Euryalona orientalis (Daday, 1898)
|
publication ID |
https://doi.org/ 10.11646/zootaxa.4941.3.4 |
|
publication LSID |
lsid:zoobank.org:pub:DF53F8C8-C023-446C-8458-F2E0D2937A07 |
|
persistent identifier |
https://treatment.plazi.org/id/B67887A9-FFCA-FFC9-1EF8-AA22FC38FC77 |
|
treatment provided by |
Plazi |
|
scientific name |
Euryalona orientalis (Daday, 1898) |
| status |
|
Euryalona orientalis (Daday, 1898) View in CoL
Common species in Cat Tien ( Sinev & Korovchinsky 2013). It was abundant in localities 4 and 7; few parthenogenetic females were present in some samples from localities 1 and 6. Several ephippial females and males were found in locality 7 on 28.12.2017, a single male was found in locality 5 on 21.01.2018.
Morphology of Euryalona orientalis from South-East Asia was studied by Rajapaksa & Fernando (1987a), but their description of male appendages is not detailed enough. Morphology of parthenogenetic females of E. orientalis from South-East Thailand was recently studied by Van Damme & Maiphae (2013). Morphology of studied parthenogenetic females from Cat Tien fully agrees with these descriptions, the only difference was slightly greater maximum size of the male (0.72 mm instead of 0.66 mm). Morphology of ephippial female was studied using SEM for the first time.
Ephippial female. Body high, oval ( Fig. 3C View FIGURE 3 ), dorsal margin of valves almost straight, postero-dorsal angle of valves not defined. Ephippium ( Fig. 3D View FIGURE 3 ) high oval, with large, well-developed egg locules, without any distinctive sculpture; intensive yellow-brown in preserved specimens.
Male. Body ( Fig. 2F View FIGURE 2 ) irregular oval, lower than in female, with maximum height at midline, height/length ratio about 0.55. with weakly convex dorsal margin, and strongly convex ventral margin of valves. Ocellus and eye of same size as female.
Postabdomen ( Fig. 2G View FIGURE 2 ) of same shape as in female, long and narrow, slightly narrowing distally in postanal portion, with prominent distal angle with rounded tip. Maximum height at postanal angle. Dorsodistal angle not defined. Sperm duct openings located ventrally at 1/3 distance from the end of postabdomen. Preanal and postanal angles well-defined. Distal part of postabdomen is 4.5 times longer than preanal; postanal portion is 2.5 times longer than anal one. Marginal denticles ( Fig. 2H View FIGURE 2 ) and lateral fascicles of setulae same as in female. Postabdominal claw ( Fig. 2I View FIGURE 2 ) similar to that of female, long, almost straight, with short blunt basal spine; basal spine slightly shorter than width of postabdominal claw base. Basal pecten of spinules well-developed; length of distal spinule exceed width of postabdominal claw at spinule base.
Antennule ( Fig. 2J View FIGURE 2 ) thicker than in female; length about 2 widths, with 7 terminal and 3 subterminal aesthetascs located near base of male seta. Longest terminal aesthetascs as long as antennule itself; subterminal aesthetascs slightly shorter than antennule. Male seta arising at 1/4 length from tip, about 2/3 of antennule length.
Thoracic limb I ( Fig. 2 View FIGURE 2 K–N) stouter than that of female, with short U-shaped copulatory hook, 2.5 times shorter than the limb itself. IDL seta 1 very small; seta 2 of moderate thickness, armed with setulae in distal portion, slightly shorter than seta 3; seta 3 thick and straight, much thinner and shorter than in female, almost straight, with three robust denticles at the middle and thin distal portion armed with thin setulae; male seta almost straight, as long as seta 3. Copulatory brush seta 2 times shorter than male seta. Two rows of about 15 short setulae and numerous irregularly spaced spinules on ventral face of limb under copulatory brush. Inner seta (1) of endite 3 more slender than in female, much shorter than other setae of endite 3.
Size: In adult male, length 0.67–0.72 mm, height 0.42–0.45 mm.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.