Cymadusa tattersalli Peart, 2004

Hughes, L. E. & Lowry, J. K., 2009, Ampithoidae *, Zootaxa 2260 (1), pp. 153-219 : 198-201

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.

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).

Figures

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).