Protohyale sp. Common name(s): Sea flea
Synonyms: Hyale frequens, Hyale rubra frequens
Phylum Arthropoda  Subphylum Crustacea  Class Malacostraca  Subclass Eumalacostraca  Superorder Peracarida  Order Amphipoda Suborder Gammaridea Superfamily Talitroidea  Family Hyalidae
	Protohyale sp. about 1 cm long, found intertidally near Rosario.
	(Photo by:  Dave Cowles, July 2009)

Pereon:
Coxa 1 is not much reduced and coxa 4 is not greatly enlarged--the coxae are of similar size range though they become gradually larger posteriorly.  The proximal posterior margin of coxa 4 has a deep concavity.

Pleon: Pleosome/Urosome:
The urosome is laterally compressed.
Uropod 1 has an enlarged peduncular spine at the base of and lateral to the rami.
Uropod 3 has a stout peduncle which does not greatly exceed the length of the telson.  The third uropod has a single, distinct main ramus, which is conical or bladelike (not flattened and paddlelike) and at least 1/2 as long as the peduncle.  This ramus has only one section.  Uropod 3 has stiff spines.  There is no second ramus on uropod 3.
The telson is naked (no spines or setae) and cleft to its base.  The apical margins are smooth.

Note:  This is a species complex.  What originally keyed to Hyale frequens in Kozloff (1987, 1996) has subsequently been subdivided into a whole group of species, some of which are found in our area and some are not.  See Bousfield and Hendrycks, 2002 for a more detailed breakdown of the species.  The species group now includes Protohyale frequens (not in our area), P. lamberti, jarretteae, P. seticornis, P. oclairi, and P. hiwatarii.

How to Distinguish from Similar Species:  Several other hyalid species have a short 2nd antennal flagellum with <20 segments and the telson has slender spinules.  Also see the note above.

Geographical Range:

Depth Range:  Intertidal to 6 m

Habitat:  A common amphipod in the rocky intertidal, in tidepools, and in kelp holdfasts,

Biology/Natural History:   Predators include the tidepool sculpin Oligocottus maculosus and the fluffy sculpin Oligocottus snyderi.

References:

General References:

Scientific Articles:
Bousfield, E.L. and E.A. Hendrycks, 2002.  The talitroidean amphipod family Hyalidae revised, with emphasis on the North Pacific fauna: systematics and distributional ecology. Amphipacifica 3(3):17-134
Web sites:

General Notes and Observations:  Locations, abundances, unusual behaviors: