Cerapus murrayae, Lowry & Berents, 2005

Lowry, K. & Berents, P. B., 2005, Algal-tube Dwelling Amphipods in the Genus Cerapus from Australia and Papua New Guinea (Crustacea: Amphipoda: Ischyroceridae), Records of the Australian Museum 57 (2), pp. 153-164 : 157

Cerapus murrayae n.sp.

Figs. 3–6

Type material. HOLOTYPE, 3, 7.04 mm, AM P31037; PARATYPE, ♀, 4.64 mm, AM P51220; PARATYPE, 3, 4.32 mm, AM P51218; PARATYPE, 3, 3.04 mm, AM P51219; PARATYPE, 3, 6.08 mm, AM P61568; PARATYPE, 3, 8.9 mm, AM P62508; 36 PARATYPES, AM P61567; near bridge, Queenscliff Lagoon, Queenscliff, New South Wales, Australia, 33°47.1'S 151°16.8'E, washed in at high tide on drift algae Lobophora variegatus or Zonaria , intertidal,A. Murray, 26 October 1980. PARATYPE, 3, 5.08 mm, AM P61569, Balmoral Beach, New South Wales, Australia, 32°49.6'S 151°15.2'E, C. Short, 3 m, sand, 7 September 1978. PARATYPE, 3, AM P 61570, 150 m N of Horseshoe Bay, Trial Bay, New South Wales, Australia, 30°53'S 153°03'E, sediment and detritus from around reef edge, hand dredge, 7 m, R. T. Springthorpe, 15 June 1986. PARATYPE, 3, AM P61571, Split Solitary Island, New South Wales, Australia, 30°14.61'S 153°10.73'E, Zonaria sp. , soft corals, bryozoans and sponges, 18 m, P.B. Berents, J.K. Lowry and R. Peart, 12 February 2000.

Diagnosis. Head, rostrum short, apically acute; anteroventral corner subquadrate. Antenna 1 peduncular article 1 longer than article 3, slightly swollen along posterior margin. Pereonite 2 without sternal keel. Pereopod 5 merus posterior lobe with 7 plumose setae.

Description. Based on holotype male, 7.04 mm (P31037). Head, rostrum short, apically acute, length 0.2× head; lateral cephalic lobe with ventral corner rounded, subocular margin deeply recessed, anteroventral corner subquadrate, ventral margin horizontal, posterior margin vertical. Antenna 1 long, length 0.5× body length; peduncular article 1 longer than (1.2×) peduncular article 3, not produced anterodistally and anteromedially, slightly swollen along posterior margin, posterodistal corner not produced; flagellum 6-articulate; article 1 short. Antenna 2 subequal in length to antenna 1; flagellum 6-articulate; article 1 long. Epistome and upper lip fused, straight. Mandible with palp article 2 long and slender, length 3.4× breadth, 1.4× article 3; palp article 3 slender, blade-like, long, 3.1× breadth.

Pereon. Pereonite 1 with lateral keel; without sternal keel. Pereonite 2 without sternal keel. Pereonite 3 without sternal keel. Pereonite 5 length 2× depth.

Gnathopod 1 coxa not fused to pereonite 1, length 1.4× depth, without anteroventral lobe; basis length 1.8× depth; carpus length 1.3× depth with setose posterior lobe, broad; palm extremely acute, with simple robust setae. Gnathopod 2 carpochelate; coxa not fused to pereonite 2, length 1.6× depth, without anteroventral lobe or cusp; basis short, broad, length 1.3× breadth; carpus long, broad, length 1.2× breadth; palm shallowly excavate, anterodistal tooth small, located near articulation with propodus, posterodistal tooth well defined, medium in size, length 1.4× width; propodus very broad, slightly curved, length 2.2× width, without tooth on posterior margin, posterodistal corner smooth, without tooth; dactylus, length 0.7× propodus.

Pereopod 3 coxa fused to pereonite 3, with broad anteroventral lobe; basis, length 1.7× breadth, evenly rounded, with simple setae along anterior margin, without denticles along anterior margin; ischium long, length 2.8× breadth; merus short, length 1× breadth, without ridges. Pereopod 4 coxa fused to pereonite 4, with anterior lobe; basis length 1.3× breadth, with simple setal group midway along anterior margin; ischium long, length 2.1× breadth; merus short, subequal in length 1 to breadth. Pereopod 5 coxa length 1.2× depth, without patches of small setae, with setae along ventral margin; merus with anterior lobe extending beyond anterior margin of carpus, posterior lobe with 7 plumose setae; propodus with 3 setae along posterior margin; dactylus short, uncinate with one accessory hook. Pereopod 6 coxa without setal fringe ventrally, without patch of small setae near anterior margin; basis without patch of small setae near anterior margin; merus, length 2× breadth; dactylus short, uncinate, with two accessory hooks. Pereopod 7 coxa without posterodorsal lobe, without patch of small setae; merus, length 1.6× breadth; dactylus, short, uncinate, with two accessory hooks.

Pleon. Pleopods 1 to 3 decreasing in size. Pleopod 1 inner ramus 9-articulate; outer ramus 3-articulate, article 1 with medial lobe. Pleopod 2 biramous; inner ramus reduced, 1- articulate; outer ramus, broad, 1-articulate. Pleopod 3 present; inner ramus present, reduced; 1-articulate; outer ramus broad, 1-articulate. Uropod 1 biramous, peduncle with distoventral corona of cuticular teeth, length 1.5× outer ramus; rami with distoventral corona of cuticular teeth; outer ramus with lateral row of denticles, without medial setae, and with 5 lateral setae, with large apical robust seta without smaller slender setae; inner ramus, length 0.7× outer ramus, without medial or lateral setae, with large apical robust seta without smaller slender setae. Uropod 2 uniramous, length of peduncle 2.8× breadth, 5.8× ramus; ramus small, with 4 denticles and 1 apical seta. Uropod 3 uniramous, peduncle Remarks. Cerapus murrayae is currently known only from the New South Wales central coast, the most restricted distribution of the three known species that make parchmentlike tubes. These spectacular tubes, decorated with pieces of algae, distinguish C. murrayae from C. bundegi and C. volucola . Morphologically C. murrayae can be distinguish- ed from both C. bundegi and C. volucola by the shape of the male gnathopod 2 and the number of dorsal recurved hooks on the telson (17–18 in C. bundegi and 14–15 in C. volucola ) is different.