Waldeckia bamberi, Lowry, J. K. & Kilgallen, N. M., 2015

Lowry, J. K. & Kilgallen, N. M., 2015, A new species of Waldeckia from the Austral Isles, Society Islands (Amphipoda, Lysianassoidea, Lysianassidae, Waldeckiinae), Zootaxa 3995 (1) : -

Waldeckia bamberi sp. nov.

( Figs 1–3 )

Types. Holotype, female, 7.1 mm, AM P.42163, French Polynesia, Austral Isles, off Tubuai (23°19'S, 149°29.3'W), 485 m, baited trap, 12 August 1991, J.M. Poupin & J.K. Lowry, RV Marara [FRP-39].

Other material examined. 1 female, AM P.42164, French Polynesia, Austral Isles, Rapa, Ha'urei Bay (27°36.55'S, 144°18.65'W), 3 m, baited trap, reef with large patches of brown algae, 17 August 1991, J.K. Lowry & J.M. Poupin, RV Marara [FRP-63]. 6 specimens, AM P.42161, French Polynesia, north-east side of Maria Island, between Isle du Nordet and Isle du Centrale (21°47.7'S, 154°42'W), 1 m, rubble and coarse sand from lagoon, 7 August 1991, J.K. Lowry & J.M. Poupin [FRP-1].

Etymology. The species is named for the late Roger Bamber in recognition of his distinguished career in pycnogonid and tanaidacean taxonomy.

Description. Based on holotype, female, 7.1 mm, AM P.42163.

Head exposed, deeper than long; lateral cephalic lobe large, narrowly rounded; rostrum absent; eyes black, reniform. Antenna 1 short; peduncular article 1 short, length 1.1 × breadth, without anterodorsal lobe, distal margin without spines on distomedial margin; article 2 short, 0.3 × article 1; peduncular article 3 short; 0.2 × article 1; accessory flagellum medium length, 0.5 × primary flagellum, 5-articulate, article 1 short; primary flagellum 11- articulate, with weak 1-field callynophore, flagellum without aesthetascs on distal articles; calceoli absent. Antenna 2 flagellum 12-articulate; peduncle strongly geniculate between article 3 and 4; calceoli absent. Labrum (epistome and upper lip) fused; sinusoidal, concave proximally, bulging distally. Mandible incisors with slightly convex margins; lacinia mobilis present only on left mandible; with accessory setal row, 4 setae on right, 2 on left; molar a strongly setose tongue, with vestigial distal triturating patch; palp attached extremely proximally; article 1 long; article 3 slender, blade-like. Maxilla 1 inner plate with 2 well-developed apical pappose setae; outer plate broad, setal-teeth in an 8/3 arrangement, outer row with cusps in 1 row; palp 2-articulate, with apical robust setae (short, blunt, peg-like). Maxilla 2 inner and outer plates narrow; inner plate length 0.8 × outer plate. Maxilliped inner plate subrectangular with 3 apical nodular robust setae; outer plate subovate, large, almost reaching dactylus of palp; palp 4-articulate, article 3 long, slender, article 4 well-developed.

Gnathopod 1 parachelate; coxa anterior margin slightly concave, anteroventral corner rounded, posterior margin straight; basis anterior margin with slender setae; carpus short, length 1.1 x breadth, shorter than (0.75 ×) propodus; propodus subrectangular, narrowing distally, length 2 × breadth, posterior margin with 3 slight indentations each with 1 robust seta; palm obtuse, margin straight, smooth. Gnathopod 2 minutely chelate; carpus long, length 3.7 × breadth; propodus subovate, 0.6 × carpus length, palm obtuse with convex, minutely denticulate margin; dactylus reaching corner of palm. Pereopod 3 merus expanded anteriorly; carpus 0.6 × propodus length; propodus linear, with robust setae lining posterior margin. Pereopod 4 merus expanded anteriorly; carpus 0.66 × propodus length; propodus linear, with robust setae lining posterior margin. Pereopod 5 coxa large, distinctly longer than broad, bilobate, posterior lobe produced ventrally; basis expanded posteriorly, posterior margin almost straight, posteroventral margin rounded, anteroventral margin with row of simple setae; merus broadly expanded posteriorly; carpus short, 0.45 × propodus length; dactylus short. Pereopod 6 coxa large, longer than broad, not lobate posteriorly; basis anterior margin rounded distally, straight proximally, with row of simple setae on medial surface; merus broadly expanded posteriorly; carpus short, 0.45 × propodus; dactylus short. Pereopod 7 basis expanded posteriorly, posteroventral corner rounded, slightly excavate; merus expanded posteriorly; carpus short, 0.45 × propodus length; dactylus short.

Epimeron 3 posteroventral corner subacute. Urosomite 1 with strong dorsal notch and rounded boss. Uropod 1 outer ramus longer (1.38 x) than inner ramus. Uropod 2 rami subequal in length. Uropod 3 peduncle short; inner ramus shorter than outer ramus, almost reaching article 2 of outer ramus, outer ramus with long plumose setae. Telson longer than broad, length 1.7 x breadth, cleft to 80%, with 2 apical robust setae on each lobe.

Gills on gnathopod 2 to pereopod 7.

Oostegites on gnathopod 2 to pereopod 5.

Remarks. The depth range of W. bamberi (1 to 485 m) may seem wide, but other species such as W. australiensis (2 to 1000 m) ( Lowry & Kilgallen 2014) are even wider.

It is difficult to consider relationships between W. bamberi and other species of Waldeckia because this is the first species reported from the Pacific Plate and it is living in a very geographically isolated position. We suspect that there must be more undiscovered species to the north and west of the Austral Isles which would be helpful in determining species relationships. At this time Waldeckia bamberi sp. nov. appears to be most similar to Waldeckia brachycephala Ren, 1998 from the South China Sea. Morphological differences between these taxa are subtle. The posterior margin of the gnathopod 1 propodus has 3 weak indentations bearing robust setae in W. bamberi but appears to be straight, with only one robust seta in W. brachycephala ; the posteroventral corner of the pereopod 7 basis is subtly excavate in W. bamberi , but rounded in W. brachycephala ; urosomite 1 is more strongly notched in W. bamberi in comparison with W. brachycephala ; W. brachycephala lacks the plumose setae on the outer ramus of uropod 3, present in W. bamberi ; finally, W. bamberi bears two robust setae on the apical tip of each telson lobe, whereas the telson of W. brachycephala only has one apical robust seta on each lobe.

Figures

FIGURE 1. Waldeckia bamberi sp. nov., habitus, holotype, female, 7.1 mm, AM P. 42163, from off Tubuai, Austral Isles, Society Islands.

FIGURE 2. Waldeckia bamberi sp. nov., holotype, female, 7.1 mm, AM P. 42163, from off Tubuai, Austral Isles, Society Islands. Uropod 3 missing inner ramus. Scale bars: head and urosome, 0.5 mm; remainder, 0.1 mm.

FIGURE 3. Waldeckia bamberi sp. nov., holotype, female, 7.1 mm, AM P. 42163, from off Tubuai, Austral Isles, Society Islands. Scale bars: 0.2 mm.