Epikopais poorei, Merrin, 2009

Merrin, Kelly L., 2009, Epikopais gen. nov. (Isopoda: Asellota: Munnopsidae), a new genus of munnopsid isopod with three new species from the south-western Pacific., Memoirs of Museum Victoria 66 (1), pp. 129-145 : 130-136

Epikopais poorei sp. nov.

Figures 1–5

Material examined. All off south-eastern Australia. Holotype. Ovigerous female (2.4 mm), 44 km E of Nowra , NSW, stn SLOPE 56 , 34 ° 55.79–56.06'S, 151°08.06–07.86'E, 22 October 1988, WHOI epibenthic sled, 429–466 m, RV Franklin, muddy coarse shell ( NMV J18844 ) . Paratypes. 22 females, 21 males (1 male, 2.0 mm, dissected) 2 fragments, type locality ( NMV J54112 ), 2 females (2.3 mm, dissected, 2.0 mm partially dissected), south of Point Hicks , Victoria, stn SLOPE 33 , 38°19.60'S, 149°24.30'E , 23 July 1986, 930 m, WHOI epibenthic sled, RV Franklin ( NMV J18845 ) .

Additional material. 8 females, 7 males, 5 fragments, south of Point Hicks , Victoria, stn SLOPE 40 , 38°17.70'S, 149°11.30'E, 24 July 1986, WHOI epibenthic sled, 400 m, RV Franklin , coarse sand, gravel, mud ( NMV J18843 ) .

Description. Female. Body length 2.1 times width of pereonite 2; cuticle not highly calcified, setose. Cephalon spines absent; anterior cephalic flanges small. Pereonites 1–4 anterior margins with few SS. Pereonite 5 anterior margin smooth; anterolateral margins of pereonites 4, 6 and 7 with small lobes; pereonite 6 ventrally with no ornamentation; pereonite 7 ventrally with pair of setae. Pleon length 0.9 times proximal width, with scattered SS.

Female antenna 1 of 9 articles; article 1 length 1.8 times width, mesial margin with 1 sensillate RS and 4 SS, surface with 4 SS, 2 penicillate setae and 1 sensillate RS, lateral margin with 7 SS, distal margin with 5 SS and 1 penicillate seta; article 2 length 0.6 times article 1, with 4 sensillate RS and 1 penicillate seta, distal extension with 2 penicillate setae; article 3 with 1 SS; article 4 with 2 penicillate setae; article 5 with 1 SS; terminal article with 1 penicillate seta and 2 SS.

Mandible spine row absent, molar distally with 4 serrate setae; socket-like structure with 1 SS at approximate place of mandibular palp. Maxilla 1 lateral and mesial margins with fine SS; lateral lobe width 1.5 times mesial lobe width, distal margin with few fine SS, 3 RS, 3 dentate RS and 6 pectinate RS, mesial lobe distally with many fine SS and 2 long pectinate setae. Maxilla 2 lateral lobe margins with fine SS; middle lobe width 1.2 times lateral lobe width; mesial lobe width 2.2 times lateral lobe width, margins with fine SS, proximally mesial margin also with 8 elongate setae (unable to tell what type), distally with 3 blunt SS, 4 toothed setae, 1 long pectinate seta and few fine SS. Maxilliped coxa length 0.9 times width, and 3.2 times basis length; basis length 3.7 times width, with 5 SS, distolateral margin with 1 SS; endite with 4 coupling hooks, 2 toothed setae, 4 fan setae and few fine SS; palp article 1 distolateral margin with 1 SS, distomesial margin with 1 SS; article 2 length 3.2 times article 1 length, lateral margin with cuticular scales and 4 SS, surface with 6 SS, mesial margin with 2 distally pappose setae and 2 SS; article 3 length 1.6 times article 1 length, lateral margin with 1 SS, mesial margin with 4 SS and 11 distally pappose setae; article 4 length 0.7 times article 1 length, mesial margin with 4 distally pappose setae; article 5 length 0.6 times article 1 length, lateral margin with 1 SS, distally with 2 SS and 2 distally pappose setae; epipod length 2.0 times width, margins with cuticular scales and surface with scattered SS.

Pereopod 1 basis length 4.9 times width, lateral surface with 18 SS, superior margin with 16 SS; ischium length 3.2 times width, inferior margin with 4 SS, lateral surface with 7 SS, superior margin with 4 SS and 1 RS; merus length 0.9 times width, inferior margin with 3 SS and 5 RS, lateral surface with 1 SS, distosuperior margin with 2 SS; carpus length 2.1 times width, inferior margin with 5 SS, superior margin with 4 SS; propodus length 5.4 times width, inferior margin with 6 SS, lateral surface with 3 SS, superior margin with 4 SS; dactylus length 3.4 times proximal width, distosuperior margin with 3 small SS.

Pereopod 2 broken; ischium damaged, inferior margin with 18 sensillate RS, lateral surface with 5 sensillate RS and 36 SS; merus length 1.7 times width, inferior margin with 10 sensillate RS, lateral surface with 4 SS and 6 sensillate RS, superior margin with 2 sensillate RS, distosuperior margin with 2 sensillate RS and 1 SS; carpus length 5.1 times width, inferior margin with 17 sensillate RS, lateral surface with 10 sensillate RS and 4 SS, superior margin with 19 sensillate RS and 1 penicillate seta; propodus length 8.0 times width, inferior margin with 8 sensillate RS, lateral surface with 3 sensillate RS and 2 SS, distal margin with 7 SS, superior margin with 1 penicillate seta, 8 sensillate RS and 7 SS; dactylus length 4.5 times proximal width, superior margin with 6 SS, inferior margin with 2 SS and 3 sensillate RS.

Pereopod 3 basis length 1.2 times width, inferior margin with 2 sensillate RS and 7 SS, lateral surface with 15 SS, superior margin with 5 penicillate setae and 5 SS; ischium length 5.2 times width, inferior margin with 8 sensillate RS and 3 SS, lateral surface with 55 sensillate RS, superior margin with 14 sensillate RS; merus length 2.6 times width, inferior margin with 6 sensillate RS, lateral surface with 5 sensillate RS, distosuperior margin with 3 sensillate RS; carpus length 9.9 times width, inferior margin with 12 sensillate RS, lateral surface with 11 SS, 1 penicillate seta and 6 sensillate RS, superior margin with 11 sensillate RS; propodus damaged; dactylus absent.

Pereopod 4 basis length 1.2 times width, inferior margin with 5 sensillate RS and 2 SS, lateral surface with 6 SS, superior margin with 3 sensillate RS and 6 SS, distally with 5 penicillate setae; ischium length 4.7 times width, inferior margin with 1 SS and 8 sensillate RS, lateral surface with 4 sensillate RS, superior margin with 9 sensillate RS, distally with 11 sensillate RS; merus length 3.8 times width, inferior margin with 6 sensillate RS, lateral surface with 2 sensillate RS, superior margin with 7 sensillate RS; carpus length 10.6 times width, inferior margin with 17 sensillate RS and 1 SS, lateral surface with 1 SS and 13 sensillate RS, superior margin with 1 penicillate seta, 14 SS and 18 sensillate RS; propodus length 12.4 times width, inferior margin with 14 sensillate RS, lateral surface with 5 SS and 6 sensillate RS, superior margin with 9 SS, 1 penicillate seta and 10 sensillate RS; dactylus length 5.4 times proximal width, inferior margin with 3 sensillate RS and 4 SS, superior margin with 6 SS.

Pereopod 5 basis length 3.4 times width, inferior margin with 11 SS, lateral surface with 9 sensillate RS and 27 SS, superior margin with 5 penicillate setae and 2 SS; ischium length 2.2 times width, inferior margin with 7 sensillate RS and 9 SS, lateral surface with 14 SS; merus length 1.2 times width, inferior margin with 7 SS, distosuperior margin with 1 short plumose setae; carpus 2.4 times as long as wide, distosuperior margin with 1 SS; propodus length 2.4 times width, lateral surface with 12 SS, superior margin with 1 sensillate RS and 1 penicillate seta; dactylus length 3.1 times proximal width, with 4 SS.

Pereopod 6 basis length 4.9 times width, inferior margin with 8 SS and 4 plumose setae, lateral surface with 4 plumose setae and 25 SS, superior margin with 1 SS and row of plumose setae; ischium length 1.9 times width, inferior margin with 8 sensillate RS and 4 SS, lateral surface with 12 SS and 3 sensillate RS; merus length 1.3 times width, inferior margin with 7 SS, lateral surface with 1 SS; carpus length 1.2 times width, distosuperior margin with 1 sensillate RS; propodus length 3.1 times width, distoinferior margin with 2 SS, lateral surface with 7 SS, distosuperior margin with 1 SS and 1 penicillate seta; dactylus length 3.4 times proximal width, inferior margin with 1 SS, lateral surface with 1 SS and superior margin with 2 SS.

Pereopod 7 basis length 6.3 times width, inferior margin with 8 SS, lateral surface with 6 SS, superior margin with 8 SS; ischium length 2.2 times width, inferior margin with 6 SS; merus length 1.1 times width, inferior margin with 3 SS, distosuperior margin with 1 SS and 1 short plumose seta; carpus length 2.3 times width, distosuperior margin with 1 SS; propodus length 5.2 times width, distoinferior margin with SS, lateral surface with 4 short SS, distosuperior margin with 4 SS; dactylus length 3.4 times proximal width, with 4 SS.

Operculum length 2.8 times proximal width, distally with medial excision and veined lamellar extension, medial keel with row of RS and SS, surface with scattered SS, margins anterolaterally with 4 SS, laterally with numerous plumose setae. Pleopod 3 endopod length 1.5 times width, with 6 long plumose setae; exopod with 4 long plumose setae and 1 SS. Pleopod 4 endopod length 1.4 times width. Pleopod 5 length 1.8 times width.

Uropod protopod length 1.7 times width, lateral margin with 6 SS and 12 plumose setae, distal margin with 4 SS and 3 plumose setae, surface with 13 scattered SS; exopod length 0.2 times protopod length, with 2 SS; endopod length 0.3 times protopod length, with 2 penicillate setae and 3 SS.

Male. Antenna 1 of 28 articles; article 1 length 1.4 times width, lateral margin with 1 SS, surface with 1 penicillate seta, distomesial corner with 3 sensillate RS and 1 penicillate seta; article 2 length 0.6 times that of article 1, distal margin with 3 sensillate RS, distal extension with 3 penicillate setae; article 3 with 1 SS; article 4 with 2 penicillate setae; terminal article with 2 SS and 1 penicillate seta. Antenna 2 article 1 missing, article 2 damaged, with 2 SS; article 3 with 3 sensillate RS, scale with 3 RS; article 4 with no ornamentation; article 5 longer than articles 1–4, mesial margin with 12 sensillate RS, surface with 9 RS, lateral margin with 13 sensillate RS and 1 penicillate seta, distal margin with 1 sensillate RS; article 6 longer than article 5, mesial margin with 11 sensillate RS, surface with 38 sensillate RS, lateral margin with 15 sensillate RS; flagellum of 31 articles, each setose.

Pleopod 1 length 4.2 times proximal width, ventral surface with 37 SS and 8 sensillate RS, distal lobes with 8 SS. Male pleopod 2 protopod length 2.1 times width, lateral margin with 2 SS and row of plumose setae, surface with 6 SS, distally with lamellar extension; exopod elongate and hooked, length 0.1 times protopod length; stylet short, length 0.4 times protopod length, terminating to a point; sperm duct length 0.3 times stylet length.

Remarks. Epikopais poorei sp. nov. is distinguished from all other species in this genus by: body dorsally covered with setae; small anterolateral cephalic flanges; a small seta on the mandible in the approximate location of the palp; elongate operculum keel and an elongate uropodal protopod. E. poorei sp. nov. is further distinguishable from E. waringa sp. nov. and E. mystax sp. nov. as this species does not have any elongate setae on the frons above the labrum and the endopod of pleopod 3 has many more plumose setae than found in the other two species.

Distribution. South-eastern Australia, from Nowra, NSW to south of Point Hicks, Victoria, from depths between 400– 930 m.

Etymology. For Gary Poore, who was my undergraduate honours supervisor between 2000–2001 and was the first to introduce me to asellote isopods.

Figures

Figure 1. Epikopais poorei gen. nov., sp. nov. a–c, female holotype, 2.4 mm (NMV J18844); d, f, female paratype, 2.3 mm (NMV J18845); e, g, male paratype, 2.0 mm (NMV J54112): a, lateral view; b, dorsal view; c, cephalon; d, ventral view of pereonite 7; e, right antenna 2; f, left antenna 1; g, right antenna 1. Scale bar = 1 mm, for dorsal and lateral views only.

Figure 2. Epikopais poorei gen. nov., sp. nov. All figures from female paratype, 2.3 mm (NMV J18845): a, left mandible; b, left mandibular molar; c, right mandible; d, right mandible molar; e, left maxilla 1; f, left maxilla 2; g, right maxilliped palp; h, right maxilliped; i, right maxilliped endite; j, right pereopod 1.

Figure 3. Epikopais poorei gen. nov., sp. nov. a–d, female paratype, 2.3 mm (NMV J18845); e, female paratype, 2 mm (NMV J18845): a, left pereopod 2; b, left pereopod 5; c, right pereopod 4; d, left pereopod 3; e, operculum.

Figure 4. Epikopais poorei gen. nov., sp. nov. a, b, e, female paratype, 2.3 mm (NMV J18845); c, d, male paratype, 2 mm (NMV J54112): a, right pereopod 6; b, left pereopod 7; c, pleopod 1; d, left pleopod 2; e, left uropod.

Figure 5. Epikopais poorei gen. nov., sp. nov. All figures from female paratype, 2.3 mm (NMV J18845): a, right pleopod 3; b, right pleopod 4; c, right pleopod 5.