Ampithoidae * Author Hughes, L. E. Author Lowry, J. K. text Zootaxa 2009 2009-10-08 2260 1 153 219 https://www.biotaxa.org/Zootaxa/article/view/zootaxa.2260.1.8 journal article 10.11646/zootaxa.2260.1.8 1175-5326 5322208 Cymadusa tattersalli Peart, 2004 ( Figs 27 , 28 ) Cymadusa setosa . — Tattersall, 1922: 19 , figs. Cymadusa filosa . — Ledoyer, 1983: 130 , figs. 44–45 (form A). Cymadusa tattersalli Peart, 2004: 314 , figs 8–11. — Peart, 2007a: 33 , figs 27–28. Material examined. 4 unsexed, AM P61927 ( QLD 1342). Type locality . Woodman Point , Cockburn Sound , Western Australia , Australia (~ 32°9’S 115°46’E ) . Description. Based on male, 11 mm , AM P61927. Head. Head as long as deep. Antenna 1 subequal to antenna 2; peduncular article 1 subequal to article 2; primary flagellum 38 articles; accessory flagellum with 2 articles. Antenna 2 peduncle with short, dense slender setae on ventral margin; article 4 subequal in length to article 5; flagellum 35 articles. Upper lip directed nearly straight down, lateral margins each with midlateral notch. Mandible molar well developed, triturating, accessory setal row with 7 serrate setae; palp 3–articulate, marginally setose; article 1 shorter than article 2; article 2 subequal in length to article 3, slender setae present. Lower lip outer plates notched, forming a medial excavation, lateral lobe distinctly longer than medial lobe; mandibular lobe with curved margins, rounded apically. Maxilla 1 inner plate with 7 setae; palp article 2 broad. Maxilla 2 inner plate narrower than outer plate. Maxilliped outer plate with row of large robust setae along medial margin. Pereon. Coxae 1–4 deeper than broad. Gnathopod 1 smaller than gnathopod 2, margins lined with long slender setae; coxa distinctly larger than coxa 2, anteroventrally produced, anterior margin straight, anteroventral corner rounded, with long setal fringe on ventral margin; basis shorter than coxa, anterodistal lobe absent; merus posterodistal lobe subacute; carpus about 1.75 x as long as broad, longer than propodus, anterior margin with slender setae, posterior margin truncated; propodus broad, subovoid, anterior margin with fringe of long slender setae; palm acute, convex, with rounded posterodistal corner, with 1 robust seta defining palm; dactylus subequal in length to palm, inner margin crenate. Gnathopod 2 coxa with long, plumose setal fringe on ventral margin; basis with fringe of long, slender setae; merus margin with short, subacute distal lobe; carpus shorter than propodus, subtriangular; propodus broad, less than 1.5 x as long as broad, subovoid, not produced into an anterodistally setose lobe; palm acute, entire, with proximal broad subquadrate projection near base of dactylus, with short (length 1 x breadth) posterodistal tooth, apically subacute, without palm defining robust setae; dactylus shorter than palm, tapering evenly, apically acute, inner margin crenate. Pereopods 3–4 basis slightly expanded; merus subequal in length to carpus. Pereopods 5–7 weakly prehensile. Pereopod 5 with medial slender setae; distal articles slender; propodus not expanded distally, with 3 anterodistal striated robust setae; dactylus slightly curved. Pereopod 6 basis posterior margin straight, with several marginal robust setae; distal articles slender; propodus not expanded distally, with 3 anterodistal striated robust setae; dactylus slightly curved. Pereopod 7 similar to pereopod 6. Pleon. Epimera 2–3 posteroventral corner with small acute cusp. Uropod 1 peduncle with 12 robust setae, with short fringe of slender setae (less than 0.5 x length of peduncle), with large, acute distoventral spine; outer ramus with 11 lateral setae; inner ramus with 10 lateral robust setae. Uropod 2 peduncle with 5 robust setae; outer ramus with 9 lateral robust setae; inner ramus with 10 lateral robust setae. Uropod 3 peduncle longer than broad, more than 2 x length of rami, marginal slender setae rounded, with 7 distal peduncular robust setae, with 4 slender setae; outer ramus with 2 large recurved distal robust setae, with 1 lateral robust seta and 4 lateral slender setae; inner ramus with 8 distal slender setae, with 2 lateral robust setae. Telson subrectangular, apically truncated, with small apical cusp on each distolateral corner, with more than 8 pairs of oblique slender setae. FIGURE 27. Cymadusa tattersalli Peart, 2004 , male, 11 mm, AM P61927, Heron Island, Great Barrier Reef (based on Peart 2007a ). FIGURE 28. Cymadusa tattersalli Peart, 2004 , male, 11 mm, AM P61927, female, 12 mm, AM P61927, Heron Island (based on Peart 2007a ). Female (sexually dimorphic characters). Based on paratype , female, 12 mm , AM P61927. Gnathopod 1 subequal in size to gnathopod 2; coxa subequal to coxa 2; basis anterodistal lobe with 1 slender seta; carpus about 2 x as long as broad, subequal in length to propodus, anterior margin without setae, posterior margin truncated; palm convex, posterodistal corner rounded. Gnathopod 2 coxa with ventral row of slender setae of varying lengths; basis rounded anterodistal lobe, anterodistal corner without setae; palm with posterodistal corner, rounded, with 1 robust seta defining palm; dactylus subequal in length to palm . Habitat. Brown algae. Remarks. Cymadusa tattersalli is closely related to Cymadusa setosa ( Haswell, 1879 ) and Cymadusa filosa Savigny, 1816 . According to Peart (2004) C. tattersalli differs from both species in the gnathopod 1 merus which is produced to form a small, subacute or rounded anteroventral lobe (short and acute in C. filosa and C. setosa ) and the carpus which is short and robust (elongate and narrow in C. filosa and C. setosa ). Cymadusa tattersalli is distinct from all other GBR ampithoids, except C. wistari , because of the dense plumose setae lining the margins of gnathopods 1 and 2 and pereopods 3 and 4. Cymadusa tattersalli has a sculptured palm on the propodus of gnathopod 2, which is entire in C. wistari . Distribution. Australia . Queensland : Heron Island ( Peart 2007a ). Western Australia : Cockburn Sound; Abrolhos Islands; Dampier Archipelago ( Peart 2007a ). Madagascar ( Ledoyer 1983 ).