Leucon (Alytoleucon) polarsterni Ledoyer, 1993

Mühlenhardt-Siegel, Ute, 2011, New and known species of the family Leuconidae (Cumacea, Peracarida) from Antarctic deep-sea basins 3117, Zootaxa 3117 (1), pp. 1-68 : 6-10

publication ID	https://doi.org/ 10.11646/zootaxa.3117.1.1
persistent identifier	https://treatment.plazi.org/id/03EE87EE-FFCD-FFB9-FF1F-F851FC319EF4
treatment provided by	Felipe
scientific name	Leucon (Alytoleucon) polarsterni Ledoyer, 1993
status

Treatment

Previous records. Described for the Weddell Sea (1153–1223 m).

Diagnosis. Leucon with long dorsomedian row of teeth, no lateral teeth on carapace; accessory flagellum rudimentary, uropod endopod united with terminal seta, without articulation.

New records. ( Figures 1–4 View FIGURE 1 View FIGURE 2 View FIGURE 3 View FIGURE 4 ). Peninsula: ANT XIX #42: 1 female (dissected), 5 subadult males, 14 non-ovigerous females, 3 mancas; ANT XIX # 43 : 2 subadult males, 8 non-ovigerous females, 7 mancas; ANDEEP III #153: 3 non-ovigerous females, 5 mancas; ANDEEP III #154: 3 subadult males, 1 ovigerous and 18 non-ovigerous females, 9 mancas; W Weddell Sea: ANT XIX #46 : 4 subadult males, 4 non-ovigerous females; ANT XIX #131 : 2 subadult male, 3 non-ovigerous females, 2 mancas; ANDEEP III #121: 1 adult and 7 subadult males, 4 ovigerous and 8 non-ovigerous females, 10 mancas; ANDEEP III #133: 2 mancas; ANDEEP III #142: 1 subadult male, 1 ovigerous and 4 non-ovigerous females; ANDEEP III #150: 1 female (dissected), 11 subadult males, 26 non-ovigerous females, 9 mancas; ANDEEP III #151: 1 non-ovigerous female; E Weddell Sea: ANT XV #89: 1 female (used for SEM), 3 subadult males, 18 females (non-ovigerous and with developing oostegites), 10 mancas; ANT XV #114: 1 subadult male, 1 non-ovigerous female; ANT XV #272: 1 adult (broken) and 4 subadult males, 13 females (nonovigerous and with developing oostegites), 4 mancas; ANT XV #134 AGT: 1 female (dissected), 1 adult male, 7 non-ovigerous females; ANDEEP III #78: 5 subadult males, 1 ovigerous and 15 non-ovigerous females (1 dissected), 29 mancas; ANDEEP III #80: 1 non-ovigerous female; S Sandwich Trench: ANT XIX #140 : 3 specimens; ZMH K 42932 View Materials .

Morphometric measurements:

Antenna 1: relative length of peduncle articles 1 to 3: 46/26/28 (in Ledoyer, 1993: 46 /28/26);

maxilliped 2: B/R ratio 0.7, relative length of articles I to D: 14/27/30/18/11;

maxilliped 3: B/R ratio 1.3 (1.4 in Ledoyer, 1993), relative length of articles I to D: 11/21/33/21/14 (in Ledoyer, 1993: 9 /30/28/20/13);

pereiopod 1: B/R ratio 0.5 (0.6 in Ledoyer, 1993), relative length of articles I to D: 5/18/29/27/21 (in Ledoyer, 1993: 8 /21/24/28/19);

pereiopod 2: B/R ratio 1.0, relative length of articles I to D: 3/22/29/16/29;

pereiopod 3: B/R ratio 1.5, relative length of articles I to D: 14/25/36/14/11;

pereiopod 4: B/R ratio 1.2, relative length of articles I to D: 12/23/35/20/10;

pereiopod 5: B/R ratio 1.0, relative length of articles I to D: 16/22/36/20/7.

Uropod measurements: pleotelson length to width: slightly wider than long;

pleotelson 0.7 times as long as uropod peduncle;

uropod endopod longer than exopod owing to terminal seta;

uropod endopod basal to distal article: 1.7 (1.8 in Ledoyer, 1993).

Remarks. The length proportion in the antenna 1 peduncle and the pereiopod 1 is slightly different between the specimens from Ledoyer (1993) and the Antarctic deep sea, as the peduncle article 3 is longer than article 2 in the type material but vice versa in the ANDEEP material. The pereiopod 1 propodus is the longest article in the type material but the carpus is longest in the deep-sea material. However, the carpus and propodus are both rather long and of similar length in both specimens, so the difference may be not really important.

Obviously this species has a wide distribution in Antarctic waters.