Coronatella (Coronatella) circumfimbriata ( Megard, 1967 )

Sinev, Artem Y., 2020, Revision of the elegans-group of Alona s. lato and its status as a subgenus of Coronatella Dybowski & Grochowski, 1894 (Cladocera: Anomopoda Chydoridae), Zootaxa 4732 (4), pp. 501-526 : 518-519

Coronatella (Coronatella) circumfimbriata ( Megard, 1967)

Figs (9A-H).

Megard, 1967: 37-40, Fig. 1-7 , Pl. I, Fig. 1-6 ( Alona ); Smirnov, 1971: 359, Fig. 414 ( Alona ); Sinev, 2009: 65-70, Fig. 4-5 ( Alona ); Sinev & Silva-Briano, 2012: 20, Fig. 11A-D.

Type locality. Lake Itasca , Clearwater County, Minnesota, U.S.A.

Type material. Holotype. Female , The Natural History Museum, London, U.K., 1966.3.21.3.

Material examined here. Over 100 parthenogenetic females from pond #9, North Dog Leg, Texas State University Campus, San Marcos, Texas, USA, 15.02.1978, coll. S. Sisson, DGF-4492; over 40 parthenogenetic females, 4 males from pond at south side of Federal Road 1, 5 miles West from Wiscasset, Maine, USA, 4.09.1981, coll. D. B. Berner, DGF-6224.

Material studied earlier. See list of material in Sinev (2009) and Sinev & Silva-Briano (2012).

Morphology of studied females agrees with the earlier descriptions of the species ( Megard 1967; Sinev 2009). Rudimentary seta 1 on IDL of limb I and additional seta near scraper 1 of limb II ( Fig. 9C ) was found in both studied populations.

Redescription. Male. Redescription of male morphology by Sinev (2009) was based on a single specimen from slide from D.G. Frey collection, so new description of male, based on more abundant material, is provided.

General. Body ( Fig. 6L ) low oval, maximum height at the middle of the body, height/length ratio about 0.55.

Ocellus two times smaller than eye.

Postabdomen ( Fig. 6M ) short, evenly narrowing distally along all length, with broadly rounded dorso-distal angle. Ventro-distal angle well-defined, obtuse. Sperm duct openings located ventrally almost at the end of posta- bdomen. Preanal angle well-defined; postanal angle weakly defined. Distal part of postabdomen 1.5 times longer than preanal; anal portion 1.5 times longer than postanal one. Clusters of short setulae in place of marginal denticles; lateral fascicles of setulae same as in female. Postabdominal claw 1.5 times shorter than preanal portion of postabdomen, with five-six moderately thick spines on the inner side. Basal spine long, about 0.25-0.5 length of claw.

Antennule ( Fig. 6O ) thicker than in female, with 10 terminal and 2 lateral aesthetascs. Longest terminal aestetascs as long as antennules itself; lateral aestetascs about 2/3 length of antennule. Male seta arising at 3/4 length from tip, about 1/4 of antennule length.

Thoracic limb I ( Fig. 8 G-H) with short U-shaped copulatory hook 2 times shorter than limb itself. Copulatory brush present; copulatory brush seta very short. Ventral face of limb below them with double row of short thick setulae. Inner distal lobe without seta 1; setae 2 and 3 shorter and thinner than in female, armed with moderately thick spinules; male seta curved, shorter than seta 2.

Taxonomic notes. Morphology of studied males agrees well with initial description of Megard (1967). Male studied by Sinev (2009) was labelled as Alona circumfimbriata by D.G. Frey, it has similar habitus and limb I morphology, but differ from studied here in morphology of postabdominal claw, with long curved basal spine, more similar to that of C. (C.) poppei (see Sousa et al. 2015 for comparison). It is unclear if Sinev (2009) deal with either abnormal specimen or with male of some other Coronatella (Coronatella) species.

Distribution: Canada, USA, North and Central Mexico (Sinev 2009; Sinev & Silva-Briano 2012).

Figures

FIGURE 1. Coronatella (Ephemeralona) elegans (Kurz, 1875) comb. nov. from Laguna de El Hito, Cuenca, Castilla La Mancha, Spain. A-C, juvenile female of instar I. A, lateral view. B, head shield. C, head pores. D, juvenile female of instar II. E-M, adult parthenogenetic female. E-F, lateral view. G, ventral margin of valves. H, ventral margin of valves, setae of posterior group. I, posteroventral angle of valves. J-K, head shield. L-M, head pores. N, ephippial female. O-P, juvenile males of instar I and II. Q, adult male.

FIGURE 2. Coronatella (Ephemeralona) elegans (Kurz, 1875) comb. nov. from Laguna de El Hito, Cuenca, Castilla La Mancha, Spain. A-G, adult parthenogenetic female.A, lateral view. B, dorso-lateral view. C, sculpture of valves. D, head pores. E, postabdomen. F, postanal margin of postabdomen. G, antenna. H-I, ephippial female. H, lateral view. I, sculpture of ephippium.

FIGURE 3. Coronatella (Ephemeralona) elegans (Kurz, 1875) comb. nov. from Laguna de El Hito, Cuenca, Castilla La Mancha, Spain. A-D, adult parthenogenetic female. A, labrum. B-C, postabdomen. D, antennule. E-F, antenna. G, juvenile male of instar I, postabdomen. H-I, juvenile male of instar II. H, postabdomen. I, antennule. J-L, adult male. J, postabdomen. K, postabdominal claw. L, antennule.

FIGURE 4. Coronatella (Ephemeralona) elegans (Kurz, 1875) comb. nov. from Laguna de El Hito, Cuenca, Castilla La Mancha, Spain. A-I, thoracic limbs of adult parthenogenetic female.A-B, limb I. C, limb II. D, exopodite of limb III. E-F, inner portion endite of limb III. G, exopodite of limb IV. H, inner portion of limb IV. I, limb V. J, juvenile male of instar I, inner side of thoracic limb I. K, juvenile male of instar II, inner side of thoracic limb I. L-M, thoracic limb I of adult male.

FIGURE 5. Coronatella (Ephemeralona) elegans (Kurz, 1875) comb. nov. from Mainzer Sand, Germany. A-C, adult parthenogenetic female. A, lateral view. B, postabdomen. C, IDL and ODL of thoracic limb I. D-G, adult male..D, lateral view. E, postabdomen. F, frontal part of thoracic limb I (copulatory brush seta not shown). G, IDL of thoracic limb I.

FIGURE 6. Coronatella (Coronatella) cf. bukobensis (Weltner, 1897) from Dune Pan, near Road 27, North of Blauwbergstrand, Cape Town, Republic of South Africa. A-B, juvenile females of instar I and II. C-I, adult parthenogenetic female. C, lateral view. D, ventral margin of valves. E, posteroventral angle of valves. F, head shield. G, head pores. H-I, postabdomen, J, antennule. K, ephippial female. L-O, adult male. L, lateral view. M, postabdomen. O, antennule.

FIGURE 7. Coronatella (Coronatella) cf. bukobensis (Weltner, 1897) from Dune Pan, near Road 27, North of Blauwbergstrand, Cape Town, Republic of South Africa, adult parthenogenetic female. A-B, lateral view. C, dorso-lateral view. D, postabdomen. E, postanal margin of postabdomen. F, postabdominal claw. G, antenna. H, setae of IDL of limb I.

FIGURE 8. Coronatella (Coronatella) cf. bukobensis (Weltner, 1897) from Dune Pan, near Road 27, North of Blauwbergstrand, Cape Town, Republic of South Africa.A-L, adult parthenogenetic female. A, labrum. B, antenna, C-D, limb I. E, limb II. F, exopodite of limb III. G-H, inner portion endite of limb III. I, exopodite of limb IV. J-K, inner portion of limb IV. L, limb V. M-O, adult male. M, thoracic limb I. N-O, IDL setae and copulatory hook of thoracic limb I.

FIGURE 9. A-H, Coronatella (Coronatella) circumfimbriata (Megard, 1967) from forest pond at south side of Federal Road 1, 5 miles West from Wiscasset, Maine, USA. A-B, adult parthenogenetic female.A, IDL and ODL of thoracic limb I. B, exopodite and distal scrapers of limb II. C-H, adult male. C, lateral view. D, posteroventral corner of valves. E, postabdomen. F, antennule. G, thoracic limb I (copulatory brush seta not shown). H, copulatory hook and IDL of thoracic limb I. I-O, Coronatella (Coronatella) rectangula (Sars, 1861) from pond near 9th Dachnaja street, Saratov, Russia. I-K, adult parthenogenetic female. I, postabdomen. J, IDL and ODL of thoracic limb I. K, exopodite and distal scrapers of limb II. L-O, adult male. L, postabdomen. M, antennule. N, thoracic limb I (copulatory brush seta not shown). O, copulatory hook and IDL of thoracic limb I.