Flavalona natalensis (Sinev, 2008) Sinev & Dumont, 2016

Sinev, Artem Y. & Dumont, Henri J., 2016, Revision of the costata-group of Alona s. lato (Cladocera: Anomopoda: Chydoridae) confirms its generic status, European Journal of Taxonomy 223, pp. 1-38 : 15-16

Flavalona natalensis (Sinev, 2008) comb. nov.

Fig. 3 B–C

Alona natalensis Sinev, 2008: 24–32 , fig. 1–4.

Diagnosis

Female

Length of adult 0.46–0.54 mm. Body ( Fig. 3B ) regular oval, maximum height at the middle of body, height/length ratio about 0.6. Valves from previous molts not retained. Posteroventral angle without setules protruding beyond valve margins. Ventral margin with ca 50 setae. Valves covered by dense, broad longitudinal lines.

Eye larger than ocellus. Rostrum short, broadly rounded. Posterior margin of head shield broadly rounded. Three major head pores ( Fig. 3C ), middle pore slightly smaller than others, located near the posterior pore. Connection between middle and posterior pore wide, connection between middle and anterior pore narrow. PP ca 1.1–1.5 IP. Lateral head pores of ca 1.0–1.2 IP length, lateral pore pockets shallow, with depth about 1/3 of pore length. Labral keel without denticles.

Postabdomen truncated, length 2.2–2.4 heights. Distal margin straight, distal angle prominent, acute, with rounded tip. Dorsal margin weakly convex in preanal part, concave in anal part, straight in postanal part. Distal part of dorsal margin 3 times longer than preanal one, with preanal portion 1.3–1.5 times longer than anal one. Preanal and postanal angles weakly defined. Postanal margin of postabdomen provided with 8–10 marginal denticles. Anal margin with 4–5 clusters of marginal setules. 10–12 lateral

fascicles of setules, distal setules in fascicle being longest. Postabdominal claw of moderate length, 1.5 times longer than preanal portion of postabdomen. Basal spine about 0.2 of length of claw.

Antennule with longest aesthetasc of about 2/3 length of antennule. Scrapers of limb II of similar morphology. Exopodite III with seta 6 of about 2/3 length of seta 3. Exopodite IV with seta 3 being longest, setae 1–2 slightly shorter, setae 4 about half length of seta 3, setae 5–6 about 2/3 length of seta 3. Epipodites IV–V with processes about 1.5 of epipodite length. Exopodite V weakly bilobed.

Male

Unknown.

Differential diagnosis

Flavalona natalensis comb. nov. has a characteristic sculpture of the valves, composed of thick, closely spaced longitudinal lines.

Type material

Holotype

Parthenogenetic ♀, Zoological Museum of Moscow State University , Ml-44.

Paratypes

Seven parthenogenetic ♀♀, Zoological Museum of Moscow State University, Ml-45.

Material studied earlier

See Sinev (2008) for a list of material from the Republic of South Africa and Lesotho.

Type locality SOUTH AFRICA: Lakes Cave Tarn 3, Cobham, KwaZulu-Natal Province, 29°39ʹ50″ S, 29°18ʹ47″ E,

altitude 2190 m.a.s.l.

Distribution

Inhabits small, possibly temporary, water bodies (pools and tarns) in the East Escarpment portion of the Drakensberg Mountains in KwaZulu–Natal and Lesotho (Sinev 2008). At the time of sampling, pH was 6 to 7.6, and temperature 16.4 to 22ºC. It belongs to the complex of endemic species of the Drakensberg mountains, which includes five other benthic cladocerans viz. Pleuroxus carolinae (Methuen, 1910) , Dumontiellus africanus Smirnov, 2007 , Alona meridionalis Sinev, 2006 , A. martensi Sinev, 2009 (Chydoridae) and Ilyocryptus martensi Kotov & Štifter, 2005 (Ilyocryptidae) (see Van Damme et al. 2013). All are restricted to the eastern escarpment of the Drakensberg, which lies within an area with an effective temperature index below 14°C ( Stuckenberg 1969). The index of temperature expresses the relative duration of the warm period of year.

Figures

Fig.3. A. Flavalona cheni (Sinev, 1999) comb. nov., head pores of parthenogenetic ♀. B–C. Flavalona natalensis (Sinev, 2008) comb. nov., parthenogenetic ♀. B. Lateral view. C. Head pores. D. Flavalona setigera (Brehm, 1931) comb. nov., head pores of parthenogenetic ♀. E–F. Flavalona weltneri (Keilhack, 1905) comb. nov., parthenogenetic ♀. E. Head pores. F. Postabdomen. Figures A and D from Sinev (1999a), B–C from Sinev (2008), E redrawn from Flössner (2000) and F redrawn from Van Damme et al. (2010).