| 1a |
Protandrichermaphrodites
in which the last larval stage (cryptoniscus), after functioning as a free-living
male, becomes transformed into a parasitic female; this loses all or most
appendages and becomes hypertrophied in such a way that the body has 2
to several lobes (section Cryptoniscina) |
2 |
| 1b |
Sexes separate and both parasitic, the male being much smaller and
more isopodlike than the female (there is usually a male closely associated
with each female)(section Bopyrina) |
3 |
| 2a |
Parasitic in barnacles (Balanus
glandula, Chthamalus dalli); adult female conserving only the cephalon
and some of the more anterior segments of the cryptoniscus, the rest of
the body consisting of several lobes; basal article
of antenna 1 and coxal
plates of male toothed |
Hemioniscus balani |
| 2b |
Hyperparasitic on the rhizocephalans Peltogaster paguri and
Peltogasterella
gracilis, which are parasites of hermit crabs; adult female, after
a period of completely internal parasitism, becomes constricted into 2
nearly spherical portions, the anterior one being buried in the host, the
posterior one being external; basal article
of antenna 1 and coxal
plates of male smooth |
Liriopsis pygmaea |
| 3a |
Endoparasitic (not visible externally) in the visceral cavity of the
crabs Hemigrapsus
oregonensis and H.
nudus (body of female bent into a V, the cephalon
divided into 2 hemispheres, the pereopods
reduced to stubs, the pleon with 5 pairs of wrinkled lateral lobes; male
with only 6 pairs of pereopods |
Portunion conformis |
| 3b |
Ectoparasitic, either located in the branchial
chamber of the crustacean host, attached to the dorsal surface, or
attached to the underside of the abdomen |
4 |
| 4a |
Attached to the dorsal surface of the host, which is either a decapod
or mysid (female asymmetrical, with only 5 pairs of pereopods,
these grouped around the oral region, and with most of the posterolateral
portion covered by a pair of enlarged oostegites) |
5 |
| 4b |
In the branchial
chamber or under the abdomen of decapod crustaceans |
7 |
| 5a |
Parasitic on the shrimp Pasiphaea pacifica; female with all
pereonites
and pleonites
fused or so nearly fused that they are indistinct (male with pleonites
fused) |
Holophryxus alaskensis |
| 5b |
Parasitic on mysids (possibly other planktonic crustaceans); female
with at least some pereonites
and pleonites
distnct dorsally |
6 |
| 6a |
Female with all pereonites
and pleonites
distinct dorsally (male with all pleonites
distinct)(parasitic on the mysid Eucopia australis, collected in
very deep water, and perhaps associated with other mysids) |
Arthophryxus beringanus |
| 6b |
Female with pereonites
1-3 and pleonites
distinct dorsally (type specimen found in a collection of mysids from very
deep water) |
Prophryxus alascensis |
| 7a |
Female symmetrical or only slightly asymmetrical, with all pereonites
distinct, and with 5 pairs of nearly equal oostegites;
female with 7 pars of pereopods
and generally with 6 distinct pleonites |
8 |
| 7b |
Abdominal parasites of shrimps in the genera Lebbeus,
Spirontocaris,
Eualus,
and Heptacarpus; female very asymmetrical, with pereonites
not completely separated dorsally; on the swollen side, the oostegites
are large and form a closed brood
pouch, and generally only pereopod
1 persists; on the nearly straight side, oostegites
2-4 are reduced to small plates and there are 7 pereopods;
pleon with 5 pleonites,
4 pairs of leaflike lateral plates, and small uniramouspleopods;
male with fused pleonites |
Hemiarthrus abdominalis |
| 8a |
Parasitic on the underside of the abdomen of the thalassinid Upogebia
pugettensis (pleon
of female without lateral plates but with well developed biramous pleopods
and uniramous
uropods; pleon
of male with lateral plates) |
Phyllodurus abdominalis |
| 8b |
Parasitic in the branchial
chamber of thalassinids,
hermit
crabs, galatheids,
and shrimps of the families Crangonidae,
Hippolytidae,
and Pandalidae |
9 |
| 9a |
On the thalassinid Neotrypaea
californiensis; pleon
of female with 6 pairs of lateral plates which are long and thin and whose
posterior margins are fringed by slender outgrowths (brood
pouch of female closed; pleon
of male with elongated lateral plates but these are not fringed) |
Ione cornuta |
| 9b |
On hermit
crabs, galatheids,
or shrimps; pleon
either with 5 pairs of lateral plates, with rudimentary
plates, or without any plates |
10 |
| 10a |
Pleon
with 5 pairs of lamellar
and smooth lateral plates; brood
pouch closed; pleonites
of male fused or not fused |
11 |
| 10b |
Pleon
either without lateral plates or with rudimentary
plates; brood
pouch open; pleonites
of male fused (photo) |
13 |
| 11a |
On the galatheid Munida
quadrispina (see also choice 12b); female with 2 pars of lateral
lamellae
on the posteroventral border of the cephalon;
coxal
plates of the pereon
well developed; pleopods
visible when the animal is viewed from the dorsal side; pleotelson
elongated and swollen near its tip and bearing biramous
uropods; pleonites
of male fused |
Munidum parvum |
| 11b |
Female with 1 pair of lateral lamellae
on the posteroventral border of the cephalon;
pereon
without coxal
plates; pleopods
not visible when the animal is viewed from the dorsal side; pleotelson
short, rounded or truncate
at its tip and bearing uniramousuropods;
pleonites
of male not fused |
12 |
| 12a |
On hermit
crabs; endopodites
of pleopods
of female much longer than the exopodites,
their surfaces more or less tuberculated |
Pseudione giardi |
| 12b |
On the galatheid Munida
quadrispina (see also choice 11a); endopodites
of pleopods
of female only slightly longer than the exopodites, their surfaces smooth |
Pseudione galacanthae |
| 13a |
On shrimps of the family Crangonidae (Crangon,
Argis);
female with well developed biramouspleopods
and uniramousuropods |
Argeia pugettensis |
| 13b |
On shrimps of the families Hippolytidae (Spirontocaris,
Eualus,
Heptacarpus)
and Pandalidae; female either without pleopods
or with pleopods
reduced to tubercles,
and without uropods |
Bopyroides hippolytes |