Tirons of the world: a review of ‘ tironid’ amphipods, description of new genera and species, and establishment of a new subfamily Tironinae Stebbing, 1906 stat. nov. (Crustacea, Synopiidae)
Author
Just, Jean
text
Zootaxa
2022
2022-05-23
5139
1
1
89
http://zoobank.org/145cb6f5-2ea8-40b0-9cca-3e942aa4a5b9
journal article
95147
10.11646/zootaxa.5139.1.1
8ab25605-ec09-4d57-9dbd-7da2b032e5e8
1175-5326
6572023
145CB6F5-2EA8-40B0-9CCA-3E942AA4A5B9
Glandulotiron curvispinus
sp. nov.
(
Figs 31–32
)
Type fixation.
Holotype
, sex not determined.—Here designated.
Etymology.
This species is named for the large, recurved dorsal spine on urosomite 3.
Material.
Holotype
, sex not known,
4.2 mm
,
Australia
,
New South Wales
,
Jervis Bay
, off
Moona Creek
, southeast of
Huskisson
,
35°03’S
,
150°40’E
,
8 m
, fine sand with detritus and coarse shelly broadly rippled sand, just inside low rock reef covered with large brown algae, hand dredge,
SCUBA
,
J. Just
,
P.B. Berents
&
R
.
T
.
Springthorpe
, stn AU65,
15 November 1984
.
AM
P105643
, (unique.)
Description
.
Head
evenly curved dorsally, surface smooth
rostrum
broadly rounded, turned slightly forward; projecting
interantennal lobes
absent, lower corner of lateral head margin broadly rounded;
eyes or single ommatidia
not seen.
Mouthparts
.
Maxilla 1
palp apex with 3 short, serrate spine-seta and 1 pointed lateral spine-seta.
Maxilliped
outer plate with 2 spatulate spine-setae, inner plate with 2 similar spine-setae (not illustrated). Mouthparts otherwise appear normal.
Antenna 1
as long as pereonites 1–5.5 combined along dorsum, peduncle article 2 about 2/3 length of 1, article 3 about 5/6 length of article 2, article 1 with single penicillate seta ventrally and dorsally;
flagellum
as long as peduncle article 1 and half of article 2, of 4+ articles,
accessory flagellum
of 2+ articles, first article as long as peduncle article 3.
Antenna 2
about 1.4 length of antenna 1, peduncular article 4 the longest,
flagellum
of 4+ articles, a few articles with single slender robust seta dorsodistally; antenna otherwise sparsely setose.
Coxal plates
1–4 distally with a single or two setae, without brim of fine setules.
Gnathopod 1 carpus
0.8 length of basis, with a few long setae on posterior margin;
basis
essentially naked;
propodus
about 0.5 length of carpus, with a single pectinate setae on midposterior margin;
dactylus
with unguis 0.6 length of propodus, moderately curved.
Gnathopod 2
similar. Both gnathopods very sparsely setose except along posterior margin of carpus.
Pereopods 3–4
nearly naked, basis about as long as remaining articles combined;
merus
and
propodus
of equal length,
carpus
about 2/3 length of either with single robust seta in anterodistal corner.
Pereopod 5
basis broadest distally, posterior margin straight, posterodistal corner rounded rectangular.
Pereopod 6 basis
not widening distally, posterior margin straight, posterodistal corner broadly rounded rectangular,
merus
as long as carpus and propodus combined,
carpus
the shortest article.
Pereopod 7
basis broadest in proximal half, tapering to weakly rounded posterodistal corner,
ischium
and
merus
combined as long as carpus and propodus together,
propodus
2/3 length of carpus. All three pereopods sparsely setose with robust setae. Pereopods (5)6–7
propodus
with 2 long robust setae in posterodistal corner;
dactylus
somewhat more oval then in other species of the genus.
Urosomite 3 dorsal spine long, pointed, recurved, with a few long setae; both spine and dorsal part of urosomite covered with small cuticle scales.
Uropod 1
rami of equal length, as long as peduncle, reaching to 1/2 along uropod 3 outer ramus.
Uropod 2
peduncle reaching as far as uropod 1 peduncle, rami of subequal length, reaching 1/3 along uropod 3 outer ramus.
Uropod 3
peduncle about 0.6 as long as outer ramus, rami reaching beyond apex of telson; outer ramus basal article with row of 4 robust setae dorsally, and 2 tiny robust setae ventrally, small second article with 3 dorsal robust setae; inner ramus reaching to 6/7 of basal article of outer ramus, dorsal margin with a single long plumose seta and 2 robust setae apically.
Telson.
Length about 3.0 times greatest depth in lateral view, reaching 2/3 along outer ramus of uropod 3, with single robust seta and doublet of plumose setae dorsally on each lobe, apices with 1 long and 1 short robust seta.
Size
.
4.2 mm
.
Distribution
.
Australia
,
New South Wales
, Jervis Bay,
8 m
.
Remarks
. The single specimen is damaged with soft-parts nearly completely dissolved. It differs from the other species of
Glandulotiron
by the somewhat forward pointing rounded rostrum, the lack of an interantennal projecting lobe, and an unusual forward curving dorsal spine on ursomite 3, but I tentatively refer it to
Glandulotiron
on account of the mouthparts (observed
in situ
only), coxal plates, and uropods with the distinctive second article on uropod 3 outer ramus.