A new species of the genus Dactylopleustes (Crustacea: Amphipoda: Pleustidae) from Japan, with a partial redescription of D. echinoides Bousfield and Hendrycks, 1995
Author
Tomikawa, Ko
Author
Hendrycks, Ed A.
Author
Mawatari, Shunsuke F.
text
Zootaxa
2004
674
1
14
journal article
10.5281/zenodo.158124
45e277ac-5921-4c12-b8ac-1ca07ec3857c
11755326
158124
B3918004-07FC-415A-A908-3722EA9D40D3
Dactylopleustes echinoides
Bousfield and Hendrycks, 1995
(
Figure 6
)
Dactylopleustes echinoides
Bousfield and Hendrycks, 1995
: 121
–122, figure 40.
Type
material
Holotype
: ovigerous female,
3.3 mm
(slide mount),
CMNC
19950079, Station N16, British
Columbia
, Johnstone Strait, Port Neville,
50°29'N
,
126°05'W
,
17 July 1959
, collector E. L. Bousfield.
Paratypes
: 2 ovigerous females, one juvenile female, one juvenile (undissected),
CMNC
19950080, same data as
holotype
.
Other material
Three females,
3–3.5 mm
, taken from the green sea urchin
Strongylocentrotus droebachiensis
, dredged from about
91 m
depth from San Juan Channel, near Friday Harbor Lab, Washington,
May 2000
.
Redescription
Antennae 1–2: flagellum with four–six and four–five articles respectively. Maxilla 2: outer plate with six stout, spinelike setae apically. Maxilliped: inner plate with twothree apical spines.
FIGURE 6.
Dactylopleustes echinoides
Bousfield and Hendrycks, 1995
, holotype female, 3.3 mm (CMNC 19950079). Scale bars = 0.1 mm unless indicated otherwise.
Pereopod 5: propodus, anterior margin with 11 short spines, length 2.7 times width; dactylus, anterior margin with distinct teeth. Pereopod 6: as for pereopod 5 except; propodus, anterior margin with seven short spines, length 2.9 times width. Pereopod 7: as for pereopod 6 except; propodus, anterior margin with eight short spines, length 2.8 times width.
Uropod 1: peduncle spinose, length 1.1 times inner ramus, with eight dorsolateral and 4 dorsomedial spines; outer ramus length 0.95 times inner ramus, with seven dorsolateral and four dorsomedial marginal spines; inner ramus with four dorsolateral and seven dorsomedial marginal spines. Uropod 2: peduncle length 0.9 times inner ramus, with one dorsolateral, one apicodorsal and one apicomedial spine; outer ramus length 0.8 times inner ramus, with six dorsolateral and one dorsomedial marginal spine; inner ramus with three dorsolateral and five dorsomedial marginal spines.
Remarks
The
type
specimen of
Dactylopleustes echinoides
was examined and compared with the material at hand. Supplemental drawings are presented (
Fig 6
) to show characters which differ from
D. yoshimurai
.
There are a few discrepancies noted in the description of this species by
Bousfield and Hendrycks (1995)
. They described the outer plate of maxilla 2 as having 12 apical spines, but their figure only shows six spines. After examining the
holotype
, we have found that the outer plate indeed has only six spinelike setae apically, as was shown correctly in figure 40. The maxilliped inner plate was figured as having no apical spines, but the description mentions three. After a detailed examination, it was found to have very minute apical spines, with two on one side and three on the other. The counts of anteromarginal spines on the propodus of pereopods 5–7 were not specified by
Bousfield and Hendrycks (1995)
, but these characters have been found to be useful in distinguishing
D. echinoides
from
D. yoshimurai
.
See remarks section under
Dactylopleustes yoshimurai
for relationship to this species.