Celsinotum macronyx (Daday, 1898)
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publication ID |
https://doi.org/ 10.11646/zootaxa.4941.3.4 |
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publication LSID |
lsid:zoobank.org:pub:DF53F8C8-C023-446C-8458-F2E0D2937A07 |
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persistent identifier |
https://treatment.plazi.org/id/B67887A9-FFCD-FFCC-1EF8-AFEBFC85F80C |
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treatment provided by |
Plazi |
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scientific name |
Celsinotum macronyx (Daday, 1898) |
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Celsinotum macronyx (Daday, 1898)
Rare species in Cat Tien ( Sinev & Korovchinsky 2013). Several parthenogenetic females were found in locality 1; single ephippial female and single male were found on 5.12. 2017 in locality 1.
Morphology of parthenogenetic specimens fully agree with the previous descriptions of the species ( Rajapaksa & Fernando 1985, 1987b; Sinev & Kotov 2012). Ephippial females were never studied before, and male morphology was studied only once by Sinev & Kotov (2012) of a single specimen from Thailand, no data on antenna were provided.
Ephippial female. Body ( Fig. 2A View FIGURE 2 , 3 View FIGURE 3 A–B) high oval, with maximum height before midline; height/length ratio about 0.79. Dorsal margin with broad keel, unlike in parthenogenetic female, posterodorsal angle well-developed. Ephippium narrow triangular, with weakly developed egg locules, covered by very thick longitudinal lines, weakly yellow-brown in preserved specimens.
Male. Body ( Fig. 2B View FIGURE 2 ) similar to that of juvenile females, high oval, strongly compressed laterally. Dorsal keel developed. Maximum height before the midline, height/length ratio about 0.78. Eye and ocellus of same shape as in female.
Postabdomen ( Fig. 2C View FIGURE 2 ) long, narrowing distally, maximum height at postanal angle. Length about 4 heights. Ventral margin almost straight. Postabdominal claws situated on a large protrusion. Sperm ducts open laterally, at some distance from the end of postabdomen. Distal margin weakly developed, dorsodistal angle broadly rounded. Dorsal margin almost straight in postanal portion, weakly concave in anal portion. Preanal angle well-defined, postanal angle not defined. Preanal margin sigmoid. Clusters of thin setulae in position where marginal denticles are located in females. Lateral fascicles of setulae same as in female. Postabdominal claw curved, much shorter than in female, of about 2/3 length of postanal margin. Basal spine shorter than in female, straight, about 1/3 length of claw itself.
Antennule ( Fig. 2D View FIGURE 2 ) moderately long, with 10 terminal and 2 lateral aesthetascs. Longest terminal aesthetascs almost as long as antennule itself; lateral aesthetascs of about 2/3 length of antennule. Male seta arising at 1/3 length from tip, about 2/3 of antennule length.
Limb I ( Fig. 2E View FIGURE 2 ) with U-shaped copulatory hook, 1.5 times shorter than limb itself. IDL with three setae, seta 1 absent; IDL setae 2 and 3 similar in size, armed with thick spinules, male seta curved, about 2/3 length of seta 2. Copulatory brush seta about 1/2 length of IDL seta 2. Ventral face of the limb under copulatory brush with two rows of 20–25 short stiff setulae. Endite 3 with inner seta (1) longer and thinner than in female, significantly longer than setae a–c.
Size. In single studied ephippial female length was 0.48 mm, height 0.36 mm; in single studies adult male, length was 0.37 mm, height 0.29 mm.
Taxonomic notes. Shape of postabdomen in studied male slightly different from that reported by Sinev & Kotov (2012), but this difference is within the usual morphological variability of Aloninae ; there are no differences between these two specimens in other characters. Antennule of C. macronyx have only two lateral aesthetascs, unlike that of West Australian species of the genus (see Frey 1991), suggesting that increase of aesthetascs number in the latter species can be an adaptation for saline waters.
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.