Brucerolis hurleyi, Storey & Poore, 2009

Storey, Melissa J. & Poore, Gary C. B., 2009, New species of Brucerolis (Crustacea: Isopoda: Serolidae) from seas around New Zealand and Australia, Memoirs of Museum Victoria 66 (1), pp. 147-173 : 159

Brucerolis hurleyi sp. nov.

Figures 1e , 10 − 13

Material examined. Holotype: New Zealand, Chatham Rise , 43°29.69'S, 178°59.55'W, 499 m, 08 Sep 1989. ( NIWA stn V366 TAM), NIWA 27424 (adult male, 23 mm).

Paratypes: collected with holotype, NIWA 27423 (adult female, 23 mm) , NIWA 27425 (12 males, 17 females, 15 juveniles). New Zealand, Chatham Rise , 43°30'S, 179°15'E, 410 m, 24 Jan 1968 ( NIWA stn G273), NIWA 27419 (6 males, 5 females, 1 juvenile); 43°31'S, 179°07'E, 413 m, 24 Jan 1968 ( NIWA stn G283A), NIWA 27424 (5 males, 4 females, 3 juveniles); 43°58.5'S, 178°40'W, 460 m, 30 Mar 1969 ( NIWA stn D904 TAS), NIWA 27420 (5 males, 4 females, 1 juvenile); 44°13.5'S, 177°04.7'W, 403 m, 23 Mar 1978 ( NIWA stn Q33), NIWA 27418 (7 males, 6 females, 1 juvenile); 43°49.62 − 49.23'S, 176°59.82 − 59.57'E, 498 − 497 m, 16 Sep 1989 ( NIWA stn V387 TAM), NMV J55314 (5 males, 16 females, 26 juveniles). Chatham Rise (Portobello Marine Laboratory Chatham Expedition stn 6), NIWA 27422 (2 males, 5 females, 3 juveniles). W of Chatham Is, 44°00'S, 178°06'E to 44°03'S, 178°09'E, 430 m, USS Eltanin, 29 Nov 1964, NMV J11625 (donation from USNM 123962 ) (1 male, 1 female).

Other material: numerous specimens from 82 NIWA stations.

Description of male holotype. Body length 29 mm. Body 0.9 times as long as greatest width (at coxae 3). Middorsal line without midposterior processes, not elevated in lateral view. Head, anterolateral margins concave, lateral corners acute and projecting anteriorly; width between anterolateral corners 1.2 times as wide as maximum span between lateral margins of eyes; head with paired strongly projecting curving acute processes on transverse ridge at bases of antennae 1, with prominent paired tubercles between eyes, with small, blunt median posterior tubercle, with obscure lobes lateral to median posterior tubercle. Pereonite 1 lateral margin convex anteriorly, straight over most of length, lateral margin upturned over anterior half, sharply crested, with sinuous rounded oblique ridge more or less parallel to margin, separated from it by a deep trough occupying about one-third of width, dorsal surface with obsolete oblique-transverse ridge reaching sinuous ridge. Coxal dorsal plate 2 1.1 times as long as half pereonal tergite 2 width (following plates increasing in length); plate 4 1.8 times as long as half pereonal tergite 4 width; plate 6 extending beyond tip of pleotelson by 2.6 times middorsal length of pleotelson, the pair diverging over entire length, almost straight except at apex; pleonal epimeron 2 1.8 times length of pleotelson; pleonal epimeron 3 1.1 times length of pleotelson; pleonal epimera 2 and 3 with acute apices. Ventral coxal plates 2–4 with a prominent tubercle at anteromesial corner, without marginal ridges. Antenna 1 peduncle articles 3+4 1.9 times as long as article 2 (anterior margin); flagellum of about 41 articles. Antenna 2 peduncle article 5 1.2 times as long as article 4; flagellum of 17 articles. Pereopod 1 propodus 2 times as long as greatest width. Pereopod 2 palm dorsal length 1.3 times greatest width, with short heel, straight setose proximal palm, convex distal palm, with 16 robust setae in U-shaped row. Pereopod 7 carpus 3.1 times as long as greatest width; propodus 4 times as long as greatest width, propodus elongate oval, widest at midpoint; dactylus curved, 0.4 times as long as propodus. Pleopod 2 endopod with evenly tapering distal angle bearing appendix masculina; appendix masculina 4.8 times as long as straight margin of endopod. Uropodal exopod 0.8 length of endopod.

Female. Pereonite 1, lateral margin of female as in male. Coxal dorsal plate 2 of female 0.6 times as long as half pereonal tergite 2 width; plate 4 of female 1.1 times as long as half pereonal tergite 4 width (following plates increasing in length); plate 6 of female extending beyond tip of pleotelson by 2 times middorsal length of pleotelson, the pair diverging over entire length, almost straight except at apex.

Size. Adult male and female body length 17 − 30 mm.

Distribution. New Zealand, western Cook Strait to eastern slope of New Zealand, Chatham Rise, Bounty Plateau, Campbell Plateau, 40°'S − 53°S, 168°E − 176°W, 315 − 1024 m.

Etymology. Brucerolis hurleyi is named for Dr Desmond E. Hurley, who first noted morphological variation within what he called Serolis bromleyana around New Zealand.

Remarks. Brucerolis hurleyi and B. osheai are similar, both with acute epimera apices, similarly shaped anterior head margin (although in B. hurleyi , the anterolateral corners of head are not continuous with anterior margin of pereonite 1), setose lower margins of the ischium, merus and carpus of male pereopod 2 and setulose carpus and propodus of male pereopod 7. Brucerolis hurleyi can be recognised by: strongly convex propodus palm of male pereopod 2; ventral coxal plates with an anteriorly projecting, circular tubercle on the anterior margin adjacent to the midline suture; lack of setules on the merus of the male pereopod 7; and absence of the colour pattern seen in most individuals of B. osheai . The species is unusual in the possession on antenna 1 flagellum articles of a row of denticles.

One unusual adult male specimen (NIWA stn D9 DR, SE Macquarie Island) has an appendix masculina on pleopods 2 and 3 on both sides.

Figures

Figure 1. Head and pereonite 1 of species of Brucerolis. a, B. brandtae sp. nov. (NMV J55313). b, B. bromleyana (syntype, BMNH 1889.4.27.20, negative of drawing by Kate Thompson published by Poore & Brandt, 1997). c, B. cidaris (NMV J27642). d, B. howensis (NMV J55315). e, B. hurleyi (NMV J55314). f, B. nowra (NMV J19213). g, B. osheai (NMV J55316). h, B. victoriensis (NMV J19201). Scale bar in each case = 10 mm.

Figure 10. Brucerolis hurleyi sp. nov. Holotype male (NIWA 27424): dorsal and lateral views, sternites of pereonites 1–7, pleonites 1–3, medial ridge of pleonites 1–3. Paratype female (NIWA 27423): dorsal and lateral views, medial ridge of pleonites 1–3. Scale = 10 mm.