Mangatangi parvum

Taylor, Christopher K., 2013, Further notes on New Zealand Enantiobuninae (Opiliones, Neopilionidae), with the description of a new genus and two new species, ZooKeys 263, pp. 59-73: 61-62

publication ID

http://dx.doi.org/10.3897/zookeys.263.4158

publication LSID

lsid:zoobank.org:pub:55F84F6E-9D91-45BD-B957-42B77C3FD3E3

persistent identifier

http://treatment.plazi.org/id/F3982336-8FDC-49EF-B17D-E899B32F312D

taxon LSID

lsid:zoobank.org:act:F3982336-8FDC-49EF-B17D-E899B32F312D

treatment provided by

ZooKeys by Pensoft

scientific name

Mangatangi parvum
status

sp. n.

Mangatangi parvum  ZBK  sp. n. Figure 1

Holotype.

♂. New Zealand, AK. Mangatangi, Hunua Ra., 8 Feb– 8 Mar 1977, I. Barton, ARA Kauri Seed Project, pit trap.

Paratypes.

1 ♀, as for holotype; 1 ♂, Cuvier Is, July, R. Forster.

Etymology.

From the Latin parvus, small, in reference to its small size compared to other New Zealand Enantiobuninae  .

Diagnosis.

Mangatangi parvum  can be distinguished from all other New Zealand Enantiobuninae  by the presence of a well developed tooth comb on the pedipalpal tarsal claw. It can be distinguished from Monoscutum titirangiense  , Acihasta salebrosa  and Templar incongruens  by its relatively long legs and unsclerotised dorsum. It differs from ‘Megalopsalis’ triascuta, all Pantopsalis  and most Forsteropsalis  species in the absence of either a mediodistal apophysis or hypersetose region on the pedipalpal patella, from Pantopsalis  species by its relatively bowed cheliceral fingers, and from Forsteropsalis  species by the absence of denticles on the medial side of the pedipalp coxa. Mangatangi parvum  can also be distinguished from all other New Zealand species, so far as is known, by its genital morphology: all other New Zealand species investigated to date have a relatively long glans that is either narrow in lateral view (most species) or possesses a distinct dorsal keel ( Pantopsalis  ). The deep and short glans of Mangatangi parvum  is also distinct from that of Enantiobuninae  elsewhere: Neopantopsalis  species have a very elongate and relatively flat glans, and Megalopsalis  and Spinicrus  species have a short but also distally flattened glans. The only other Enantiobuninae  in Australasia to possess comparatively deep glans are Australiscutum  and Tercentenarium linnaei  ; Mangatangi parvum  differs from Australiscutum  in possessing relatively long legs and retaining an anterior grill of spines over the spiracle, and from Tercentenarium linnaei  in lacking a large dorsolateral flange at the junction between shaft and glans. The glans of Thrasychirus  has never been illustrated in lateral view, but Mangatangi parvum  is clearly distinguished from that genus by possessing paired bristle groups at the junction between shaft and glans rather than single bristles.

Description.

Male (Figs 1 a–b, d–e, g–i, l): Total body length 2.06-2.74 (larger value in all measurements represents holotype), prosoma length 0.97-1.19, prosoma width 1.76-2.01. Dorsal prosomal plate mostly light orange-yellow, unarmed except short, spinose black setae scattered over entire body; anterior propeltidium lighter yellow-cream, supracheliceral groove extending roughly halfway between anterior margin of carapace and ocularium; median propeltidium with diffuse purple stripes along border with anterior propeltidium with diffuse silver-white markings behind purple stripes, dark brown markings on lateral edge of dorsal prosomal plate; ocularium silver with black stripes margining eyes, unarmed; postocularium not distinguished from remainder of posterior propeltidium. Mesopeltidium forming raised ridge, medially pale yellow, laterally dark brown. Ozopores on raised lateral lobes, anterior lobes of prosoma and ozopore lobes dark brown, posterior of ozopore lobes silver-white, remainder of lateral shelves mostly yellow with dark brown lateral margins broadening to diffuse dark brown patch at about three-quarters of distance from front of prosoma. Metapeltidium and dorsum of opisthosoma with background colour of purple broken by pale yellow mottling, particularly along segment boundaries, longitudinal mediolateral broken stripes of silver-white present as well as longitudinal medial rows of silver-white spots, sides of opisthosoma with purple background heavily broken by pale yellow punctations. Mouthparts white; coxae proximally pale yellow; coxae I and II distally with purple mottling, coxae III and IV with dark yellow-brown mottling laterally; genital operculum pale yellow; venter of opisthosoma mottled light purple with pale yellow stripes along segment boundaries.

Chelicerae: Segment I 2.85-3.51, segment II 3.82-4.62. Segment I ventrally cream, dorsally orange-yellow, sparsely denticulate dorsally; segment II inflated, orange-yellow, densely dorsally and sparsely ventrally denticulate. Cheliceral fingers (Fig. 1d) long, bowed, movable finger with setae close to median tooth.

Pedipalps: Femur 1.53-2.13, patella 0.65-0.77, tibia 0.71-1.03, tarsus 1.80-2.47. Coxae unarmed. Femur to tarsus long, slender, unarmed, femur to tibia cream with paler distal ends to each segment, tarsus off-white with yellow-brown shading at distal end. Patella and tibia (Fig. 1e) straight, patella without distal prolateral apophysis or hypersetose region. Plumose setae absent. Microtrichia on distal half of tarsus only. Claw with ventral tooth-comb.

Legs: Leg I femur 2.99-3.80, patella 0.71-0.91, tibia 2.93-3.87; leg II not preserved; leg III 2.56-3.38, patella 0.77-0.93, tibia 2.70-3.45; leg IV femur 4.05-5.01, patella and tibia not preserved. All segments unarmed. Trochanters pale yellow, trochanters III and IV with dark yellow-brown mottling laterally. Femora to tarsi pale yellow, patellae and distal ends of femora and tibiae darkening to orange-yellow. Leg II not preserved; tibia IV with three pseudosegments.

Penis (Figs 1 g–i): Glans noticeably short and deep, sides parabolic in ventral view. Bristle groups of medium length. Tendon short, not extending far behind bristle groups.

Spiracle (Fig. 1l): Curtain of distally anastomosing spines extending over entire spiracle; shortening to cluster of tubercles (possibly lace tubercles) at medial corner.

Female (Figs 1c, f, j–k): Coloration similar to that of male. Other features as for male except for following: Chelicerae not enlarged, unarmed, segment I without ventral spine. Pedipalp (Fig. 1f) with microtrichia over entire patella, tibia and tarsus except glabrous dorsal line on patella and tibia. Ovipositor (Figs 1 j–k) with single pair of seminal receptacles.

Phylogeny.

Mangatangi parvum  is probably related to the clade formed by Forsteropsalis  and Pantopsalis  , with which it shares the presence of sharp papillae on the glans, and of setae close to the major tooth of the mobile finger of the chelicera (this last feature is also present in Neopantopsalis  ). The retention in Mangatangi parvum  of a plesiomorphic tooth-comb on the pedipalpal tarsal claw, together with Mangatangi parvum  's distinctly short glans, could suggest a sister relationship between Mangatangi parvum  and the Pantopsalis  + Forsteropsalis  clade, but this should perhaps be treated with caution. Pantopsalis rennelli  and Pantopsalis cheliferoides  each retain reduced teeth arrays (a single tooth in the latter species) on the tarsal claw, and that of Pantopsalis albipalpis  has a ventral rugose area that may correspond to the remains of the tooth-row. The loss of the tooth-row in Pantopsalis  and Forsteropsalis  has therefore happened at least partially in parallel. As regards the short glans of Mangatangi parvum  compared to the long glans of Pantopsalis  and Forsteropsalis  , our understanding of enantiobunine phylogeny is not yet robustly resolved ( Taylor 2011) and it is questionable which state is plesiomorphic for the clade.