Paraplatysympus echinolowryi, Gerken, 2018

Gerken, Sarah, 2018, The Lampropidae (Crustacea: Cumacea) of the World, Zootaxa 4428 (1), pp. 1-192 : 108-113

Paraplatysympus echinolowryi n. sp.

( Figs 39–41 )

Type material. Holotype: ovigerous female, NMV J62280 , 38 °26’49”– 38°29’20”S, 149°19’59”– 149°20’47”E, 1750–1840 m . Paratypes: ovigerous female, dissected, NMV J62281 , collected with holotype; adult male, dissected, NMV J62282 , 34 °55’47”– 34°56’4”S, 151°7’52”– 151°8’4”E, 429–466 m.

Diagnosis. Female exopods on pereopods 3 and 4 rudimentary, but not minute. Telson 3.3 length of pleonite 6, shorter than uropod peduncles, with 9 pairs lateral setae, with 3 equal terminal setae. Adult male carapace with same pattern of ridges, but less dentate than in female. Telson 2.9 length of pleonite 6, shorter than uropod peduncles, with 3 pairs lateral setae, with 3 terminal setae, central seta longest.

Description. Holotype ovigerous female, NMV J62280 .

Ovigerous female, 6.5 mm. Carapace dorsoventrally flattened, posterior dorsolateral expansion, dorsally serrate ridge on posterior 0.7 of carapace, short serrate posterior ridge ventral to dorsal ridge, serrate ridge starting at anterior margin, proceeding to posterior margin, marginal carina serrate, anterior dorsal crest with teeth; pseudorostral lobes 0.3 carapace length, with row of spines dorsally, parallel to suture; eyelobe 0.05 carapace length, no lenses; carapace 2.0 length of pereonites together ( Fig. 39A, B ).

Paratype ovigerous female, NMV J62281

Ovigerous female, 6.0 mm.

Antennule peduncle article 1 1.2 articles 2 and 3 together, unarmed; article 2 0.4 article 1 length, with 7 plumose and 2 simple setae; article 3 equal to article 2, with 6 plumose and 2 simple setae; main flagellum of 5 articles, 1.1 article 1 length, with simple setae and 2 aesthetascs terminally; accessory flagellum of 4 articles, 1.1 main flagellum length, with simple setae ( Fig. 39C ).

Antenna of 4 articles; articles 1 and 2 unarmed; article 3 with 1 pappose seta; article 4 1.2 article 3 length, with 1 seta with single subterminal setule terminally ( Fig. 39D ).

Mandible navicular, with row of 13–14 microserrate setae medially, lacinia mobilis with 3 cusps ( Fig. 39E ).

Maxillule with 2 endites; outer endite with 12 simple setae; inner endite with 2 simple, 1 pappose and 2 dentate setae; palp with 2 setae ( Fig. 39F ).

Maxilla with 3 endites; broad endite distal margin with simple and pappose setae; medial narrow endite with 4 microserrate setae terminally; distal narrow endite with 4 microserrate setae terminally; both narrow endites extend past distal margin of broad endite ( Fig. 39G ).

Maxilliped 1 basis produced distally as broad lobe, broad lobe margin with row of papose setae, distal margin with simple and dentate setae; ischium absent; merus with 1 pappose seta laterally; carpus 1.9 merus length, medial face with simple and comb setae, 1 pappose seta laterally; propodus 0.6 carpus length, with pappose and simple setae; dactylus 0.5 propodus length, with 3 simple setae terminally ( Fig. 39H ).

Maxilliped 2 basis with 5 setae distally; ischium with 1 pappose seta; merus 6.5 ischium length, with pappose setae; carpus 1.5 merus length, with pappose setae; propodus 0.6 carpus length, with pappose setae; dactylus 0.6 propodus length, with simple seta terminally ( Fig. 39I ).

Maxilliped 3 basis longer than all other articles together, with pappose setae distally not expanded; ischium 0.8 basis length, unarmed; merus 1.2 ischium length, with 1 pappose seta medially, 2 pappose setae laterally, 1 tooth laterally; carpus 3.3 merus length, with 10 plumose setae medially, 1 pappose seta laterally; propodus 0.6 carpus length, with simple and plumose setae medially, 4 plumose setae laterally; dactylus 0.6 propodus length, with 4 simple setae terminally; exopod longer than basis, basal article with 3 pappose setae, flagellum with plumoannulate setae ( Fig. 40A ).

Pereopod 1 basis longer than next 4 articles together, medial margin serrate, with plumose setae marginally; ischium 0.04 basis length, with unarmed; merus 5.5 ischium length, with 3 plumose setae; carpus 0.6 merus length, with 1 simple and 2 plumose setae; propodus 0.9 carpus length, with 2 simple setae; dactylus broken; exopod longer than basis, basal article with 7 plumose setae, flagellum with plumo-annulate setae ( Fig. 40B ).

Pereopod 2 basis as long as next 4 articles together, with 2 simple and 2 plumose setae; ischium 0.04 basis length, unarmed; merus 5.0 ischium length, with 2 simple setae and 1 microserrate seta with single subterminal setule; carpus 3.3 merus length, with 1 simple and 9 microserrate setae with single subterminal setule; propodus 0.2 carpus length, with 2 simple setae; dactylus 2.9 propodus length, with 7 simple setae and 1 simple seta terminally; exopod rudimentary, 0.4 basis length, of 2 articles, with plumose and simple setae ( Fig. 40C ).

Pereopod 3 basis 2.2 all other articles together, with 1 simple and 6 plumose setae; ischium 0.05 basis length, with 1 simple seta; merus 3.7 ischium length, unarmed; carpus 0.6 merus length, with 2 simple and 2 annulate setae; propodus 0.7 carpus length, with 1 annulate seta; dactylus 0.8 propodus length, with 2 simple setae terminally; exopod rudimentary, 0.2 basis length, of 2 articles with simple and plumose setae ( Fig. 40D ).

Pereopod 4 basis 1.8 all other articles together, with 6 plumose setae; ischium 0.06 basis length, with 1 plumose seta; merus 3.0 ischium length, with 1 simple seta; carpus 0.8 merus length, with 2 annulate setae; propodus 0.7 carpus length, with 1 annulate seta; dactylus 0.6 propodus length, with 2 simple setae terminally; exopod rudimentary, 0.25 basis length, of 2 articles with simple setae ( Fig. 40E ).

Pereopod 5 basis 1.2 all other articles together, with 5 simple setae; ischium 0.9 basis length, with 1 simple seta; merus 2.5 ischium length, with 1 simple seta; carpus 1.6 merus length, with 1 simple and 2 annulate setae; propodus 0.4 carpus length, with 1 annulate seta; dactylus 0.7 propodus length, with 2 simple setae terminally ( Fig. 40F ).

Telson 3.3 length of pleonite 6, with 6 lateral setae with single subterminal setule, 3 simple terminal setae, longer than lateral setae ( Fig. 40G ).

Uropod peduncles 3.6 pleonite 6 length, 1.1 telson length, with 10 setae with single subterminal setule medially. Uropod endopod of 3 articles, equal to peduncle length; article 1 1.5 articles 2 and 3 together, with 10 setae with single subterminal setule medially; article 2 0.3 article 1 length, with 3 setae with single subterminal setule medially, 2 pedunculate setae laterally; article 3 equal to article 2, with 2 with single subterminal setule medially, 1–2 simple setae laterally, simple terminal seta 1.5 article 3 length. Uropod exopod 0.8 length of endopod; article 1 0.2 length of article 2, with 1–2 simple setae laterally; article 2 with 8–10 simple setae medially, 9–14 simple setae laterally, simple terminal seta 0.6 article 2 length ( Fig. 40G ).

Adult male, NMV J62282 , broken.

Pereopod 2 basis longer than next 4 articles together, with 4 simle, 1 plumose and 3 pappose setae; ischium 0.07 basis length, with 1 simple and 2 plumose setae; merus 2.0 ischium length, with 1 simple, 2 plumose and 1 microserrate setae with single subterminal setule; carpus 3.1 merus length, with 8 microserrate setae with single subterminal setule; propodus 0.2 carpus length, with 2 microserrate setae with single subterminal setule; dactylus broken, with microserrate setae with single subterminal setule; exopod shorter than basis, basal article with 2 pappose setae, flagellum with plumo-annulate setae ( Fig. 41A ).

Pereopod 3 basis 2.0 all other articles together, with 4 simple setae; ischium 0.05 basis length, with 1 simple seta; merus 4.0 ischium length, with 1 simple seta; carpus 0.75 merus length, with 2 annulate setae; propodus 0.6 carpus length, with 1 annulate seta; dactylus 0.6 propodus length, with 1 simple seta terminally; exopod shorter than basis, flagellum with plumo-annulate setae ( Fig. 41B ).

Pereopod 4 basis 1.8 all other articles together, with 1 plumose seta; ischium 0.04 basis length, with 1 simple seta; merus 4.5 ischium length, with 1 simple seta; carpus 0.8 merus length, with 1 simple and 2 annulate setae; propodus 0.7 carpus length, with 1 annulate seta; dactylus 0.6 propodus length, with 2 simple setae terminally; exopod shorter than basis, flagellum with plumo-annulate setae ( Fig. 41C ).

Pereopod 5 basis as long as all other articles together, with 3 simple and 1 plumose setae; ischium 0.2 basis length, with 1 simple seta; merus 2.5 ischium length, with 1 simple seta; carpus 1.6 merus length, with 2 simple and 2 annulate setae; propodus 0.4 carpus length, with 1 annulate seta; dactylus 0.7 propodus length, with 1 simple seta terminally ( Fig. 41D ).

Pleopod 1 biramous, basal article with 2 plumose setae; medial ramus with projection, both rami with long plumo-annulate setae ( Fig. 41E ).

Pleopod 2 biramous, basal article with 2 plumose setae; medial ramus with projection, both rami with long plumo-annulate setae ( Fig. 41F ).

Pleopod 3 biramous, basal article with 3 plumose setae; medial ramus with projection, both rami with long plumo-annulate setae ( Fig. 41G ).

Telson 2.8 length of pleonite 6, with 3 microserrate setae with single subterminal setule laterally, 3 microserrate setae with single subterminal setule terminally, central seta 2.0 length of other 2 setae ( Fig. 41H ).

Uropod peduncles 3.5 pleonite 6 length, 1.2 telson length, with 16 microserrate setae with single subterminal setule medially. Uropod endopod of 3 articles, broken; article 1 with 9–10 microserrate setae with single subterminal setule medially, 1 pedunculate and 4 simple setae laterally; article 2 0.5 article 1 length, with 3 microserrate setae with single subterminal setule medially, 2 simple setae laterally; article 3 broken. Uropod exopod article 1 0.3 length of article 2; article 2 with 8 setae with single subterminal setule medially, 6 setae with single subterminal setule laterally, terminal seta broken ( Fig. 41H ).

Etymology. The species is named echinolowryi , because the pattern of carapace ridges is very similar to Platytyphlops lowryi , but the ridges in the new species are spiny rather than entire.

Depth. 429–1840 m.

Distribution. Southeastern Australia, 34– 38°S, 149– 151°E.

Remarks. While the adult male specimen is incomplete, it is clear that sexual dimorphism is present, with a pattern of ridges identical to the female but less dentate. Paraplatysympus echinolowryi can easily be distinguished from P. aspericristatus by the rudimentary exopods on pereopods 3 and 4 in the female being relatively well developed, vs. minute in P. aspericristatus . In addition, in P. echinolowryi the telson is shorter than the uropod peduncles, while in P. aspericristatus the telson is equal to the length of the uropod peduncles.

Figures

FIGURE 39. Paraplatysympus echinolowryi n. sp. Holotype ovigerous female NMV J62280 A, side view; B, dorsal view. Paratype ovigerous female NMV J62281, C, antennule; D, antenna; E, mandibles; F, maxillule; G, maxilla; H, maxilliped 1; I, maxilliped 2. Scale bars full body 1.0 mm, all others 0.1 mm.

FIGURE 40. Paraplatysympus echinolowryi n. sp. Paratype ovigerous female NMV J62281, A, maxilliped 3; B, pereopod 1; C, pereopod 2; D, pereopod 3; E, pereopod 4; F, pereopod 5; G, telson and uropods. Scale bars 0.1 mm.

FIGURE 41. Paraplatysympus echinolowryi n. sp. Paratype adult male NMV J62282, A, pereopod 2; B, pereopod 3; C, pereopod 4; D, pereopod 5; E, pleopod 1; F, pleopod 2; G, pleopod 3; H, telson and uropods. Scale bars 0.1 mm.