Leptocheliidae Lang, 1973

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 : 6-17

Family Leptocheliidae Lang, 1973 [sensu Larsen & Wilson 2002]

Remarks. This is a complex family whose phylogenetics have not yet been settled ( Bird & Larsen 2009). Rather than one family as seen by Lang (1973) or Larsen & Wilson (2002) it may represent a super-family grade taxon. Regardless of the higher classification, the Australasian region is rich in leptocheliid genera, including Catenarius Bamber, 2008 , Konarus Bamber, 2006 , Leptochelia Dana, 1849 , and Pseudoleptochelia Lang, 1973 . A key to the Australian species was given by Bamber (2008). Only one species has so far been recorded in New Zealand — Paratanais tenuis (= Leptochelia mirabilis ?).

Parakonarus n. gen.

Konarus: Bird (2008) : 34.

Diagnosis. (following Bamber & Chatterjee 2010, for Konarus , see below). Female: leptocheliid with robust body, 6–7 times longer than broad. Cephalothorax longer than broad, second thoracomere dorsal plate separate from first on carapace; compound eyes present. Pereonites 1–3 as long as pereonites 4–6. Antennule 4-articled (or ‘3-articled’ with small cap-like terminal article), article-1 stout, twice as long as broad, article-3 longer than article-2. Antenna 6-articled, article-2 with superior and inferior distal setae, superior margin smooth, inferior setulated; article-3 with superior seta. Maxillule palp with two terminal setae. Maxilliped bases with five distal setae; endites with three distal tooth-like spines (outer two long, inner short) and distolateral seta. Epignath long, narrow, and linguiform, with setulated margins. Cheliped coxal sclerite with triangular insertion into dorsal margin of basis and posterior margin confluent with rear of cephalothorax; basis with superior lateral tubercle-seta; merus with about seven or eight setae; carpus superior margin with several small spines, distal margin extending as cuff over base of propodus. Pereopod-1 unguis longer than dactylus. Pereopods 2–3 ischium with two setae; carpus with minute inferior spine. Pereopods 4–6 merus with two setose tubercles; carpus with three stout spines; propodus with three (pereopods 4–5) or six (pereopod-6) superior distal spines; dactylus and unguis claw-like. Pleopod peduncle with inner plumose seta; endopod and exopod setal fringe entire. Uropod exopod 1-segmented, longer than peduncle; endopod 5-segmented.

Male: Habitus of leptocheliid primary male form. Cephalothorax as long as pereonites 1–3. Antennule article- 1 less than half length of cephalothorax; articles 1–2 subequal in length; flagellum 7 or 8-segmented. Antenna articles 2–3 with simple setae. Cheliped shorter than body, subchelate; carpus with inferior rounded process; propodus inferior margin smooth, fixed finger and terminal spine pointed; dactylus twice as long as opposing propodus. Pereopod-6 basis without superior distal flange. Uropod exopod 1-segmented, endopod 5-segmented.

Type species. Parakonarus kopure n. sp., by monotypy.

Gender: male.

Etymology. The Greek prefix para, ‘beside, ‘along’, or ‘by’, with genus name Konarus .

Remarks. Very recently Bamber & Chatterjee (2010) reviewed the taxonomy of the leptocheliid Konarus and transferred Heterotanais crassicornis Stebbing, 1905 to this genus. It exhibits several unique or unusual features such as a distal cuff on the cheliped carpus, a setose tubercle on the cheliped basis and has numerous cheliped meral setae. Konarus is also among a few leptocheliid taxa that have simple setae on antenna articles 2–3 rather than a strong thorn-like spine (e.g. Leptochelia Dana, 1849 ). Unfortunately, no males have been firmly attributed to the genus although it is suspected that the male of Pseudoleptochelia bulbus Bamber, 2006 may be that of K. cheirus (Roger Bamber pers. comm.).

While Parakonarus n. gen. shares these features, there are numerous characters, small in themselves, that build up into a sizeable disparity with Konarus , including: a longer cephalothorax; shorter pereonites 1–3 compared to pereonites 4–6; antennule with distinct article-4 (cap-like); antennal article-2 with ventral setules and seta; cheliped coxal sclerite with three setae, cheliped carpus with small superior peg-like setae; pereopods 2–3 ischium with two setae, carpus with small carpal spine; pereopods 4–5 merus with setose tubercles, carpus with three spines (c.f. two), propodus with three superior distal propodal spines (c.f. two); uropod exopod 1-segmented (c.f. 2-segmented), and endopod 5-segmented (c.f. 6-segmented).

It is quite likely that this genus and Konarus will expand with the increasing rate of novel species discovery, but revision of some known taxa may also contribute. From study of the illustrations in Lang (1973), Pseudoleptochelia mortenseni may prove to be a chimaera and the small female (Lang: fig. 16g) and the male (Lang: figs 16h– j) could belong to an undescribed species of Konarus or Parakonarus ; this inference is based on the stout female antennule and the subchelate male cheliped that has an inferior carpal process. New material and re-examination of this taxon would be needed to confirm this supposition. A similar view can be made of both Heterotanais anomalus Sars sensu Smith, 1906 and Heterotanais magnus Smith, 1906 . Although both have been moved to Pseudoleptochelia , they appear to display similar characters associated with Konarus or Parakonarus , namely females with stout antennules and a cheliped cuff ( Smith 1906: 326; plate 21 figs 30, 32, 34, 37), and males with sub-chelate chelipeds, albeit without a distinct carpal process (Smith op.cit: plate 21 figs 29, 31, 36, 38). A major difficulty in re-assessing Pseudoleptochelia is that the female of the type species P. anomalus (Sars, 1882) was not described and it is unclear which species figured by Smith is the ‘real’ P. anomalus ; that Pseudoleptochelia species with ‘normal’ chelipeds (e.g. P. antarctica Lang ) and subchelate chelipeds (e.g. P. anomalus ) in males are assigned to the genus also suggests a review is needed. Specifically, the same treatment that Leptochelia savignyi (Kroyer) received in a recent paper (Bamber 2010) should be given to the type species of Pseudoleptochelia , and it ought not be assumed that males with a simple cheliped carpus (e.g. P. anomalus , P. magnus ) are of the same taxon as those with a carpal spur (e.g. P. mortenseni , P. fairgo , and Parakonarus n. gen.). Research on further aspects of Pseudoleptochelia and related genera is in progress (Richard Heard, pers. comm.).

The western Australian species Pseudoleptochelia fairgo Bamber, 2005 is a further taxonomic problem in that it too shares certain characters with Parakonarus , such as stout antennules, thin setae on antenna articles 2–3, a dense setal group on the cheliped merus, a cheliped carpal cuff, similar meral setae on pereopods 4–6 and a subchelate male cheliped with an inferior carpal process. The close similarity of P. fairgo to Konarus was also used by Bird & Larsen (2009) in their phylogenetic analysis of some paratanaoidean genera, the two considered synonymous for this purpose. However, an undescribed leptocheliid (as yet only one specimen) from New Zealand in the NIWA I.C. recently seen by me conforms very closely to P. fairgo in habitus (long undivided cephalothorax, long pereonites) and in other details (cheliped cuff, dense setal groups, etc.) and could indicate that another genus with close affinities to the Konarus -Parakonarus-Pseudoleptochelia group is warranted.

Parakonarus kopure n. sp.

Figs 1 –6

Konarus sp. : Bird (2008): 34.

Material examined. All from southern North Island , New Zealand. Holotype: ovigerous (ov.) female, 2.45 mm, GJB/1-07 lower eulittoral, Corallina turf, Pukerua Bay, 20 March 2007, [accession no. CR.21778]. Allotype: swimming male, 2.37 mm, GJB/3-07 lower eulittoral Corallina turf, Plimmerton, 28 September 2008, [ CR.21799]. Paratypes: two manca-II, two manca-III, eleven neuters (one dissected), one preparatory (prep.) female, two ov. females, two males, GJB/3-07, [ CR.21780]; two manca-III, ten neuters, one prep. female, two ov. females, two males, GJB/3-07, [ NIWA: 70534]; one manca-II, nine neuters, Hoggard [ CR.21781]. Other material: three manca- II, one manca-III, 153 neuters, five ov. females, eight males GJB/1-07; 26 neuters, one post-ov. female, three males GJB/2-07; one manca-III, 43 neuters, one ov. female, one male GJB/1-07; 30 manca-II, 14 manca-III, 42 neuters, two ov. females, two males, GJB/1-08; two manca-III, 100 neuters, three ov. females, two prep. females, 22 males, GJB/3-07; four manca-II, three manca-III, 64 neuters, two ov. females, one post-ovigerous female, four males, GJB:RW/17-11; four neuters, GJB:RW/20-11 .

Etymology. From Te reo Māori noun kopure , ’patchwork’, referring to the cephalothorax plates.

Type locality. Lower eulittoral rocky-shore, Rewarewa-Waikara headland (about 10 km north of Wellington), North Island, New Zealand; specifically, ca. 41° 01´41´´S 174° 55´25´´E or 41° 04´24´´S 174° 51´17´´ E (sourced from Google Earth) .

Description. Female: Habitus ( Figs 1A , 4G) unpigmented, cuticle pale and shiny; unfused plates in carapace conspicuous; body fairly slender, 6.4 times ltb; length 2.20–3.25 mm (prep. females 2.36–3.25 mm, ov. females 2.20–2.98 mm, post-ov. female 2.49 mm). Cephalothorax ( Figs 1B,D ) as long as pereonites 1–3, 1.4 times ltb, narrowing slightly anteriorly; coxal sclerite (see below) not fused and visible from dorsal view; anterior margin with two distolateral setae posterior to eyes with longer seta posterior to these. Pereon 56% of body length (holotype), pereonite-1 shortest and slightly trapezoidal (narrower posteriorly); pereonites 2–3 slightly longer, pereonite-2 slightly trapezoidal and pereonite-3 with slightly convex lateral margins; pereonites 4 and 5 longest, with convex lateral margin; pereonite-6 slightly wider posteriorly; 0.28, 0.39, 0.46, 0.76, 0.74 and 0.76 times as long as broad respectively; pereonite-1 with four distolateral and distomedial setae, pereonites 2–6 with two distolateral setae. Pleon just shorter than pereonites 5–6, 21% of body length (holotype), pleonites wider than pereon; pleonite-5 lon-

Antennule ( Fig. 1E ) stout, 0.67 times as long as cephalothorax; article-1 60% of total length, twice as long as broad, with two lateral proximal and distal setae with several associated PSS, mesial margin with a PSS; article-2 just shorter than broad, with a lateral seta, a mesial simple seta and a PSS; article-3 longer than article-2, twice as long as broad, with one distal seta;article-4 with five setae and one aesthetasc. Antenna ( Fig. 1F ) 0.9 times as long as antennule; article-1 simple, short and naked; article-2 larger, with setulose inferior margin, one long superior distal seta and shorter inferodistal seta; article-3 as long as broad, with superior distal seta; article-4 3.3 times ltb, with mid-superior seta, four distal setae and at least one PSS; article-5 1.8 times ltb, with two distal setae; article-6 short, cap-like, with five terminal setae.

Labrum (Fig. 2A) cap-shaped and apically setose. Labium (Fig. 2B) bilobate, lobes equal and distally setose. Mandibles (Figs 2C–D) left incisor with weak distal process, lacinia mobilis broad, with three or four processes; right incisor with crenulated distal margin and weakly bifid tip; molar process larger than incisor, of grinding type, with numerous ridges and granular crushing surface. Maxillule (Fig. 2E) endite with nine terminal spines and distal longitudinal rows of setae. Maxilliped (Figs 2F–G) bases longer than broad, each with five setae near palp articulation; endites subrectangular, each with setulated distolateral margin, strong incurving seta on distolateral apex, three tooth-like distal spines, innermost ovate, and two coupling hooks; palp article-1 naked, with small distolateral spur, article-2 with lateral seta and three mesial setae; article-3 curved, with seven mesial pinnate setae; article-4 as long as article-3, with about seven pinnate setae. Epignath (Fig. 2H) typical of family.

Cheliped ( Figs 1B , 2J–K) coxal sclerite extending posteriorly to rear margin of cephalothorax, with three setae; basis 1.7 times ltb, with posterior free process smaller than anterior part, with superior lateral setose tubercle; merus subtriangular, inferior margin just less than half of that of carpus, with group of seven long and short setae; carpus subovate, about as long as basis, 1.6 times ltb, inferior margin with three setae, superior margin with distal seta and about four small peg-like spines; propodus shorter and narrower than carpus, 2.2 times ltb, palm narrower distally, almost 2.5 times longer than fixed finger, with strong lateral seta near articulation with dactylus and mesial comb of five setae; fixed finger with raised crushing incisive margin, two inferior setae and three setae near incisive margin, terminal spine conical; dactylus narrower than fixed finger, with mesial seta.

Pereopod-1 ( Fig. 3A ) coxa with long seta; basis curved, narrower than pereopods 2–3, 3.6 times ltb, with proximal seta on slight process and with one PSS; ischium with two setae; merus twice as long as broad, with strongly oblique articulation with carpus, with one inferior seta; carpus ca. 1.5 times longer than merus, four times ltb, with three distal setae; propodus about as long as carpus, 3.6 times ltb, with three superior distal setae and long inferodistal seta; dactylus half length of propodus; unguis much longer than dactylus, together 1.4 times longer than propodus. Pereopod-2 ( Fig. 3B ) stouter than pereopod-1; coxa with long seta; basis 2.5 times ltb (greatest width), with three superior PSS; ischium with two unequal setae; merus subrectangular, 1.5 times ltb, naked (?); carpus just longer than merus, distal margin with a few microtrichia, one superior seta, one inferodistal seta and one minute inferior spine; propodus 1.2 times longer than carpus, narrower, distally with one superior distal seta, one longer inferodistal seta, and small stout inferior spine; dactylus and unguis of equal length, together 0.75 times as long as propodus. Pereopod-3 ( Fig. 3C ) similar to pereopod-2, but slightly smaller, basis with one superior seta, and merus and carpus slightly shorter.

Pereopod-4 ( Fig. 3D ) basis robust, 1.8 times ltb, with a superior PSS; ischium with two setae; merus curved, with oblique articulation with carpus, with two pedestal-based inferior spines; carpus about as long as merus, subrectangular, inferior margin with many microtrichia, distal margin with three stout bifid (or complex) spines and small superior seta; propodus about 0.75 times as long as carpus, superior margin with transverse microtrichia, distal margin with three unequal superior spines, and two stout inferior spines; dactylus and unguis fused, claw-like, shorter than propodus. Pereopod-5 ( Fig. 3E ) similar to pereopod-4. Pereopod-6 ( Fig. 3F ) similar to pereopods-4–5 but slightly larger, propodus with two long and four shorter superior distal spines.

FIGURE 2. Parakonarus kopure n. sp. Paratype preparatory female: A labrum; B labium; C left mandible; D right mandible;

Pleopod ( Fig. 3G ) peduncle broader than long, with mesial plumose seta; endopod subovate, with one mesial plumose seta at just over half mid length of ramus margin, lateral margin with 16 plumose setae, the stoutest most proximal; exopod longer and more slender than endopod, with ca. 24 plumose setae on lateral margin, the stoutest most proximal.

Uropod ( Fig. 1G ) peduncle 1.6 times ltb, with mesial distal seta; exopod 1-segmented, reaching as far as midpoint of segment-2 of endopod, with one mesial seta and two long, unequally thick, terminal setae; endopod 4-5 segmented (prep. females) or 5-segmented (ov. females), about twice as long as pleotelson, all segments longer than broad, segments 1–4 with two distal setae, segment-3 with mesial PSS; segment-5 with four long unequal setae and one PSS.

Manca-II: Habitus generally similar to neuter; length 0.78–1.02 mm. Uropod endopod 3 or 4-segmented.

Manca-III: Habitus (Fig. 4A) generally similar to manca-II; overall 5.3 times ltb; length 1.02–1.34 mm. Maxilliped (Fig. 4B) basis with three setae. Uropod (Fig. 4C) endopod 3 or 4-segmented.

Neuter: Habitus (Fig. 4D) similar to female but pereon outline generally more linear, with or without interpereonal gaps; fairly stout to fairly slender, about 5.5–6.5 times ltb; length 1.22–3.21 mm. Maxilliped (Fig.4E) basis with 3–5 setae. Uropod (Fig. 4F) endopod 3, 4 or 5-segmented. Last two characters size-related;

Primary male: Habitus (Fig. 5A) swimming form; overall fairly stout, 4.9 times ltb, length 1.70–2.67 mm. Cephalothorax (Fig. 5B) flask or pear shaped, narrower anteriorly than female, 1.3 times ltb, as long as pereonites 1–3 and half of pereonite-4 combined, with larger compound eyes. Pereon proportionately shorter than female, 46% of body length, pereonites 4–6 shorter than female. Pleon well developed, 25% of body length. Pleotelson similar to female.

Antennule (Fig. 5C) almost as long as cephalothorax and pereonite-1, with 3-articled peduncle and seven or eight flagellar segments; article-1 with several proximal PSS, a distal seta, and a PSS; article-2 just over half length of article-1, with distal seta; article-3 short, annular, with superior seta; flagellar segment-1 with three aesthetasc bundles (composite segment?), segments 2–7 with single ventrodistal aesthetasc bundle; segment-8 small, cap-like with five setae. Antenna (Fig. 5D) similar to female but article-4 with additional medial simple seta and two PSS; article-5 more slender than female.

Mouthparts largely absent. Maxilliped (Fig. 5E) small, basis with four distal setae, palp reduced, naked.

Cheliped (Figs 5F, 6A) pre-carpal articles similar to female; carpus with inferior protuberance, with three setae and without distal cuff; propodus as long as carpus, palm twice as long as broad, with incisive margin perpendicular to main axis, with three inferior setae, three setae near incisive margin, wide mesial comb of about nine setae, and seta near dactylus articulation; fixed finger very short; dactylus longer than inferior margin of propodus, with stout anterior seta; i.e. cheliped of subchelate form.

Pereopod-1 (Fig. 6B) slender, similar to female, basis just over three times ltb; ischium with one seta; merus about 2.4 times ltb, with oblique articulation with dactylus, with one small inferior seta; carpus rectangular, 1.5 times longer than merus, four times ltb, with five distal setae; propodus longer and more slender than carpus, with three distal setae; dactylus and unguis subequal, together about 0.6 times length of propodus. Pereopods 2–3 (Fig. 6C) of different type to female, more slender; basis 3.7 times ltb, with one simple and two PSS; ischium one seta; merus about twice as long as broad, with small inferior spine; carpus longer than merus, slightly expanded distally, with one superior seta, three inferior spines and one inferior seta; propodus 1.3 times longer than carpus, with superior and inferior transverse microtrichia, distally with one superior and two inferior setae; dactylus and unguis subequal, together only just over one third length of propodus.

Pereopods 4-5 (Fig. 6D) of different type to female, more slender; basis thicker than that of pereopods 2–3, 2.7 times ltb, with two proximal PSS; ischium with two unequal setae; merus bent, distally wider, with two inferior spines; carpus longer than merus, subrectangular, 2.3 times ltb, with distal microtrichia and four spines of different shape; propodus narrower and longer than carpus, with inferior microtrichia, two inferodistal spines and three pectinate superior distal spines; dactylus half as long as propodus, with inferior setules; unguis half as long as dactylus, tip bifid. Pereopod-6 (Fig. 6E) similar to pereopods 4–5 but propodus with five superior distal spines.

Pleopod (Fig. 6F) similar to female but setae fewer and much longer; endopod with 13 lateral setae and gap between most proximal and the remainder; exopod with 20 lateral setae, proximal four short.

Uropod (not figured) similar to female, endopod 5-segmented.

Remarks. At first glance this tanaidacean can be mistaken for a species of Paratanais Dana, 1852 (with typically short cephalothorax). This is an illusion created by the separate carapace plates. Sight of the multi-segmented uropod endopods, a leptocheliid character, dispels this at once.

Distribution and ecology. Little can be said about the distribution of P. kopure n. sp. other than current records are limited to a small section of the southern coast of North Island, i.e. between Pukerua Bay in the west and Te Awaite, 25 km northeast of Cape Palliser. It was not found by me during searches of suitable habitats at New Plymouth (North Island) or Kaikoura (South Island) in August/ September 2005 and January 2009 respectively.

Where found, P. kopure is fairly abundant in the lower eulittoral rocky shore among the teeming micro-fauna of Corallina officinalis turf and other encrusting/mat-forming red and brown algae, as well as serpulid tubes ( Pomatoceros caeruleus ). It constructs weakly-consolidated tubes or galleries of mucus to which sand grains, shell fragments and other detritus adhere. Sympatric tanaidaceans include robust apseudomorphans such as Apseudomorpha timaruvia ( Chilton, 1882) , Metapseudes sp. , and a Cyclopoapseudes sp. (= Apseudes latus Chilton, 1883 ?), the superficially similar Paratanais paraoa n. sp. (see below), and the pigmented tanaid, Zeuxoides rimuwhero Bird, 2008 .

Collections of P. kopure in both autumn (March-April) and spring (September) included all life-cycle stages from manca-II (newly released from the female’s marsupium) to ovigerous females and swimming males. The fairly low sex ratio of neuters/females to swimming males of 4.9: 1 in September compared to 21: 1 in March/ April might imply that breeding activity is higher in the spring. This species would be a very good candidate for further ecological study.

Figures

FIGURE 1. Parakonarus kopure n. sp. Holotype ovigerous female: A dorsum (pleon decurved slightly); B cephalothorax ante-

FIGURE 3. Parakonarus kopure n. sp. Paratype preparatory female: A–F pereopods 1–6 respectively, pereopod-1 with variant