Uroptychus nitidus (A. Milne-Edwards, 1880) and related species (Crustacea: Decapoda: Anomura: Chirostylidae) from the western Atlantic
Author
Baba, Keiji
Author
Wicksten, Mary K.
text
Zootaxa
2017
4221
3
251
290
journal article
37296
10.5281/zenodo.250215
3bc9de72-e44b-477a-8585-3df5d9bd9e27
1175-5326
250215
0A7277F4-550E-49F1-9AEA-7B5BE1F10498
Uroptychus nitidus
(
A. Milne-Edwards, 1880
)
(
Figs. 1
,
2
,
23A
)
Diptychus nitidus
A. Milne-Edwards, 1880
: 62
(part).—
Milne-Edwards & Bouvier 1897
: 134
(part), pl. 11, figs. 21–22, pl. 12, figs. 10–16.
Uroptychus nitidus
.—
Henderson 1888
: 174
, pl. 21, figs. 6, 2a.—de
Melo 1999
: 168
, fig. 102.
Uroptychus nitidus
(typical form).—
Chace 1942
: 11
, fig. 3.—
Pequegnat & Pequegnat 1970
: 161
, fig. 5–15.
Uroptychus nitidus nitudus
.—de
Melo-Filho 1999
: 384
, fig. 1 (copy of
Chace 1942
: fig. 3).
Not
Uroptychus nitidus
var. A.—
Chace, 1942
: 14
, fig. 4 [=
U. fenneri
n. sp.
].
Not
Uroptychus nitidus
var. B.—
Chace, 1942
: 15
, fig. 5 [=
U. janiceae
n. sp.
].
Not
Uroptychus nitidus
var. C.—
Chace, 1942
: 17
, fig. 6 [=
U. alphonsei
n. sp.
].
Dubious identification:
Uroptychus nitidus
.—
Kensley 1977
: 167
, fig. 4.—
Barnard 1950
: 495
, figs
92g
–i.—
Alcock & Anderson 1894
: 173
.—
Anderson 1896
: 101
.
Type
material
.
Lectotype
:
MCZ
CRU-
2756
, female (CL 7.1), off
Martinique
,
14°31’55”N
,
61°07’28”W
, 472 fms [
863 m
],
7 Feb. 1879
,
Blake
Sta. 200.
Paralectotypes
:
MCZ
CRU-
2695, 2
females (CL 7.3, 8.6), off
Martinique
,
14°42’35”N
,
61°13’15”W
, 502 fms [
918 m
],
5 Feb. 1879
,
Blake
Sta. 195
.
MCZ
CRU-
2700, 1
male (CL 9.5), off
Guadeloupe
,
16°15.405'N
,
61°32.902'W
, 734 fms [
1342 m
],
22 Jan. 1879
,
Blake
Sta. 173
.
MCZ
CRU-
2747, 1
female (CL 3.3), off
Dominica
, 15°32’18’N,
61°32’00”W
, 611 fms [
1117 m
],
24 Jan. 1879
,
Blake
Sta. 175
. MCZ CRU-2831, 1 male (CL 4.9),
3 females
(CL 3.0, 3.1, 4.2), northwest of Dry
Tortugas
,
Florida
,
25°33’0”N
,
84°35’0”W
, 539 fms [
986 m
],
Dec. 1877
–
Mar. 1878
,
Blake
Sta. 44.
MCZ
CRU-
3072, 2
females (CL 3.4, 5.2), off
St. Lucia
,
13°58’37”N
,
61°4’45”W
, 422 fms [
772 m
],
16 Feb. 1879
,
Blake
Sta. 222
. MCZ CRU-3073, 1 male (CL 5.3), 1 ov. female (CL 10.7),
1 female
(CL 4.6), off
Dominica
,
15°18’12”N
61°26’32”W
, 542 fms [
991 m
],
29 Jan. 1879
,
Blake
Sta. 190
.
MCZ
CRU-
4770, 2
males (CL 8.2, 11.7), off
St. Vincent
,
13°10’10”N
,
61°18’15”W
, 573 fms [
1048 m
],
19 Feb. 1879
,
Blake
Sta. 227
.
MCZ
CRU-
4771, 1
male (CL 11.0), off
St. Vincent
,
13°06'45"N
,
61°06'55"W
, 88 fms [
161 m
],
21 Feb. 1879
,
Blake
Sta. 232.
Other
material examined
.
USNM
309623, 1
female (CL 9.6), northern Gulf of
Mexico
, off
Louisiana
,
27°27’42” N
,
89°45’30”W
,
1420–1600 m
, 0
7 Dec. 1984
, LGL/
MMS
NGoMBCS
Sta. C
4, id.
L.H. Pequegnat
.
USNM
1014166,1
female (CL 11.5), northern Gulf of
Mexico
, off
Louisiana
,
26°44’24”N
,
93°18’36”W
,
1372– 1454 m
,
9 Apr. 1984
, LGL/
MMS
NGoMBCS
Sta. W
4,
Id. W.E.
& L.H. Pequegnat
.
USNM
29168, 1
male (CL 6.8), northern Gulf of
Mexico
, off
Mississippi Delta
,
28°38’30”N
,
87°02’W
, commensal host
Acanella eburnea
(Pourtalès)
, 420 fms (
768 m
),
13 March 1885
,
Albatross
Sta.
2394
. USNM 136680, 6 males (CL 7.2–10.0), 6 ov. females (CL 8.6–10.0),
1 female
(CL 5.1),
Straits
of
Florida
,
23°58’N
,
82°54’W
,
805–842 m
,
18 June 1963
. USNM 136684, 7 males (CL 6.8–10.4), 3 ov. females (CL 9.3–11.2),
3 females
(CL 4.5–10.0),
Straits
of
Florida
,
23°51’N
,
81°02’W
,
1107–1162 m
,
16 Sept. 1964
. USNM 136685, 1 male (CL 9.8), 1 ov. female (CL 10.2),
1 female
(CL 9.0),
Straits
of
Florida
,
23°50’N
,
81°37’W
,
1208–1241 m
,
17 Sept 1964
.
USNM
309622, 1
male (CL11.0), northern Gulf of
Mexico
continental slope, off
Louisiana
,
27°31’04”N
,
89° 48’59”W
,
1064 m
,
15 Nov.1984
, LGL/
MMS
NGoMCS
Sta. C
8
.
USNM
1027022, 1
ov. female (CL 9.0), northern Gulf of
Mexico
,
27°29’27”N
,
89°47’47”W
,
1355–1362 m
,
31 May 2000
, DGOMB Sta. C-4.
USNM
136688, 1
female (CL 6.5),
Straits
of
Florida
,
23°59’N
82°09’W
,
979–1027 m
, 0
1 Dec. 1964
.
TCWC
2-0425, 3
males (CL 8.6–11.6),
northwestern Caribbean Sea
off eastern
Mexico
,
18°57’N
,
87°09’W
,
1144 m
, commensal host gorgonian,
7 Jul. 1970
,
Alaminos
Sta.
70A10-9, id.
L. Pequegnat
.
TCWC
2-0426, 1
ov. female (CL 12.0),
southern Caribbean Sea
off
northern Columbia
,
11°31.8’N
,
73°45.1’W
,
1144 m
,
16–17 Jul. 1970
,
Alaminos
Sta.
70A10-29, id.
L. Pequegnat
.
TCWC
2- 6947, 1
ov. female (CL 13.0),
southern Caribbean Sea
off northern
Venezuela
,
12°39’N
69°44’W
,
1345 m
, commensal host
Isididae
,
19 Jul. 1970
,
Alaminos
Sta.
70A10-42, id.
W. Pequegnat
.
TCWC
2-6864, 1
female (CL 11.5), southwestern Gulf of
Mexico
,
24°28’N
,
96°35’W
, 600 fms [
1097 m
],
12 Apr. 1964
,
Oregon
Sta. 4813 (identified as
Uroptychus
sp. by
Michele de
St. Laurent
)
.
TCWC
2-8142
, ov. female (CL 14.5), southwestern Gulf of
Mexico
,
18°54'N
,
94°58.8'W
,
777–823 m
,
14 Aug. 1969
,
Alaminos
Sta.
69A11-27 (
Fig.
5-15
in
Pequegnat
&
Pequegnat
1970
).
Description
.
Carapace
: [1.1] × longer than broad; greatest breadth 1.3–1.7 [1.5] × distance between anterolateral spines (smaller in small specimens). Dorsal surface nearly smooth, with pair of granulate epigastric ridges, moderately convex from side to side and anterior to posterior, with shallow depression between gastric and cardiac regions. Lateral margin weakly convexly divergent posteriorly, with fine granulations (or obscurely denticulate), and ridged along posterior third of length. Anterolateral spine directed slightly anterolaterally, overreaching acuminate lateral limit of orbit. Rostrum sharp, triangular, with interior angle of [17]–23°, curving dorsally or horizontally directed straight forward; dorsal surface flattish, length [1.3]–1.5 × breadth, 0.4–[0.5] × length of remaining carapace, breadth 0.5–[0.6] × (0.7–0.8 × in small specimens) that of carapace measured at posterior margin. Lateral limit of orbit angular and acuminate, not spiniform. Pterygostomian flap smooth on surface, anteriorly roundish with tiny spine.
FIGURE 1.
Uroptychus nitidus
(A. Milne-Edwards, 1880)
, lectotype, female (CL 7.1), MCZ CRU-2756. A, carapace and anterior part of abdomen, dorsal. B, same, lateral. C, sternal plastron, with excavated sternum, proximal part of Mxp1 included. D, telson. E, left antenna, ventral. F, left Mxp3, ventral. G, same, lateral. Scales = 1 mm.
FIGURE 2.
Uroptychus nitidus
(A. Milne-Edwards, 1880)
, lectotype, female (CL 7.1), MCZ CRU-2756. A, left P1, proximal part, dorsal. B, same, ventral. C, same, distal part, dorsal. D, same, mesial. E, left P2, lateral; F, same, distal part, setae omitted, lateral. G, left P3, setae omitted, lateral. H, same, distal part, lateral. I, left P4, lateral. J, same, distal part, lateral. Scales = 1 mm.
Sternum
: Excavated sternum anteriorly triangular and sharply pointed, with posteriorly diminishing ridge in midline. Sternal plastron [as long as] or slightly shorter than broad; lateral extremities slightly divergent posteriorly between sternites 4 and 6, subparallel between sternites 6 and 7. Sternite 3 moderately depressed, anterior margin deeply excavated with pair of submedian spines, anterolateral angle blunt, occasionally angular, anterolateral end with small spine. Sternite 4 anterolateral margin irregular, bearing small or moderate-sized anterior spine not reaching anterior end of sternite 3, followed by posterior diminishing processes or spines; length [1.3]–1.6 × that of posterolateral margin. Anterolateral margin of sternite 5 as long as posterolateral margin of sternite 4.
Abdomen
: Smooth. Somite 1 without transverse ridge, weakly convex from anterior to posterior. Somite 2 tergite 2.3–2.5 [2.4] × broader than long, pleuron with lateral margin concavely divergent posteriorly, blunt on posterolateral terminus. Pleura of somites 3–5 posterolaterally blunt angular. Telson 0.5–[0.6] × as long as broad; posterior lobe 1.4–2.2 [1.5] × longer than anterior lobe (longer in small specimens), [emarginate] or feebly concave on posterior margin.
Eyes
: [1.3]–1.6 × (1.2 × in smallest specimen) longer than broad, reaching point 0.6 of rostral length, mesial margin concave. Cornea slightly inflated, slightly longer than remaining peduncle.
Antennule and antenna
: Ultimate article of antennule 2.8–3.5 [3.1] × longer than high (shorter in small specimens). Antennal peduncle overreaching eye. Article 2 with distinct distolateral spine. Antennal scale terminating in between midlength and [distal fourth] of article 5, breadth [1.3]–1.6 × that of article 5, 0.4 × height of ultimate antennular article. Articles 4 and 5 unarmed; article 5 [2.2]–2.5 × longer than article 4. Flagellum of [17]–22 segment usually not reaching, rarely terminating in distal end of P1 merus.
Mxp
: Mxp1 with bases close to each other but not contiguous. Mxp3 basis with 3–[4] denticles on mesial ridge. Ischium with 18–26 [20] denticles on crista dentata, flexor margin not rounded distally. Merus [2.0]–2.3 × longer than ischium, flexor margin roundly ridged.
No
spine on merus and carpus.
P1
: 4.7–5.4 × (males), 4.1–5.7 [5.5] × (females) longer than carapace (shorter in small specimens), nearly smooth and glabrous, but fingers setose. Ischium with small dorsal spine, ventromesially unarmed. Merus 1.1–1.5 [1.2] × longer than carapace; ventral surface with furrow mesial to lateral margin. Carpus [1.3] × longer than merus, dorsal surface with rounded longitudinal ridge in midline of anterior portion in large specimens, well depressed dorsoventrally, height much smaller than breadth (height-breadth ratio, 0.6–[0.7]). Palm 0.7–0.9 [0.8] × length of carpus, 2.6–3.0 × (males), 3.1–3.9 [3.5] × (females) longer than broad. Fingers not gaping, 0.5–[0.6] × length of palm, distally with small incurved spine; movable finger with bicuspid proximal process, fixed finger with low prominence (obsolescent in small specimens) distal to opposite process of movable finger.
P2–4
: Slender, setose on distal 3 articles; Meri and carpi unarmed. Meri successively shorter posteriorly (P3 merus 0.8–[0.97] × length of P2 merus, P4 merus [0.8]–0.9 × length of P3 merus). P2 merus as long as or very slightly shorter than carapace, [1.2]–1.3 × longer than P2 propodus, P3 merus [1.1]–1.2 × length of P3 propodus, P4 merus [0.9]–1.0 × length of P4 propodus; length-breadth ratio, 6.5–7.6[7.2] on P2, 5.6–6.5 [6.6] on P3, 4.8–6.3 [5.8] on P4. Carpi successively shorter posteriorly, length 0.6 × that of propodus on P2, 0.6 × on P3, 0.5 × on P4. Propodi [subequal] or slightly longer on P4 than on P2 and P3; flexor margins straight, with pair of terminal spines preceded by 4–9 [7] basally articulated, long spines on P2 and P3, 4–7 [6] spines on P4 (fewer in small specimens). Dactyli subequal in length, curving at proximal fourth, length 0.4 × that of propodus, flexor margin with 10 or [11] (rarely 8 or 12) subtriangular, obliquely directed spines, distal 4 or 5 subequal, occasionally ultimate slightly longer.
Eggs
: Number of eggs carried, ca. 20; size, 1.30 ×
1.31 mm
–
1.60 mm
×
1.85 mm
.
Color in life
: Pale pink to dark orange (
Fig. 3
A).
Habitat
: Symbiotic with gorgonians of families
Chrysogorgiidae
and
Isididae
growing on muddy sea floor (
Fig. 3
A). The only one of these gorgonians identified to species among the material we examined is
Acanella eburnea
(Pourtalès)
(
USNM
29168).
Pequegnat and Pequegnat (1970)
reported that
U. nitidus
also associates with
Chrysogorgia elegans
(Verrill)
(family
Chrysogorgiidae
) and
A. arbuscula
(Johnson)
. One of us (MKW) reexamined the specimen shown resting among the branches of
C. elegans
in their fig. 5-15, and confirmed that it is indeed
U. nitidus
(
TCWC
2-8142).
Remarks
. The species is characterized by the rostrum usually distinctly upcurved distally (rarely feebly so); the epigastric region with a pair of granulate ridges behind eyes; the lateral orbital angle acuminate, not spiniform; the excavated sternum ridged in midline, without a spine in center; and the P1 carpus noticeably depressed dorsoventrally (0.6–0.7 as high as broad).
The ovigerous female (CL 10.7) of the specimens from
Blake
Sta. 190 (MCZ CRU-3073) seems to be aberrant in having a broader carapace (as long as broad), a broader and shorter rostrum (with the interior angle of 26°, 1.1 times longer than broad), shorter pereopods (P1 merus slightly shorter than carapace, P2 merus 0.7 times as long as carapace), broader P2–4 (length-breadth ratios of meri, 4.1, 3.6, 3.1 on P2, P3, P4 respectively). This specimen is provisionally placed in this species, awaiting a discovery of more material that allows molecular analyses.
The
syntypes
of
U. nitidus
from the
Blake
Stations 260 and 283, which were classified in variety A along with specimens from four
Atlantis
stations (
Chace 1942
)
, are referred to a new species named
U. fenneri
n. sp.
(see below). The material from Station 130 registered under the
syntype
of
U. nitidus
(MCZ CRU-2734) proved to be identical with variety B of Chace, which is herein named
U. janiceae
n. sp.
(see below).
Chace (1942)
noted that the
Blake
specimens from 147, 232, 241, 254, 269, 273, 277, 296, 297 and 299 were referable to
U. uncifer
. His identification was correct for those from Stations 232 and 297 (
syntypes
of
U. nitidus
), and from Stations 269 and 299 (
syntypes
of
U. uncifer
), but the other specimens from Stations 147, 241, 254, 277, all
syntypes
of
U. nitidus
, are referred to
U. reedae
n. sp.
in this paper. The material from Station 273 could not be located. Distinguishing characters between
U. nitidus
and the other species are given under the respective species.
The identification of the
Challenger
material by
Henderson (1888)
was verified by direct examination.
Distribution
. Straits of
Florida
, northern and southwestern Gulf of
Mexico
, north coast of
Cuba
, the Lesser Antilles from the
Virgin Islands
to
St. Vincent
(St. Croix,
Culebra
, Sombrero Islands,
Guadeloupe
,
Dominica
,
Martinique
,
St. Lucia
,
St. Vincent
),northwestern and southern Caribbean Sea, and
Brazil
(
Pernambuco
,
Espírito Santo
.
Rio de Janeiro
,
São Paulo
and
Rio Grande
do Sul
);
161–1362 m
.