Bathylamprops paraleucon, Gerken, 2018

Gerken, Sarah, 2018, The Lampropidae (Crustacea: Cumacea) of the World, Zootaxa 4428 (1), pp. 1-192 : 31-36

Bathylamprops paraleucon n. sp.

( Figs 5–7 )

Type material. Holotype ovigerous female, NIWA 93174 ; paratype ovigerous female dissected, NIWA 93170 ; paratype subadult male dissected, NIWA 93202 Chatham Rise, 44.49°S, 177.14°E, 1235–1239 m, 6 April 2007.

Other material. 1 individual NIWA 95417, 1 individual NIWA 95418, Challenger Plateau, 40.13°S, 170.21°E, 803–805 m, 5 June 2007; 2 individuals in poor condition, NIWA 95419 , Chatham Rise, 43.53°S, 178.5°E, 346 m, 24 April 2007 ; 2 females, 1 subadult male, 2 juveniles, NIWA 95420 , 4 subadult females NIWA 95421 , 2 subadult females NIWA 95422 , Chatham Rise, 44.49°S, 177.14°E, 1235–1239 m, 6 April 2007 . 4 individuals NIWA 95423 , Chatham Rise, 44.56°S, 178.48°W, 1076–1103 m, 10 April 2007 .

Diagnosis. Carapace without lateral ridges, not rugose, without tubercles, with row of teeth on anterior margin; eyelobe without spine. Antennule main flagellum terminal article long. Maxilliped 3 carpus 1.0 width of merus. Telson 1.0 uropod peduncles, with 2 pairs of lateral setae. Adult male unknown.

Description. Holotype ovigerous female, NIWA 93174; paratype ovigerous female, NIWA 93170.

Ovigerous female, holotype 4.5 mm, paratype 4.3 mm. Carapace unarmed, with row of denticles on anterior margin; pseudorostral lobes 0.6 carapace total length, extending 0.3 carapace length anterior of eyelobe; eyelobe 0.1 carapace length, without lenses; carapace 1.1 length of pereonites together; pereonites and pleonites stout ( Fig. 5A, B ).

Antennule peduncle article 1 equal to articles 2 and 3 together, with 1 simple and 2 plumose setae; article 2 0.6 article 1 length, with 3 plumose setae; article 3 0.6 article 2 length, with 2 simple setae; main flagellum of 3 articles, terminal article longer than subterminal article, with 1 simple and 2 aesthetasc setae; accessory flagellum 0.4 main flagellum length, of 2 articles, with simple setae ( Fig. 5C ).

Antenna–maxilliped not examined.

Maxilliped 2 basis 0.9 all other articles together, with 2 thickly plumose setae; ischium 0.1 basis length, unarmed; merus 2.5 ischium length, with sparsely plumose setae medially; carpus 1.2 merus length, with sparsely plumose setae medially; propodus 0.8 carpus length, with sparsely plumose setae medially and thickly plumose seta laterally; dactylus 0.5 propodus length, with simple setae terminally ( Fig. 5D ).

Maxilliped 3 basis 1.2 all other articles together, with pappose setae medially, 2 plumose setae at distal corner; ischium 0.1 basis length, with pappose seta medially; merus 1.2 ischium length, with pappose seta medially, plumose seta laterally; carpus 2.1 merus length, with pappose and plumose setae medially, 2 plumose setae laterally; propodus 0.9 carpus length, with plumose setae medially and laterally; dactylus 0.5 propodus length, with simple setae terminally; exopod 0.9 basis length, basal article with 3 plumose setae, flagellum with plumo-annulate setae ( Fig. 5E ).

Pereopod 1 broken, basis with simple setae proximally, plumose setae distally; exopod 0.8 basis length, basal article with 3 plumose setae, flagellum with plumo-annulate setae ( Fig. 5F ).

Pereopod 2 basis 1.1 all other articles together, with simple, plumose and complex pedunculate setae; ischium apparently absent; merus with 3 plumose and 1 stout microserrate setae; carpus 0.9 merus length, with 3 plumose and 3 stout microserrate setae; propodus 0.5 carpus length, unarmed; dactylus 2.3 propodus length, with 5 slender simple setae and stout simple seta terminally; exopod broken ( Fig. 5G ).

Pereopod 3 basis 1.3 all other articles together, with 4 plumose setae; ischium 0.1 basis length, with 1 plumose and 2 annulate setae; merus 2.0 ischium length, with 2 plumose and 2 annulate setae; carpus 1.1 merus length, with 2 plumose and 2 annulate setae; propodus 0.5 carpus length, with annulate seta; dactylus 0.8 propodus length, with 2 simple setae and simple stout seta terminally; exopod rudimentary, 0.2 basis length, of 2 articles with 3 simple setae ( Fig. 5H ).

Pereopod 4 and pereopod 5 broken.

Telson 1.1 length of pleonite 6, with 2 microserrate with subterminal setule lateral setae, 5 subequal terminal microserrate setae with subterminal setule ( Fig. 5I ).

Uropod peduncles 1.1 pleonite 6 length, 1.0 telson length. Uropod endopod broken; article 1 with 14 microserrate setae with single subterminal setule medially. Uropod exopod of 2 articles; article 1 0.3 article 2 length, with simple seta; article 2 with 2 plumose setae medially, 5 simple setae laterally, 3 stout simple setae terminally ( Fig. 5I ).

Paratype subadule male, NIWA 93202 .

Subadult male, 3.7 mm. Carapace smooth; pseudorostral lobes 0.6 carapace length, extending 0.3 carapace length anterior of eyelobe; eyelobe 0.07 carapace length, without lenses; carapace 1.3 pereon length; pereonites and pleonites stout ( Fig. 6A, B ).

Antennule peduncle article 1 equal to articles 2 and 3 together, with pappose seta; article 2 0.6 article 1 length, with 1 simple and 2 complex pedunculate setae; article 3 0.7 article 2 length, unarmed; main flagellum of 3 articles, terminal article longer than subterminal article, with 2 aesthetasc setae; accessory flagellum 0.4 main flagellum length, of 2 articles, with simple setae ( Fig. 6C ).

Antenna immature, with pappose setae on peduncle ( Fig. 6D ).

Mandible navicular, with 5 microserrate setae medially, lacinia mobilis stout, with 4 cusps ( Fig. 6E ).

Maxillule with 2 endites; outer endite with 6 stout setae terminally; inner endite with 3 simple and 1 microserrate setae; palp with 2 setae ( Fig. 6F ).

Maxilla with 3 endites; broad endite rectangular, with 1 pappose, simple, and microserrate setae distally, medial row of pedunculate setae; medial narrow endite with 4 simple setae terminally; distal narrow endite with 5 simple setae terminally; both narrow endites extend past distal border of broad endite ( Fig. 6G ).

Maxilliped 1 basis produced as broad lobe medially, with 5 pappose setae medially, 2 hook, 1 tricuspid and 1 stout setae distally, pappose seta at interior corner; ischium absent; merus with pappose seta medially; carpus 3.0 merus length, with simple and beak setae medially, plumose seta laterally; propodus 0.7 carpus length, with simple and pappose setae medially, plumose seta laterally; dactylus 0.6 propodus length, with stout simple seta terminally ( Fig. 6H ).

Maxilliped 2 basis equal to all other articles together, with 1 simple and 1 thickly plumose setae; ischium 0.05 basis length, unarmed; merus 6.0 ischium length, with thickly plumose seta medially; carpus 0.9 merus length, with sparsely plumose setae medially, plumose seta laterally; propodus 1.1 carpus length, with sparsely plumose setae medially, 2 plumose setae laterally; dactylus 0.4 propodus length, with 3 simple setae terminally ( Fig. 6I ).

Maxilliped 3 basis 1.3 all other articles together, with pappose setae medially, 4 plumose setae at distal corner; ischium 0.03 basis length, with pappose seta; merus 5.0 ischium length, with 2 pappose setae medially, 2 plumose setae laterally; carpus 1.5 merus length, with pappose setae medially, lateral margin produced as tooth, with plumose seta laterally; propodus 1.2 carpus length, with sparsely plumose setae medially, 3 plumose setae laterally; dactylus 0.6 propodus length, with plumose seta laterally, 3 simple setae terminally; exopod 0.8 basis length, basal article unarmed, flagellum with plumo-annulate setae ( Fig. 7A ).

Pereopod 1 broken, basis with plumose setae; exopod 1.0 basis length, basal article with 2 plumose setae, flagellum with plumo-annulate setae ( Fig. 7B ).

Pereopod 2 basis with 6 plumose setae; ischium 0.07 basis length, with 3 plumose setae; merus 3.8 ischium length, with 2 plumose and 2 stout setae with single subterminal setule; carpus broken; exopod 1.0 basis length, basal article with 3 plumose setae, flagellum with plumo-annulate setae ( Fig. 7C ).

Pereopod 3 basis 1.4 all other articles together, with 3 plumose setae; ischium 0.08 basis length, with 3 annulate setae; merus 2.5 ischium length, with 1 plumose and 2 annulate setae; carpus 1.0 merus length, with 2 annulate setae; propodus 0.5 carpus length, with annulate seta; dactylus 1.2 propodus length, medial margin serrate, with 2 simple setae terminally; exopod not fully developed ( Fig. 7D ).

Pereopod 4 basis 0.8 all other articles together, with 5 plumose setae; ischium 0.2 basis length, with 1 plumose and 3 annulate setae; merus 2.0 ischium length, with 1 plumose and 3 annulate setae; carpus 1.1 merus length, with 3 plumose and 2 annulate setae; propodus 0.5 carpus length, with annulate seta; dactylus 1.0 propodus length, medial margin serrate, with 2 simple setae terminally; exopod not fully developed ( Fig. 7E ).

Pereopod 5 broken.

Telson 1.3 length of pleonite 6, with 3 microserrate lateral setae, 5 subequal microserrate terminal setae ( Fig. 7F ).

Uropod peduncles 1.3 pleonite 6 length, 1.0 telson length, with 6 microserrate setae medially. Uropod endopod of 3 articles, 1.8 peduncle length; article 1 1.4 articles 2 and 3 together, with 10–11 microserrate setae medially, 1 seta with single subterminal setule laterally; article 2 with 2 microserrate setae medially, 1 seta with single subterminal setule laterally; article 3 1.0 article 2 length, with 1 microserrate seta medially, terminal seta simple? Uropod exopod 0.6 length of endopod; article 1 0.4 article 2 length, unarmed; article 2 with 2 plumose, 5 microserrate, and 4 simple with single subterminal setule setae laterally, microserrate terminal seta 0.9 exopod length ( Fig. 7F ).

Etymology. The new species is named paraleucon because the overall body form greatly resembles species of Leucon with long pseudorostral lobes, and with which the new species could easily be misidentified.

Depth. 346–1239 m.

Distribution. Challenger Plateau, Chatham Rise, New Zealand, 40.13– 44.49°S, 170.21°E– 178.48°W.

Remarks. Within the Cumacea , the long terminal article on the antennule main flagellum is unusual. Within the genus, all other species have the carapace expanded dorsolaterally, but Bathylamprops paraleucon has no such dorsolateral expansion, producing the Leucon -like impression

Figures

FIGURE 5. Bathylamprops paraleucon n. sp. Holotype ovigerous female NIWA 93174, A side view. Paratype ovigerous female NIWA 93170, B, side view; C, antennule; D, maxilliped 2; E, maxilliped 3; F, basis of pereopod 1; G, pereopod 2; H, pereopod 3; I, telson and uropods. Scale bars full body 1.0 mm, all others 0.1 mm.

FIGURE 6. Bathylamprops paraleucon n. sp. Paratype subadult male NIWA 93202, A, side view; B, dorsal view; C, antennule; D, antenna; E, mandible; F, maxillule; G, maxilla; H, maxilliped 1; I, maxilliped 2. Scale bars full body 1.0 mm, all others 0.1 mm.

FIGURE 7. Bathylamprops paraleucon n. sp. Paratype subadult male NIWA 93202, A, maxilliped 3; B, basis of pereopod 1; C, pereopod 2, broken; D, pereopod 3; E, pereopod 4; F, telson and uropods. Scale bars 0.1 mm.