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Epimeria Schiaparelli Sp. Nov., An Amphipod Crustacean (Family Epimeriidae) From The Ross Sea, Antarctica, With Molecular Characterisation Of The Species Complex

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  • Institute for Marine Ecosystems and Fisheries Science

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Epimeria schiaparelli sp. nov. from the Ross Sea, Antarctica, is described in detail. The new species occurs on the shelf in 130–350 m depth. Epimeria schiaparelli can be distinguished from the most similar species, E. similis Chevreux, 1912 and E. macrodonta Walker, 1906 by a relatively short rostrum and a short second pereonite amongst other characters. Two distinct colour patterns are reported. Partial gene sequences of the mitochondrial cytochrome oxidase subunit I (COI) from 11 specimens of E. schiaparelli confirm that this species is new to science and closely related to E. similis, E. macrodonta and E. reoproi. The recent and historical separation of this Antarctic species is discussed. The syntypes of E. macrodonta consist of two species, so a lectotype is here designated.
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Accepted by S. Ahyong: 6 Dec. 2006; published: 1 Feb. 2007 23
ZOOTAXA
ISSN 1175-5326 (print edition)
ISSN 1175-5334 (online edition)
Copyright © 2007 · Magnolia Press
Zootaxa 1402: 2337 (2007)
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Epimeria schiaparelli sp. nov., an amphipod crustacean (family Epimeriidae)
from the Ross Sea, Antarctica, with molecular characterisation of the species
complex
ANNE-NINA LÖRZ1 ELIZABETH W. MAAS1, KATRIN LINSE2 & GRAHAM D. FENWICK3
1National Institute of Water & Atmospheric Research, Private Bag 14901, Kilbirnie Wellington, New Zealand; corresponding author.
2British Antarctic Survey, Natural Environmental Research Council, High Cross, Madingley Road, Cambridge, CB3 0ET, UK
3National Institute of Water & Atmospheric Research, P.O. Box 8602, Christchurch, New Zealand.
Abstract
Epimeria schiaparelli sp. nov. from the Ross Sea, Antarctica, is described in detail. The new species occurs on the shelf
in 130350 m depth. Epimeria schiaparelli can be distinguished from the most similar species, E. similis Chevreux, 1912
and E. macrodonta Walker, 1906 by a relatively short rostrum and a short second pereonite amongst other characters.
Two distinct colour patterns are reported. Partial gene sequences of the mitochondrial cytochrome oxidase subunit I
(COI) from 11 specimens of E. schiaparelli confirm that this species is new to science and closely related to E. similis, E.
macrodonta and E. reoproi. The recent and historical separation of this Antarctic species is discussed. The syntypes of E.
macrodonta consist of two species, so a lectotype is here designated.
Key words: Antarctica, taxonomy, Amphipoda, Crustacea, Epimeriidae, Epimeria, Cytochrome oxidase I.
Introduction
Species of the amphipod family Epimeriidae dominate the Antarctic shelf benthos (Coleman & Barnard 1991;
Lörz 2003). Currently 24 species in five genera of Epimeriidae are known from the Southern Ocean, 21 of
these belonging to the genus Epimeria. During the joint New Zealand–Italian BioRoss Expedition TAN0402
to the western Ross Sea and the Balleny Islands in early 2004, more than 3000 amphipods were collected from
20–1200 m depths. Lysianassidae was the most speciose amphipod family, followed by the Epimeriidae and
Eusiridae. The Ischyroceridae was most abundant numerically, comprising nearly one-third of all specimens
collected (868 specimens), followed by the Lysianassidae (528) and Epimeriidae (291).
Among the epimeriid amphipods obtained were several specimens belonging to the diverse Antarctic
genus Epimeria Costa, 1851. Preliminary examination revealed at least eight species, one of which proved
new to science and is here described.
Material and methods
Four different gear types were used to collect benthic invertebrates from RV Tangaroa during the expedition:
Van Veen grabs, Agassiz trawls, an epibenthic sled and a rock dredge. Amphipods were sorted from collec-
tions immediately (often alive), fixed in 98% ethanol and transferred to 70% ethanol about four months later.
Specimens were examined and dissected using a Leica MZ9.5 stereomicroscope and drawn using a camera
LÖRZ ET AL.
24 · Zootaxa 1402 © 2007 Magnolia Press
lucida attachment. Small appendages (mouthparts, uropods, telson) were temporarily mounted in lactic acid,
stained with lignin pink and examined and drawn using a Nikon compound microscope fitted with a camera
lucida. The body lengths of specimens examined were measured by tracing individual’s mid-trunk lengths (tip
of the rostrum to end of telson) using a camera lucida, measuring this curved length and then converting this
to actual animal body length by correcting for magnification. All illustrations were inked electronically using
a Wacom Board.
Setal terminology follows Watling (1989). Within the description, abbreviations are used for slender setae
(SS) and robust setae (RS). We use the terms cusp and spine to refer to non-articulating processes or exten-
sions of the cuticle.
Type material is held in the National Institute of Water and Atmospheric Research Invertebrate Collection
at Wellington (NIWA), New Zealand. Additional paratypes were deposited at the Museum für Naturkunde
(ZMB), Berlin, Germany, and the National Museum of New Zealand Te Papa Tongarewa (NMNZ), Welling-
ton, New Zealand.
Genomic DNA was isolated from amphipod pereopods using the DNEasy tissue extraction kit (Qiagen
Ltd) and quantified using the PicoGreen quantification kit (Molecular Probes, Invitrogen Ltd). The partial
mitochondrial cytochrome oxidase subunit I (COI) gene was amplified using the universals primers described
by Folmer et al. 1994 using Eppendorf HotMaster® Mix (Eppendorf, Germany), 0.2 µM of each primer and
between 20–200 ng of genomic DNA. PCR reactions were carried out in a GeneAmp 2720 thermocycler
(Applied Biosystems, Foster City, California, USA) using the following conditions: an initial hold at 95ºC for
5 minutes and then 30 cycles of 95ºC for 30 seconds; 50ºC for 30 seconds; 72ºC for 1.5 minutes; and a final
extension at 72ºC for 7 minutes. PCR products were purified using QIAquick Spin Columns (Qiagen Ltd) and
quantified using the PicoGreen Kit (Molecular Probes, Invitrogen Ltd). Sequencing of the COI gene was car-
ried out by the Allan Wilson Centre Genome Service, Massey University, Palmerston North, New Zealand,
using the amplification primers.
The proof-read sequences of the 11 specimens were aligned using ARB software (Ludwig et al. 2004)
against reference sequences of other Epimeria species (E. georgiana, E. macrodonta, E. reoproi, E. robusta,
E. rubrieques, E. similis) and Eusirus cf. perdentatus Chevreux, 1912 obtained from European Molecular
Biology Laboratory (EMBL) genome sequence database. Eusirus cf. perdentatus was chosen as the outgroup,
as it had previously been used by Lörz & Held (2004) for this purposes for the analysis of species within the
Epimeriidae family and had proven to be useful. Evolutionary distances were calculated from sequence pair
dissimilarities using only unambiguously sequenced positions, and phylograms were generated using
PAUP*4.0b10 (Swofford 2002) under the heuristic search (parameters used: random addition sequence, TBR
100 replicates). To assess relative support for clades, 1000 bootstrap replicates were calculated in PAUP*. The
partial COI gene sequences determined in this study are deposited in the EMBL database and the accession
number for each specimen is shown in Table 2.
Systematics
Order AMPHIPODA Latreille, 1816
Suborder GAMMARIDEA Latreille, 1802
Family EPIMERIIDAE Boeck, 1871
Genus Epimeria Costa, 1851
The most recent family diagnosis for the Epimeriidae is that of Coleman and Barnard (1991), and Barnard and
Karaman (1991), respectively. The first volume of Synopsis of benthic Amphipoda of the Southern Ocean by
Charles Oliver Coleman, including a key to the Antarctic species of Epimeriidae, will be published shortly.
Zootaxa 1402 © 2007 Magnolia Press · 25
EPIMERIA SCHIAPARELLI SP. NOV.
Epimeria schiaparelli sp. nov. (Figs 1–7)
Material examined (all western Ross Sea, Antarctica)
Holotype: ovig. ? (29.9 mm,), NIWA 18174, TAN0402/195, epibenthic sled, 71° 37.32–37.14' S, 170°
55.38–55.54' E, 28 February 2004, 244 m.
FIGURE 1. Epimeria schiaparelli sp. nov. Holotype, 29.9 mm, NIWA 18174. A, lateral habitus; B, head; C, dorsal habi-
tus.
Paratypes: Each registration number refers to a single specimen unless otherwise stated; NIWA 18175,
adult ?, 21.6 mm, NIWA 18187, seven specimens, TAN0402/195, epibenthic sled, 71° 37.32–37.14'S, 170°
55.38–55.54E, 28 February 2004, 244 m; NIWA 18181, NIWA 18183, NIWA 18193, NIWA 18198,
TAN0402/22, epibenthic sled, 71° 48.06'–47.91'S, 170° 56.48'-57.56'E, 09 February 2004, 151 m; NIWA
18184, TAN0402/25, epibenthic sled, 71° 47.92–47.78'S, 170° 55.97-56.95'E, 09 February 2004, 127 m;
NIWA 18202, TAN0402/33, epibenthic sled, 71° 45.28–45.35'S, 171° 25.02– 23.94'E, 10 February 2004, 282
m; NIWA 18176, ovigerous, NIWA 18178, NIWA 18190, NIWA 18191, ZMB 27576–78, TAN0402/39,
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26 · Zootaxa 1402 © 2007 Magnolia Press
epibenthic sled, 71° 45.30–45.53'S, 171° 8.55–9.16'E, 10 February 2004, 251 m; NIWA 18180, ZMB 27576–
78 (former NIWA 18196), TAN0402/112, epibenthic sled, 71° 17.61–17.77'S, 170° 34.60–35.45'E, 18 Febru-
ary 2004, 346 m; NIWA 18194, TAN0402/116, epibenthic sled, 71° 17.93–18.21'S, 170° 32.43–33.02'E, 18
February 2004, 312 m; NIWA 18182, TAN0402/33, epibenthic sled, 71° 45.28–45.35'S, 171° 25.02–23.94'E,
10 February 2004, 282 m; NIWA 18188, TAN0402/189, van Veen Grab, 71°34.49'S, 170°52.24'E, 27 Febru-
ary 2004, 231 m; NIWA 18177, NIWA 18195, NIWA 18197, NIWA 18199, TAN0402/140, epibenthic sled,
72° 0.81–1.08'S, 170° 46.47–45.97' E, 26 February 2004, 231 m; NIWA 18192, TAN0402/190, Epibenthic
Sled, 71° 34.75–34.97'S, 170° 52.37–52.43'E, 27 February 2004, 230 m; NIWA 18187, NMNZ Cr. 10024
(former NIWA 18201, 3 specimens), TAN0402/195, epibenthic sled, 71° 37.32–37.14' S, 170° 55.38–55.54'E,
28 February 2004, 244 m; NIWA 18179, TAN0402/197, epibenthic sled, 71° 37.24–37.11'S, 170° 51.99–
52.73'E, 28 February 2004, 198 m; NIWA 18185, TAN0402/198, Van Veen grab, 71°37.04'S, 170°53.61'E, 28
February 2004, 222 m.
FIGURE 2. Epimeria schiaparelli sp. nov. Holotype, 29.9 mm, NIWA 18174. A, maxilla 2; B, maxilla 1; C, mandible;
D, maxilliped; E, lower lip.
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EPIMERIA SCHIAPARELLI SP. NOV.
Etymology
The species is dedicated to Dr Stefano Schiaparelli, who kindly shared his enthusiasm and knowledge on
board during the BioRoss Antarctic expedition.
FIGURE 3. Epimeria schiaparelli sp. nov. Holotype, 29.9 mm, NIWA 18174. A, antenna 1; B, antenna 1 peduncle; C,
antenna 2; D, coxa 1; E, coxa 2; F, coxa 3; G, coxa 4; H, coxa 5.
Description
Head higher than long, anterior cephalic margin sinuous, lateral cephalic lobe acutely produced; rostrum
(Fig. 1A, B) c. 1.5 x head length, reaching proximal part of antenna 1 peduncle article 2; eye oval, 0.5 x head
height, set back from anterior cephalic lobe margin. Pereonite 1 subequal in length to head (excluding ros-
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28 · Zootaxa 1402 © 2007 Magnolia Press
trum), pereonite 2 c. 0.5 x length of 1, pereonites 1 and 2 lacking mid-dorsal or dorsolateral processes; pereo-
nite 3 c. 1.3 x longer than 1, posterior margin with weak tooth appearing as thickening in lateral aspect, with
weak dorsolateral process; pereonite 4 with blunt mid-dorsal process overhanging pereonite 5, blunt dorsolat-
eral carina weakly developed; pereonites 5–7 and pleonites 1–3 with large, acute mid-dorsal teeth curved pos-
teriorly to overhang following somite and distinct, dorsolateral processes, obtuse on 5–6, acute on 7 and
pleonites 1–3. Epimeron 1 (Fig. 6A) narrow, anteroventral angle rounded, with acute posterodistal tooth, pos-
terior margin concave distally; epimera 2–3 similar to 1, transverse ventral margins increasingly longer, poste-
rior excavations shallower, posterodistal cusps increasingly produced. Urosomite 1 (Fig. 1A) with acute cone
mid-dorsally, lacking dorsolateral processes; urosomite 2 shortest; urosomites 2 and 3 lacking mid-dorsal pro-
cesses, with acute dorsolateral carinae at posterior margin.
FIGURE 4. Epimeria schiaparelli sp. nov. Holotype, 29.9 mm, NIWA 18174. A, gnathopod 1; B, detail of gnathopod 1;
C, gnathopod 2; D, detail of gnathopod 2.
Antenna 1 (Fig. 3A, B): peduncle article 1 with many plumose setae distal margin with 2 short and 1 long
processes; article 2 with 2 long acute processes distally, length (including processes) slightly shorter than arti-
cle 1; article 3 shortest; accessory flagellum scale-like; primary flagellum of 35 articles. Antenna 2 (Fig. 3C)
(longer than A1; article 2 with 2 large acute distal cusps; peduncle article 3 with short obtuse distal cusps; arti-
cles 4 and 5 lacking distal processes, lengths subequal; flagellum with 75 articles.
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EPIMERIA SCHIAPARELLI SP. NOV.
Mandible (Fig. 2C): incisor and lacinia mobilis strongly dentate; molar produced and triturative; palp arti-
cle 3 densely setose medially, with long stout SS distally. Lower lip (Fig. 2E) (hypopharynx) with wide lobes
and groups of setae on distomedial angles, hypopharyngeal gap narrow. Maxilla 1 (Fig. 2B) medial plate sub-
triangular, obliquely convex inner margin with 11 stout, plumose SS; lateral plate distal margin oblique, with
11 medially lobate RS; palp strongly exceeding outer plate; palp article 1 short, article 2 slightly curved medi-
ally with stout SS distomedially, stout RS distally. Maxilla 2 (Fig. 2A) with long, distally crenulate setae dis-
tally on lateral and medial plates. Maxilliped (Fig. 2D) lateral plate broadly rounded distally, reaching
midpoint of carpus, medial plate with nodular RS and a row of long plumose SS on medial, anterior face; palp
medial margin strongly setose; merus distally expanded; dactyl with serrate medial margin.
Gnathopod 1 (Fig. 4A, B): coxa 1 long and slender, anterior margin straight, broadly rounded anterodis-
tally to form acute posterodistal corner, posterior margin straight; basis linear, slender, both margins with
numerous fine SS; merus slightly longer than ischium, anterior margin very short, distal margin oblique, pos-
terodistal angle acute, setose; carpus slightly expanded distally, distal margin transverse, anterodistal angle
with SS, distal half of posterior margin with long SS; propodus subrectangular, 0.6 x carpus length, anterior
margin naked except for distal fringe of short SS, palm finely crenulate, slightly oblique, with cluster of RS
defining rounded distal margin, posterior margin with numerous long SS; dactylus slender, slightly curved,
posterior margin strongly serrate. Gnathopod 2 (Fig. 4C, D) slightly longer than gnathopod 1; coxa 2 similar
in shape to coxa 1, tapering distally, posterior margin slightly concave; basis linear, extending 50% below
coxa; merus short, 1.3 x ischium length, anterior margin very short, distal margin obliquely articulating with
carpus, with group of 4 or 5 SS posterodistally; carpus curved proximally, widened distally to 0.3 x length, 4.5
x merus length, anterior margin naked except for transverse row of SS distally, posterior margin with numer-
ous stout SS distally; propodus 0.6 x carpus length, 0.5 x as wide as long, palm almost transverse, rounded,
finely crenulated, lined with numerous submarginal RS; dactylus large, slightly exceeding palm, posterior
margin serrate. Pereopod 3 (Fig. 5A): coxa wider and slightly longer than coxa 2, posterior margin strongly
concave; basis linear, extending just further than coxa, anterior margin finely setulose, posterior margin with 7
groups of SS; merus slightly expanded distally, anterodistal angle weakly produced into narrow flange over-
hanging distal c. 0.2 of carpus; carpus c. 0.5 x merus length, slightly widened distally, anterior margin naked,
posterior margin with 6 pairs of RS; propodus 1.3 x carpus length, naked anteriorly, posterior margin with 8–
10 pairs of RS; dactylus stout, curved, 0.5 x propodus length. Pereopod 4 (Fig. 5B): coxa slightly longer than
3, 1.5 x longer than wide, anterior margin strongly convex, produced into stout, acute posterodistal cusp
directed posterodistally, posterior margin divided at mid point by subacute cusp into two concave sections;
basis to dactylus as for pereopod 3. Pereopod 5 (Fig. 5D): coxa subrectangular, wider than long, posterodistal
corner produced as slender cusp c. 0.5 x length of rest of coxa; posterior margin weakly concave; basis
scarcely covered by coxa, expanded into irregular posterior flange with proximal rounded lobe and acute tri-
angular posterodistal tooth; merus constricted proximally, posterodistally produced to overhang c. 0.2 carpus;
carpus slightly widened distally, 0.8 x merus length; propodus sublinear, subequal in length to merus, poste-
rior margin with 8 pairs of RS; dactylus curved, stout, c. 0.5 x propodus length. Pereopod 6 (Fig. 5E): coxa
anterior half hidden by coxa 5, anterior margin weakly concave, posterodistal corner produced into short, pos-
terolateral tooth, posterior margin broadly rounded; basis to dactylus as in pereopod 5. Pereopod 7 (Fig. 5C):
coxa subrectangular, 1.1 x wider than long, slightly narrower distally; basis expanded posteriorly, margin sin-
uous, broadly rounded proximally, distal concavity forming acute cusp at posterodistal angle; ischium to dac-
tylus as in pereopods 5 and 6.
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30 · Zootaxa 1402 © 2007 Magnolia Press
FIGURE 5. Epimeria schiaparelli sp. nov. Holotype, 29.9 mm, NIWA 18174. A, pereopod 3; B, pereopod 4; C, pereo-
pod 7; D, pereopod 5; E, pereopod 6.
Uropods extending equally, rami apices naked. Uropod 1 (Fig. 6C): peduncle subequal in length to inner
ramus, medial margin with few RS proximally and 1 distally, distal 0.6 of lateral margin with close row of
short RS; inner ramus lateral margin with spaced row of short RS, medial margin with sparse RS; outer ramus
marginally shorter than inner, marginal setation as in inner ramus. Uropod 2 (Fig. 6D): peduncle naked except
for 1 or 2 short RS distally on each margin; inner ramus length 1.3 x outer ramus, medial margin with sparse
Zootaxa 1402 © 2007 Magnolia Press · 31
EPIMERIA SCHIAPARELLI SP. NOV.
RS, distal lateral margin with close RS; outer ramus 1.2 x peduncle length, both margins with close rows of
short RS over mid 0.5 of length. Uropod 3 (Fig. 6E): peduncle short, c. 0.5 x length of inner ramus, produced
into acute process extending c. 0.15 alongside inner ramus; outer ramus over 0.6 of its length, medial margin
with sparse row of short RS along full length, inner margin with sparse short RS along distal 0.5 of length;
outer ramus 0.8 x length of inner, almost twice as long as peduncle, lateral margin with dense row of RS over
proximal 0.6 of length, medial margin with RS confined to distal 0.3 of length. Telson (Fig. 6B) weakly taper-
ing to c. 0.8 of basal width proximally, 1.2 x longer than wide, v-shaped emargination 0.3 x length, lobes tri-
angular, subacute, narrowly rounded apically.
FIGURE 6. Epimeria schiaparelli sp. nov. Holotype, 29.9 mm, NIWA 18174. A, lateral view of epimeral plates, uro-
some; uropods 1–3, and telson; B, telson; C, uropod 1; D, uropod 2; E, uropod 3.
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32 · Zootaxa 1402 © 2007 Magnolia Press
Remarks
The new species, Epimeria schiaparelli sp. nov., superficially resembles Epimeria similis Chevreux, 1912
and E. macrodonta Walker, 1906 in the dorsal armature of pereonites 3–7 and pleonites 1–3. Epimeria schia-
parelli, however, lacks carinae on pereonites 1 and 2, has a relatively short flexed rostrum and pereonite 2 is
short relative to pereonite 1. The main differences between species of this complex are summarized in Table 1.
TABLE 1. Summary of morphological differences between Epimeria schiaparelli n. sp., Epimeria similis Chevreux,
1912 and E. macrodonta Walker, 1907.
Morphological variation
The large dorsal pereonite and pleonite spines are so characteristic of species of Epimeria vary in size and
shape in E. schiaparelli. The rostrum varies in relative length (mean rostrum: head ratio is 1:1.33 (n = 18)). In
comparison, this ratio is greater in E. macrodonta (> 2:1) and up to at least 3:1, as in the newly designated lec-
totype.
The lateral spine on article 2 of antenna 1 always exceeds the length of the unproduced article (mean ratio
spine: article is 5.9 (n = 19)) in E. schiaparelli. In E. macrodonta the lateral spine of article 2 of the first
antenna is always longer than article 2. In E. similis, however, the lateral spine of antenna 1 article 2 is always
shorter than the unproduced article.
Slight variation is present in development of the mid-dorsal and dorsolateral processes on pereonite 3. In
none of the specimens examined did the size of the pereonite 3 processes approach the equivalent processes
on pereonite 4. A few specimens had slightly (c. 1.3 x) enlarged cusps on urosomites 2 and 3.
Similar variation is present in the development of the posteroproximal cusp on coxa 4 of E. schiaparelli.
In some specimens, this cusp was represented by a small irregularity on the concave posterior margin. Usu-
ally, however, this cusp was strong and acute, with its length averaging 80% of the width of coxa 4 (n = 19).
Molecular results
Analysis of the data recovered 12 most parsimonious trees (TL = 457, CI = 0.702, HI = 30298, RI =
Characters E. schiaparelli E. similis E. macrodonta
Rostrum: head length 1:1 1:1 2:1
Antenna 1 article 2 lateral spine reaches article
3 Yes No Yes
Pereonite 1 mid-dorsal process None None Thickened posterior margin
Pereonite 2: l mid-dorsal length 1:2 1:1 1:2
Pereonite 2 mid-dorsal process None Thickened posterior
margin None
Pereonite 2 posterolateral process None Weak None
Pereonite 3 mid-dorsal process Thickened posterior margin Distinct carina Distinct carina
Pereonite 3 dorsolateral process Weak Well developed Distinct process
Dorsal teeth (carinae) Short and wide Short and wide Long and narrow
Gnathopods 1–2, carpus: propodus, 1.5: 1 1:1 1.5: 1
Pereopods 3–4, basis: merus 1: 1 1.5: 1 1: 1
Uropod 3 peduncle: rami 1: 4 1: 3 1: 3
Coxae 1–3 Broader Broader Narrow
Coxa 5 posterior spine extends to pereonite > Mid 7 Mid 6 Mid 7
Pleonite 3 mid-dorsal carina Single, upright Bilobed, keel-like with
dorsal depression Single, upright
Basis of pereonite 5 Straight Straight Concave
Posterior margin of coxae 6–7 Rounded Straight Rounded, convex
Zootaxa 1402 © 2007 Magnolia Press · 33
EPIMERIA SCHIAPARELLI SP. NOV.
0.717, RC = 0.503). The strict consensus and bootstrap values greater than 50% are shown in Fig. 8. Analysis
of the partial COI gene showed a 0–2.19% sequence divergence within the E. schiaparelli specimens (Table 2,
Fig. 8) and that these specimens form a distinct clade within Epimeria. This divergence within E. schiaparelli
is much less than this group’s divergence from E. macrodonta (8.93–8.38%), the most closely related species.
Divergences between other species were much larger (e.g., 12.02% divergence for E. similis and E. macro-
donta (Table 2, Fig. 8)) further supporting the conspecificity of all specimens identified as E. schiaparelli,
despite conspicuous variation in some morphological characters.
TABLE 2. Uncorrected genetic COI distances (549 bases analysed).
Discussion
Validity of Epimeria similis and E. macrodonta
The identities of Epimeria macrodonta and E. similis have long been confused. This confusion started
with Walkers (1906) very short original description of E. macrodonta. Walker’s (1907) later, more detailed
description and illustrations of this species referred to four specimens from two collections from the Antarctic
Peninsula that constitute the syntype series. Examination of the syntypes, now held at the Natural History
Museum, London, revealed one dissected specimen with most mouthparts and coxae missing. Further, the
largest of the four specimens (Natural History Museum, London, labelled “No 13”) differs appreciably from
Accession
number E. reoproi AB CDEF GHI JKL
A—E. macrodonta AF451343 10.75
B—E. similis AF451346 11.66 12.02
C—E. schiaparelli
(NIWA18181) AM176763 11.11 8.93 12.93
D—E. schiaparelli
(NIWA18184) AM176764 11.48 8.56 13.12 1.64
E—E. schiaparelli
(NIWA18180) AM398942 11.11 8.38 12.57 0.55 1.09
F—E. schiaparelli
(NIWA18178) AM176765 11.29 8.74 13.66 2.19 1.64 1.64
G—E. schiaparelli
(NIWA18179) AM176767 11.48 8.56 13.12 1.28 1.09 0.73 1.64
H—E. schiaparelli
(NIWA18185) AM176768 11.32 8.40 12.78 0.73 0.91 0.18 1.46 0.55
I—E. schiaparelli
(NIWA18183) AM176769 11.14 8.40 12.60 0.55 1.09 0.00 1.64 0.73 0.18
J—E. schiaparelli
(NIWA18198) AM176770 11.32 8.40 12.96 1.46 0.18 0.91 1.46 0.91 0.73 0.91
K—E. schiaparelli
(NIWA18195) AM176771 11.32 8.76 13.69 2.19 1.82 1.64 0.18 1.82 1.64 1.64 1.64
L—E. schiaparelli
(NIWA18199) AM176772 11.34 8.59 12.81 0.73 1.28 0.18 1.83 0.92 0.37 0.18 1.10 1.83
M—E. schiaparelli
(NIWA18194) AM176773 11.14 8.40 12.60 0.55 1.09 0.00 1.64 0.73 0.18 0.00 0.91 1.64 0.18
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34 · Zootaxa 1402 © 2007 Magnolia Press
the Walkers (1907) description of E. macrodonta. In particular, it lacks lateral teeth on pereonite 1, pereonite
1 is 1.5 x pereonite 2 in length (pereonite 2:1 is 1.2 x pereonite 1 in the illustrated specimen) and the carinae
on pereonites 3–7 and urosomites 1–2 are broader and shorter than those of the illustrated specimen. The larg-
est specimen is not the same species as illustrated by Walker, and the type series is a composite. We draw the
conclusion that the type series comprises more than one species and therefore a lectotype designation is neces-
sary to fix the identity of the species. The paralectotypes, including the ‘large’ specimen, are identified as
Epimeria cf. similis, for which further genetic characterisation will hopefully give final clarification. There-
fore, another specimen (Natural History Museum, London, labelled “J107”) which closely resembles that
described and illustrated by Walker (1907) is here designated the lectotype of E. macrodonta.
In erecting E. similis, Chevreux (1912) noted that it differed from E. macrodonta Walker, 1906 in several
characters, including the presence of a dorsal carina on pereonite 2. The validity of this separation was sup-
ported by Schellenberg (1926) who added that E. similis possessed dorsolateral teeth on all pereonites. Subse-
quently, Barnard (1930) synonymised the two species, regarding many of Walker’s (1907) and Chevreux’s
(1912) reported differences between the two as morphological variation. Despite making the synonymy, Bar-
nard (1932) continued to identify two forms within Discovery expedition material: E. macrodonta forma mac-
rodonta (one juvenile specimen from the Palmer Archipelago) and E. macrodonta forma similis (80
specimens from South Shetlands and the Palmer Archipelago).
Watling & Holman (1981) accepted Barnard’s (1930) synonymy, identifying their northern Antarctic Pen-
insula material as E. macrodonta forma similis, and regarding as aberrant the one specimen (of 14) that bore a
midventral tooth distally on antenna 1 peduncle article 2, and lacked a carina on pereonite 1.
Andres (1985) checked Barnard’s (1932) Discovery material and subsequently regarded E. similis as a
valid species. According to Andres (1985), E. similis is the only species of Epimeria with lateral teeth on all
pereonites and pleonites, and lacking a dorsal carina on pereonite 2, whereas pereonites 1–2 are smooth in E.
macrodonta. Andres (1985) may have not checked the type material of E. macrodonta, because the largest
syntype does bear lateral teeth on pereonites 1–2 (contrasting with Walker’s (1907) description and illustra-
tions of E. macrodonta). The present investigation confirms the validity of E. similis based on type material in
the Muséum national Histoire naturelle, Paris, genetic evidence, and from a better understanding of the
intraspecific morphological variation within the closely related E. schiaparelli.
Distribution of Epimeria macrodonta complex species
The distributions of the three species comprising the Epimeria macrodonta complex can now be clarified.
Epimeria macrodonta appears to be limited to the Weddell Sea and the Antarctic Peninsula at 0–900 m depth,
and has not been found in the Ross Sea (Andres 1985; present study). Epimeria similis is distributed through-
out the eastern Antarctic and the Scotia area, inhabiting 165–420 m depth (Andres 1985). In comparison, E.
schiaparelli has been found only in the Ross Sea, at 130–350 m depth.
Variation and radiation of Epimeria cf. similis
In addition to E. schiaparelli, the BioRoss Expedition 2004 collected more than 40 specimens of an
Epimeria species that closely resembles E. similis. These specimens closely resemble E. similis morphologi-
cally, but had only a single acute process on coxa 4. These specimens also differed from E. similis in that the
distal spines on antenna 1 peduncle articles 1–2 were shorter, pereonite 2 was longer and the acute lateral pro-
cess on coxa 5 was shorter than in E. similis. Since subtle morphological distinctions have proven to be reli-
able in the distinction of Epimeria species, we have good evidence that we have another new species within
the Epimeria similis complex. It is presently under study and the further genetic studies will reveal its phylo-
genetic position.
Zootaxa 1402 © 2007 Magnolia Press · 35
EPIMERIA SCHIAPARELLI SP. NOV.
Molecular data
In a morphological analysis of Antarctic Epimeria, Lörz & Brandt (2004) noted that some species, such as
E. similis and E. robusta, are highly variable morphologically. They suggested that recent speciation of the
Epimeriidae had occurred in the Southern Ocean. Molecular data on the phylogeny of Antarctic Epimeria spe-
cies (Lörz & Held 2004) supports the theory of recent speciation when Antarctica cooled, and after the Drake
Passage formed.
The molecular data presented here clearly supports E. schiaparelli as a new species, with the nearest con-
geners, E. macrodonta, E. reoproi and E. similis, all showing greater than 8% sequence divergence. This level
of sequence divergence is similar to that previously documented between species of Epimeria (see Lörz &
Held 2004). In addition, Väinölä et al. (2001) observed 4.8–12.5% COI gene sequence divergences between
species of the amphipod genus Gammaracanthus Bate, 1862. These interspecific data are consistent with our
findings, which show a minimum interspecific divergence of 8.38% between Epimeria species. The intraspe-
cific variation within the 11 specimens of E. schiaparelli sequenced was 0–2.19% sequence divergence, cor-
roborating the validity of E. schiaparelli despite the small morphological differences observed.
Colouration
Two colour patterns were recorded from freshly captured specimens of E. schiaparelli (Figs 7A, B). The
most common form was a pattern of irregular orange patches (Fig. 7A), but five specimens (NIWA 18177–
18180) had distinctive red–orange bands when alive (Fig. 7B). Large and small specimens of both males and
females had each colour pattern, so colouration was not size or sex related. The colour pattern was also inde-
pendent of locality or depth of occurrence. Further, molecular data using the COI revealed that the different
colour morphotypes do not form a separate clade and that the sequence differences between the two coloured
forms (NIWA18180, NIWA18178 and NIWA18181) and the other morphotype (all other sequences) is the
same as the interspecific divergence (0–2.19%). The sequence divergences within the colour morphotypes is
0.55–2.19% and the divergence within the non coloured morphotype is 0.0–1.83.
FIGURE 7. Epimeria schiaparelli sp. nov. Colour patterns. A, irregular orange patches, paratype, NIWA 18182; B,
striped form, ovigerous female paratype, NIWA 18176.
Acknowledgements
The material examined during the current study was obtained during a biodiversity survey of the northwestern
Ross Sea and Balleny Islands undertaken by the National Institute of Water and Atmospheric Research and
financed by the Ministry of Fisheries (Project ZBD200303). Thanks are due to the captain, officers, crew and
scientific personnel of RV Tangaroa. We are especially grateful for Dr. Stefano Schiaparelli for photographing
specimens in their live colours while on board ship. We are grateful to Miranda Lowe, The Natural History
LÖRZ ET AL.
36 · Zootaxa 1402 © 2007 Magnolia Press
Museum, London, and Dr. Danielle Defaye, Muséum National Histoire Naturelle, Paris, for the loan of
Epimeria type material. We thank Dr. Niel Bruce (NIWA) for his critical comments on an earlier version of
the paper and for heaps and heaps of clever, sophisticated, and repeated editorial assistance; and Kareen
Schnabel (NIWA) for electronically inking four plates. We are also grateful for the friendly assistance in the
genetic lab from Cara Brosnahan (NIWA) and Therese Cope (BAS). The authors Lörz and Fenwick received
Fisheries Science Fund (FSF2004) for the taxonomic component of this research. The authors Lörz and Linse
gratefully received an International Science and Technology (ISAT) Linkage fund to conduct the molecular
work. The taxonomy work was partially funded through the Foundation for Research Science and Technology
programme CO01X0502.
FIGURE 8. Strict consensus tree (n= 12 trees) of a maximum parsimony analysis based on 549 nucleotides from the
COI gene (TL= 457, CI= 0.702, HI= 30298, RI= 0.717, RC= 0.503). Numbers at branches indicate bootstrap support
(1000 replicates) of over 50%.
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... Both regions share 129 species, i.e., 23% of the Antarctic fauna or 31% of the sub-Antarctic fauna (De Broyer et al. 2007, updated). Moreover, in addition to ongoing identification of new records and taxonomic revisions of several genera, recent molecular studies revealed a number of cryptic species increasing the known species richness (e.g., Lörz et al. 2007, 2011, 2012 Baird et al. 2011 Baird et al. , 2012 Havermans 2012, Havermans et al. 2010, 2011) and this trend should obviously continue. Amphipods present a high diversity in terms of life styles (Steele 1988, Bousfield & Shih 1994), trophic types (e.g., Dauby et al. 2001), habitats (e.g., De Jażdżewska 2011), and size spectra (De Broyer 1977; Chapelle & Peck 1999). ...
... Both regions share 129 species, i.e., 23% of the Antarctic fauna or 31% of the sub-Antarctic fauna (De Broyer et al. 2007, updated). Moreover, in addition to ongoing identification of new records and taxonomic revisions of several genera, recent molecular studies revealed a number of cryptic species increasing the known species richness (e.g., Lörz et al. 2007, 2011, 2012 Baird et al. 2011 Baird et al. , 2012 Havermans 2012, Havermans et al. 2010, 2011) and this trend should obviously continue. Amphipods present a high diversity in terms of life styles (Steele 1988, Bousfield & Shih 1994), trophic types (e.g., Dauby et al. 2001), habitats (e.g., De Jażdżewska 2011), and size spectra (De Broyer 1977; Chapelle & Peck 1999). ...
... Both regions share 129 species, i.e., 23% of the Antarctic fauna or 31% of the sub-Antarctic fauna (De Broyer et al. 2007, updated). Moreover, in addition to ongoing identification of new records and taxonomic revisions of several genera, recent molecular studies revealed a number of cryptic species increasing the known species richness (e.g., Lörz et al. 2007, 2011, 2012 Baird et al. 2011 Baird et al. , 2012 Havermans 2012, Havermans et al. 2010, 2011) and this trend should obviously continue. Amphipods present a high diversity in terms of life styles (Steele 1988, Bousfield & Shih 1994), trophic types (e.g., Dauby et al. 2001), habitats (e.g., De Jażdżewska 2011), and size spectra (De Broyer 1977; Chapelle & Peck 1999). ...
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