Ampharetidae Malmgren 1866

Key to Ampharetidae genera occurring in Antarctica

In order to simplify the task of genera recognition of not trained people we have assembled a dichotomic key hoping that this would speed the recognition of the different Antarctic ampharetid genera.

1. Three or four anterior segments with vertical rows of minute acicular chaetae....................................................................................................................................... Melinninae Chamberlin, 1919...2

– Minute acicular chaetae absent................................................ Ampharetinae Malmgren, 1866 …3

2. Hooks (usually one pair) and dorsal crest (usually one and dentate) behind the branchiae present........................................................................................................ Melinna Malmgren, 1866

– Hooks absent, dorsal crest present.............................................. Melinnides Wesenberg-Lund, 1950 (= Melinnantipoda)

– Hooks and dorsal crest absent............................................................... Melinnopsis McIntosh, 1885 (= Amelinna, Melinnexis, Melinnopsides)

3. Buccal tentacles attached outside the mouth, methylene blue staining pattern of ventral glandular shields well marked............................................................. Noanelia Desbruyères & Laubier, 1977

– Buccal tentacles attached inside the mouth (seldom may be everted), methylene blue staining pattern of ventral glandular shields poor marked......................................................................................... 4

4. Prostomium Amphicteis -like: with prominent straight transversal nuchal ridges; middle lobe anteriorly more of less incised, usually with pair of longitudinal ridges; rudimental notopodia AU1 several times smaller than normal thoracic................................................. Amphicteis Grube, 1850

– Prostomium Ampharete or Amage -like: trilobed, without prominent nuchal organs or ridges; middle lobe anteriorly rounded; rudimental notopodia AU1 several times smaller normal thoracic or absent................................................................................................................................................ 5

– Prostomium without lobes, without prominent nuchal organs or ridges........................................ 13

5. Middle lobe of prostomium anteriorly incised or with horns (Fig. 1 A–B)...................................... 6

– Middle lobe of prostomium anteriorly rounded or pointed.............................................................. 8

6. Abdominal neuropodia with very long cirri, longer than width of segment.................................................................................................................................................... Samythopsis McIntosh, 1885 (= Neopaiwa, Paiwa, Weddelia)

– Abdominal neuropodial cirri, if present much shorter than width of segment (Fig. 1G)................. 7

7. All abdominal neuropodia, including AU1 pinnuli (Fig. 1G), no more than 16 AU................................................................................................................................................ Amage Malmgren, 1866 (= Egamella, Mexamage, Paramage, Phyllampharete)

– All abdominal neuropodia pinnula, except AU1, neuropodia AU1 tori (like thoracic), more than 20 AU......................................................................................................... Grubianella McIntosh, 1885

8. Distinct transversal dorsal ridge between TC3 and TC4 present........................................................................................................................................................... Melinnampharete Annenkova, 1937 (= Eusamytha Hartman, 1967 non McIntosh, 1885, Eusamythella, Neosamytha)

– Dorsal ridge absent........................................................................................................................... 9

9. One, usually from 5 th (4 th– 6 th) to the last pair of posterior notopodia slightly shifted dorsally and connected by low ridge.......................................................................... Anobothrus Levinsen, 1884

– One pair of posterior notopodia (last, 2 nd or 3 rd from last) flattened and shifted dorsally........................................................................................................................................ Sosane Malmgren, 1866

– Posterior notopodia neither flattened, nor shifted dorsally, ridges also absent............................... 10

10. 1 st segment with ‘horns’.................................................................. Abderos Schüller & Jirkov, 2013

– 1 st segment without ‘horns’..............................................................................................................11

11. Lower lip enlarged, longitudinally grooved............................................... Lysippe Malmgren, 1866 (= Lysippides, Paralysippe, Pseudampharete, Pterolysippe, Samytha)

– Lower lip not enlarged.................................................................................................................... 12

12. A pair of nephridial papillae medially behind the branchiae. Paleae well developed, paleal chaetae bigger then most developed notochaetae (paleae of species outside Antarctic may be smaller or even absent).................................................................................................... Ampharete Malmgren, 1866 (= Asabellides, Parampharete, Pseudosabellides, Pterampharete, Sabellides,? Amythasides)

– Nephridial palillae medially behind the branchiae absent (Fig. 4C). Paleae absent.................................................................................................................................................. Amythas Benham, 1921

13. Two last pairs of notopodia (or only second counting from the back) slightly shifted dorsally and connected by low, transverse ridges............................................................. Zatsepinia Jirkov, 1986

– Dorsally shifted notopodia and dorsal transverse ridges absent..................................................... 14

14. Prostomium with pair of tranversal nuchal organs......................................................................... 15

– Prostomium without nuchal organs............................................. Glyphanostomum Levinsen, 1884

15. The shape of neuropodia slightly changed along the body (Fig. 5B)....... Phyllocomus Grube, 1877 (= Shistocomus,? Amphisamytha)

– Neuropodia of thorax, AU1, and AU2 are tori, the rest are abdominal pinnuli, change is well marked.................................................................................................... Neosabellides Hessle, 1917