Leydigia (Leydigia) louisi Jenkin, 1934

Kotov, Alexey A., 2009, A revision of Leydigia Kurz, 1875 (Anomopoda, Cladocera, Branchiopoda), and subgeneric differentiation within the genus, Zootaxa 2082 (1), pp. 1-84 : 14-16

II. Leydigia (Leydigia) louisi Jenkin, 1934

( Figs 1–22 )

Leydigia macrodonta var. louisi Jenkin, 1934, p. 283 –285, fig. 14.

Type locality. "River Makalia, Elmenteita district" ( Jenkin 1934), Nakuru-Elmenteita basin, Rift Valley Province, central Kenya.

Lectotype. Parth. ♀, 720 µm, on slide, NHM 2002.701 . (there are two females on the slide, the specimen closest to a label "type" is the lectotype.

Paralectotype. Parth. ♀, 670 µm, NHM 2002.702 ., on same slide as lectotype .

Diagnosis. Female. Body ovoid in lateral view, maximum height in middle, dorsum regularly curved, postero-dorsal angle completely absent, postero-ventral angle rounded ( Figs 1–2 ). Neither coarse nor fine striations on carapace. Body compressed laterally, dorsum a rounded triangle in section. Eye much smaller than ocellus, PP = 6–7 IP, lateral head pores about 0.8–1.1 IP distance from midline at level of central major head pore or somewhat posteriad. Labral keel wide, with more or less distinct apex, without setules on posterior margin, with short setules on anterior margin ( Figs 3–4 ), and a few short setules on side. Posterior to the last marginal seta, a submarginal row of setules on inner valve face ( Fig. 5 ); in region of postero-ventral angle these are fine and dense, while in middle of margin robust, unequal in size and sparse; marginal membrane with minute 'setules' ( Fig. 6 ).

Postabdomen broad, robust, preanal margin short, straight, sometimes with 1–2 low incisions ( Figs 7–8 ). Preanal angle well defined, postanal angle ill-defined, but not completely smooth. Postanal margin regularly curved, basis of claws bordered from postanal margin by shallow incision, distal margin and distal angle of postabdomen absent. Postanal marginal denticles organised in about 14–17 clusters, 8–10 fascicles of long lateral setae, decreasing in size basad, 3–4 setae in each fascicle, distalmost seta longest, next only slightly shorter, third short. Fascicles of lateral setae continuous with 8–10 fascicles of lateral setules on basal half of postanal and anal margin ( Fig. 9 ). Postabdominal claw relatively short (somewhat shorter than anal plus preanal portions) gently and evenly curved, basal spine stout, with pointed tip, somewhat adpressed to claw, slightly shorter than claw diameter at base, no setules on base of claw ( Figs 10–11 ).

Antenna I not reaching tip of rostrum, with 4 transverse rows of short, sparse setules on anterior face. Sensory seta relatively long, arising 1/3 way from distal end, longest aesthetasc more than half length of antennule. Antenna II with long coxal setae, first and second endopod segments with 3–4 stout spine-like setules. Apical swimming setae with basal segments bilaterally armed with fine setules, and distal segments with similar setules on one side and short setules on other side. Basal and distal lateral setae of different size, both shorter than apical setae. Chitinous insertions within distal segments of all swimming setae ( Figs 12, 18 ). 21. Setae of exopodite IV. 22. Gnathobase V. Scale bar denotes 100 µm.

Trunk limb I with ODL large, elongated, without setules, IDL with three medial clusters of small setules, and 3 marginal clusters of setules ( Figs 14, 19 ), first IDL seta small, with several short setules distally; others subequal in length, but setulated in different manner. Endite 3 with a long, seta 1, supplied with short setules distally, endite 2 with seta 2 small and thick, endite 1 without seta 3, a sensillum on each of endites; two ejector hooks of similar size. Limb II, exopodite ovoid, relatively large (longer than distal lobe), with a cluster of short setules, distal scraper on limb II with naked basal segment, on a lobe. Limb III exopodite with three large lateral and two large distal setae ( Figs 13, 15, 20 ), in filter plate distalmost seta with inflated basal segment. Limb IV exopodite with setae 1 and 2 slender, armed with short setules ( Figs 16, 21 ), filter plate with distalmost seta with inflated basal segment, all setae with inflated tips. Limb V gnathobase as setulated hillock, plus a hook or hillock near base of basalmost seta at inner limb margin ( Figs 17, 22 ).

Length 440–945 µm.

Ephippial female, male. Unknown for nomenotypical subspecies, see description for L. louisi mexicana .

Redescription. See Kotov (2003).

Distribution. See two subspecies.

Differential diagnosis. See L. leydigi .

Taxonomic comments. Jenkin (1934) described L. macrodonta var. louisi , then Smirnov (1971) decided that her taxon is a subspecies of L. macrodonta Sars, 1916 . In reality, Leydigia macrodonta is a member of the L. (Neoleydigia) subgen. nov. (see below), but L. louisi is good species of subgenus L. ( Leydigia ).

Leydigia trispinosa Methuen, 1910 was described earlier from Africa, and the author referred to a basal spine on the postabdominal claw. I am not sure that this spine of Methuen's (1910) specimens was large enough to put this taxon in the subgenus L. ( Leydigia ). In addition, R. Gurney, well-known investigator of Cladocera , said that L. trispinosa is a junior synomym of L. propinqua Sars, 1903 (as mentioned by Methuen 1911). The author himself ( Methuen 1911, p. 255) said that "it is now evident that neither africana nor trispinosa have any claims to be separated from previously known species". I therefore regard L. trispinosa as incertae sedis, and it cannot have priority under L. louisi before examination of material from the type locality of the former, Lake Chrissie, Republic of South Africa near the border with Swaziland.

Dr J. C. Paggi (personal communication) decided that populations from Patagonia ( Argentina) are a new subspecies, but this suggestion must be checked.

Figures

FIGURES 1–22. 1–13. Leydigia louisi louisi, parthenogenetic females from River Makalia, Elmenteita district, Nakuru- Elmenteita basin, Rift Valley Province, central Kenya, lectotype (1, 3, 5–10, 12–13) and paralectotype (2, 4, 11), and from Verlorenvlei wetland, Cape of Good Hope province, Atlantic Coast, Republic of South Africa, coll. 11.08.2000 by G. Jones (14–17). 1–2. Lateral view. 3–4. Labral keel. 5–6. Armature of postero-ventral portion of valve and posterior margin in inner view. 7–9. Postabdomen, preanal and middle portion. 10–11. Postabdominal claws. 12. Joint of basal and distal segments of apical swimming seta. 13. Armature of largest seta on exopodite III. 14. IDL I. 15. Two distal setae of exopodite III. 16. Setae of exopodite IV. 17. Gnathobase V. 18–22. Leydigia louisi mexicana, parthenogenetic females from the type locality, Los Baños lagoon, State of Mexico, Mexico, coll. 25.02.1994 by J. Ciros-Pérez and M. Elías- Gutiérrez. 18. Joint of basal and distal segments of apical swimming seta. 19. IDL I. 20. Two distal setae of exopodite III.