Philomedes cf. heptathrix

Chavtur, Vladimir G. & Keyser, Dietmar, 2016, Benthic myodocopid Ostracoda (Philomedidae) from the Southern Ocean, Zootaxa 4141 (1), pp. 1-70 : 45

Philomedes cf. heptathrix

( Figs. 24 H; 25 C, D, G, H; 26 A, B)

Studied material (coordinates, depth and sediment see Appendix). RV “Polarstern”, ANT XV/3 station 148: adult female or A-1 female (1.77 mm).

Description of adult female (or A- 1 female) ( Fig. 24 H). Length 1.77 mm.

Second antenna ( Fig. 25 H). Endopodite: first joint only with 1 distal seta.

Mandible ( Fig. 26 A, B). Basale: dorsal margin with 7 setae, 5 near middle and 2 subterminal; lateral surface with 5 setae; ventral margin with 3 distal setae.

Sixth limb. Epipodial appendage with 3–4 setae.

Seventh limb. Each limb with 11 setae, 5 (2+3) in distal group and 6 (3+3) in proximal group; each seta with 3– 5 bells. Terminal comb with 13 alate teeth; 2 pegs present on opposite comb.

Caudal furca. Limb with 9+10 claws.

Remarks. Carapace and limbs are similar to Kornicker’s and our specimens of P. heptathrix . It differs in the following: first endopodial joint of second antenna only with 1 distal seta.

Figures

FIGURE 24. Philomedes heptathrix (Female: A—MIMB 18297; B— 13 SAE, 1.12. 1967, St. 4; C—MIMB 182300; D, E— 8 SAE, 19.02. 1963, St. E, sample 2; F— 52 RAE, 4.01. 2007, St. 6, sample 28; G, I – M—ZMH-K- 42266), Philomedes cf. heptathrix (Immature female: H—ZMH-K- 42267). Carapace: A – F—left valve in lateral view; G, H—right valve in lateral view; I, J—rostrum of right valve in lateral and inside views; K—infold of antero-ventral margin of left valve; L—caudal process of left valve in lateral view; M—infold of caudal process of left valve.

FIGURE 25. Philomedes heptathrix (Female: A, B, E, F, K, L—MIMB 18297; I, J—MIMB 18300; M, N—MIMB 18302), P. cf. heptathrix (Immature female: C, D, G, H—ZMH-K- 42267). A—detail of ornamentation and setae in central area of right valve in lateral view; B, C—upper lip, anterior process, medial eye, Bellonci organ, 1 st and 2 nd joints of 1 st antenna; D—medial eye, Bellonci organ and details of 1 st joint of 1 st antenna; E—upper lip; F, G— 2 nd joint of 1 st antenna; I – N—endopodite of 2 nd antenna.

FIGURE 26. Philomedes cf. heptathrix (Immature female: A, B—ZMH-K- 42267), P. heptathrix (Female: C, D—MIMB 18297; E, F—MIMB 18300. Male: G – J—MIMB 18296). A—basale, exopodite and 1 st endopodial joints of mandible (not all setae shown); B—basale of mandible (ventral setae not shown); C— 6 th limb (not all setae shown, end joint only with lateral setae); D – F—epipodite and end joint of 6 th limb (marginal setae not shown); G—left valve in lateral view; H—infold of rostrum and detail anterior margin of left valve; I—infold of caudal process of right valve; J—detail of reticulation and setae in central area of left valve, lateral view.