Revision of the pulchella - group of Alona s. lato leads to its translocation to Ovalona Van Damme et Dumont, 2008 (Branchiopoda: Anomopoda: Chydoridae)
Author
Sinev, Artem Y.
text
Zootaxa
2015
4044
4
451
492
journal article
39399
10.11646/zootaxa.4044.4.1
288c1afe-5a7f-4f05-9e8f-57cb036ff030
1175-5326
235320
58357227-54BB-4B37-9B03-5E8BBA9C5AC2
XII.
Ovalona capensis
(Rühe, 1921)
comb. nov.
(
Figs. 8A–D
)
Rühe, 1921: 19–20,
Fig. 5a–b
(
Alona
);
Smirnov, 1971
: 341–342, Fig. 387 (
Alona
); Van Damme, Bekker, Kotov, 2013: 442– 447,
Fig. 1–3
,
4
b–c (
Alona
).
Type
locality.
Simonstown, Western Cape,
South Africa
(established by Van Damme
et al
. (2013) for the
lectotype
).
Type
material.
Lectotype
and two
paralectotypes
on same slide, Museum fur Naturkunde Berlin, (accession number 17 469).
Diagnosis.
Diagnosis based on published descriptions.
Parthenogenetic female.
General.
Length of adult up to
0.63 mm
. Body low oval, height/length ratio about 0.55, maximum height at the middle. Postero-dorsal angle with about 50 setulae not organized into groups. Unlike in all other species of the genus, rostrum elongated, with large posterior bulge.
FIGURE 8
. A–D,
Ovalona capensis
(Rühe, 1921)
, parthenogenetic female, redrawn from Van Damme
et al
., 2013. A, lateral view; B, rostrum; C, head pores; D, postabdomen; E–H,
Ovalona bromelicola
(Smirnov, 1988)
parthenogenetic female, from Sinev (2002b). E, lateral view; F, head pores; G, postabdomen; H, antennule; I–M,
Ovalona
glabra
(Sars, 1901)
, I and K–M from Sinev & Silva-Briano (2012), J from Sinev (2001a). I–K, parthenogenetic female. I, lateral view; J, head pores; K, postabdomen; L–M, adult male. L, lateral view; M, postabdomen.
Head
. Posterior part of headshield broadly rounded, with notches. Three major head pores without connection between them, PP less than 0.3 IP. Lateral head pores minute.
Labrum
of moderate size, labral keel broad, with convex anterior margin and a rounded apex, posterior margin of keel with two clusters of setulae.
Second abdominal segment
without dense setulae.
Postabdomen
moderately wide, with almost parallel margins in postanal portion, length about 2.5 heights. Distal margin straight; dorso-distal angle prominent, acute with rounded tip. Dorsal margin with distal part about 1.5 times longer than preanal one; anal and postanal parts of similar length. Postanal portion of distal margin almost straight; anal portion weakly concave. Preanal angle welldefined, postanal angle weakly defined. 7–8 short marginal denticles, decreasing in size basally and 3–5 groups of marginal setulae on anal margin. Eleven-twelve moderately wide lateral fascicles of setulae; in postanal portion, longest setule in each fascicle 2 times longer than marginal denticles. Postabdominal claw as long as preanal portion of postabdomen. Basal spine about 0.2 length of claw.
Antennule
with antennular seta of 0.2 length of antennule, arising at 2/5 distance from the base. Aesthetascs of different length, two longest of them of about 1/3 length of antennule.
Antenna
with seta arising from basal segment of endopodite reaching the end of endopodite. Spine on basal segment as long as middle segment. Spines on apical segments slightly longer than apical segments.
Limb I
with accessory seta about 1/3 length of ODL seta.
Limb III
with exopodite seta 3 being longest; setae 4 about 2/5 length of seta 3; other setae shorter.
Limb IV
with epipodite without projection. Exopodite seta 3 longest; setae 1–2 about 2/3 length of seta 3; setae 4–5 about 1/2 length of seta 3; seta 6 shorter about 1/3 length of seta 3. Two basalmost flaming-torch setae (3–4) with reduced distal portion.
Limb V
with epipodite without projection. Exopodite seta 4 three times shorter than seta 1.
Ephippial female and male
unknown.
Full redescription.
See Van Damme et al. (2013).
Differential diagnosis.
O
. capensis
can be easily separated from all other species of the genus by presence of posterior bulge on the rostrum, and by unique morphology of postabdomen.
Distribution.
Cape peninsula of
South Africa
.