Key:  Phylum Ctenophora


Taken primarily from  Kozloff, 1987, 1996 p.79  (Copyright 1987, 1996, University of Washington Press.  Used in this web page by permission of University of Washington Press)
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1a  Body resembling a sac, without tentacles and not divided into a pair of large lobes at the oral end 2
1b Body solid, not saclike, either with a pair of conspicuous tentacles arising within sheaths on opposite sides of the body or with a pair of large lobes at the oral end (in which case there are small tentacles of 2 types in the cavity enclosed by the oral lobes) 4
2a
2b
3a
3b
4a Body with a pair of large lobes at the oral end; tentacles small, of two types (a pair of branched tentacles in sheaths near the mouth, and numerous small tentacles in tracts leading toward the mouth; both types are in the cavity enclosed by the oral lobes) 5
4b Body without a pair of large lobes at the oral end; tentacles conspicuous when extended, arising from sheaths on opposite sides of the body some distance from the mouth 6
5a Body surface smooth, colorless except for rows of darkly pigmented spots in line with the comb rows, but nearer to the mouth than these; length less than 12 (15) cm. Bolinopsis infundibulum
5b Body surface covered with yellow-orange papillae; length sometimes more than 20 cm (rare; an undescribed species) Leucothea sp
6a Tentacle sacs opening toward the aboral end of the body; tentacles with side branches (tentillae); mouth and pharynx relatively small 7
6b Tentacle sacs opening toward the oral end of the body; tentacles without side branches; mouth and pharynx relatively large 10
7a Tentacle sacs angling away from the pharynx toward the body surface for their entire length 8
7b Tentacle sacs lying close to the pharynx for most of their length 9
8a Body nearly spherical; tentillae fairly numerous and not coiled into neat, pear-shaped bundles when contracted Pleurobrachia bachei
8b Body somewhat ovoid and flattened in the tentacular plane; tentillae sparse and coiled into neat pear-shaped bundles when contracted (an undescribed species) Euplokamis dunlapae
9a Body elongate, approximately cucumber-shaped, the length sometimes attaining 10 cm; tentillae sparse (rare) Hormiphora cucumis
9b Body ovoid, up to 2 cm long; tentillae numerous and crowded (tentacles red or pinkish purple, an undescribed species) Mertensia sp
10a
10b



Taxonomic Levels Represented in This Key:

  Bolinopsis infundibulum
  Hormiphora cucumis
  Pleurobrachia bachei
 



Page created by Dave Cowles, 2007
Edited by: Dave Cowles, 2012