Key:  Family Polynoidae

Phylum Annelida
 Class Polychaeta
  Order Phyllodocida
   Superfamily Aphroditidae

Taken primarily from  Kozloff, 1987, 1996 p. 137 (Copyright 1987, 1996, University of Washington Press.  Used in this web page by permission of University of Washington Press)
Jump to:
Lower taxonomic level Main Page Alphabetic Index Systematic Index Glossary
1a  With 12 pairs of elytra Lepidonotus squamatus
1b With at least 15 pairs (rarely 13 or 14 pairs) of elytra 2
2a With 15 pairs (rarely 13 or 14 pairs) of elytra 3
2b With at least 18 pairs of elytra 23
3a With more than 50 segments; elytra restricted to the anterior and middle regions of the body, at least 18 of the posterior segments not covered by them 4
3b With fewer than 50 segments; elytra covering nearly all segments 6
4a
4b
5a
5b
6a At least some of the neurosetae  bifid at the tip (the 2 teeth are not equal, however) 7
6b None of the neurosetaebifid at the tip 12
7a Notosetae thicker than the neurosetae 8
7b Notosetae about the same thickness as the neurosetae Tenonia priops
8a Anterior pair of eyes (on the dorsolateral surfaces of the prostomium) not visible from the dorsal side (they are covered by outgrowths of the prostomium)(photo)(free-living in various habitats, and also commensal with other polychaetes) Harmothoe imbricata
8b Anterior pair of eyes visible from the dorsal side (not covered by outgrowths of the prostomium) 9
9a
9b
10a
10b
11a
11b
12a
12b
13a
13b
14a
14b
15a
15b
16a
16b
17a
17b
18a
18b
19a
19b
20a
20b
21a
21b
22a
22b
23a With 18 pairs (rarely 19 pairs) of elytra (free-living or commensal, usually with other polychaetes) Halosydna brevisetosa
23b With more than 18 pairs of elytra 24
24a Elytra on every segment posterior to segment 38; dorsal nuchal fold prominent and covering part of the prostomium Hololepida magna
24b Elytra not on every segment posterior to segment 38; without a prominent nuchal fold 25
25a Lateral prostomial antennae inserted on the edge of the prostomium; notopodia abortive, with an acicula but without other setae 26
25b Lateral prostomial antennae inserted slightly ventral to the edge of the prostomium; notosetae present, though not necessarily on all notopodia, and sometimes few in number 27
26a
26b
27a Elytra on segments 2, 4, 5, then every other segment to 23, 26, 30, 32, 35; following segment 35, the arrangement of elytra is irregular, because they are not in sequence and not always in pairs; notosetae numerous, with pointed tips (commensal with the terebellid polychaetes Thelepus crispusand Neoamphitrite robusta, perhaps others) Polyeunoa tuta
27b Elytra on segments 2, 4, 5, then every other segment to 23, 26, 29, then every other segment to the end of the body; relatively few segments near the posterior end have unpaired elytra; notosetae few, with rather blunt, indistinctly bifid tips, or absent 28
28a Margins of elytra extensively ruffled or folded (commensal with various sea stars) Arctonoe fragilis
28b Margins of elytra smooth or only slightly wavy 29
29a Neurosetae (except on segment 2) of 2 types:  those above the acicula slender and with blunt, bifid tips, those below the acicula stouter and with falcate, pointed tips; with a band of dark pigment extending across segments 7 and 8 (commensal with a wide variety of invertebrates, including sea stars, terebellid polychaetes, gastropods [especially Diodora aspera], and Cryptochiton stelleri) Arctonoe vittata
29b Neurosetae essentially of 1 type: falcate and with pointed tips; without a dark band of pigment extending across segments 7 and 8 (commensal with a variety of invertebrates, including sea stars, the sea cucumber Parastichopus californicus, Cryptochiton stelleri, and terebellid polychaetes) Arctonoe pulchra



Taxonomic Levels Represented in This Key:

  Arctonoe fragilis
  Arctonoe pulchra
  Arctonoe vittata
  Harmothoe imbricata
  Lepidonotus squamatus



Page created by Dave Cowles, 2005
Edited by: