On the subfamily Cypricercinae McKenzie, 1971 (Crustacea, Ostracoda) from Thailand, with the description of six new species 2379
Author
Savatenalinton, Sukonthip
Author
Martens, Koen
text
Zootaxa
2010
2010-02-26
2379
1
77
journal article
11755334
Strandesia perakensis
Victor & Fernando, 1981
(
Figs 12–15
)
Material examined.
Two
females from 2 samples: 1) one from
Kwan
Phayao
lake,
Muang district
,
Phayao Province
,
24 September 2005
, coordinates:
19° 09´32.6˝ N
and
99° 54´36.2˝ E
(TH028); 2) one from Mae Peum reservoir,
Maejai district
,
Phayao Province
,
7 October 2007
, coordinates:
19° 21´28.6˝ N
and
99° 51´44.6˝ E
(TH143)
.
Diagnosis.
Carapace in lateral view subovate, greatest height situated in front of mid-length, anterior margin broadly rounded, posterior margin bluntly pointed; valve surface set with tiny shallow pits, spines and long setae; LV overlapping RV, LV slightly longer than RV anteriorly and posteriorly; LV with internal groove along valve margin, inner lamella without inner list; Wouters organ small, Rome organ short, aesthetasc ya on terminal segment longer than short apical seta on A1; aesthetasc Y on A2 long, aesthetasc y2 long; two large bristles on third endite serrated; d seta on T1 present; length of distal claw of caudal ramus c. half of that of ramus, distal seta short, proximal seta short; caudal ramus attachment stout, with Triebel’s loop situated at middle of distal part of main branch, dorsal and ventral branches well-developed.
Differential diagnosis.
See differential diagnosis for
Strandesia sanoamuangae
sp. nov.
(above).
Measurements (in
µ
m).
LV (n=1), L=784, H=456; RV (n=1), L=754, H=460; Carapace (n=1), L=744, W=414.
Ecology.
Victor & Fernando (1981b)
found this species in ponds and in a marsh in
Malaysia
and
Indonesia
. The present study expands the range of ecological habitats in which this species can be found. It is encountered in lakes and man-made reservoirs with a pH range of 6.79–7.20 and a temperature range of 28.4– 30° C in our study.
Abbreviated redescription.
Carapace in lateral view (
Fig. 12A
) subovate, with length c. 1.8 times height, dorsal margin arched, greatest height situated in front of mid-length, ventral margin straight, anterior margin broadly rounded, posterior margin bluntly pointed; valve surface (
Fig. 12B
) set with tiny shallow pits, spines and long setae.
FIGURE 12.
Strandesia perakensis
Victor & Fernando, 1981
, female. A. Carapace, right lateral view (MSU-ZOC.058). B. LV, exterior view, valve surface (MSU-ZOC.057). C. Carapace, dorsal view (MSU-ZOC.058). Scale bar: A, C: 200 µm; B: 75 µm. Arrow points toward the anterior end.
A2 (
Fig. 14B–C
): exopodite with longest seta reaching tip of first endopodal segment; first endopodal segment with long aesthetasc Y, natatory setae long, length of shortest c. 1/3 of that of penultimate segment, apical seta long (reaching tip of terminal segment); penultimate segment distally with three serrated claws (length c. 1.25 times of that of penultimate segment), aesthetasc y2 long (reaching beyond tip of terminal segment); terminal segment with two serrated claws, long g seta and aesthetasc y3, the latter c. 3/4 of accompanying seta.
Md-palp as in
Fig. 14D–E
. Md-coxa as in
Fig.
14F
.
Lateral subapical seta on basal segment of Mx1-palp short (
Fig. 15A
), two large bristles on third endite serrated, sideways directed setae on first endite unequal (short one c. 2/3 of that of long one) (
Fig. 15 B
).
T1 (
Fig. 15C–D
) with a-, b- and d-setae present.
T2 (
Fig. 15E
) with d1 c. 1.4 times as long as d2.
T3
(
Fig. 15F
) as in
Fig.
15F
.
Caudal ramus (
Fig. 15G
) stout, with ventral margin serrated, distal and proximal claws long, serrated, length of distal claw c. half of that of ramus, distal seta short (c. half of that of distal claw), proximal seta short (not reaching tip of ramus). Caudal ramus attachment (
Fig. 15H
) stout, with Triebel’s loop situated at middle of distal part of main branch, dorsal and ventral branches well-developed.
Remarks.
Victor & Fernando (1981b)
described
Strandesia perakensis
Victor & Fernando, 1981
, based on material from
Malaysia
and
Indonesia
. The morphology of both valves and soft parts of Thai specimens corresponds to that of the
type
material.
Strandesia perakensis
is a rare species. We found only
two specimens
from two localities. These are the first records after the original description of this species.