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