Lepechinella Stebbing 1908

Genus Lepechinella Stebbing, 1908

Lepechinella Stebbing, 1908: 344–346, plate XVI.

Dorbanella Chevreux, 1914: 1–4, figs 1–3.

Diagnosis

The characters given in the diagnosis of the genus Lepechinella by Sittrop & Serejo (2009: 475) are: “Body with projections on the dorsal midline; cephalic tooth divided into two cusps pointed anteriorly; upper lip bilobate; mandible with palp, article 2 of palp of mandible longer than article 3, incisor process dentate, lacinia mobilis dentate, molar triturative; article 2 of palp of maxilla 1 expanded distally; inner plate of maxilla 2 narrower than outer plate; article 2 of palp of maxilliped longer than articles 1 and 3 combined; peraeopods 3 to 7 slender, all articles elongated, except for article 3”.

Key to the species of Atlantic and Arctic Lepechinella

1. Peraeon segment 1 without dorsal teeth ……………………………………………………………2

– Peraeon segment 1 with 1 or 2 dorsal teeth (may be small) ……………………………………3

2. Coxal plate 3 clearly bifid; peraeon segment 4 with dorsal tooth …………………………………… ………………………… L. campensis Sittrop & Serejo, 2009. Campos Basin slope, coast of Brazil

– Coxal plate 3 not bifid; peraeon segment 4 dorsally smooth ………………………………………… …………………………… L. laurensi Sittrop & Serejo, 2009. Campos Basin slope, coast of Brazil

3. Peraeon segment 1 with a single dorsal tooth … L. skarphedini Thurston, 1980. East Iceland Basin

– Peraeon segment 1 with 2 dorsal teeth (may be small) ……………………………………………4

4. Dorsal teeth on peraeon segment 1 small ……………………………………………………………5

– Dorsal teeth on peraeon segment 1 well-developed …………………………………………………6

5. Gnathopod 1 very slender, carpus much longer than propodus; not heavily setose dorsally ……………………………………………………… L. grimi Thurston, 1980. East Iceland Basin

– Gnathopod 1 moderately slender, carpus and propodus subequal in length. Heavily setose along dorsal midline … L. hirsuta Sittrop & Serejo, 2009. Campos Basin slope, coast of Brazil

6. Urosome segments 2–3 not fused ……………………………………………………………………7

– Urosome segments 2–3 fused ………………………………………………………………………8

7. Coxal plate 1 bifid, both lobes with serration; Pleon segments 1–3 with 1 large and 1 smaller dorsal tooth …………… L. eupraxiella (Barnard, 1973). Between Spitzbergen and Greenland

– Coxal plate 1 bifid, both lobes with smooth margins; Pleon segments 1–3 with one large and two smaller dorsal teeth ……… L. chrysotheras Stebbing, 1908, North of British Isles

8. Coxal plate 1 long, acute, not bifid …………… L. echinata Chevreux, 1914. Bay of Biscay

– Coxal plate 1 clearly bifid ……………………………………………………………………………9

9. Pleon segments 1–3 with one large dorsal tooth only …… L. victoriae sp. nov., South of Iceland

– Pleon segments 1–3 with additional dorsal teeth, besides the large posterior one ………………10

10. Pleon segments 1–3 with several smaller teeth (or humps) besides the large posterior one ……11

– Pleon segments 1–3 with one smaller tooth (or hump) besides the large posterior one ………12

11. Coxal plate 3 clearly bifid, with posterior lobe small, but acute. Uropod 1 rami subequal …………………………………………………………… L. manco Barnard, 1973. Mediterranean

– Coxal plate 3 acute, posterior lobe vestigial. Uropod 1 inner ramus clearly shorter (65 %) than outer ramus ……………………………………… L. helgii Thurston, 1980. East Iceland Basin

12. Coxal plate 4, width 2x the width of basis ………………………………… L. norvegica sp. nov.

– Coxal plate 4, width 3–4x the width of basis ……………………………………………………13

13. Peraeopod 7 carpus 1.2x propodus, coxal plate 7 posterodistal corner rounded, posterior margin of peraeopod 7 basis with spines …… L. schellenbergi Stephensen, 1944, Western Greenland

– Peraeopod 7 carpus is 1.6x propodus, coxal plate 7 parallelogram shaped with acute posterodistal corner, posterior margin of peraeopod 7 basis with setae…………………… ………………………………………………… L. arctica (Schellenberg, 1926), Arctic Polar Basin

The most important differences between L. arctica, L. schellenbergi and L. norvegica sp. nov. are shown in Table 1.