Belongs within: Senticaudata.
Contains: Gammaridae, Anisogammaridae, Pallaseidae, Pontogammaridae, Acanthogammaridae, Micruropodidae, Typhlogammaridae.
The Gammaroidea are a large group of mostly freshwater (though some are marine) amphipods. The gammaroids as listed below were united by Bousfield (1977); however, his description of the superfamily as ‘plesiomorphic’ suggests that he regarded this group as potentially paraphyletic with regard to the other ‘gammaroid’ superfamilies (Melitoidea, Crangonyctoidea and Melphidippoidea), though he did not conduct a formal phylogenetic analysis. Among the Gammaroidea are the extensive radiation(s) of amphipods found in Lake Baikal. These include the planktivorous Macrohectopus branickii, the only exclusively pelagic amphipod.
Characters (from Bousfield 1977): Both antennae (especially peduncle of antenna II) strongly developed, segment 2 of antenna I not elongate, acessory flagellum prominent (rarely absent); head with inferior antennal sinus deeply emarginate; eye well developed, basically reniform; body often carinate and/or processiferous, and/or rostrum moderately to well developed; urosome segments with well developed dorsal groups of spines and setae; sexual dimorphism usually strongly expressed in body size, and in characters of antennae, gnathopods, peraeopods and uropod III, but not in a specialised male instar; calceoli of antenna II cup- or plate-shaped. Mandibular palp strongly 3-segmented, terminal segment strong, usually with D-setae; lower lip with inner lobes lacking or weakly developed; maxilla I with inner plate large, strongly setose, outer plate with 11-9 (rarely fewer) apical spine-teeth; maxilla II with plates strongly setose; maxilliped with large, marginally spinose inner plates, palp strong, dactylate; coxal plates I-IV deep, contiguous (overlapping); coxae V-VII with anterior lobe usually deeper than posterior lobe. Gnathopods I and II strongly subchelate, subequal, II usually larger; peraeopods III larger than IV, may be sexually dimorphic in armature (not form); peraeopods V-VII with basis usually expanded, VII longest; pleopods with well developed rami, subequal; epimeral plates subquadrate or acute behind; peduncle of uropod I with basofacial spine; uropod III with rami usually subequal, spinose and setose (natatory), terminal segment of outer ramus present; telson basically bilobed, spinose and setose marginally and apically, apices rounded. Coxal gill of peraeon VII usually present; accessory (sternal) gills absent; brood lamellae large (or distally expanded), marginally with strong simple setae.
Gammaroidea [Gammaridira]LM13
| i. s.: BehningiellidaeLM13
| |--Behningiella Derzhavin 1948LM13
| | `--*B. brachypus Derzhavin 1948B77
| |--Cardiophilus Sars 1896LM13
| | `--*C. baeri Sars 1896B77
| `--Zernovia Derzhavin 1948LM13
| `--*Z. volgensis Derzhavin 1948B77
| Macrohectopus Stebbing 1906 [Macrohectopidae]LM13
| `--*M. branickii (Dyb. 1874) [=Gammarus branickii]B77
|--+--+--FalklandellidaeLM13
| | | |--Osornodella Pérez-Schultheiss 2013LM13
| | | |--Praefalklandella Stock & Platvoet 1991LM13
| | | `--Falklandella Schellenberg 1931LM13
| | | `--*F. obtusa Schellenberg 1931B77
| | `--ParaleptamphopidaeLM13
| | |--Ringanui Fenwick 2006LM13
| | |--Rudolphia Grosso & Peralta 2009LM13
| | `--Paraleptamphopus Stebbing 1899LM13
| | |--*P. subterraneus (Chilton 1882)B83
| | `--P. ceruleusB83
| `--+--Sensonator Notenboom 1986 [Sensonatoridae]LM13
| `--+--MesogammaridaeLM13
| | |--Paramesogammarus Bousfield 1979LM13
| | `--Mesogammarus Tzvetkova 1965LM13
| | `--*M. melitoides Tzvetkova 1965B77
| `--+--+--GammaridaeLM13
| | `--+--Lucioblivio Tomikawa 2007 [Luciobliviidae]LM13
| | `--AnisogammaridaeLM13
| `--PhreatogammaridaeLM13
| |--Caledonietta Iannilli & Ruffo 2007LM13
| |--Ruffia Bréhier, Vonk & Jaume 2010LM13
| `--Phreatogammarus Stebbing 1899LM13
| `--*P. fragilis (Chilton 1882) [=Gammarus fragilis]B77
`--+--PallaseidaeLM13
`--+--+--BathyporeiidaeLM13
| | |--Amphiporeia Shoemaker 1929LM13
| | | `--*A. lawrenciana Shoemaker 1929B69
| | `--Bathyporeia Lindstrom 1855LM13 [incl. Thersites Bate 1857 non Pfeiffer 1855B69]
| | |--*B. pilosa Lindstrom 1855B69
| | |--B. gracilis Sars 1891N00
| | |--B. guilliamsoniana (Bate 1857)BD95 [=Thersites guilliamsoniiN00]
| | |--B. megalops Chevreux 1911BD95
| | |--B. norvegica Sars 1891N00
| | |--B. pelagica [incl. B. tenuipes Meinert 1877]N00
| | |--B. phaiophthalma Bellan-Santini 1973BD95
| | |--B. robertsoniN00
| | `--B. sophiae Bellan-Santini & Vader 1988BD95
| `--GammarellidaeLM13
| |--Austroregia Barnard 1989LM13
| |--Gondogeneia Barnard 1972LM13
| |--Chosroes Stebbing 1888LM13
| | |--*C. incisus Stebbing 1888B69
| | `--C. decoratus Barnard 1932B69
| `--Gammarellus Herbst 1793LM13 (see below for synonymy)
| |--*G. homari (Fabricius 1779) [=Astacus homari]B77
| `--G. angulosusCS77
`--+--+--PontogammaridaeLM13
| `--+--Iphigenella Sars 1896 [Iphigenellidae]LM13
| | `--*I. acanthopoda Sars 1896B77
| `--+--Baikalogammarus Stebbing 1899 [Baikalogammaridae]LM13
| | `--*B. pullus (Dyb. 1874) [=Gammarus pullus]B77
| `--+--AcanthogammaridaeLM13
| `--+--MicruropodidaeLM13
| `--TyphlogammaridaeLM13
`--+--Pachyschesis Bazikalova 1945 [Pachyschesidae]LM13
| `--*P. branchialis (Dyb. 1874) [=Gammarus branchialis]B77
`--Gammaracanthus Bate 1862LM13 (see below for synonymy)
| i. s.: *G. loricatus (Sabine 1821) [=Gammarus loricatus]B77
| |--G. l. loricatusB50
| `--G. l. baicalensisB50
| G. insularisB50
|--G. lacustris Sars 1867VVP01 (see below for synonymy)
`--+--G. aestuariorum Lomakina in Guryanova 1951 [incl. G. loricatus var. ostiorum]VVP01
`--G. caspius Sars 1896VVP01 [=G. loricatus caspicaB50]
Gammaracanthus Bate 1862LM13 [incl. PseudacanthusVVP01, Relictacanthus Bousfield 1989VVP01; GammaracanthidaeLM13]
Gammaracanthus lacustris Sars 1867VVP01 [=G. loricatus lacustrisB50, Relictacanthus lacustrisVVP01; incl. G. relictus Sars 1895VVP01]
Gammarellus Herbst 1793LM13 [incl. Amathia Rathke 1837 non Lamouroux 1812B69, Amathilla Bate & Westwood 1863B69, Grayia Bate 1862B69]
*Type species of generic name indicated
References
[BD95] Bakalem, A., & J.-C. Dauvin. 1995. Inventaire des crustacés amphipodes (Gammaridea, Caprellidea, Hyperiidea) des costes d’Algérie: essai de synthèse. Mésogée 54: 49–62.
[B69] Barnard, J. L. 1969. The families and genera of marine gammaridean Amphipoda. United States National Museum Bulletin 271: i–vi, 1–535.
[B77] Bousfield, E. L. 1977. A new look at the systematics of gammaroidean amphipods of the world. Crustaceana Suppl. 4: 282–316.
[B83] Bousfield, E. L. 1983. An updated phyletic classification and palaeohistory of the Amphipoda. In: Schram, F. R. (ed.) Crustacean Phylogeny pp. 257–277. A. A. Balkema.
[B50] Brooks, J. L. 1950. Speciation in ancient lakes. Quarterly Review of Biology 25: 30–60.
[CS77] Cramp, S., & K. E. L. Simmons (eds) 1977. Handbook of the Birds of Europe, the Middle East and North Africa: The Birds of the Western Palaearctic vol. 1. Ostrich to Ducks. Oxford University Press: Oxford.
[LM13] Lowry, J. K., & A. A. Myers. 2013. A phylogeny and classification of the Senticaudata subord. nov. (Crustacea: Amphipoda). Zootaxa 3610: 1–80.
[N00] Norman, A. M. 1900. British Amphipoda: families Pontoporeidae to Ampeliscidae. Annals and Magazine of Natural History, series 7, 5: 326–346.
[VVP01] Väinölä, R., J. K. Vainio & J. U. Palo. 2001. Phylogeography of “glacial relict” Gammaracanthus (Crustacea, Amphipoda) from boreal lakes and the Caspian and White Seas. Canadian Journal of Fisheries and Aquatic Science 58: 2247–2257.