Aotearocumella echinoseta, Gerken, 2012

Gerken, Sarah, 2012, 3524, Zootaxa 3524, pp. 1-124 : 9-13

Aotearocumella echinoseta n. sp.

Figures 4–5

Type material. Holotype ovigerous female, NIWA 80704 , 44.4862°S, 177.1413°E – 44.4841°S, 177.1416°E, 1235–1239 m, 6 April 2007 . Paratype ovigerous female, NIWA 80705 , 43.7967°S, 175.3158°E – 43.8045°S, 175.3148°E, 418–422 m, 27 April 2007 .

Other material examined. 2 ovigerous females, 1 subadult female, NIWA 79356 , 44.4862°S, 177.1413°E – 44.4841°S, 177.1416°E, 1235–1239 m, 6 April 2007 . 3 ovigerous females, NIWA 79357 , 44.4862°S, 177.1413°E – 44.4841°S, 177.1416°E, 1235–1239 m, 6 April 2007 . 3 ovigerous females, NIWA 79358 , 43.9790°S, 179.6298°E – 43.9850°S, 179.6218°E, 529–530 m, 9 April 2007 . 4 subadult females, 2 subadult males, 1 juvenile, NIWA 46005 , 44.5607°S, 178.4762°W – 44.5592°S, 178.4830°W, 1076–1103 m, 10 April 2007 . 2 subadult females, NIWA 46006 , 43.2903°S, 175.5522°W – 43.2933°S, 175.5630°W, 638–644, 15 April 2007 . 1 subadult female, NIWA 79359 , 40.1277°S, 170.2140°E – 40.1352°S, 170.2090°E, 803–805 m, 5 June 2007 . 8 ovigerous females, NIWA 79360 , 40.8800°S, 170.8555°E – 40.8883°S, 170.8565°E, 529–534 m, 6 June 2007 .

Diagnosis. Females and subadult males. Carapace with many long setae and single large spine middorsally anteriorly; eyelobe short; pseudorostral lobes not dorsally directed. Uropod peduncles 0.9 times pleonite 6 length. Male. Adult unknown.

Description of female.

Holotype ovigerous female, 2.6 mm, NIWA 80704. Paratype ovigerous female, 2.5 mm, NIWA 80705. Carapace with many long setae, single large spine middorsally anteriorly, ventral margin produced as teeth, increasing in size anteriorly; pseudorostral lobes 0.3 times carapace length, weakly dorsally directed, ventral margin serrate; eyelobe 0.04 times carapace length. Pereonites 3–5 with spines, pereonite 2 with strong dorsal spine. Pleonites 1–4 with small spines ( Figures 4A–B).

Antennule peduncle article 1 very short, with plumose seta; article 2 1.9 times article 1 length, with 2 simple setae; article 3 0.9 times article 2 length, with 2 simple setae; main flagellum of 3 articles, with 2 aesthetascs; accessory flagellum of 2 articles, with 2 simple and 2 pedunculate setae ( Figure 4C).

Mandible navicular, 5–7 microserrate setae medially, lacinia mobilis with 3 cusps ( Figure 4D).

Maxillule with 2 endites; outer endite with row of simple setae terminally, margin with simple seta, margin lined with fine hair-like setae; inner endite with 2 simple, 1 pappose and 1 tricuspid setae, margin lined with fine hair-like setae; palp with 2 microserrate setae ( Figure 4E).

Maxilla with 3 endites; broad endite distal margin with row of simple setae and 2 plumose setae, medial corner with pappose seta, medial row of setae; medial narrow endite with 4 simple setae terminally; distal narrow endite with 5 simple setae terminally; both narrow endites extending only to distal margin of broad endite ( Figure 4F).

Maxilliped 1 basis produced as lobe, with 4 simple, 2 hook and 2 dentate setae; ischium absent; merus 0.2 times basis length, unarmed; carpus 3.0 times merus length, with 8 simple and 5 comb-like setae; propodus 0.5 times carpus length, with 4 simple and 1 plumose setae; dactylus 0.6 times propodus length, with 3 simple setae ( Figure 4G).

Maxilliped 2 basis 0.8 times length of all other articles together, with pappose seta; ischium compressed; merus with pappose seta; carpus 1.3 times merus length, with 2 plumose setae; propodus 0.6 times carpus length, with 2 simple and 3 plumose setae; dactylus 0.4 times propodus length, with 4 simple setae ( Figure 4H).

Pereopod 1 basis with 3 simple setae; ischium unarmed; merus 1.1 times ischium length, unarmed; carpus 2.0 times merus length, with 2 simple setae; propodus equal to carpus length, with 4 simple setae; dactylus 0.5 times propodus length, with 5 simple setae terminally ( Figure 5A).

Pereopod 2 basis 1.3 times length of all other articles together, with 6 simple setae; ischium 0.05 times basis length, with simple seta; merus 2.0 times ischium length, with 2 simple setae; carpus 2.5 times merus length, with 2 simple setae; propodus 0.5 times carpus length, with simple seta; dactylus 1.7 times propodus length, with 3 simple setae, 5 simple setae terminally ( Figure 5B).

Pereopod 3 basis 1.2 times length of all other articles together, with 4 simple setae; ischium 0.1 times basis length, with simple seta; merus 1.4 times ischium length, with simple seta; carpus 1.7 times merus length, with 1 simple and 1 annulate setae; propodus 0.4 times carpus length, with annulate seta; dactylus 0.6 times propodus length, with 2 simple setae terminally ( Figure 5C).

Pereopod 4 basis 0.7 times length of all other articles together, with 2 simple setae; ischium 0.2 times basis length, with simple seta; merus 1.7 times ischium length, unarmed; carpus 1.8 times merus length, with 2 simple and 1 annulate setae; propodus 0.4 times carpus length, with annulate seta; dactylus 0.5 times propodus length, with 3 simple setae terminally ( Figure 5D).

Pereopod 5 basis 0.6 times length of all other articles together, with 2 simple setae; ischium 0.2 times basis length, with simple seta; merus 1.3 times ischium length, with 2 simple setae; carpus 2.0 times merus length, with 2 simple and 1 annulate setae; propodus 0.3 times carpus length, with 1 simple and 1 annulate setae; dactylus 0.6 times propodus length, with 3 simple setae terminally ( Figure 5E).

Uropod peduncles 0.9 times pleonite 6 length, with 2 stout and 3–4 slender simple setae. Uropod endopod uniarticulate, 0.9 times peduncle length, with 4 stout and 0–1 slender simple setae, terminal seta broken. Uropod exopod of 2 articles, 0.7 times length of endopod; article 1 0.1 times article 2 length, with 0–1 simple setae; article 2 with 0–1 simple setae, terminal seta simple ( Figure 5F).

Etymology. The species is named echino from the Greek, in combination with seta, in reference to the combination of spines and setae present on the carapace, pereon and pleon.

Remarks. The New Zealand species most similar to Aotearocumella echinoseta is A. watlingi , which shares the long setae on the body and the lack of exopods in the female. However, in A. echinoseta there is a single large spine dorsally on the carapace, and A. watlingi has no spines on the carapace. In addition, in A. echinoseta the first peduncle article of the antennule is short, while in A. watlingi the first peduncle article of the antennule is the longest peduncle article. The other species of Aotereaocumella, A. acantha , has no setae on the carapace, pereon, or pleon, unlike A. echinoseta .