Anonyx compactus
Antenna 1 shorter than antenna 2; flagellum article 1 distinctly elongate. Antenna 2 between 40 to 60% of body length; calceoli present. Eyes large, reniform. Lateral cephalic lobes subacute to acute. Maxilliped palp 4-articulate; inner plate poorly developed, not reaching half length of outer plate.
Gnathopod 1 subchelate; coxa large, about as long as coxa 2, subrectangular with concave anterior margin; ischium short; carpus long, of subequal length to propodus; propodus margins tapering, palm transverse to slightly acute. Gnathopod 2 subchelate; carpus longer than propodus; dactylus minute. Pereopods 3 and 4 propodus with blunt, locking robust setae at posterodistal corner. Pereopod 5 coxa equilobate; basis about as long as broad.
Epimeron 1 anterodistal corner producing small, up-turned spine; epimeron 3 posterodistal corner produced, forming a large upturned spine or forming 2 spines, the superior the largest (see remarks below). Urosomite 1 with dorsal depression. Uropods 1 and 2 rami subequal; uropod 2 inner ramus with marginal constriction; uropod 3 outer ramus 2-articulate, article 2 short, rami subequal with inner ramus extending past article 1 of outer ramus. Telson distinctly longer than broad, deeply cleft.
Female (sexually dimorphic characters): Antenna 2 less than 40% of body length. Calceoli absent. Epimeron 3 posterodistal corner forming a large upturned spine.
12 -17 mm
Mainly a Pacific species which seems to have spread into the Atlantic. There are few records of this in the Northeast Atlantic, and these are mostly in the Norwegian Sea.
The original illustrations of Gurjanova (1962) show slight variations on those of Steele & Brunel (1968). In Gurjanova's illustration the 1st coxa is shown to be somewhat convexed anteriorally, whereas that of Steele & Brunel shows a clearly concaved margin. Also Gurjanova shows a miniscule spine beneath the large spine on the 3rd epimeron posterodistal corner. This is not illustrated in the female by either author, and Steele & Brunel do not illustrate the male epimeron 3 for comparison. It is possible that this character is slightly variable between sexes and/or individuals. It is unknown whether a type specimen was designated for this species.