Camptocercus dadayi Stingelin, 1913

Sinev, Artem Y., 2018, Genus Camptocercus (Cladocera: Anomopoda: Chydoridae) in North America, Zootaxa 4459 (3), pp. 583-599: 591-592

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Camptocercus dadayi Stingelin, 1913


Camptocercus dadayi Stingelin, 1913 

(fig. 5)

Daday 1902: 266–269, Tab. 10, fig. 2–5 (australis); Daday 1905: 189; Tab. 12, fig. 4 (australis); Stingelin 1913: 620–621, fig. 21–22 (australis var. dadayi  ); Smirnov 1971, p. 438, fig. 539 (lilljeborgi var. dadayi  ); Rey & Vasquez 1986: 177–180, fig. 1–13; Frenzel 1987: 498–501, Аbb. 4А–H (australis var. dadayi  ); Сiros-Pérez & Elías-Gutiérrez 1996: 298, fig. 3; Elías- Gutiérrez et al. 1997: 69–70, fig. 14–18; Sinev, 2015a: 179–183, fig. 6–8.

Material examined. Over 30 parthenogenetic females from a creek 4 miles south from Natchez Trace Рarkway and 16 from Highway junction, Madison county, Mississippi, USA, 12.05.1977, DGF 3829. Over 50 parthenogenetic and ephippial females, 6 males from Wolf Lake, southwest from Sebring, Highlands County, Florida, USA, 28.03.1979, coll. D.G. Frey, DGF 5124. Over 100 parthenogenetic females Josephine Lake, southwest from Sebring, Highlands County, Florida, USA, 24.03.1979, coll. D.G. Frey, DGF 5127. Over 30 parthenogenetic females from Santa Fe Lake, Santa Fe park, Avalacha County, Florida, USA, 15.04.1979, coll. D.G. Frey, DGF 5155.

Morphology of parthenogenetic females ( Fig 5A–G View Figure ) from studied populations fully agree with the earlier redescription ( Sinev 2015a) based on Mexican populations. Distinctive characters of females include truncated rostrum ( Fig. 5B View Figure ), posteroventral corner of valves without denticles ( Fig. 5C View Figure ), postabdominal claw with pecten of about ten strong spines ( Fig. 5F View Figure ). Morphology of studied gamogenetic specimens agreed with that recorded for Mexican populations ( Elías-Gutiérrez et al. 1997), but gamogenetic specimens were never studied in details, so full descriptions are provided.

Description, Ephippial female. General. Similar in shape to parthenogenetic female ( Fig 5H View Figure ). Ephippium with developed egg locules, covered by irregular longitudinal lines thicker than on the rest of the valve. In studied preserved specimens, ephippium not pigmented.

Male. Body lower than in female, low oval ( Fig. 5I View Figure ), with well developed dorsal keel on head and valves; height/length ratio about 0.65; maximum height at the second quarter of the body. Body strongly compressed laterally. Head ( Fig. 5J View Figure ) with truncated rostrum. Ocellus and eye of same proportion as in female.

Postabdomen ( Fig. 5K View Figure ) long and narrow, with almost parallel margins in postanal portion, without defined distal margin. Рostabdomen height at postanal angle only slightly greater than at the distalmost group of marginal setulae. Length about 5–5.5 heights. Sperm ducts openings located at the end of postabdomen at some distance from the base of claws. Weak incursion between base of claws and dorsal margin. Dorsal margin almost straight in both postanal and anal portions, with postanal portion 3 times longer than anal one. Рreanal angle well-defined, postanal angle not defined. Рreanal margin straight. Marginal denticles replaced with clusters of setulae; 5–10 setulae in each; setulae much thinner than in the previous species. Lateral fascicles of setulae as in female. Рostabdominal claw weakly curved, shorter than in female, with basal pecten consisting of about 10 elements; distal 2–3 elements strong spines, length of distalmost spine 1.5 times greater than width of the claw at the spot. Basal spine short, weakly curved, with several short setulae.

Antennule ( Fig. 5L View Figure ) as in the previous species.

Limb I ( Fig. 5M–N View Figure ) with U-shaped copulatory hook, 1.5 times shorter than limb itself. IDL as in the previous species, but seta 1 longer, about 1/3 length of seta 3; setae 2 and 3 shorter and thinner than in female; male seta almost straight, of moderate thickness, about 2/3 length of IDL seta 3. Ventral face of limb below copulatory hook with several rows of short thick setulae (over 60 in total).

Size. Length of males in studied material was 0.52–0.54 mm, height 0.33–0.35 mm.

Distribution. South-East USA (Florida and Mississippi states), Mexico, Central and South America ( Sinev, 2015a). This is the first record of Camptocercus dadayi in USA.