Paratanais paraoa, Bird, 2011

BIRD, GRAHAM J., 2011, Paratanaoidean tanaidaceans (Crustacea: Peracarida) from littoral and shallow sublittoral habitats in New Zealand, with descriptions of three new genera and seven new species, Zootaxa 2891 (1), pp. 1-62 : 34-41

publication ID	https://doi.org/ 10.11646/zootaxa.2891.1.1
publication LSID	lsid:zoobank.org:pub:1DF47466-0448-4EE7-8D7C-456BA1D0E152
persistent identifier	https://treatment.plazi.org/id/B6D072D6-C2E9-41DB-BF32-B3DB8C371FF2
taxon LSID	lsid:zoobank.org:act:B6D072D6-C2E9-41DB-BF32-B3DB8C371FF2
treatment provided by	Felipe
scientific name	Paratanais paraoa
status	sp. nov.

Treatment

Paratanais paraoa View in CoL n. sp.

Figs 18–22 View FIGURE 18 View FIGURE 19 View FIGURE 20 View FIGURE 21 View FIGURE 22

Material examined. From east coast of North and South Island , and southwest coast of North Island , New Zealand. Holotype: neuter/non-ovigerous female, 3.16 mm, GJB/2-09 lower eulittoral, Corallina turf, Armer’s Bay , Kaikoura , [ CR.21768]. Allotype: swimming male, 1.46 mm, GJB/2-09 lower eulittoral, Corallina turf, Armer’s Bay, Kaikoura, [ CR.21769]. Paratypes: one manca-II, five manca-III, 40 neuters, one ov. female, one post-ov. female, GJB/2-09, [ CR.21770]; four neuters, GJB/2-09, [ NIWA: 70536]; one neuter dissected on microslide, GJB/ 4-09, [ CR.21771]. Other material: five manca-III, four neuters, one female, GJB/3-07; two neuters, one male, GJB/4-08; one neuter, GJB/5-08; one manca-III, one neuter, GJB/1-08; one neuter, GJB/2-08; two neuters, one ov. female, GJB/2-09; two neuters, SA-898, [ CR.13157]; one neuter, SA-928, [ CR.21767] .

Diagnosis. Paratanais with pereonite-2 less than 1.5 times longer than pereonite-1. Pleon shorter than pereonites 5–6; circumplumose setae on pleonites 1–4 only. Antenna article-2 with subdistal seta on convex margin. Mandible lacinia mobilis with crenulated distal margin. Maxilliped palp article-2 with only one unspecialised pinnate seta (i.e. similar to those on articles 3–4); endite with strong medial seta. Cheliped propodus with seta near articulation with dactylus; dactylus inferior margin with one proximal seta and two spines. Pereopod-1 merus 2.5 times ltb. Pereopods 4–6 carpal spines (four) stout. Uropod just longer than pleotelson, exopod 2-segmented.

Male: Habitus: typical paratanaidid. Cephalothorax longer than pereonites 1–4. Pereonites and pleonites length subequal, not well differentiated. Pleotelson with round apex bordered by two setae. Antennule peduncle 3-

Etymology. From Te reo Māori noun p ā raoa, ‘sperm whale’; this alludes to their spectacular presence a few kilometres offshore of Kaikoura, the type locality for this new Paratanais species.

Type locality. Lower eulittoral rocky-shore, Armer’s Bay , Kaikoura, South Island, New Zealand; ca. 42° 25´08´´S 173° 42´28´´E (sourced from Google Earth) GoogleMaps .

Description. Female: Habitus ( Fig. 18A View FIGURE 18 ) typical Paratanais ; fairly slender or slender, 6.6–7.8 times ltb (extended condition); length 2.68–3.34 mm (post-ovigerous female 3.30 mm). Cephalothorax pear-shaped, 1.2 times ltb, as long as pereonites 1–2 combined; setation as P.tara n. sp. Pereon 57% of body length, pereonites with almost straight lateral margins, pereonite-1 shortest, pereonites 2–4 similar length to each other, pereonite-5 longest; all pereonites shorter than broad, pereonites 1–6 respectively 0.41, 0.55, 0.57, 0.59, 0.77 and 0.57 times as long as broad; pereonite-1 setation as P. tara . Pleon shorter than pereonites 5–6, 18% of body length, just longer than broad; pleonite-5 slightly longer than rest; pleonite setation as P. tara . Pleotelson ( Fig. 18B View FIGURE 18 ) shorter than pleonites 4–5, about 0.4 times as long as broad, with two posteriolateral setae, weakly rounded posterior margin (dorsal view), setation as P. tara .

Antennule ( Fig. 18E View FIGURE 18 ) similar to P. tara , almost as long as cephalothorax; article-4 more slender and just longer than articles 2–3 together; article-5 with one PSS, four simple setae, and one aesthetasc. Antenna ( Fig. 18F View FIGURE 18 ) similar to P. tara but 0.9 times as long as antennule; article-2 of different shape, with convex ventral margin with subdistal seta on small apophysis; article-3 and article-4 narrower; article-4 shorter than article-2, 2.7 times ltb, without medial seta; article-5 narrower, 2.3 times ltb as long as broad, with one distal seta; article-6 with six or seven terminal setae.

Labrum ( Fig. 19A View FIGURE 19 ) typical of genus. Labium ( Fig. 19B View FIGURE 19 ) similar to P. tara . Mandibles ( Figs 19C–G View FIGURE 19 ) similar to P. tara but right incisor with more acuminate tip. Maxillule ( Fig. 19H View FIGURE 19 ) similar to P. tara but endite with eight (?) terminal spines. Maxilla ( Fig. 19J View FIGURE 19 ) more elongate than that of P. tara . Maxilliped ( Figs 19K–L View FIGURE 19 ) similar to P. tara but basis distal setae shorter, not reaching distal of palp article-2; palp article-2 inner pectinate seta shorter, not similar to those of article-3; endite spines proportionately smaller. Epignath ( Fig. 19M View FIGURE 19 ): thin and strap-like.

Cheliped ( Figs 18C View FIGURE 18 , 19N–O View FIGURE 19 ) similar to P. tara but basis anterior to coxal sclerite proportionately smaller; propodus slightly stouter, twice as long as broad, 4.4 times longer than fixed finger, dorsomesial comb of three stouter pectinate seta, distolateral margin with stiff seta near dactylus articulation; fixed finger shorter, with more dentate incisive margin; dactylus inferior margin with proximal seta in addition to two peg-like spines.

Pereopod-1 ( Fig. 20A View FIGURE 20 ) similar to P. tara but merus with superior and inferodistal setae; carpus slightly more slender, 2.2 times ltb; propodus slightly shorter, about 1.5 times longer than carpus, with two superior distal; dactylus and unguis together 0.8 times as long as propodus. Pereopod-2 ( Fig. 20B View FIGURE 20 ) similar to P. tara but basis stouter, 2.75 times ltb; merus slightly stouter; carpus with shorter superior distal and inferodistal spines; propodus about as long as merus and carpus combined, narrower, with one dorsodistal seta and one longer ventrodistal seta, apex setulated; dactylus and unguis, together 0.75 times as long as propodus. Pereopod-3 ( Fig. 20C View FIGURE 20 ) similar to pereopod-2, but carpus with microtrichia; propodus with two superior distal setae.

Pereopod-4 ( Fig. 20D View FIGURE 20 ) similar to P. tara but basis stouter, 2.2 times ltb, naked; merus shorter, with stouter inferodistal spines; carpus with more prominent ‘prickly tubercle’ on inferodistal margin, and distal spines shorter and more complex; propodus stouter, 2.7 times ltb, with shorter inferodistal spines. Pereopod-5 ( Fig. 20E View FIGURE 20 ) similar to pereopod-4 but basis with two superior delicate PSS and inferior margin with simple seta and larger PSS. Pereopod-6 ( Fig. 20F View FIGURE 20 ) similar to pereopods 4–5 but basis with one superior PSS; meral, carpal and inferodistal propodal spines smaller than those of P. tara .

Pleopod ( Fig. 21A View FIGURE 21 ) similar to P. tara of equal size, but endopod more slender, 2.3 times ltb, outer margin with 17 plumose setae; exopod slightly more slender than endopod, with 26 plumose setae on outer margin.

Uropod ( Fig. 18D View FIGURE 18 ) similar to P. tara but just longer than pleotelson; exopod 2-segmented, slender, five times ltb, reaching just beyond article-1 of endopod; endopod five times ltb, segment-1 0.6 times total length.

Manca-II: Habitus ( Fig. 21B View FIGURE 21 ) generally similar to preparatory female, but fairly stout, 5.3 times ltb; length 0.83–0.87 mm. Pleonites without plumose lateral setae. Antenna ( Fig. 21C View FIGURE 21 ) article-2 less inflated than in female. Uropod ( Fig. 21D View FIGURE 21 ) stouter, exopod 1-articled.

Manca-III: Habitus ( Fig. 21E View FIGURE 21 ) similar to manca-II, but fairly slender, six times ltb; length 0.99–1.53 mm. Uropod similar to that of manca-II ( Fig. 21F View FIGURE 21 ).

F left and right molars; G right mandible full molar profile; H maxillule; J maxilla; K maxilliped (palp articles 2–4 excluded); L palp; M epignath; N right cheliped; O left chela (mesial view). Scale bars: (i) 0.125 mm for A–M, and O; (ii) 0.125 mm for N.

Neuter: similar to female, length 1.19–3.65 mm.

Male: Habitus ( Fig. 21G View FIGURE 21 ) similar to P. tara but stout, 4.2 times ltb, length 1.46–1.55 mm. Cephalothorax stouter, just longer than broad, longer than pereonites 1–4; eyes proportionately larger, 0.37 times as long as cephalothorax; rostrum more obtuse. Pereon only 36% of total length, pereonites 4–6 just longer than very short pere-

Antennule ( Fig. 22A View FIGURE 22 ): similar to P. tara but stouter peduncle articles 1–2 and longer flagellum segment-2. Antenna ( Fig. 22B View FIGURE 22 ): similar to that of female but articles 2–3 with longer superior setae; article-4 with two inferior proximal PSS.

Mouthparts: reduced (maxilliped present), typical of genus.

Cheliped ( Figs 22C–E View FIGURE 22 ) similar to P. tara but carpus stouter, 1.3 times ltb; propodus distinctly longer than carpus, palm 0.75 times as long as whole; fixed finger and dactylus with crenate proximal incisive margins, dactylus with mid-inferior spine.

Pereopod-1 ( Fig. 22F View FIGURE 22 ) similar to P. tara . Pereopods 2–3 ( Fig. 22G View FIGURE 22 ) similar to those of P. tara .

Pereopods 4–5 ( Figs 22H–J View FIGURE 22 ) similar to P. tara but basis with inferior simple seta; carpus longer than merus and superior distal seta small. Pereopod-6 ( Fig. 22K View FIGURE 22 ) similar to P.tara but propodus inferior margin with more obvious setal combs.

Pleopod similar to female but rami less elongate and with fewer, longer setae.

Uropod ( Fig. 21J View FIGURE 21 ) stouter than female; exopod 1-segmented.

Remarks. Aside from the clear difference in antennal article-2 shape and setation, P. paraoa n. sp. has, compared to P. tara n. sp., proportionately shorter pereonites, stouter pereopod carpal spines, different basis setation on pereopods 4–6, and has a 2-segmented uropod exopod in mature specimens. The male is more different from that of P. tara , with quite different body proportions, the antenna echoing that of the female and the cheliped fixed finger and dactylus have a crenulated proximal incisive margin.

Of the six described Australian species, P. paraoa resembles P. malignus , P. perturbatius and P. vetinari in having a mid-inferior seta on antenna article-2. It differs from the first and second in, at least, having longer uropods (with a 2-segmented exopod) and the cheliped palm spine is not leaf-shaped as in P. malignus . It is most similar to P. vetinari but has only simple setae on pleonite-5, more rounded maxilliped endite teeth, a longer pereopod-1 carpus, shorter pereopod-1 dactylus-unguis, and four spines on the carpus of pereopods 4-6. The male is very similar in shape to that of P. maleficus , P. wanga (but with 7-segmented flagellum), P. impressus Kussakin & Tsareva, 1972 and P. clarkae and its antennule and pleotelson apex have similar configurations to that of the last-named species.

Distribution and ecology. Like Paratanais tara , P. paraoa n. sp. inhabits the lower eulittoral and upper sublittoral rocky shore to a depth of 12 m, and also intertidal muddy-sand associated with the marine angiosperm Zostera . Sympatric tanaidaceans include Apseudomorpha timaruvia , Cyclopoapseudes sp. , Parakonarus kopure , Zeuxoides rimuwhero and Tanaopsis rawhitia n. sp. (see below).

So far, it is known from the Snares Islands, the east coast of South Island and North Island from Kaikoura to Napier, but also occurs north of Cook Strait on the southwest coast of North Island. Specimens from the two Snares Islands samples were originally recorded as Paratanais oculatus by J. Sieg.