| 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 |
Meridional digestive canals with branching diverticula
in a layer just below the body surface (the branches between the canals,
however, do not anastomose) |
3 |
| 2b |
Meridional digestive canals without diverticula
just below the body surface, although there are a few diverticula
directed inward toward the pharynx (with spots of golden brown pigment,
an undescribed species) Note: some other references seem to regard this
species also as Beroe cucumis) |
Beroe sp. |
| 3a |
Body colorless or with pink pigmentation (this pigment may be on the
outer surface, especially near the ctenes,
or distributed throughout the mesoglea,
but it is not concentrated in the lining of the pharynx);
pharyngeal canals not branched. |
Beroe cucumis |
| 3b |
Pharynx intensely pigmented
giving the ctenophore a striking red, purple, or nearly black color; pharyngeal
canals with many diverticula
(rare) |
Beroe abyssicola |
| 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 (tentillae);
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 |
With only 4 meridional
digestive canals, these widely separated from the comb
rows; tentacles with
nematocysts
(??), but without colloblasts;
tentacle
sheaths very long, with orange to brick-red pigment at the tentacle
bases and also near the middle of the tentacle
sheaths (rare) |
Haeckelia rubra |
| 10b |
With 8 meridional
digestive canals, these directly beneath the comb
rows; tentacles without
nematocysts,
but with
colloblasts;
tentacle sheaths
short and sometimes containing red pigment (additional orange-brown pigment
may be present near the mouth and gonads) |
Dryodora glandiformis |