Philomedes charcoti Daday, 1908

Chavtur, Vladimir G. & Keyser, Dietmar, 2016, Benthic myodocopid Ostracoda (Philomedidae) from the Southern Ocean, Zootaxa 4141 (1), pp. 1-70 : 45-47

publication ID	https://doi.org/ 10.11646/zootaxa.4141.1.1
publication LSID	lsid:zoobank.org:pub:6033C3F3-85B8-4665-A7AF-7C0E4B230ABC
DOI	https://doi.org/10.5281/zenodo.6069977
persistent identifier	https://treatment.plazi.org/id/18659911-FF9D-C91E-FF08-B2A2FD40F87E
treatment provided by	Plazi
scientific name	Philomedes charcoti Daday, 1908
status

Treatment

Philomedes charcoti Daday, 1908 View in CoL

( Figs. 28 View FIGURE 28 H–K, 29, 30)

1908 Philomedes charcoti Daday ,: 9, Figs. 11 View FIGURE 11 , 12 View FIGURE 12 .

1912 Philomedes charcoti Daday, 1908 View in CoL —Müller: 26 [key], 31.

1920 Philomedes charcoti Daday, 1908 View in CoL —Skogsberg: 418.

1971 Philomedes charcoti Daday, 1908 View in CoL —Kornicker: 171, Figs. 4 View FIGURE 4 , 5 View FIGURE 5 . 1975 Philomedes charcoti Daday, 1908 View in CoL —Kornicker 236–238, Figs. 131, 133, 134, 135 (map). 1989 Philomedes charcoti Daday, 1908 View in CoL —Hartmann: 234–235.

1991 Philomedes charcoti Daday,m 1908 View in CoL —Hartmann: 212.

Studied material (coordinates, depth and sediment see Appendix). 52th Russian Antarctic Expedition, Prydz Bay, station 2, sample 43: MIMB 18303 View Materials and 18 304— 2 adult females (2.02 and 2.05 mm).

Station 2, sample 44: MIMB 18305—adult female (1.87 mm) and MIMB 1 8306—adult male (2.02 mm).

Station 10, sample 55: MIMB 18 307—immature male (1.72 mm).

Additional material. See Appendix.

Diagnosis of female ( Kornicker 1975, with additional remarks)

Carapace: with truncate posterior and rounded postero-ventral corner, surface distinctly reticulate, length 1.71–2.05 mm.

First antenna: 2nd joint with 2–3 setae, 1 ventral, 0–1 lateral and 1 dorsal.

Second antenna: 1st joint of endopodite with 6 setae, 5 proximal and 1 distal; 2nd joint with 1 long ventral and 1 long terminal seta.

Mandible: dorsal margin of basale with 3 setae, 1 near middle and 2 subterminal.

Sixth limb: epipodite with 2–3 setae.

Seventh limb: each limb with 15–18 setae, 4–5 distal and 10–13 proximal; 2 pegs present on opposite terminal comb.

Caudal furca: each lamella with 9 (rarely) or 10 claws, main claws short, stout, often with rounded tips.

Bellonci organ: 1- or 2-jointed, with pointed tip.

Lateral eye: elongate, with 2 ommatidia.

Anterior process (above upper lip): developed, with rounded tip.

Diagnosis of male. Carapace: length 2.20 mm.

First antenna: 2nd joint with 3 setae, 1 ventral, 1 lateral and 1 dorsal.

Second antenna: 1st joint of endopodite with 4–5 setae, 3–4 proximal and 1 distal; proximal seta of 3rd joint about 3/4 of its length.

Mandible: dorsal margin of basale with 3 setae, 1 near middle and 2 subterminal; coxale endite present.

Sixth limb: epipodite with 3 setae.

Seventh limb: each limb with 12–15 setae, 4–6 distal and 5–10 proximal; 2 pegs present on opposite terminal comb.

Caudal furca: each lamella with 8 or 9 claws.

Bellonci organ: 1-jointed, with rounded tip.

Anterior process (above upper lip): undeveloped and slightly rounded.

Supplementary description of adult female. Carapace. ( Fig. 29 View FIGURE 29 A–C). Length 1.80–2.05 mm (in literature: 1.71–1.96 mm). Carapace with truncate posterior and rounded postero-ventral corner. Infold on rostrum with 10–11 setae forming a row and 3 setae near incisure. Antero-ventral inside with 12–13 striations and 1–9 setae. Infold on caudal process with 2–8 short setae. Carapace with distinctly reticulate pattern.

First antenna ( Fig. 29 View FIGURE 29 E). Second joint with 3 setae, 1 dorsal, 1 lateral and 1 vertical.

Second antenna ( Fig. 29 View FIGURE 29 F, G). Endopodite: first joint with 5 proximal and 1 distal setae; second joint with 1 long spinous ventral seta and 1 subterminal short bare seta.

Mandible ( Fig. 29 View FIGURE 29 H). Basale: dorsal margin with 3 setae, 1 near middle and 2 subterminal; medial side with 6 setae, 3 pectinate and 3 usual type; lateral surface with 5 setae parallel to ventral margin; ventral margin usually with 2 distal setae. Endopodite: first joint with 4 ventral setae; dorsal margin of second joint with 2 setae in proximal group, 6 (rarely 5) setae in distal group and 1 seta between these groups; ventral margin with 2 setae in subterminal and 3 setae in terminal group.

Sixth limb. Endite I with 1 or 2 terminal and 1 medial setae, endite II with 3 terminal and 1 medial setae, endite III with 8 terminal and 1 medial setae, endite IV with 7 (rarely 6) terminal and 1 medial setae, end joint with 16–18 setae; 2 or 3 setae present in place of epipodial appendage.

Seventh limb. Each limb with 15–18 setae, 4–5 distal (usually 3+2 and rarely 2+2) and 11–13 proximal (5+6, 5+7 or 5+8) setae; each seta with 2–8 bells. Terminal comb with 12 teeth; 2 pegs present on opposite comb.

Caudal furca ( Fig. 29 View FIGURE 29 I). Limb with 10+10 or 10+9 claws. Claws 1–4 stout and short.

Medial eye ( Fig. 29 View FIGURE 29 D). Large, smooth.

Bellonci organ ( Fig. 29 View FIGURE 29 D). Elongate, 2-jointed with pointed tip.

Upper lip ( Fig. 29 View FIGURE 29 D). Ventrally hirsute, terminally with several glandular processes.

Anterior process on body ( Fig. 29 View FIGURE 29 D). Developed, rounded.

Supplementary description of adult male. Carapace ( Figs. 29 View FIGURE 29 J–L; 30 A): Length 2.20 mm. Carapace elongated and reticulated. Height subequal in anterior and posterior. Infold on rostrum with about 11 setae forming a vertical row and 2 setae placed near ventral margin of rostrum. Below incisure 1 minute seta is present. Anteroventral inside with 8 or 9 setae. Infold on caudal process with 3 or 4 spine-like minute setae.

First anten na ( Fig. 30 View FIGURE 30 C, D). Second joint with 3 setae, 1 thick and long ventral seta and 1 lateral and 1 dorsal short normal type setae. Sensory seta of fifth joint evenly tapered from base to tip (without knee in middle) and with 4 terminal filaments ( Fig. 30 View FIGURE 30 D).

Second antenna ( Fig. 30 View FIGURE 30 E, F). Endopodite: first joint with 3 or 4 proximal and 1 distal setae; second joint with 2 muscle bands, one extends from first joint to posterior margin of third joint and another from middle of ventral margin of second joint to posterior margin of third joint ( Fig. 30 View FIGURE 30 E); third joint with 4 terminal ridges (on both limbs); proximal seta about 4/5 length of this joint. Exopodite: distal margin of first joint bare; seta of second joint with 13 ventral spines ( Kornicker 1971: 24 spines); ninth joint with 4 long and 2 short setae.

Mandible ( Fig. 30 View FIGURE 30 G–J). Coxale endite bifurcate above middle of its length ( Fig. 30 View FIGURE 30 G, J) ( Kornicker 1971: bifurcate from base of endite). Basale: dorsal margin with 3 setae, 1 near middle and 2 subterminal; medial side with 6 setae, 3 pectinate and 3 normal type; lateral surface 4 setae parallel to ventral margin; ventral margin with 2 distal setae. Exopodite about 1/2 length of first endopodial joint or somewhat shorter. Endopodite: first joint with 4 ventral setae; dorsal margin of second joint with 2 setae in proximal group, 6 setae in distal group and 1 seta between these groups; ventral margin with 2 setae in subterminal and 3 setae in terminal group.

Sixth limb. Endite I broken, endite II with 3 terminal and 1 medial setae, endite III with 8 terminal and 1 medial setae, endite IV with 6 or 7 terminal and 1 medial setae, end joint with 13–14 setae; 3 setae present in place of epipodial appendage.

Seventh limb ( Fig. 28 View FIGURE 28 J, K). Each limb with 13 setae (in literature: 12–15 setae), 4 distal (3+1) and 9 proximal (4+5) setae (in literature: 2+3 or 3+ 3 in distal group and 3+4 or 3+ 7 in proximal group). Terminal comb with 10 alate teeth ( Kornicker 1971: 13 teeth) and 2 pegs on opposite comb.

Caudal furca ( Fig. 30 View FIGURE 30 K). Limb with 8+9 claws (in literature: 9+9 claws). Claws 1–4 relatively short.

Copulatory appendage ( Fig. 30 View FIGURE 30 K). Organ very small, about ¼ length of lamella of furca (shorter than that in specimen described by Kornicker 1971).

Bellonci organ ( Fig. 30 View FIGURE 30 B, C). Elongated, somewhat longer than first joint of first antenna, and with rounded tip.

Supplementary description of A- 1 male. Carapace. Length 1.72 mm.

First antenna. Second joint with 3 setae, 1 dorsal, 1 lateral and 1 ventral.

Second antenna ( Fig. 28 View FIGURE 28 I). Endopodite: first joint with 4 proximal and 1 distal setae; second joint with 1 long spinous and 2 short bare ventral setae; third joint with 1 midlength dorsal and 2 short terminal setae.

Mandible. Basale: dorsal margin with 3 setae, 1 near middle and 2 subterminal; lateral surface with 4 setae parallel to ventral margin; ventral margin with 3 distal setae. Endopodite: first joint with 4 ventral setae; dorsal margin of second joint with 2 setae in proximal group, 6 setae in distal group and 1 seta between these groups; ventral margin with 2 setae in subterminal and 3 setae in terminal group.

Sixth limb. Endite I broken, endite II with 3 terminal and 1 medial setae, endite III with 8 terminal and 1 medial setae, endite IV with 7 terminal and 1 medial setae, end joint with 14 setae; 2 setae present in place of epipodial appendage.

Seventh limb. Each limb with 15 setae, 5 (3+2) in distal group and 10 (5+5) in proximal group; each seta with 2–5 bells. Terminal comb with 12 teeth; 2 pegs present on opposite comb.

Caudal furca ( Fig. 28 View FIGURE 28 L). Limb with 9+9 claws. Claws 1–4 relatively stout and short.

Medial eye ( Fig. 28 View FIGURE 28 H). Large, smooth.

Bellonci organ ( Fig. 28 View FIGURE 28 H). Elongate, 2-jointed with pointed tip.

Upper lip ( Fig. 28 View FIGURE 28 H). Ventrally hirsute, terminally with several glandular processes.

Anterior process on body ( Fig. 28 View FIGURE 28 H). Developed, rounded.

Distribution and ecology. Antarctic sublitoral species. It was collected in the Scotia subregion of the Antarctic ( Daday 1908; Kornicker 1971, 1975; Hartmann 1989), Prydz Bay and near the Russian Polar station “Molodezhnaya” (present study) between 63° and 69°S ( Fig. 23 View FIGURE 23 ) at the depths of 4.5 to 1135 m, on hard and soft substrates: rock, stone, gravel, sand and muddy sand.