Bathycuma dayae, Gerken, Sarah, 2013

Gerken, Sarah, 2013, New Zealand Bodotriidae (Crustacea: Cumacea), Zootaxa 3630 (1), pp. 1-38 : 10-17

Bathycuma dayae n. sp.

Figures 5–8

Type material. Holotype ovigerous female, NIWA 46003; Paratype ovigerous female, dissected, NIWA 80741; 42.7820°S, 176.7152°W – 42.7817°S, 176.7042°W, 1023–1026 m, 16 April 2007. Paratype adult male, dissected, NIWA 80742, 40.1277°S, 170.2140°E – 40.1352°S, 170.2090°E, 803–805 m, 5 June 2007.

Other material examined. 1 ovigerous female, 3 mancae, NIWA 45835, 36.9202°S, 167.5302°E – 36.9120°S, 167.5325°E, 1207–1213 m, 30 May 2007. 2 juveniles, NIWA 45830, 42.7820°S, 176.7152°W – 42.7817°S, 176.7042°W, 1023–1026 m, 16 April 2007. 1 juvenile, 4 mancae, NIWA 46003, 42.7820°S, 176.7152°W – 42.7817°S, 176.7042°W, 1023–1026 m, 16 April 2007. 2 juveniles, 1 manca, NIWA 84493, 44.4862°S, 177.1413°E – 44.4841°S, 177.1416°E, 1235–1239 m, 6 April 2007. 1 subadult male, 4 juveniles, 1 manca, NIWA 84492, 44.4862°S, 177.1413°E – 44.4841°S, 177.1416°E, 1235–1239 m, 6 April 2007. 1 subadult female, 5 juveniles, 3 mancae, NIWA 84496, 44.4862°S, 177.1413°E – 44.4841°S, 177.1416°E, 1235–1239 m, 6 April 2007. 1 ovigerous female, NIWA 84495, 43.9790°S, 179.6298°E – 43.9850°S, 179.6218°E, 529–530 m, 9 April 2007. 1 ovigerous female, 2 mancae, NIWA 84494, 40.1277°S, 170.2140°E – 40.1352°S, 170.2090°E, 803–805 m, 5 June 2007. 1 adult male, 3 juveniles, 2 mancae, NIWA 46002, 43.2903°S, 175.5522°W – 43.2933°S, 175.5630°W, 638–644, 15 April 2007. 1 juvenile, NIWA 84497, 43.2903°S, 175.5522°W – 43.2933°S, 175.5630°W, 638–644, 15 April 2007.

Diagnosis. Female. Carapace with teeth in two disorganized rows dorsally, concentrated anteriorly; antennal notch deep; anteroventral corner serrate; carapace longer than pereon; pleon longer than carapace and pereon together; pleonite 6 with dorsal teeth. Uropod peduncles shorter than pleonite 6; uropod endopod biarticulate, article 1 1.5 times length of article 2; uropod exopod shorter than endopod, both articles subequal in length. Male. Carapace with teeth dorsally only on frontal lobe; antennal notch oblique; anteroventral corner smooth; carapace longer than pereon; pleon longer than carapace and pereon together; pleonite 6 smooth. Antennule with brush of aesthetascs on first article of main flagellum. Antennal flagellum extending past uropod peduncles. Uropod peduncles slightly shorter than pleonite 6; endopod biarticulate, articles subequal; exopod with first article much shorter than second. Appendages much more setose than in female.

Description of the ovigerous female. Holotype ovigerous female, 10.2 mm, NIWA 46003. Paratype ovigerous female, 7.9 mm, NIWA 80741. Carapace with disorganized double row of teeth dorsally, with lateral sulcus anteriorly, antennal notch deep, anteroventral corner strongly serrate, with arched ridge posteriorly on carapace, below midline; pseudorostral lobes 0.4 times carapace length, anterior margin weakly serrate; eye lobe 0.07 times carapace length; carapace 1.05 times pereon; abdomen 1.3 times carapace and pereon together ( Figures 5 A–C).

Antennule peduncle article 1 longest, unarmed; article 2 0.5 times article 1 length, unarmed; article 3 equal to article 2 length, with simple seta; main flagellum of 3 articles, with 2 aesthetascs and 2 simple setae; accessory flagellum of 2 articles, with 3 simple setae ( Figure 5 D).

Mandible navicular, lacinia mobilis with 4 cusps ( Figure 5 E).

Maxillule with 2 endites; outer endite broad, with microserrate setae distally, lateral margin with fine hairlike setae and plumose seta; inner endite with 2 simple, 1 tricuspid and 1 microserrate setae; palp with 2 microserrate setae ( Figure 5 F).

Maxilla with 3 endites; broad endite with simple setae distally, several pappose setae around distal medial corner, row of setae medially; medial narrow endite with 5 microserrate setae terminally; distal narrow endite with 5 microserrate setae terminally; both narrow endites extending well past distal margin of broad endite ( Figure 5 G).

Maxilliped 1 basis 1.3 times length of all other articles together, produced as lobe medially, with 8 simple setae laterally, 2 hook and 1 stout setae distally; ischium absent; merus 0.2 times basis length, with 2 pappose setae; carpus 1.5 times merus length, with 6 simple and 6 beak setae medially, pappose seta laterally; propodus 0.6 times carpus length, with 2 simple and 1 pappose setae; dactylus 0.7 times propodus length, with 5 simple setae terminally ( Figure 5 H).

Maxilliped 2 basis 2.0 times length of all other articles together, with 9 plumose setae distally; ischium absent; merus 0.1 times basis length, with 2 plumose setae; carpus equal to merus length, with 3 plumose setae medially, plumose seta laterally; propodus 0.8 times carpus length, with 5 plumose setae; dactylus 0.8 times propodus length, with 5 simple setae terminally ( Figure 6 A).

Maxilliped 3 basis 2.2 times length of all other articles together, with 5 plumose setae on distal expansion, medial margin with strong teeth distally; ischium 0.08 times basis length, with plumose seta; merus 0.8 times ischium length, with 2 plumose setae; carpus 1.8 times merus length, with 3 plumose setae medially, plumose seta laterally; propodus 0.9 times carpus length, with 2 plumose and 2 simple setae; dactylus 0.8 times propodus length, with 5 simple setae terminally; exopod shorter than basis, flagellum with plumo–annulate setae ( Figure 6 B).

Pereopod 1 basis 0.7 times length of all other articles together, with 6 plumose and 4 simple setae; ischium 0.08 times basis length, unarmed; merus 2.6 times ischium length, with simple seta and several teeth distally; carpus 1.7 times merus length, with 4 simple setae; propodus 1.2 times carpus length, with 6 simple setae; dactylus 0.7 times propodus length, with 4 simple setae and 4 simple setae terminally; exopod shorter than basis, flagellum with plumo–annulate setae ( Figure 6 C).

Pereopod 2 basis 0.9 times length of all other articles together, with 1 plumose and 1 simple setae; ischium 0.02 times basis length, unarmed; merus 8.0 times ischium length, with 2 plumose and 2 microserrate with single subterminal setule setae; carpus 1.6 times merus length, with 3 plumose setae and 3 microserrate with single subterminal setule setae; propodus 0.4 times carpus length, unarmed; dactylus 3.4 times propodus length, with 7 microserrate with single subterminal setule setae and 3 microserrate with single subterminal setule setae terminally; exopod longer than basis, flagellum with plumo–annulate setae ( Figure 6 D).

Pereopod 3 basis 1.2 times length of all other articles together, with 1 plumose and 1 simple setae; ischium 0.09 times basis length, with annulate seta; merus 1.3 times ischium length, with 1 annulate and 1 simple setae; carpus 2.0 times merus length, with 1 simple and 4 annulate setae; propodus 0.4 times carpus length, with annulate seta; dactylus 0.8 times propodus length, with 3 simple setae terminally; exopod shorter than basis, flagellum with plumo–annulate setae ( Figure 6 E).

Pereopod 4 basis broken, with 2 simple, 1 plumose and 1 pedunculate setae; ischium with 2 annulate setae; merus 2.3 times ischium length, with annulate seta; carpus 2.0 times merus length, with 1 simple, 1 plumose and 6 annulate setae; propodus 0.3 times carpus length, with annulate seta; dactylus 0.8 times propodus length, with 3 simple setae terminally ( Figure 6 F).

Pereopod 5 basis 0.4 times length of all other articles together, with 1 simple, 1 plumose and 1 pedunculate setae; ischium 0.3 times basis length, with plumose seta; merus 2.3 times ischium length, with 1 plumose and 1 annulate setae; carpus 2.4 times merus length, with 1 simple, 1 plumose and 5 annulate setae; propodus 0.2 times carpus length, with annulate seta; dactylus 0.7 times propodus length, with 3 simple setae terminally ( Figure 6 G).

Uropod peduncles 0.9 times pleonite 6 length, with 4 simple and 7–8 setae with single subterminal setule medially. Uropod endopod biarticulate, 0.7 times peduncle length; article 1 with 11–12 microserrate with single subterminal setule setae medially, simple seta laterally; article 2 0.7 times article 1 length, with 7 microserrate with single subterminal setule setae medially, simple seta laterally, terminal seta microserrate with single subterminal setule. Uropod exopod of 2 articles, 0.9 times length of endopod; article 1 subequal to article 2 length, unarmed; article 2 with 10 simple setae, no terminal seta ( Figure 6 H).

Description of adult male. Paratype adult male, 11.8 mm, NIWA 80742. Carapace with disorganized dorsal teeth on frontal lobe; antennal notch oblique; anteroventral corner smooth; pseudorostral lobes 0.4 times carapace length; eye lobe 0.06 times carapace length; carapace 1.2 times pereon length ( Figure 7 A).

Antennule peduncle article 1 longest, unarmed; article 2 0.6 times article 1 length, with 4 pedunculate setae; article 3 equal to article 2 length, with simple seta; main flagellum of 3 articles, first article expanded with group of aesthetascs, with 2 aesthetascs terminally on flagellum; accessory flagellum of 2 articles, with 4 simple setae ( Figure 7 B).

Antenna peduncle of 5 articles; article 1 with pappose seta; article 2 with 2 pappose setae; article 3 with pappose setae; article 4 with ranks of thin setae; article 5 longest, with ranks of fine setae; antennal flagellum of short articles, extending past uropod peduncles ( Figure 7 C).

Maxilliped 3 basis 2.4 times length of all other articles together, margins lined with simple setae proximally, plumose setae laterally, medial margin produced as teeth distally, lateral corner expanded to distal margin of merus, with plumose setae and teeth; ischium 0.07 times basis length, with plumose seta; merus 0.9 times ischium length, with 2 plumose setae; carpus 2.0 times merus length, with 5 plumose setae medially, plumose seta laterally; propodus 0.7 times carpus length, with 2 plumose setae medially; dactylus equal to propodus length, with 4 simple setae terminally; exopod shorter than basis, flagellum with plumo–annulate setae ( Figure 7 D).

Pereopod 1 basis 0.7 times length of all other articles together, with 9 plumose setae laterally, 17 plumose setae medially, 15 microserrate with single subterminal setule setae medially; ischium 0.04 times basis length, unarmed; merus 4.3 times ischium length, unarmed; carpus 2.0 times merus length, with 2 simple setae; propodus 1.5 times carpus length, with 5 simple setae; dactylus 0.6 times propodus length, with 7 simple setae and 4 simple setae terminally; exopod shorter than basis, flagellum with plumo–annulate setae ( Figure 8 A).

Pereopod 2 basis shorter than all other articles together, with 14 plumose, 2 pedunculate and 5 simple setae; ischium 0.05 times basis length, with plumose setae; merus 6.0 times ischium length, with 4 plumose and 7 microserrate with single subterminal setule setae; carpus 0.8 times merus length, with 3 plumose and 6 microserrate with single subterminal setule setae; propodus 0.4 times carpus length, unarmed dactylus broken, with plumose and microserrate with single subterminal setule setae; exopod longer than basis, flagellum with plumo–annulate setae ( Figure 8 B).

Pereopod 3 basis 1.5 times length of all other articles together, with 10 plumose and 3 simple setae; ischium 0.1 times basis length, with 2 plumose setae; merus 1.3 times ischium length, with 7 annulate setae; carpus 2.4 times merus length, with 7 annulate and 3 simple setae; propodus 0.3 times carpus length, with annulate seta; dactylus equal to propodus length, with simple seta terminally; exopod longer than basis, flagellum with plumo–annulate setae ( Figure 8 C).

Pereopod 4 basis equal to all other articles together, with 2 plumose setae; ischium 0.1 times basis length, with 2 plumose setae; merus 2.0 times ischium length, with 4 annulate setae; carpus 1.5 times merus length, with 6 annulate setae; propodus 0.4 times carpus length, with annulate seta; dactylus 0.6 times propodus length, with 2 simple setae terminally; exopod longer than basis, flagellum with plumo–annulate setae ( Figure 8 D).

Pereopod 5 basis broken, with 5 plumose, 3 simple and 1 complex pedunculate setae; ischium with 2 annulate setae; merus 2.0 times ischium length, with 2 annulate setae; carpus 1.6 times merus length, with 8 annulate setae; propodus 0.3 times carpus length, with 1 simple and 1 annulate setae; dactylus 0.5 times propodus length, with 2 simple setae terminally ( Figure 8 E).

Pleopod 1 longest, exopod and endopod subequal, endopod biarticulate, without process, lined with plumose setae ( Figure 8 F).

Pleopod 5 shortest, exopod and endopod subequal, endopod biarticulate, without process, lined with fewer plumose setae than pleopod 1 ( Figure 8 G).

Uropod peduncles 1.3 times pleonite 6 length, with 20–22 microserrate setae medially. Uropod endopod biarticulate, 0.9 times peduncle length; article 1 subequal to article 2 length, with many microserrate with single subterminal setule setae medially and laterally; article 2 with many microserrate with single subterminal setule setae medially and laterally, terminal seta subequal to article 2 length, microserrate with single subterminal setule. Uropod exopod 0.9 times length of endopod; article 1 unarmed; article 2 2–3 times length of article 1, margins lined with long plumose setae, no distinct terminal seta ( Figure 8 H).

Etymology. The species is named for Jennifer Day, for all her work on the South African Cumacea .

Remarks. There are no other species of Bathycuma known from New Zealand or Australian waters. Unusually for species of Bathycuma , I had complete specimens of both adult males and ovigerous females. Therefore, it is useful to point out some differences in addition to the typical changes in setation between the males and females. The ovigerous female has teeth dorsally on pleonite 6, while pleonite 6 is smooth dorsally in the male. In the ovigerous female, the uropod peduncle is barely shorter than pleonite 6, while in the male the peduncles are distinctly longer than pleonite 6. The first article of the uropod endopod is longer than the second article, and the exopod articles are subequal in the ovigerous female, while in the male the uropod endopod articles are subequal and the first article of the exopod is much shorter than the second article. The uropod exopod proportions in the male appear to be a result of a lengthening of uropod exopod article 2, rather than a shortening of article 1, as the article 1 lengths are similar in both.

Figures

FIGURE 5. Bathycuma dayae n. sp. Holotype ovigerous female, NIWA 46003. A, side view; B, dorsal view. Paratype ovigerous female, NIWA 80741. C, side view; D, antennule; E, mandibles; F, maxillule; G, maxilla; H, maxilliped 1.

FIGURE 6. Bathycuma dayae n. sp. Paratype ovigerous female, NIWA 80741. A, maxilliped 2; B, maxilliped 3; C, pereopod 1; D, pereopod 2; E, pereopod 3; F, pereopod 4; G, pereopod 5; H, pleonite 6 and uropods.

FIGURE 7. Bathycuma dayae n. sp. Paratype adult male, NIWA 80742. A, side view; B, antennule; C, antenna; D, maxilliped 3.

FIGURE 8. Bathycuma dayae n. sp. Paratype adult male, NIWA 80742. A, pereopod 1; B, pereopod 2; C, pereopod 3; D, pereopod 4; E, pereopod 5; F, pleopod 1; G, pleopod 5; H, pleonite 6 and uropods.