Taken primarily from Kozloff, 1987, 1996 p. 296 (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 | Legs thick, shorter than (or at least not conspicuously longer than) the combined length of the proboscis and trunk; outline of the animal as a whole oval or elliptical; without chelicerae or pedipalps; without conspicuous spiny projections | 2 |
| 1b | Legs usually much longer than the combined length of the proboscis and trunk (pycnogonids of this type are usually awkward and gangly, but sometimes are fairly compact); outline of the animal as a whole approximately circular; with either chelicerae or pedipalps, or both; often spiny or setose | 3 |
| 2a | Color uniform (ivory to pink); height of dorsal tubercles, when these are present, not greater than their basal diameter | Pycnogonum stearnsi |
| 2b | Color not uniform (generally light brown with dark lines, or with clear areas between dark patches); height of dorsal tubercles greater than their basal diameter | Pycnogonum rickettsi |
| 3a | With both chelicerae and pedipalps (the pedipalps are conspicuous and have several articles); chelicerae either with functional chelae or with chelae reduced to knobs (juveniles of some species, however, have chelae that are lost as the animals mature); ovigerous legs usually present in both sexes and conspicuous | 4 |
| 3b | With chelicerae, but without pedipalps; chelicerae with chelae and conspicuous; ovigerous legs reduced or entirely absent in females | 17 |
| 4a | Chelicerae with 2 basal articles; small chelae sometimes present (the chelae may, however, be reduced to nonfunctional knobs) | 5 |
| 4b | Chelicerae with a single basal article (scape); with a chela or a knoblike second article (or the entire appendage may be reduced to a knob or to an elongate, tuberclelike structure) | 7 |
| 5a | ||
| 5b | ||
| 6a | ||
| 6b | ||
| 7a | Chelicerae reduced to knobs or tubercles | 8 |
| 7b | Chelicerae consisting of a basal article (scape) and either a well developed terminal chela that extends beyond the proboscis or with a knoblike article (if functional chelae are present in sub-adults, these do not extend beyond the proboscis) | 11 |
| 8a | Each chelicera consisting of an easily recognized, papillate process; a gangly species with rather long and slender legs, these often with brownish purple bands; pedipalps with 9 articles | Ammothea hilgendorfi |
| 8b | Chelicerae small and difficult to see; animal rather compact; pedipalps with 6 or fewer articles | 9 |
| 9a | Body covered with short setae, thus appearing hairy; associated with the alcyonacean Gersemia rubriformis | Tanystylum anthomasti |
| 9b | Body not covered with short setae (it may, however, have sparse spines); not normally associated with Gersemia | 10 |
| 10a | Proboscis about twide as long as its diameter at the base, rounded at the tip, trunk very compact, the lateral projections indistinct | Tanystylum occidentalis |
| 10b | Proboscis at least 3 times as long as its diameter at the base, tapering to a blunt, subconical tip; trunk not so compact as in T. occidentalis, the lateral projections touching, but distinct | Tanystylum sp. |
| 11a | ||
| 11b | ||
| 12a | ||
| 12b | ||
| 13a | ||
| 13b | ||
| 14a | ||
| 14b | ||
| 15a | ||
| 15b | ||
| 16a | ||
| 16b | ||
| 17a | Lateral projections very close together; auxiliary claws minute and inconspicuous; legs slender (intestine bright green, its branches clearly visible in the legs; eye tubercle at least twice as high as broad) | Anoplodactylus viridintestinalis |
| 17b | Lateral projections separated by at least half their diameter; auxialiary claws small but well developed; legs stout | Phoxichilidium femoratum |
Phoxichilidium femoratum
Pycnogonum stearnsi
Tanystylum occidentalis