusp; basis short, broad, length 1.35× breadth; carpus long, broad, length 1.1× breadth; palm deeply excavate, anterodistal tooth large, located distal to articulation with propodus, posterodistal tooth well defined, medium, length 1.3× width; propodus very broad, slightly curved, length 2.5× width, without tooth on posterior margin, posterodistal corner smooth, without tooth; dactylus, length 0.7× propodus.  Pereopod 3coxa fused to pereonite 3, with narrow anteroventral lobe; basis, length 1.5× breadth, evenly rounded, with plumose setal group and simple setae along anterior margin, without denticles along anterior margin; ischium long, length 1.6× breadth; merus short, length 1× breadth, without ridges. Pereopod 4coxa fused to pereonite, with anterior lobe; basis length 1.3× breadth, with plumose setal group midway along anterior margin; ischium long, length 1.8× breadth; merus short, length 1× breadth. Pereopod 5coxa length 1.3× depth, without patches of small setae, without setae along ventral margin; merus with anterior lobe extending beyond anterior margin of carpus, posterior lobe with 2 plumose setae; propodus with 1 seta along posterior margin; dactylus short, uncinate with one accessory hook. Pereopod 6coxa without setal fringe ventrally, without patch of small setae near anterior margin; basis without patch of small setae near anterior margin; merus, length 1.6× breadth; dactylus short, uncinate, with two accessory hooks. Pereopod 7coxa without posterodorsal lobe, without patch of small setae; merus, length 2.2× breadth; dactylus, short, uncinate, with two accessory hooks.  Pleon. Pleopods 1 to 3decreasing in size. Pleopod 1inner ramus 7-articulate; outer ramus 5-articulate, article 1 evenly swollen. Pleopod 2biramous; inner ramus reduced, 1- articulate; outer ramus, broad, 2-articulate. Pleopod 3present; inner ramus present, reduced; 1-articulate. Uropod 1biramous, peduncle with distoventral corona of cuticular teeth, length 1.3× outer ramus; rami with distoventral corona of cuticular teeth; outer ramus with lateral row of denticles, without medial setae, with 5 lateral setae, with large apical robust seta without smaller slender setae; inner ramus, length 0.6× outer ramus, without medial or lateral setae, with large apical robust seta without smaller slender setae. Uropod 2uniramous, length of peduncle 2.5× breadth, 4.6× ramus; ramus small, with 4 denticles and 1 apical seta. Uropod 3uniramous, peduncle length 1.5× breadth; ramus with 3 curved hooks. Telsonlength 0.4× breadth, moderately cleft, 0.6× length, each lobe with 14–15 anteriorly directed hooks in 2 rows.  Female(sexually dimorphic characters). Based on paratypefemale, 3.92 mm(P62410). Gnathopod 1coxa not fused to pereonite 1, length 1.5× depth; basis length 2.3× depth; carpus, length 1.1× depth with setose posterior lobe, narrow. Gnathopod 2subchelate; basis length 1.6× breadth; carpus length 1.3× breadth; propodus palm extremely acute; dactylus length 0.8× propodus. Oostegitesfrom gnathopod 2 to pereopod 5.   Etymology. The species name is derived from the Latin words volumenfor scroll and colafor inhabit.  Fig. 8.  Cerapus volucola n.sp., holotype male, 3.20 mm (P62408),  Tube. Wrapped, parchment-like; seagrass and algae “wrapped” to form a tube.  Habitat. Littoral, 3 to 38 mdepth.  Life-style. Algal or seagrass dwellers.   Remarks.  Cerapus volucolais a widespread species known from MadangLagoon in northern Papua New Guinea, all along the Great Barrier Reef in northeastern Australia, to North Stradbroke Island in southern Queensland. The tubes of  C. bundegiand  C. volucolaare almost identical, but morphologically the species differ in many ways. The most obvious differences are the shape of male gnathopod 2, and the number of dorsal recurved hooks on the telson ( 17–18 in  C. bundegiand 14–15 in  C. volucola).   Distribution.  Papua New Guinea: Padoz Natun reef, MadangLagoon.  Australia, Queensland: False Orford Ness, northeast of Cape York; Lizard Island and Carter Reef; Magnetic Island; Wistari Reef, Capricorn Group; Middle Reef, North Stradbroke Island ( 5°Sto 27 °S).  ACKNOWLEDGMENTS. We thank the late Sharne Wiedland for her beautiful illustrations of the whole animals and tubes; Roger Springthorpe for assistance with illustrations. This research was supported by a grant from the Australian Biological Resources Study. P62408 [970,1421,1844,1868] AM 7 160 1 holotype P62407 [794,1075,1873,1896] AM 7 160 1 paratype P62409 AM 7 160 1 paratype P62410 1979-02-18 AM D. Blake Australia 4 -11.383333 False Orford Ness 1295 142.86667 Cape York 7 160 1 1 Queensland paratype P62419 [395,619,1616,1635] AM 8 161 2 P62413 1993-12-15 AM D. Gochfeld Papua New Guinea 8 -5.16 Padoz Natun 13 145.81284 Lagoon 8 161 1 1 Madang P62414 1994-01-02 AM D. Gochfeld Papua New Guinea 8 -5.16 Padoz Natun 13 145.81284 Lagoon 8 161 3 Madang P62411 1981-11-26 AM J. Leis Australia 38 -14.616667 Lizard Island 1287 145.55 Carter Reef 8 161 5 Queensland P62417 1981-08-13 AM G. Edgar Australia 3 -19.133333 Magnetic Island 1273 146.83333 8 161 1 Queensland P62415 1978-11-11 AM D. Fisk Australia Great Barrier Reef 24 -23.483334 north Wistari Reef 1255 151.88333 Capricorn Group 8 161 1 1 Queensland P62416 1978-12-16 AM D. Fisk Australia 24 -23.483334 Wistari Reef 1255 151.88333 Great Barrier Reef 8 161 1 1 Queensland P62418 1993-06-04 AM K. B. Attwood & E. L. A. Ho Australia 20 -27.406666 Middle Reef 826 153.53334 North Stradbroke Island 8 161 1 Queensland