Aparatanais timutimu, Bird & Bamber, 2013

BIRD, GRAHAM J. & BAMBER, ROGER N., 2013, New littoral, shelf, and bathyal Paratanaidae (Crustacea: Peracarida: Tanaidacea) from New Zealand, with descriptions of three new genera, Zootaxa 3676 (1), pp. 1-71 : 16-20

Aparatanais timutimu sp. nov.

Figures 7–9 , 36H–K

Material examined. Holotype: non-ovigerous ♀, CR.23397, Stn ‘ Cooper’, clumps of weed, East of Ward Island , Wellington Harbour , July 1966.

Paratypes: one manca-II, one manca-III, ten non-ov. ♀♀, one post-ov. ♀, CR.23493 one partly dissected on microslides CR.23493/1, details as for holotype; one non-ov. ♀ [CR.23494] partly dissected on microslide [CR.23494/1], Stn GJB/40-11, Old Quarry Bay , Wellington south coast, ELWS, Corallina , 41.3483°S, 174.7417°E, 31 August 2011 .

Diagnosis. Female: carapace entire. Antenna article-2 weakly expanded, without superodistal apophysis [c.f. vicentetis ], inferior seta subproximal; antenna article-4 longer than article-2. Chela longer than carpus; palm spine kukri-shaped. Pereopod-1 merus elongate [>three times ltb]. Pereopod-2 carpus with strong superodistal spine.

Etymology. From Te reo Māori ‘ timutimu’, ‘stump [of a tree]’, alluding to the many setal ‘stumps’ in these specimens; noun in apposition.

Description. Female (non-ovigerous and post-ovigerous): Habitus ( Figs 7A , 9A ) fairly slender, 6.6–7.4 times ltb, length 2.3–5.8mm (post-ov. female 5.4 mm). Cephalothorax longer than pereonites 1–2 combined (contracted), 1.1–1.2 times ltb, weakly hexagonal. Pereon with all pereonites shorter than broad, pereonites 4–5 longest. Pleon slightly longer than broad, as long as pereonites 5–6 combined, about 20% of body length; pleonites 1–4 with pappose epimeral setae ( Fig. 7K ). Pleotelson ( Fig. 7B ) shorter than broad, slightly longer than pleonites 5–6, with weakly projecting rounded apex.

Antennule over three-quarters length of cephalothorax, without distinct cap-like segment; article-1 half of total length; article-4 longer than articles 2–3 combined. Antenna ( Fig. 7C ) article-2 weakly inflated, with mid-inferior seta, small distolateral seta and superodistal seta, superior margin finely setulate; article-3 superior spine acute; article-4 1.3 times length of article-3. Mandibles ( Fig. 7D ) right incisor with crenulate superior margin, apex not bifid.

Maxillule ( Fig. 7E ) with distal setules and at least seven apical spines. Maxilliped ( Fig. 7F–G , 36H ) endite tubercles rounded; palp article-2 modified spine with about eight serrations [denticles] ( Fig. 7H ).

Cheliped ( Figs 8A–C , 9B , 36J ) basis stout; merus unremarkable; carpus stout, 1.4–1.6 times ltb; propodus 1.3 times as long as carpus, palm typical, with two medial spines; fixed finger shorter than palm, distal tooth large, rounded; dactylus with large proximal peg-like spine on incisive margin.

Pereopod-1 ( Figs 8D , 9C ) basis six times ltb, with superoproximal seta; merus 2.7 to five times ltb; carpus 2.5 times ltb, with at least two or three distal setae; propodus as long as merus. Pereopod-2 ( Fig. 9D ) 0.7 times length of pereopod-1; basis stouter, 2.8 times ltb; merus inferodistal margin with spine and stiff seta; carpus as long as lateral; C antenna; D right mandible; E maxillule endite, distal; F maxilliped endite: G maxilliped palp; H maxilliped palp article-2 serrate spine; J uropod. Paratype non-ov. female [CR.23494]: K pleon epimeral setae. Scale bars: i: 2 mm for A; 1 mm for B, J–K; ii: 0.25 mm for C, G; 0.125 mm for D–F, H.

distal seta and one PSS; merus longer than carpus; carpus with stout, serrate spines; propodus longer than carpus; claw short, half as long as propodus. Pereopod-6 ( Fig. 9F ) similar to pereopod-5 but propodus with three superodistal spines.

Uropod ( Fig. 7J , 36K ) visible in dorsal view, projecting beyond pleotelson, stout; peduncle as long as broad; endopod one-segmented, as long as peduncle; exopod just over half length of endopod.

Manca-II: length 1.1 mm.

Manca-III: length 1.2 mm.

Distribution and ecology. There are only two certain records of this species, both from Wellington. Aparatanais timutimu was found with Paratanais paraoa in Wellington Harbour, and in coralline algae on Wellington’s exposed southern coast.

Remarks. Because the main sample of material was not in very good condition, with many setae and spines broken or missing, the smaller, intact specimen from Old Quarry Bay (Stn GJB/40-11) was also used for the illustrations. Some allometric differences exist, principally in pereopod article lengths.

Of the described species, Aparatanais timutimu sp. nov. is most similar to its trans-Tasman neighbour, A. malignus , but differs in having a shorter antenna article-2 with its inferior seta more proximal, even smaller maxilliped endite tubercles, a stouter cheliped carpus, a proportionately larger chela, a longer pereopod-1 merus, and a longer pereopod-2 propodus. A. timutimu is distinct from A. denticulatus in its lack of distinct plates on the carapace, the presence of pappose epimeral setae, the proportionately stouter antennal article 2, the stouter cheliped carpus, and the more elongate pereopod-1 merus and uropod-endopod segments.

Figures

FIGURE 7. Aparatanais timutimu gen. et sp. nov. Holotype non-ovigerous female [CR.23397]: A habitus; B pleotelson,

FIGURE 8. Aparatanais timutimu gen. et sp. nov. Paratype non-ovigerous female [CR.23493/1]: A cheliped [right]; B cheliped kukri-shaped spines, variants; C cheliped dactylus inferior spine; D pereopod-1; E pereopod-3; F pereopod-5. Scale bar: 0.25 mm.

FIGURE 9. Aparatanais timutimu gen. et sp. nov. Paratype non-ovigerous female [CR.23494 and CR.23494/1]: A habitus; B cheliped; C pereopod-1; D pereopod-2; E pereopod-5; F pereopod-6. Scale bars: i: 1 mm for A; ii 0.5 mm for B; iii 0.25 mm for C–F.

FIGURE 36. A Metatanais sp. antennule, lateral; B Metatanais sp. uropod; C Xeplenois pleon-pleotelson, dorsal and lateral (pleopod & setae omitted), after Bamber 2005; D Penteparatanais pereopod-4 carpus; E Paratanais hamulus pereopod- 5carpus; F Acallocheirus pereopod-2 carpal spines; G P. incomptus pereopod-2 carpal spines; H Aparatanais timutimu maxilliped palp article-2 spine; J A. timutimu cheliped kukri spine: K A. timutimu uropod; L Paratanais caterae cheliped spine; M P. puia uropod; N P.hamulus antenna article-3. O Atemtanais antenna article-3, after Bird 2011; P Atemtanais pereopod-2 carpal spines, after Bird 2011; Q Paratanais caterae pereopod carpal spines; R P.caterae maxilliped palp article-2 spine; S P.