Colurostylis castlepointensis, Gerken, Sarah & Lörz, Anne-Nina, 2007

Gerken, Sarah & Lörz, Anne-Nina, 2007, Colurostylis castlepointensis, a new shallow-water diastylid (Crustacea: Cumacea) from New Zealand, Zootaxa 1520, pp. 37-49 : 38-49

publication ID	https://doi.org/ 10.5281/zenodo.177401
DOI	https://doi.org/10.5281/zenodo.6246946
persistent identifier	https://treatment.plazi.org/id/782987C2-D056-FFB9-8FD8-FBA8FB26FDCF
treatment provided by	Plazi
scientific name	Colurostylis castlepointensis
status	sp. nov.

Treatment

Colurostylis castlepointensis View in CoL sp. nov.

Material examined

Holotype ovigerous female, 3.0 mm, NIWA 27867, Castle Point, North Island, New Zealand, 40º 54.120 S, 176º 13.732 E, 0–0.5 m, 11 June 2005.

Paratypes: (all same data as holotype), ovigerous female, 3.1 mm, dissected, NIWA 27868; adult male, broken, NIWA 27869; adult male, 4.0 mm, dissected, NIWA 27870; 1 ovigerous female, 26 subadult females, 11 subadult males, 6 juveniles, NIWA 27871.

Diagnosis

Antennal notch weak to absent, without prominent tooth at anterolateral corner, carapace without distinct ridges, uropods with peduncles longer than pleonites 5 and 6 together, but much less than pleonites 4–6 together, uropod exopod distinctly longer than endopod, uropod exopod with spatulate setae with terminal setule, lateral margin with several setae and 5 setae terminally, adult male telson entirely without setae.

Description

Holotype.

Ovigerous female. Carapace with very fine sculpturing, antennal notch weak or absent; pseudorostral lobes 0.55 carapace length; eye lobe 0.05 carapace length, without distinct lenses or pigmentation; carapace longer than thoracic segments together; pleon subequal to carapace and thorax together ( Figure 1 View FIGURE 1 A).

Paratype ovigerous female ( Figure 1 View FIGURE 1 B).

Antennule extending past pseudorostral lobes; peduncle article 1 longest, margin with fine hair-like setae and pappose seta; article 2 with complex pedunculate setae; article 3 equal to article 2 length, with complex pedunculate seta; main flagellum of 2 articles, nearly as broad as peduncle article 3, with 4 aesthetascs terminally; accessory flagellum minute, less than 0.5 length of first article of main flagellum, of 2 articles ( Figure 2 View FIGURE 2 A).

Antenna of 3 articles, each article with 1or 2 pappose setae ( Figure 2 View FIGURE 2 B).

Mandible navicular, with 10 setae ( Figure 2 View FIGURE 2 C).

Maxillule with 2 endites; lateral endite with double row of stout setae distally; mesial endite with 5 setae terminally; palp with 2 setae ( Figure 2 View FIGURE 2 D).

Maxilla with 3 endites; broad endite distal margin with many simple, microserrate and pappose setae, mesial margin with row of 14 setae; mesial narrow endite with 4 microserrate setae terminally; distal narrow endite with 5 terminal microserrate setae; both narrow endites extend beyond distal margin of broad endite ( Figure 2 View FIGURE 2 E).

Maxilliped 1 basis produced distally as blunt lobe, mesial margin with 2 hooks, 5 pappose and 1 stout setae; ischium absent; merus unarmed; carpus with 1 long plumose seta at distal corner, mesial face lined with simple and comb setae; propodus shorter than carpus, with 4 long plumose setae; dactylus as long as propodus, slender, with 2 terminal microserrate setae ( Figure 2 View FIGURE 2 F).

Maxilliped 2 basis shorter than all other articles together, with 4 plumose setae; ischium small, triangular; merus 0.6 carpus length, with 1 plumose and 1 pappose setae; carpus mesial face with many plumose setae, 1 plumose seta at distal corner; propodus with 2 plumose setae laterally, mesial face with brush of many simple setae; dactylus shorter than propodus, slender, with several simple setae distally and single stout terminal seta ( Figure 3 View FIGURE 3 A).

Maxilliped 3 basis longer than all other articles together, mesial margin with pappose setae, margins lined with fine hair-like setae, distal corner produced with 4 plumose setae; ischium small, unarmed; merus shorter than carpus, with 1 pappose seta; carpus with 4 pappose setae mesially and 1 plumose seta distally; propodus with brush of many simple setae, 1 plumose seta distally; dactylus subequal to propodus, slender, with several simple terminal setae; exopod shorter than basis, flagellum with plumo-annulate setae ( Figure 3 View FIGURE 3 B).

Pereopod 1 basis shorter than next 4 articles together, margin with many pappose setae, surface with many small teeth, distal corner with 1 plumose and 1 simple setae; ischium subequal to merus, unarmed; merus with 1 long and 2 small simple setae; carpus twice length of merus, with many simple setae; propodus 1.3 length of carpus, with many simple setae; dactylus subequal to carpus, with many simple setae and stout terminal seta; exopod shorter than basis, flagellum with plumo-annulate setae ( Figure 4 View FIGURE 4 A).

Pereopod 2 basis expanded, subequal to all other articles together, with several pappose setae; ischium small, with 1 pappose seta; merus equal to carpus, with 1 pappose seta; carpus unarmed; propodus shorter than dactylus, with 1 simple seta; dactylus with several simple setae terminally; exopod as long as basis, flagellum with plumo-annulate setae ( Figure 4 View FIGURE 4 B).

Pereopod 3 basis as long as next 3 articles together, with many plumose and pappose setae; ischium with 2 simple setae; merus longer than carpus, with 4 simple setae; carpus with 8 annulate setae; propodus 0.5 carpus length, with 1 annulate seta; dactylus equal to propodus, with 1 short stout simple seta; exopod rudimentary, of 2 articles, with 2 simple setae ( Figure 4 View FIGURE 4 C).

Pereopod 4 basis as long as next 4 articles together, with 8 plumose and 2 pappose setae; ischium with 6 annulate setae; merus unarmed; carpus with 6 annulate setae; propodus with 1 annulate seta; dactylus equal to propodus, with short stout terminal seta and 2 simple setae; exopod rudimentary, of 2 articles, with 2 simple setae ( Figure 4 View FIGURE 4 D).

Pereopod 5 basis subequal to next 4 articles together, with 4 pappose setae; ischium with 1 simple seta; merus with 5 simple setae; carpus with 8 annulate setae; propodus with 1 annulate seta; dactylus equal to propodus, with short stout terminal seta and 2 simple setae ( Figure 4 View FIGURE 4 E).

Telson 0.5 length of pleonite 6, triangular, unarmed ( Figure 5 View FIGURE 5 ).

Uropod peduncles 1.1 times length of pleonites 5-6, shorter than pleonites 4-6, 3.3 pleonite 6 length, with single seta at medial corner. Uropod endopod of 2 articles, 0.6 peduncle length; article 1 0.8 length of article 2, with 1 seta mesially; article 2 with 2 mesial setae, distal seta spatulate, terminal seta 0.2 endopod length, with single subterminal setule. Uropod exopod of 2 articles, 1.2 length of endopod, article 1 0.2 length of article 2, article 2 with 5 lateral setae and 5 terminal setae, longest terminal seta 0.5 exopod length, all setae are spatulate, broadened at tip with single terminal setule ( Figure 5 View FIGURE 5 ).

Paratype adult male NIWA 27870.

Adult male 4.0 mm. Carapace with very fine sculpturing, antennal notch absent; pseudorostral lobes 0.55 carapace length; eye lobe 0.05 carapace length, without distinct lenses; carapace longer than thoracic segments together ( Figure 6 View FIGURE 6 A).

Antennule extending past pseudorostral lobes; peduncle article 1 longest, margin with fine hair-like setae; article 2 unarmed; article 3 equal to article 2 length, with brush of many slender aesthetascs; main flagellum of 4 articles, with 2 aesthetascs and 2 simple setae terminally; accessory flagellum longer than first two articles of main flagellum, of 2 articles, with single terminal simple seta ( Figure 6 View FIGURE 6 B).

Antenna peduncle of 5 articles, article 2 with 2 setae, article 5 longest, with ranks of fine setae; flagellum of 22 articles, extending to end of pereon, with ranks of fine setae ( Figure 7 View FIGURE 7 A).

Maxilliped 3 basis longer than all other articles together, mesial margin with 9 pappose setae, lined with fine hair-like setae, distal corner produced with 4 plumose setae; ischium small, with 1 pappose seta; merus shorter than carpus, with 1 mesial pappose seta, 1 distal plumose seta, mesial margin serrate; carpus with 3 pappose setae medially and 1 plumose seta distally; propodus with brush of many simple setae, 1 plumose seta distally; dactylus subequal to propodus, slender, with 4 simple setae terminally; exopod shorter than basis, flagellum with plumo-annulate setae ( Figure 7 View FIGURE 7 B).

Pereopod 1 basis longer than next 4 articles together, margin with 14 pappose setae, distal corner with 2 pappose setae; ischium shorter than merus, with 1 pappose seta; merus with 1 long plumose seta; carpus 1.8 length of merus, with 4 simple setae; propodus 1.5 length of carpus, with 10 simple setae; dactylus shorter than propodus, with 11 simple setae and 2 terminal setae; exopod shorter than basis, flagellum with plumoannulate setae ( Figure 7 View FIGURE 7 C).

Paratype adult male (broken) NIWA 27869.

Pereopod 2 basis expanded, longer than all other articles together, with 12 pappose setae; ischium small, unarmed; merus equal to carpus, with 1 pappose seta; carpus unarmed; propodus shorter than dactylus, with 1 simple seta; dactylus with 10 simple setae; exopod longer than basis, flagellum with plumo-annulate setae ( Figure 8 View FIGURE 8 A).

Pereopod 3 basis longer than all other articles together, with 8 pappose setae; ischium with 5 annulate setae; merus longer than carpus, with 3 annulate setae; carpus with 6 annulate setae; propodus 0.5 carpus length, with 1 annulate seta; dactylus equal to propodus, with 1 short stout terminal seta and 2 simple setae; exopod longer than basis, flagellum with plumo-annulate setae ( Figure 8 View FIGURE 8 B).

Pereopod 4 basis longer than all other articles together, with 3 annulate and 3 pappose setae; ischium with 4 annulate setae; merus with 6 annulate setae; carpus with 12 annulate setae; propodus with single annulate seta; dactylus longer than propodus, with 1 short stout terminal seta and 2 simple setae; exopod longer than basis, flagellum with plumo-annulate setae ( Figure 9 View FIGURE 9 A).

Pereopod 5 basis longer than next 3 articles together, with 2 sparsely plumose setae and 2 pappose setae; ischium with 2 sparsely plumose setae; merus with 7 annulate setae; carpus with 9 annulate setae; propodus with 1 annulate seta; dactylus longer than propodus, with short stout terminal seta with subterminal setule ( Figure 9 View FIGURE 9 B).

Pleopod 1 peduncle with 7 plumose setae; rami 0.25 peduncle length, mesial ramus without projection, both rami with long stout plumose setae ( Figure 9 View FIGURE 9 C).

Pleopod 2 peduncle with 3 simple setae; rami 0.3 peduncle length, mesial ramus without projection, both rami with long stout plumose setae ( Figure 9 View FIGURE 9 D).

Telson 0.25 length of pleonite 6, triangular, unarmed ( Figure 9 View FIGURE 9 D).

Uropod peduncles 1.3 times length of pleonites 5–6, shorter than pleonites 4–6, 3.3 pleonite 6 length, unarmed. Uropod endopod of 2 articles, 0.5 peduncle length; article 1 0.8 length of article 2, with 8-9 microserrate setae medially; article 2 with 8 microserrate setae medially, terminal seta 0.2 endopod length, with single subterminal setule. Uropod exopod of 2 articles, 1.2 length of endopod, article 1 0.2 length of article 2 with 1 simple seta, article 2 with 4 mesial and 5 terminal setae, longest terminal seta 0.3 exopod length, all setae are spatulate, broadened at tip with single terminal setule ( Figure 10 View FIGURE 10 ).

Etymology

The species is named castlepointensis after the type locality, Castle Point, North Island, New Zealand.

Remarks

Colurostylis castlepointensis can clearly be differentiated from C. lemurum , as the latter has two oblique lateral ridges on the carapace and the uropod exopod is shorter than the endopod, while the former has a smooth carapace and the uropod exopod is longer than the endopod. Colurostylis castlepointensis can also easily be differentiated from C. pseudocuma by the uropods; in C. pseudocuma the uropod rami are subequal in length, while in C. castlepointensis the uropod exopod is longer than the endopod. Colurostylis castlepointensis can also easily be differentiated from C. longicauda by the anterolateral angle and the length of the uropod peduncles; in C. longicauda , the anterolateral angle is toothed and the uropod peduncles are longer than pleonites 4–6 together, while in Colurostylis castlepointensis the anterolateral angle is smooth and the uropod peduncles are longer than pleonites 5 and 6 but shorter than pleonites 4 to 6 together.