Pleuroxus scopuliferus Ekman, 1900

Smirnov, Nikolai N., Kotov, Alexey A. & Coronel, Jorge S., 2006, Partial revision of the aduncus-like species of Pleuroxus Baird, 1843 (Chydoridae, Cladocera) from the southern hemisphere with comments on subgeneric differentiation within the genus, Journal of Natural History 40 (27 - 28), pp. 1617-1639 : 1629-1630

Pleuroxus scopuliferus Ekman, 1900

( Figure 49 )

Pleuroxus scopuliferus Ekman 1900, p 78 –82, Plate 4, Figures 25–29 ; Frey 1993b, p 163 – 171, Figures 69 –99; Smirnov 1996, p 55 –56, Figures 207–211; Kotov and Gololobova 2005, p 3063.

Pleuroxus scopulifer (Ekman) in Daday 1902, p 262 –263; Olivier 1962, p 250 –251, Plate 7: Figures 5, 6 .

Not Pleuroxus scopuliferus Ekman in Pugh et al. 2002, p 1054.

See further synonymy in Frey (1993b).

Lectotype: a single parthenogenetic female, length 0.70 mm, with two eggs, SMNH 5846, selected by Kotov and Gololobova (2005). The ‘‘neotype’’ ZMU 21290a earlier selected by Frey (1993b) is rejected due to finding of original author’s material ( International Commission on Zoological Nomenclature 2000, Article 75.8).

Type locality

Unknown water body near Morro Chico, km. 146 of the 9, Punta Arenas-Puerto Natales, southern Chile (approximately 52 u 059200S, 71 u 229270W).

Material examined

A single female, the lectotype. The diagnosis below is based predominantly on Frey’s (1993b) redescription.

Diagnosis

Body dark brown, not transparent, dorsum with medial keel, postero-ventral angle with one to two denticles. Rostrum long ( Figure 49 ), projecting behind apex of labral keel. Head shield pointed at posterior end, anteriorly makes a long rostrum, PP53.7–4.8 IP. Wellexpressed prominent striation on head shield and valve. Setae at posterior portion of valve ventral margin situated submarginally. Setules on posterior margin of valve situated exactly marginally. Postabdomen wide, significantly narrowing distally, with rounded and slightly prominent dorso-distal angle, its anal margin roughly as long as postanal margin and longer than preanal margin, anal teeth strong, solitary at dorso-distal angle, represented as series of two to four strong denticles in distal half of postanal margin, and then as series of fine setules in its basal portion. Antenna I not reaching tip of rostrum, with short, rounded basal peg. On antenna II, one apical seta on each branch shorter than two other setae. On limb I smallest ODL seta short, two largest IDL setae subequal in size. On inner-distal portion of limb II, scrapers 1–3 with size decreasing basally; setules on gnathobase naked, filter plate II with eight setae. On exopodite III setae 1 and 3 subequal in length, filter plate III with nine setae. Filter plate IV with six setae. Exopodite V with two projections distally to distal seta 1, distalmost projection especially large.

Description

See Frey (1993b).

Distribution

Southern portions of Chile and Argentina, see Frey (1993b).

Figures

Figures 47–55. Different species of Pleuroxus from the southern hemisphere. (47, 48) Pleuroxus carolinae from small rockpools near Fika Patso, Republic of South Africa, postabdominal claws. (49) Pleuroxus scopuliferus from unknown water body near Morro Chico, southern Chile, lectotype. (50–52) Pleuroxus varidentatus, ephippial female from La Quinta, Argentina. (53–55) Pleuroxus hardingi sp. nov. from pools near the city of Cochabamba, Bolivia, general view, postabdomen and postero-ventral portion of valve. Scale bars: 0.01 mm (47, 48, 55); 0.1 mm (49–54).

Figures 24–32. Pleuroxus carolinae, parthenogenetic female from small rockpools near Fika Patso, Qwaqwa, Freestate, Republic of South Africa. (24) Large adult, lateral view. (25) Head, lateral view. (26) Head shield. (27) Valve. (28, 29) Armature of antero-ventral and postero-ventral portion of valve. (30) Postabdomen. (31, 32) Its distal portion. Scale bars: 0.1 mm.

Figures 67–75. Pleuroxus hardingi sp. nov., parthenogenetic female from pools near the city of Cochabamba, State of Carrasco, Bolivia. (67, 68) Antenna I. (69, 70) Apical setae of antenna II. (71) Distal portion of limb I. (72) Inner-distal portion of limb III. (73, 74) Inner portion and of limb IV in anterior and posterior view. (75) Limb V. Scale bars: 0.1 mm.

Figures 1–11. Pleuroxus wittsteini, parthenogenetic female from ponds near Port-aux-Français, Grande Terre, Iles Kerguelen. (1) Adult in lateral view. (2) Head, lateral view. (3, 4) Head shield and head pores. (5) Anterior half of valve. (6, 7) Armature of antero-ventral and posterior margin of valve. (8, 9) Postabdomen. (10, 11) Its distal portion. Scale bars: 0.1 mm.