Liljeborgia polosi Barnard and Karaman, 1991

d, Cédric, d, Udekem, Acoz & Vader, Wim, 2009, On Liljeborgia fissicornis (M. Sars, 1858) and three related new species from Scandinavia, with a hypothesis on the origin of the group fissicornis, Journal of Natural History 43 (33 - 34), pp. 2087-2139 : 2131-2133

Liljeborgia polosi Barnard and Karaman, 1991

Lilljeborgia dubia Kamenskaya, 1980, p. 245 –246, fig. 1, 2.

L. [ Liljeborgia ] polosi Barnard and Karaman, 1991, p. 416 (replacement name); Kamenskaya, 2001, p. 162.

Not Eusirus dubius Haswell, 1879, p. 331 , pl. 20, fig. 3.

Not Liljeborgia dubia ; Stebbing, 1906, p. 233.

Material

None.

Diagnostic characters extracted from Kamenskaya’s drawings

No eyes. Second article of mandibular palp very long and with setae only on tip; third article of mandibular palp about 0.37 times as long as second article. Dactylus of Gn1–2 apparently toothless. Posterior spines/setae of carpus and propodus of P3–P4, respectively, about as long as width of carpus, and as long as width of propodus (the drawings of Kamenskaya are very approximate, but indicate at least that these spines/setae are rather long). Basis of P5–P6–P7 very narrow (respectively 2.7, 3.1 and 2.3 as long as wide on Kamenskaya’s drawings); there are no indications of crenulations on the posterior border of the basis in Kamenskaya’s drawings (actually it is very improbable there are no crenulations at all, but this suggests they are poorly developed); distal articles of posterior pereiopods slightly spinose; propodus of P7 3.0 times as long as propodus of P6; dactylus of P5–P7 short and curved, that of P7 being 0.28 times as long as propodus. Pleonites 1–3 devoid of posterodorsal tooth; posterior tooth of Ep3 illustrated as strong. Urosomite 1 and 2 with dorsal crest posteriorly followed by a strong tooth, which is pointing obliquely upwards. Spines of uropods numerous and small; in U3 apparently only the inner ramus has spines. Telson cleft on 0.56 of its length; outer teeth of lobes considerably longer than medial teeth; distal spines overreaching outer teeth by about 0.3 of their length, 0.2 times as long as telson.

Size

Up to 36 mm ( Kamenskaya 1980, 2001).

Depth range

2710 to 3550 m depth ( Kamenskaya 1980).

Distribution

Canadian Basin of the Arctic Ocean ( Kamenskaya 1980).

Trophic biology

Kamenskaya (2001) indicated that fragments of crustaceans mixed with detritus were found in the guts of several specimens. Some of her specimens were collected with baited traps, indicating that the species can exhibit a necrophagous behaviour. She concluded that L. polosi probably has a wide trophic spectrum with a preference for animal items.

Etymology

Barnard and Karaman (1991) introduced the name L. polosi in replacement of Liljeborgia dubia Kamenskaya, 1980 . The latter is indeed a secondary junior homonym of Eusirus dubius Haswell, 1879 , which was transferred to the genus Liljeborgia by Stebbing (1906). Barnard and Karaman (1991) did not indicate the derivation of the name “ polosi ”, which is therefore explained hereafter. The species was collected by the drifting station “North Pole 22”, as indicated in the title of the paper by Kamenskaya (1980). In Russian, “Pole” is written “Hônc”, which Barnard and Karaman (1991) transliterated as “Polos”. This transliteration is incorrect and should have been “Polyus”, “Polius” or “Poljus” (depending on the system of transliteration adopted). However, the name has to be retained in its original form because the International Code of Zoological Nomenclature, 4th edition, article 32.5.1, states that “If there is in the original publication itself (...) clear evidence of an inadvertent error (...) it must be corrected. Incorrect transliteration or latinization (...) are not to be considered inadvertent errors”. Hence, “ polosi ” is the genitive of the Latin noun “ polosus ” resulting from this transliteration.

Remarks

Kamenskaya (1980) gave a short and imprecise description of this species and two very crude figures, of which the interpretation is difficult. Liljeborgia polosi should be adequately described and illustrated when specimens become available for study. The table of stations by Kamenskaya (1980) indicates that all the stations of the drifting station North Pole 22 are in East longitudes. However, this is clearly a mistake and all these stations were actually in West longitudes. Indeed, Kamenskaya (1980) indicates that her stations are located in the Canadian Basin of the Arctic Ocean, which only fits with West longitudes. Kamenskaya (2001) refers both to positions equivalent to West longitudes (albeit with an unusual coding system) and the Canadian Basin for the same stations. Finally the stations of the drifting station North Pole 22 are plotted on fig. 2 of Afanas’ev and Filatova (1980); their positions are indeed in the Canadian Basin, which confirms they are in West longitudes.

Identification table and key to Scandinavian and Arctic Liljeborgia of the group fissicornis

The differential characters of the Scandinavian and Arctic Liljeborgia of the group fissicornis are given in Table 1 and in the following key:

1. Pleonites 1–2 with large posterodorsal tooth........................ 2 Pleonite 1–2 without posterodorsal tooth.. L. polosi Barnard and Karaman

2. Pleonite 3 with posterodorsal tooth................................ 3 Pleonite 3 without posterodorsal tooth............................. 4

3. Propodus of P3 slender with posterior spines/setae usually unpaired; both rami of U3 with spines, these spines being strong; telson with very long apical spines..................................... L. ossiani sp. nov. Propodus of P3 stout, with most spines/setae in pairs or in triplets; only inner ramus of U3 with spines, these spines being small; telson with rather short apical spines................................... L. charybdis sp. nov.

4. Posterodistal corner of basis of P5–P7 blunt; Ep3 with strong tooth.................................................. L. fissicornis (M. Sars) Posterodistal corner of basis of P5-P7 forming a tooth; Ep3 with small tooth.............................................. L. caliginis sp. nov.