North-eastern Atlantic Amphipoda: Aoridae

R. King & A.A. Myers

Microdeutopus anomalus (Rathke, 1834)

Gammarus anomalus Rathke, 1843: 63, pl. 4, fig. 7.

Autonoe anomala (Rathke). --Bruzelius, 1859: 25, fig. 4.

Microdeutopus anomalus. --Boeck, 1871: 237. Sars, 1894: 540, pl. 191. --Chevreux & Fage, 1925: 298, fig. 309. --Gurjanova, 1951: 833, fig. 582. --Myers, 1969b: 110, figs. 7�10, 20. --Myers, 1982a: 143�144, fig. 94.

Microdeutopus danmoniensis (sic) Sars, 1894: 542, pl. 192.

Microdeutopus propinquus Sars, 1894: 542, pl. 192. --Stebbing, 1906: 592.

Microdeutopus stationis Sowinsky, 1895: 237, pl. 4, figs. 1�6.

Type material. Unknown.

Type locality. Christiansund, Norway.

Description. Based on Myers, 1982a: 143�144, fig. 94. --Myers, 1969b: 110, figs. 7�10, 20.

Head. Rostrum absent or vestigial; Lateral cephalic lobes apically truncate, anteroventral margin shallowly excavate, scarcely recessed. Antenna 1 flagellum with 21 or more articles; accessory flagellum present and multiarticulate. Antenna 2 with few long setae. Maxilliped basis with strong flange on anterior margin; palp with wing-like flanges on anterior margin of basis, ischium and merus.

Peraeon. Sternal spines present, on other pereonites, apically acute. Gnathopod 1 enlarged in males only; coxa distinctly produced anterodistally, acute; basis slender, much less than half as broad as long, without a spine, anterior margin without stridulating ridges, posterodistal margin with setae sparse or absent, anterodistal margin with strong flange, with a weak distomedial lobe or absent; ischium anterior margin without flange, posterior margin with setae sparse or absent; merus not greatly elongated, fused along its entire length with carpus, posterior margin with sparse setae or setae absent, without posterodistal spine; carpus one and one third to one and one half length of propodus, anterior margin without stridulating ridges, with setae sparse or absent, anterior surface with no spine, without an oblique row of long setae on medial face, posterior margin with stout spine or spines, one spine or two spines, distal the larger; propodus shorter than carpus, anterior margin weakly to moderately setiferous, posterior margin sinuous or irregular with proximal lobe, palm absent; dactylus more than half length of propodus. Gnathopod 2 subchelate; basis anterodistal margin with flange, posterodistal margin without robust setae; with few setae along length of basis; carpus longer than propodus, anterior margin not lobate, moderately to sparsely setiferous; propodus densely setose, palm with robust seta(e) defining palm. Pereopod 6 basis not or weakly produced posterodistally.

Pleon. Uropod 1 biramous, peduncle much longer than broad, distoventral interramal spine shorter than peduncle. Uropod 2 peduncle with distoventral interramal spine. Uropod 3 biramous, outer ramus shorter than inner, inner ramus subequal with length of peduncle. Telson with distal fine setae only.

Female (sexually dimorphic characters). Peraeon. Sternal spines absent. Gnathopod 1 carpus two thirds length of propodus, posterior margin without spines; propodus longer than carpus, anterior-distal margin densely clothed in long setae, palm present, palm delimited from posterior margin, margin entire, palm defined by rounded or oblique corner, with robust seta defining palm; significantly overlapping palm. Gnathopod 2 basis anterodistal margin without flange; carpus subequal with or shorter than propodus.

Habitat. Among algae and phanerogams (Myers, 1982a).

Depth zones. Littoral.

Distribution. Black Sea, Atlantic Ocean, Mediterranean Sea.

Cite this publication as: 'King, R. & A.A. Myers (2001 onwards). North-eastern Atlantic Amphipoda: Aoridae. Version 1: 1 September 2001.'. Dallwitz (1980) and Dallwitz, Paine and Zurcher (1993, 1995, 2000) should also be cited (see References).