Iphimediidae of New Zealand ( Crustacea , Amphipoda )

Over 100 species of Iphimediidae are known worldwide, yet only four were known from New Zealand waters. Many iphimediids have been recorded from Australian waters (Coleman & Lowry 2006) to the northwest and in Antarctic waters (Coleman 2007) south of New Zealand. So it is expected that discovering more species of iphimediids in New Zealand is outstanding. Improved sampling techniques, using small meshed gear in the understudied deep sea, gained two species of iphimediids new to science described here in detail. The new species belong to the genus Labriphimedia K.H. Barnard, 1931; the two other genera present in New Zealand are Iphimedia Rathke, 1843 and Anisoiphimedia G.S. Karaman, 1980.


Introduction
Over 100 species of Iphimediidae are known worldwide, yet only four were known from new zealand waters.many iphimediids have been recorded from australian waters (Coleman & lowry 2006) to the northwest and in antarctic waters (Coleman 2007) south of new zealand.So it is expected that discovering more species of iphimediids in new zealand is outstanding.Improved sampling techniques, using small meshed gear in the understudied deep sea, gained two species of iphimediids new to science described here in detail.The new species belong to the genus Labriphimedia K.H. Barnard, 1931; the two other genera present in new zealand are Iphimedia rathke, 1843 and Anisoiphimedia G.S. Karaman, 1980.Anisoiphimedia is a dubious genus (Coleman & lowry 2006), that will be revised when more material becomes available.Anisoiphimedia haurakiensis (Hurley, 1954) from subtropical northern new zealand was originally described in the genus Iphimedia.In contract, the species from cold southern new zealand waters, Iphimedia spinosa (Hurley, 1954), was originally described as belonging to the genus Panoploea Thomson, 1880.
Four of the five species of Labriphimedia are known from new zealand waters.The species Labriphimedia hinemoa (Hurley, 1954) from shallow waters of the Hauraki Gulf, northern new zealand, was originally described in the genus Maoriphimedia.Labriphimedia pulchridentata (Stebbing, 1883) was described from Heard Island at 136 m but recently found at the macquarie ridge, south of new zealand in about 700 m depth (lörz 2012).Labriphimedia vespucci Barnard, 1931 is known from the Falkland Islands at 105-115 m depth, and the two species new to science described herein were sampled on Chatham rise east of new zealand in 520-640 m depth.
For sampling location of all iphimediids in new zealand waters see Fig. 1.
as the genus concept of the Iphimediidae is still under construction, a key directly from family level Iphimediidae to species level is provided.

Material and Methods
The new iphimediid amphipoda were collected during the Ocean Survey 20/20 with r/V Tangaroa on the Chatham rise in 2007, east of new zealand.The material was sampled via an epibenthic sledge with a 500 µm mesh size.The iphimediids were fixed in 90% ethanol and later transferred into glycerol and mounted on slides for the preparation of the drawings.Pencil drawings were made with a camera lucida on a leica m 205c dissecting microscope and a leica DmlB compound microscope.The line drawings were made using the technique described in Coleman (2003Coleman ( , 2009)).length measurements were made along the outline of the animals, beginning at the tip of the rostrum to the end of the telson.The descriptions were generated from a DelTa database (Dallwitz 1993 onwards) of the Iphimedia species and related genera like Coboldus of the world, used in Coleman & lowry (2006).The DelTa text-output was modified to improve readability and adding characters that are relevant for the new taxa presented herein.The type material is deposited in the Invertebrate Collection of the national Institute of Water and atmospheric research (nIWa) in Wellington, new zealand.

Additional material
Two paratypes of unknown sex, 5.2 mm and 5 mm, nIWa 31826, same station data as holotype.

Etymology
This species is named for ms meike Snyder, the dear aunt of the senior author.

Etymology
This species is named for the amiable ms martine Willcox, the mother of the son-in-law of the senior author.
PLeon (Fig. 7a).Pleonite 1 with a low, truncated mid-dorsal carina with a small posterior point, with 2 large, pointed spines, space between spines wide.Epimeron 1 posterior margin with 1 mid-lateral spine, posteroventral corner acutely with short point.Pleonite 2 with a low truncated mid-dorsal carina with a small posterior point, dorsodistal margin with 2 large, pointed spines, space between spines wide.Epimeron 2 posterior margin with 1 mid-lateral spine, posteroventral corner pointed.Pleonite 3 with a broadly rounded, large mid-dorsal carina.Epimeron 3 posterior margin without well developed lateral spines, posteroventral corner produced into 1 smooth spine, its dorsal part minutely serrate.Urosomite 1 large with broadly rounded, large mid-dorsal carina with a shallow depression.Urosomite 2 shortest, smooth.Telson (Fig. 11F) truncate, with several small notches along the distal margin.

Discussion
The classification of the two new species turned out to be difficult.It was clear that they were new species after comparison with all known iphimediid species, but it was very difficult to decide in which genus they belong.The systematics of iphimediids is mostly based on the spination of the body, the coxae and the bases of the appendages, and on the mouthpart morphology, more specifically the shape and dentation of the incisor, and the development of the palps of maxilla 1 and the maxilliped.
The mandible of L. meikae sp.nov. is similar to that of Labriphimedia hinemoa (Hurley, 1954).In both species the incisor is toothless and apically rounded and medially excavate.also some other characters on the mouthparts correspond in the shapes: of antenna 1 peduncular article 1, upper lip, lower lip, maxilla 1 and maxilliped.The heads of both species are very different: L. meikae sp.nov.has a weakly curved rostrum (vs.strongly curved), large eyes (vs.small), anterior head margin rounded in lateral view (vs.pointed) and the ventral head margin with a sculptured rounded lobe (vs.longer subacute lobe).
The coxal plates 1-4 are not so pointed ventrally in L. hinemoa.The shapes of the pereopod 5-7 bases are similar, but the anterior margin in L. meikae sp.nov. is not so densely covered with setae as in L. hinemoa.
Both species share the 4 pairs of mid-dorsal spines, but the shape differs.In L. meikae sp.nov. the dorsal spines are slender seen from laterally and have a wide u-shaped excavation seen from dorsally.However, in L. hinemoa the spines are rather wide from lateral aspect and form a v-shaped narrow slit in the dorsal view.The telson of L. hinemoa appears to be deeper notched and has subacute lobes compared to L. meikae sp.nov., where the telson lobes are truncate.
Labriphimedia martinae sp.nov. is more difficult to classify.This species has some superficial resemblance to Labriphimedia vespucci K.H. Barnard, 1931 in the shape of coxae 1-4 and in the prominent carina on pleonite 3 and urosomite 1, which is, however, notched in lateral view in the latter species.also, both species have a serrate margin of epimeron 3 just dorsal of the posteroventral angle, but in L. vespucci there is an additional spine on the posterior margin.Compared to L. vespucci, in L. martinae sp.nov. the paired dorsal spines on pleonite 3 are missing, the eyes are much larger, covering more than half of the head (vs.less than half) and the mouthparts are very different: the mouthparts are arranged into a pointed bundle, upper lip, mandibles and lower lip are pointed, also maxilla 1 is elongate, but its palp is reduced to a small scale.In L. vespucci, however, the mouthparts do not seem to be elongate, the upper lip is much broader than long and maxilla 1 looks similar to that of L. meikae sp.nov.(not elongate, with a long 2-articulate palp).a shortened palp of maxilla 1 is known in many iphimediid species, especially in the genus Iphimedia, but there the palp is 2-articulate.a 1-articulate palp of maxilla 1 within Iphimediidae is known in the genus Coboldus Krapp-Schickel, 1974 and we were initially attracted by the idea that L. martinae sp.nov.could be classified in the genus Coboldus.In favour of Coboldus would count the shortened 1-articulate palp of maxilla 1, the pointed mouthpart bundle and the elongate 2nd article of the mandibular palp, which some species have (e.g., C. laetifucatus Just, 1990).However, other characteristics of Coboldus are not present in L. martinae: a strongly produced 2nd article of the maxillipedal palp guarding along article 3, the absence of carinae on pleonites 1-3 and urosomite 1 and the presence of a lateral spine on the posterior margin of epimeron 3. It may be that there is some phylogenetic connection between both genera, Coboldus and Labriphimedia, which we hope to resolve in a future project.
The genus Labriphimedia is so far only known from the southern hemisphere, and four of the now known five species of Labriphimedia occur in new zealand waters.