A new species of the pontoniine shrimp genus Eupontonia (Crustacea: Decapoda: Caridea: Palaemonidae) from the Ryukyu Islands, Japan
Author
Komai, Tomoyuki
Author
Minemizu, Ryo
text
Zootaxa
2014
3784
2
171
178
journal article
46116
10.11646/zootaxa.3784.2.6
a920b177-3f94-4ff5-b384-e46e5092ca87
1175-5326
224484
CC68C27D-D614-41AF-A8A6-27BDE6D5CECF
Eupontonia
Bruce, 1971
[New Japanese name: Awamori-kakure-ebi-zoku]
Eupontonia
Bruce, 1971
: 15
; 1995; 2010: 413 (key).—
Holthuis 1993
: 118
(key), 142.—
Li 2000
: 48
;
Li et al. 2007
: 171
(key), 198;
Li 2009
: 887
(key).
Emended diagnosis.
Body moderately robust, subcylindrical or slightly compressed laterally; integument glabrous. Rostrum slender, straight, dentate dorsally and ventrally, compressed laterally, lateral carinae distinct. Carapace with distinct postorbital ridge; suborbital angle not delimited; pterygostomial angle rounded; antennal tooth present; supraorbital and hepatic teeth absent. Fourth thoracic sternite with spiniform median process. Pleon with first to fourth pleura rounded; third pleomere with posterodorsal margin rounded, not produced. Telson with 2 pairs of long dorsolateral spines, posterior margin with 3 pairs of spines. Antennule normal. Antennal scale well developed. Eye with cornea narrower than eyestalk. Epistome unarmed. Mandible robust, with simple or 2- articulated palp; incisor and molar processes well developed. Maxillule with weakly divided palp, endites broad. Maxilla moderately broad scaphognathite. First and second maxillipeds normal. Third maxilliped with ischiomerus (antepenultimate segment) partially fused with basis; exopod well developed; rudimentary arthrobranch present. First pereopod slender. Second pereopods similar, subequal, fingers without conspicuous teeth. Third to fifth pereopods with simple dactyli; propodi each with spinules on flexor margin. Uropod with exopod armed with 1 or 2 movable posterolateral spines.
Composition.
Eupontonia noctalbata
Bruce, 1971
(
type
species),
E. oahu
Bruce, 2010
and
E. gracilipes
n. sp.
Remarks.
The present new species generally agrees with the generic diagnosis of
Eupontonia
, particularly in the presence of a postorbital ridge on the carapace, the absence of a hepatic tooth on the carapace, the reduced cornea and stout eyestalk, and the spinulate propodi of the third and fourth pereopods (
Bruce 1971
;
2010
). However, the presence of a postrostral tooth on the carapace in the new species requires a minor emendation to the generic diagnosis once emended by
Bruce (2010)
, in differentiating
Eupontonia
from
Vir
. In spite of the elimination of the character on the postrostral tooth,
Eupontonia
is easily differentiated from
Vir
by the characters mentioned above.