Polyphemus

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Cladus: Protostomia
Cladus: Ecdysozoa
Cladus: Panarthropoda
Phylum: Arthropoda
Cladus: Pancrustacea
Cladus: Allotriocarida
Classis: Branchiopoda
Superordo: Cladocera
Ordo: Onychopoda
Familia: Polyphemidae
Genus: Polyphemus
Species (3): P. brevicaudis – P. exiguus – P. pediculus
Name

Polyphemus O. F. Müller, 1785

References
Primary references

Müller O. F.. 1785: Entomostraca seu Insecta Testacea quae in aquis Daniae et Norvegiae reperit, descripsit et iconibus illustravit. Lipsiae et Havniae: 135 pp.

Additional references

Dumont, H.J.; Negrea, S.V. 2002: Introduction to the class Branchiopoda. Guides to the identification of the macroinvertebrates of the continental waters of the world. (Ed. H.J. F. Dumont). Backhuys Publishers, Leiden. 19:1-398. ISBN 90-5782-112-5
Rivier, I.K. 1998: The predatory Cladocera (Onychopoda: Podonidae, Polyphemidae, Cercopagidae) and Leptodorida of the world. Backhuys Publishing, Leiden: pp.213. ISBN 90-73348-85-4

Links

Polyphemus is a genus of water fleas, and the only genus in the family Polyphemidae.[1] There are two species, P. exiguus and P. pediculus, although allopatric speciation has resulted in a number of cryptic species of P. pediculus.[2] Polyphemus exiguus inhabits open zones in the Caspian Sea,[3] while Polyphemus pediculus exists throughout the Holarctic. It lives in diverse conditions, from small ponds to lakes and estuaries such as the Gulf of Saint Lawrence and the Gulf of Finland. It can be found quite far offshore.

Polyphemus are a predatory genus of water flea. The two species have four pairs of legs with exopodites, or outer branches.[3] The legs are adapted for catching mobile prey, generally smaller species of water flea such as young Daphnia and Bosmina.[4]

Polyphemus has two compound eyes that are fused to form a single unit, with a zoned set of receptors.[5] This zoned structure is paired with an eye-control system that allows the Polyphemus to visually distinguish target size to avoid predators and track prey.[4][6] P. pediculus is approximately 1 millimetre (0.04 in) in length. P. exiguus, while similar in morphology, is smaller.
References

"Polyphemus (O.F. Müller, 1785)". WoRMS. World Register of Marine Species. 2010. Retrieved March 21, 2012.
S. Xu; P. D. N. Hebert; A. A. Kotov; M. E. Critescu (2009). "The noncosmopolitanism paradigm of freshwater zooplankton: insights from the global phylogeography of the predatory cladoceran Polyphemus pediculus (Linnaeus, 1761) (Crustacea, Onychopoda)". Molecular Ecology. 18 (24): 5161–5179. doi:10.1111/j.1365-294X.2009.04422.x. PMID 19912535. S2CID 3899891.
P. D. Mordukhai-Boltovskoi (1968). "On the taxonomy of the Polyphemidae". Crustaceana. 14 (2): 197–209. doi:10.1163/156854068x00601. JSTOR 20102936.
Stephen Young & Victoria A. Taylor (1988). "Visually guided chases in Polyphemus pediculus". Journal of Experimental Biology. 137 (1): 387–398. doi:10.1242/jeb.137.1.387.
R. Odselius & D.-E. Nilsson (1983). "Regionally different ommatidial structure in the compound eye of the water-flea Polyphemus (Cladocera, Crustacea)". Proceedings of the Royal Society of London. Series B, Biological Sciences. 217 (1207): 177–189. Bibcode:1983RSPSB.217..177O. doi:10.1098/rspb.1983.0005. JSTOR 35746. S2CID 85572364.
Michael F. Land (1992). "Visual tracking and pursuit: humans and arthropods compared". Journal of Insect Physiology. 38 (12): 939–951. doi:10.1016/0022-1910(92)90002-U.