New species of Pycnogonum (Pycnogonida: Pycnogonidae) from Green Island Taiwan, with an additional note on the holotype of P. spatium
Author
Lee, Damin
Author
Kim, Won
text
Zootaxa
2020
2020-03-10
4750
1
122
130
journal article
10.11646/zootaxa.4750.1.6
7c160556-e0e1-4fd6-85e1-1f6fa0ab87d7
1175-5326
3702903
575B1970-C7B5-4688-9B41-99F046AFD3F1
Pycnogonum spatium
Takahashi
et al.
2007
Figures 3
C–D, 5A–F
Pycnogonum spatium
Takahashi
et al
., 2007: 73–75
, fig. 5
Material examined.
Holotype
,
ICHUM3172
,
Southeast of Amami Island
,
Kagoshima
,
Japan
,
28°09.20’N
,
129°31.50’E
,
332–334 m
, beam trawl,
Y. Takahashi
,
25 May 2004
.
FIGURE 5.
Pycnogonum spatium
, holotype. A, trunk, dorsal view; B, trunk, lateral view; C, trunk, anterodorsal view; D, third leg, long spine on femur broken; E, fourth leg, arrow indicating gonopore; F, second leg, arrow indicating coxal pellicula. Scale bars: 1 mm (A–B); 0.5 mm (C–D); 0.1 mm (E–F).
Remarks.
Although
Takahashi
et al
. (2007)
described
P. spatium
as having granular integument, the body integument being pitted (
Fig. 3C
), and only the dorsal surface of legs being granulated and pitted (
Fig. 3D
). The proboscis length was recorded as
0.47 mm
, while it is actually
0.89 mm
(
Fig. 5B
).
Takahashi
et al
. (2007)
determined the
P. spatium
holotype
to be a female based on gonopores being on the dorsal surface of coxa 2 of all legs (
Fig. 5F
), however the present observation reveals that there is a gonopore on the ventrodistal surface of coxa 2 on each fourth leg (
Fig. 5E
), which shows the trait of a male. In this case, we can suggest two possibilities, the first being that the specimen is a hermaphrodite and secondly the female gonopores were misdiagnosed and represent coxal pelliculae (
vide
Staples, 2007
), in which case the specimen is a male belonging to the subgenus
Nulloviger
. To solve this problem, we need additional collection of specimens and research to distinguish the coxal pellicula from the gonopore.