Anonyx Krøyer, 1838a

(Fig. 2)

Anonyx Krøyer, 1838a: 256 .— Krøyer, 1838b: 243.— Stebbing, 1906: 53.— Gurjanova, 1962: 207 (key).— Steele & Brunel, 1968: 949 (key).—J.L. Barnard, 1969: 324.— Lincoln, 1979: 76.— Barnard & Karaman, 1991: 442 (key), 463.

Chironesimus Sars, 1891: 108 (type species, Anonyx debruynii Hoek, 1882, monotypy).

Lakota Holmes, 1908: 498 (type species, Lakota carinata Holmes, 1908, original designation).

Type species. Lysianassa lagena Krøyer, 1838b, selected by Boeck, 1876 (junior synonym of A. nugax (Phipps, 1774)) .

Included species. Anonyx includes 50 species: A. abei Takekawa & Ishimaru, 2001; A. adoxus Hurley, 1963; A. affinis Ohlin, 1895; A. attenuatus Steele, 1989; A. barrowensis Steele, 1982; A. beringi Steele, 1982; A. birulai Gurjanova, 1962; A. bispinosus Steele, 1967; A. comecrudus J.L. Barnard, 1971; A. compactus Gurjanova, 1962; A. dalli Steele, 1983; A. debruynii Hoek, 1882; A. eous Gurjanova, 1962; A. eousides Steele, 1991; A. epistomicus Kudrjaschov, 1965; A. grebnitzkii Steele, 1991; A. gurjanovai Steele, 1986; A. hayashii Sekiguchi & Yamaguchi, 1983; A. hurleyi Steele, 1986; A. knipowitschi Gurjanova, 1962; A. laticoxae Gurjanova, 1962; A. lilljeborgi Boeck, 1871; A. makarovi Gurjanova,1962; A. minimus Gurjanova, 1962; A. multiarticulatus (Pearse, 1913); A. nugax (Phipps, 1774); A. ochoticus Gurjanova, 1962; A. oculatus Gurjanova, 1962; A. omorii Takekawa & Ishimaru, 2001; A. orientalis Gurjanova, 1962; A. pacificus Gurjanova, 1962; A. pareous Steele, 1991; A. pavlovskii Gurjanova, 1962; A. petersoni Steele, 1986; A. pseudeous Steele, 1991; A. robustus Gurjanova, 1962; A. sarsi Steele & Brunel, 1968; A. schefferi Steele, 1986; A. schokalsii Gurjanova, 1962; A. sculptifer Gurjanova, 1962; A. shoemakeri Steele, 1983; A. simplex Hirayama, 1985; A. stappersi Steele, 1989; A. stebbingi Steele, 1989; A. stegnegeri Steele, 1986; A. validus Gurjanova, 1962; A. volkovi Kudrjaschov, 1965 .

Incertae sedis. Anonyx anivae Gurjanova, 1962 (gnathopod 1 propodus margins subparallel, antenna 2 without brush setae, mouthparts unknown); A. derjugini Gurjanova, 1962 (accessory flagellum not forming a cap); Anonyx lebedi Gurjanova, 1962 (gnathopod 1 ischium long); Anonyx magnus Gurjanova, 1962 (gnathopod 1 very weakly subchelate and no constriction on uropod 2 inner ramus).

Removals. Anonyx lebedi Gurjanova, 1962 to Tmetonyx . Gnathopod 1 with long ischium and propodus with subparallel margins.

Diagnostic description. Antenna 1 peduncle article 1 without anterodistal lobe; accessory flagellum forming cap covering callynophore. Antenna 2 with brush setae. Mandible molar setose with vestigial triturating surface. Maxilla 1 outer plate a well developed 7/4 crown. Maxilla 2 inner plate slightly to significantly shorter than outer plate. Gnathopod 1 subchelate (occasionally parachelate); coxa 1 large, about as long as coxa 2, subrectangular with straight or concave anterior margin; ischium short (length less than 2 × breadth); carpus short (length 1 to 2 × breadth) or long; propodus margins slightly tapering distally. Uropod 2 inner ramus constricted (weak to strong). Telson moderately to deeply cleft.

Remarks. Anonyx appears to be most similar to Onisimus . Both genera have a subchelate first gnathopod with a short carpus. However Anonyx has bush setae on antenna 2 (absent in Onisimus) and the molar is a strong setose tongue (a reduced column with triturating surface in Onisimus). Both genera are scavengers with wide-spread distributions in arctic/boreal regions.

Anonyx is also similar to Tmetonyx . They differ in the accessory flagellum cap (absent in Tmetonyx), the mandibular molar (setose with a reduced column with convex triturating surface in Tmetonyx), the ischium of gnathopod 1 (long in Tmetonyx), and the margins of the propodus (subparallel in Tmetonyx).