Pentaceration novaezealandia, Just, Jean, 2011

Just, Jean, 2011, Remarkable Australasian marine diversity: 18 new species in Pentaceration Just, 2009 (Crustacea, Isopoda, Paramunnidae), Zootaxa 2813, pp. 1-54: 47-52

publication ID

http://doi.org/ 10.5281/zenodo.203856

persistent identifier

http://treatment.plazi.org/id/2F149D2B-FFA7-FFEF-FF10-FE6D1DE9FF61

treatment provided by

Plazi

scientific name

Pentaceration novaezealandia
status

sp. nov.

Pentaceration novaezealandia   sp. nov.

Figures 33–34 View FIGURE 33 View FIGURE 34

Type fixation. Holotype, male, here designated.

Etymology. The epithet is the Latinized form for New Zealand.

Material examined. Holotype, 3, 2.2 mm, New Zealand, east coast, 41 °04.10'S, 176 ° 22.05 'E, 306 m, ring net on trawl warp, 23 February 2000, RV Kaharoa, cruise KAH0001, stn 79, NIWA 60505.

Paratypes (4 specimens). Same data as holotype, NIWA 60506 (1 Ƥ, 1.95 mm; 1 3, 2 juvenile).

Description (adult male, holotype). Body square in dorsal view, pereon and pleotelson strongly vaulted dorsally; width 0.43 length, widest between pereonites 1 and 2 and 5 and 6. Head length 0.4 width; length posterior to eyestalks 0.42 anterior length. Frontal margin middle spine length 1.2 head length; lateral spines nearly straight, approximately 1.6 length of middle spine, diverging at 120 °. Eyestalks reaching to anterior rounded corner of pereonite 1, pointing directly laterad, tapering to pointed apex.

Pereonite 1 lateral margins evenly rounded, widening posteriorly, weakly denticulate, with small rounded projection on posterolateral corner; pereonites 2 and 3 lateral spines similar, approximately 0.4 width of pereonite, with broad base, diverging at approximately 50 ° with small lobe anteriorly at base and larger dentiferous lobe posteriorly at base; pereonite 4 with tiny lateral spines; pereonites 5–7 lateral spines broad, triangular, 5 the largest; pereonites 5 and 6 with single simple seta posterolaterally where overlapping succeeding pereonite.

Pleon length 0.85 width. Pleonite 1 width equals distance between uropods, length 0.12 width. Pleotelson proximal and lateral margins meeting at even curve, lateral margins broadly convex, with 11–12 denticles; distal projection triangular at 50 °, 0.47 length of entire pleotelson, apex pointed.

Antennula   articles 1 and 2 combined reaching to about apex of eyestalks; articles 1 and 2 of subequal length, 1 broader than 2, tubular; 3 and 4 of subequal length, combined barely longer than 5, 6 approximately 0.85 length of 5.

Antenna article 2 in ventral view about 5 times length of 1; 3 width 0.27 length, with short acute spines proximally and distally on lateral margin.

Pereopod I basis length 2.75 times width, with 2 tall, diverging spines on distal anterior margin; ischium 0.7 length of basis, anterior margin with single tall spine; merus with single acute spine on anterior margin; carpus oval, distal posterior margin concave, distal robust seta with 2 small translucent flanges in front; propodus narrowing distally to insertion of dactylus, with 2 robust setae on opposing margin. Pereopod II propodus with 4 slender robust setae on posterior margin.

Pleopod I lateral sublobes subequal, rounded, half overlapping, setae on distal lobe unusually long and backward curving; width 0.2 distance to midline; distal projection length 0.4 pleopod total length, forming acute angle, with bluntly pointed apices. Pleopod II protopod rounded distally, lateral margin with simple setae; endopod article 2 (stylet) forming curve of approximately 130 °.

Uropods recessed into low cuticle fold with slightly thickened, irregular rim, protopod hidden, exopod apparently absent; endopod length 1. 7 times width.

Female (ovigerous, parts illustrated). Head generally as in male, but lateral front margin spines curving slightly backwards ( Fig. 33 View FIGURE 33 cd), diverging at approximately 140 °. Pereonite 1 shoulders less well developed. Pereonites 2–3 lateral spines somewhat shorter and broader than in male. Pleotelson distal projection shorter (0.35 length of entire pleon) and broader (80 ° angle) than male. Operculum (pleopod II) ovoid, width 0.85 length, apex pointed. Pereopod I much more slender than in male; elongate ischium with tiny spine in anteroproximal half; carpus with nearly parallel margins.

Size. Largest female, 1.95 mm; largest male, 2.2 mm. Distribution. Eastern New Zealand, 306 m.

Figures 35–36 View FIGURE 35 View FIGURE 36

Type fixation. Holotype, male, here designated.

Etymology. The epithet alludes to the numerous setae on head and pereonite spines and notably the long rows of setae on pereonites 5 and 6 posterior margins.

Material examined. Holotype, 3, 1.5 mm, New Zealand, east coast, 41 °04.10'S 176 ° 22.05 'E, 306 m, ring net on trawl warp, 23 February 2000, RV Kaharoa, cruise KAH0001, stn 79, NIWA 60507.

Notes on holotype. The single male found is damaged, especially in the region of pereonites 3–5, and both antennae. The specimen is, however, clearly different from other Pentaceration   species. Being an adult male, probably terminal, it can be described reasonably well and named. No dissection has been made. All details were drawn in situ.

Description (male, holotype). Body appears to taper slightly from pereonite 1 to pleon; width approximately 0.35 length, widest between pereonites 2 and 3. Head length 0.2 width, length posterior to eyestalks 0.8 anterior length. Frontal margin mid-spine length 1.3 head length, slender, pointed; lateral spines approximately 1.5 length of mid-spine, sinuous, diverging at approximately 115 °; all 3 head spines with many small marginal setae. Eyestalks barely overreaching pereonite 1, pointing directly laterad, evenly tapering from broad base to acute point.

Pereonite 1 widening posteriorly, lateral margins straight, irregularly denticulate; pereonites 2–3 with acute lateral spines, diverging at 40 °, spine length approximately 0.5 pereonite width, both with irregularly denticulate translucent flanges at anterior and posterior base of spines; pereonites 4 with tiny mid lateral blunt points; pereonites 5 and 6 lateral spines broad, sinuous, with long broad translucent flange anteriorly and shorter similar flange on posterior margin, with long row of short setae along lateral parts of posterior margin where overlapping succeeding pereonite; pereonite 7 lateral spines triangular, with marginal flanges similar to those on pereonites 5 and 6. Pereonites 1–3 and 5–6 lateral margins with many marginal and dorsal small setae.

Pleon length 1.1 width. Pleonite 1 width equals distance between uropods, length 0.12 width. Pleotelson without proximal neck; lateral margins evenly curved, with 8–9 denticles on broad translucent flange; distal projection 0.45 length of entire pleotelson, proximal 2 / 3 triangular at 90 °, distal 1 / 3 narrower blunt spine.

Antennula   articles 1 and 2 somewhat foreshortened in Fig. 36 View FIGURE 36 au, but article 1 shorter and broader than 2, 3 and 4 subequal, slightly shorter than 5 and 6.

Pereopod I basis length 3.2 width, anterodistal margin with 2 straight spines; ischium length 0.6 basis length, with similar row of 2 anterior spines; carpus oval, posterodistal margin straight; propodus narrowing distally to insertion of dactylus, with 2 robust setae on opposing margin. Pereopods II propodus with single posterodistal robust seta.

Pleopod I lateral sublobes dissimilar, proximal one broadly rounded, nearly completely hiding narrower, apically rounded distal lobe; width 0.3 distance to midline; distal projection length 0.46 pleopod total length, forming acute angle, with pointed apices. Pleopod II protopod rounded distally, lateral margin with simple setae; endopod article 2 (stylet) forming approximately 215 ° curve.

Uropods recessed into simple cuticle fold, protopod and exopod apparently absent; endopod length 2.5 width. Size. Largest male, 1.5 mm.

Distribution. Eastern New Zealand, 306 m.

NIWA

National Institute of Water and Atmospheric Research