Anobothrus Levinsen, 1844

Säring, Friederike, Bick, Andreas & Link, Heike, 2022, A new species of Anobothrus (Polychaeta, Ampharetidae) from the Weddell Sea (Antarctica), with notes on habitat characteristics and an updated key to the genus, European Journal of Taxonomy 789, pp. 130-152 : 143-145

Key to all species of Anobothrus Levinsen, 1844

The key accounts for the 23 species of Anobothrus Levinsen, 1844 considered valid, including the new species proposed here. It is modified after Bonifácio et al. (2015) and Alalykina & Polyakova (2020).

1. Paleae absent ..................................................................................................................................... 2

– Paleae present ................................................................................................................................... 3

2. Notochaetae always without hirsute tips; with circular band on thoracic unciniger 2 ....................... .................................................................................................................... A. apaleatus Hilbig, 2000

– Notochaetae of modified notopodia with hirsute tips; without circular band on thoracic unciniger 2 ................................................................................ A. fimbriatus Imajima, Reuscher & Fiege, 2013

3. 3 pairs of branchiae in a transversal row, with or without gap ......................................................... 4

– 4 pairs of branchiae, one transversal row or anterior and posterior rows, with or without gap ....... 9

4. Branchiae with wide median gap ...................................... A. dayi Imajima, Reuscher & Fiege, 2013

– Branchiae without median gap ......................................................................................................... 5

5. Segment 14 (thoracic unciniger 9) with elevated notopodia and notochaetae with hirsute tips ................................................................... A. flabelligerulus Imajima, Reuscher & Fiege, 2013

– Segment 13 (thoracic unciniger 8) with elevated notopodia and notochaetae without modification 6

6. Two intermediate segments; segment 6 (thoracic unciniger 1) with circular band ............................ ..................................................................................... A. auriculatus Alalykina & Polyakova, 2020

– One intermediate segment, segment 7 or 8 (thoracic unciniger 2 or 3) with circular band .............. 7

7. Segment 8 (thoracic unciniger 3) with circular band ......... A. jirkovi Alalykina & Polyakova, 2020

– Segment 7 (thoracic unciniger 2) with circular band ........................................................................ 8

8. Segments 2 and 3 (thoracic chaetigers 1 and 2) fused; without ventral fold; notopodia on segment 3 present; segment 5 (thoracic chaetiger 4) with one nephridial papilla dorsally ................................. .......................................................................................................... A. laubieri ( Desbruyères, 1979)

– Segments 2 and 3 (thoracic chaetigers 1 and 2) fused; ventral fold with 8–12 rounded papillae; notopodia on segment 3 absent ............................................ A. sonne Alalykina & Polyakova, 2020

9. 11 thoracic uncinigers ..................................................................................................................... 10

– 12 thoracic uncinigers ..................................................................................................................... 12

10. Segment 11 (thoracic unciniger 6) with modified notopodia; with eye spots ..................................... ........................................................................................................... A. bimaculatus Fauchald, 1972

– Segment 12 (thoracic unciniger 7) with modified notopodia; without eye spots ............................11

11. Segment 6 (thoracic unciniger 1) with circular glandular band; notopodia with notochaetae present from segment 3 ...................................................................... A. konstantini Säring & Bick sp. nov.

– Segment 6 (thoracic unciniger 1) without circular glandular band; segments 3 and 4 fused; notopodia and notochaetae on segment 3 absent ...................................................... A. mancus Fauchald, 1972

12. Modified notopodia on segment 14 (thoracic unciniger 9, fourth-to-last thoracic segment) ............. ...................................................................................................................... A. paleatus Hilbig, 2000

– Modified notopodia on segment 13 (thoracic unciniger 8, fifth-to-last thoracic segment) ............ 13

13. Segment 6, 7 or 8 (thoracic unciniger 1, 2 or 3) without circular band; presumably dorsally shifted notopodia on segment 8 (thoracic unciniger 3); paleae abruptly to delicate tapering ........................ ................................................................................................... A. pseudoampherete Schüller, 2008

– Segment 6, 7 or 8 (thoracic unciniger 1, 2 or 3) with circular band ............................................... 14

14. Segment 6 (thoracic unciniger 1) with circular band ....................... A. patagonicus ( Kinberg, 1867)

– Segment 7 or 8 (thoracic unciniger 2 or 3) with circular band ....................................................... 15

15. Segment 7 (thoracic unciniger 2) with circular band ...................................................................... 16

– Segment 8 (thoracic unciniger 3) with circular band ...................................................................... 17

16. Branchiae arranged in transversal row; two outermost branchial pairs reduced in diameter compared to inner branchial pairs and positioned close to each other; paleae colorless, fine and more slender than notochaetae ....................................................................... A. wilhelmi Schüller & Jirkov, 2013

– First three pairs of branchiae arranged in anterior transversal row, fourth pair of branchiae posteriorly shifted between the two outermost branchiae of the anterior row; all branchiae with the same diameter; paleae stout, reddish, wider than notochaetae .................................................................... .......................................................................................... A. rubropaleatus Schüller & Jirkov, 2013

17. All notochaetae with hirsute tips ......................................................... A. gracilis ( Malmgren, 1866)

– Most notochaetae without hirsute tips; notochaetae of modified notopodia with or without hirsute tips ................................................................................................................................................... 18

18. Modified notochaetae with hirsute tips ........................................................................................... 19

– Modified notochaetae without hirsute tips ...................................................................................... 21

19. 8–9 teeth on thoracic uncini in lateral view; diameter of all branchiophores almost same; paleae conspicuous, stout and long, originating from a prominent disc-like epidermal structure ................. ............................................................................................ A. paleaodiscus Schüller & Jirkov, 2013

– 5 teeth on thoracic uncini in lateral view; inner and middle or posteriorly shifted pair of branchiophores half as thick and / or shorter than others; without prominent disc-like epidermal structure ........... 20

20. First three pairs of branchiae arranged in anterior transversal row, fourth pair of branchiae posteriorly shifted between innermost and middle branchiae of the anterior row, fourth pair of branchiophores smaller and thinner than others and their branchiostyles several times shorter than others .......................................................................................................... A. patersoni Jirkov, 2009

– First three pairs of branchiae arranged in anterior transversal row, fourth pair of branchiae posteriorly shifted between innermost and middle branchiae of the anterior row, inner and middle pairs of branchiophores ⅔ as long as and more slender than others ........................ A. mironovi Jirkov, 2009

21. Segment 3 with notopodia and notochaetae; 16 thoracic chaetigers; surface of branchiostyles papillated; 4–5 teeth on thoracic uncini in lateral view ........................... A. antarctica Monro, 1939

– Segment 3 without or with reduced notopodia and without notochaetae; 15 thoracic chaetigers; more than 6 teeth on thoracic uncini in lateral view ................................................................................ 22

22. Segment 3 (thoracic chaetiger 2) without notopodia; surface of branchiostyle smooth; 6 teeth on thoracic uncini in lateral view ........................................ A. glandularis ( Hartmann-Schröder, 1965)

– Segment 3 (thoracic chaetiger 2) with reduced notopodia, without notochaetae; surface of inner branchiostyle with transversal ciliated ridges; 6–7 teeth on thoracic uncini in lateral view .............. ......................................................... A. amourouxi Bonifácio, Lavesque, Bachelet & Parapar, 2015