Amphipoda (Crustacea) from Palau, Micronesia: Families Maeridae and Melitidae
Author
Myers, A. A.
text
Zootaxa
2016
4170
3
451
474
journal article
10.11646/zootaxa.4170.3.2
bb281016-1373-441e-bc6d-db8fcb6bc890
1175-5326
272428
40798E20-A265-4950-B608-0E80043D8979
Family
Melitidae
Bousfield, 1973
Dulichiella beluu
sp. nov.
(
Figs. 18
,
19
)
Type material.
Holotype male (OUMNH.ZC.
2002-24
-160), 4.0 mm,
Beluu
Lukes Reef, eastern side, from coralline algae encrusted with filamentous sponge, -
6 m
depth; 07°17.530'N, 134°30.870'E; leg. S. De Grave & C. Burras,
20 May 2002
.
Paratypes
.
9 males
,
7 females
(
OUMNH
.ZC.
2002-24
-161), same data as holotype
.
Additional material.
1 female
5.7 mm
,
Beluu
Lukes Reef, eastern side, from
Spondylus
sp. (Mollusca:
Spondylidae
), -
10 m
depth; 07°17.530'N, 134°30.870'E; leg. S. De Grave & C. Burras,
20 May 2002
; 9 male, 13 female, 1 juv.
Siaes
Corner, from
Chondrilla
sp. (Porifera:
Chondrillidae
), -
30 m
deep; 07°18.756'N, 134°13.515'E; leg. S. De Grave & C. Burras,
22 May 2002
; 1 female,
Beluu
Lukes Reef, reef slope, from
Pericharax heteroraphus
Polejaéff, 1884
(Porifera:
Leucettidae
), -
15m
depth; 07°17.530'N, 134°30.870'E; leg. S. De Grave & C. Burras,
27 May 2002
; 6 males, 5 females,
Beluu
Lukes Reef, reef slope, from
Leucetta
sp. 2 (Porifera:
Leucettidae
), -
15m
depth; 07°17.530'N, 134°30.870'E; leg. S. De Grave & C. Burras,
27 May 2002
; 1 male,
Siaes
Tunnel, inside tunnel, from
Leucetta
sp. (Porifera:
Leucettidae
), -
35m
depth; 07°18.690'N, 134°13.605'E; leg. S. De Grave & P. Colin,
31 May 2002
; 2 males, 1 female, Outside Malakal Harbour,
light trap
sample,
190 feet
deep; 07°16.366'N, 134°27.906'E; leg. S. De Grave & C. Burras, night
1–2 June 2002
.
Type
locality
.
Beluu
Lukes Reef
,
Palau
,
07°17.530'N
,
134°30.870'E
.
Etymology.
Named after the
type
locality.
Description.
Based on male
holotype
, 4.0 mm.
Head.
Eyes
round; lateral cephalic lobe broad, truncated, anteroventral corner with slender seta.
Antenna 1
peduncular article 1 shorter than article 2, with 3 robust setae along posterior margin.
Antenna 2
peduncular article 2 cone gland almost reaching to end of peduncular article 3; article 4 subequal to article 5.
Mandible
article 2 subequal with article 3.
Pereon.
Gnathopod
1 coxa anteroventral corner not produced, anterior margin straight, posteroventral corner notch present (minute); palm convex, weakly defined by posterodistal corner.
Gnathopod 2
coxa posteroventral corner notch absent; left larger gnathopod propodus distolateral crown with 3 rounded spines, palm sinusoidal, posterodistal corner produced, rounded, dactylus fitting against corner; dactylus apically blunt; right smaller gnathopod merus with sharp posteroventral spine; palm straight, posterodistal corner with robust seta.
Pereopods 3–7
dactylar unguis anterior margin with accessory spine.
Pereopods 6–7
basis, merus, carpus and propodus without bunches of long slender setae.
Pereopod 6
basis posterior margin substraight; dactylar unguis anterior margin with accessory spine.
Pereopod 7
basis posterior margin sinuous.
Pleon.
Pleonites/urosomites
dorsal spine formula (7–7–7–5–6–2).
Pleonites
1–3 with sparse dorsal setae.
Epimera 1–2
posteroventral corner with acute spine.
Epimeron 3
posteroventral margin smooth, corner produced with well developed spine.
Uropod 3
outer ramus very long, about
2 x
peduncle.
Telson
with dorsal robust setae.
Female
(sexually dimorphic characters).
Gnathopod 2
subequal in size, similar to smaller gnathopod 2 of male; palm substraight; dactylus posterior margin crenulate.
Pereopod 7
basis expanded, posterior margin convex and tapering distally.
Habitat.
Coralline algae and sponges.
Remarks.
There are currently 18 species of
Dulichiella
described from world seas (see
Lowry & Springthorpe 2007
,
Tomikawa & Komatsu 2012
,
Paz-Ríos & Ardisson 2014
,
Alves, Johnsson & Senna 2014
(with key to world species)). Only six species have male gnathopod 2 (left) with three spines on the propodus distolateral crown,
D. anisochir
(
Krøyer, 1845
)
,
D. tulear
Lowry & Springthorpe, 2007
,
D. terminos
Lowry & Springthorpe, 2007
,
D. oahu
Lowry & Springthorpe, 2007
,
D. australis
(Haswell, 1879)
and
D. spinosa
Stout, 1912
, but the spines of
D. terminos
are acute. Of the remaining five species,
D. anisochir
and
D. tulear
have a serrate epimeron 3 posterior margin,
D. oahu
has two accessory spines on the anterior margins of the dactylar ungues of pereopods 3 to 7 and
D.
FIGURE 18.
Dulichiella beluu
sp. nov.
, male holotype and female paratype,
Beluu
Lukes Reef, Palau.
FIGURE 19.
Dulichiella beluu
sp. nov.
, male holotype and female paratype,
Beluu
Lukes Reef, Palau.
australis
has bunches of long setae on pereopods 6 to 7 merus to propodus.
Dulichiella beluu
sp. nov
is most similar to
D. spinosa
from
California
but that species has a pleosome/urosome dorsal spine formulae of 9–9–7–5– 4–2, whereas in
D. beluu
sp. nov
it is 7–7–7–5–6–2. It is also a much smaller species (4.0 mm in
D. beluu
sp. nov.
whereas
D. spinosa
is
7.3–12.5 mm
).
Distribution.
Known only from
Palau
.