Tryphosella Bonnier, 1893

Lowry, J. K. & Stoddart, H. E., 2011, The tryphosine genera Photosella gen. nov. and Tryphosella Bonnier, 1893 (Crustacea: Amphipoda: Lysianassoidea: Lysianassidae: Tryphosinae) in Australian waters 2956, Zootaxa 2956 (1), pp. 1-76 : 12-16

Tryphosella Bonnier, 1893

Pseudotryphosa Sars, 1891: 83 . Tryphosella Bonnier, 1893: 170 . —J.L. Barnard, 1969: 365. — Thurston, 1974: 16. — Lincoln, 1979: 82. — Ruffo, 1985: 280.

— Oleröd, 1987: 155. — Diviacco & Ruffo, 1989: 559. — Barnard & Karaman, 1991: 536. — Lowry & Stoddart, 1995:

131. — Kilgallen et al., 2006: 1067. Tryphosa . — Sars, 1891: 75 (in part). — Stebbing, 1906: 68 (in part).

Diagnostic description. Body not expanded to form a lateral bulge, without dorsal carina. Antenna 1 accessory flagellum not forming cap, terminal article not offset. Antenna 2 peduncular article 3 short; articles 4 and/or 5 sometimes enlarged in male. Mandible molar with asymmetrically reduced column, proximally setose, distally triturating; palp attached about midway. Maxilla 1 setal-tooth 7, left and right asymmetrical (rarely symmetrical), left cuspidate along most of curved inner margin, right cuspidate along most of sinsusoidal inner margin.

Gnathopod 1 subchelate (occasionally simple in male); coxa large, slightly or significantly shorter than coxa 2, tapering distally or subquadrate; carpus long (length 2 or more x breadth), (occasionally short); propodus margins subparallel (except when gnathopod 1 simple). Pereopod 4 with a well-developed posteroventral lobe. Pereopod 5 coxa without distinct lateral ridge; basis without photophore, posterior margin without mid-central spine, posteroventral lobe or posteroventral spine.

Urosomite 1 not projecting over urosomite 2. Uropod 2 inner ramus without constriction (rarely with). Uropod 3 peduncle without dorsolateral flange; plumose setae on rami in male (occasionally also in female). Telson deeply cleft (more than 64%).

Type species. Tryphosella sarsi Bonnier, 1893 , selected by J.L. Barnard, 1969.

Confirmed species. Tryphosella includes 40 species: T. abyssalis ( Stephensen, 1925) ; T. ama Lowry & Stoddart, 1994 ; T. angulata ( Sars, 1895) ; T. apalachicola Lowry & Stoddart, 1997 ; T. astrolabensis Lowry & Stoddart, 1995 ; T. bet Lowry & Stoddart, 2009 ; T. betka sp. nov.; T. bicheno sp. nov.; T. biloba ( Stephensen, 1925) ; T. californica ( Hurley, 1963) ; T. camela ( Stebbing, 1910) ; T. cameloides Lowry & Stoddart, 2009 ; T. chinchilla sp. nov.; T. cooee sp. nov.; T. flynnana Lowry & Stoddart, 2009 ; T. fortescue sp. nov.; T. freycinet sp. nov.; T. horingi ( Boeck, 1871) ; T. insignis ( Bonnier, 1896) ; T. longidactyla Ruffo, 1985 ; T. longiseta Ren in Ren & Huang, 1991; T. lowryi Kilgallen, Myers & McGrath, 2006 ; T. martrudan sp. nov.; T. metacaecula J.L. Barnard , l967; T. minima (Chevreux, 1911) ; T. moana Kilgallen, 2009 ; T. orana J.L. Barnard, 1972 ; T. oupi Lowry & Stoddart, 1994 ; T. quadrata (J.L. Barnard, 1962) ; T. rodondo sp. nov.; T. sarsi Bonnier, 1893 ; T. seasana Lowry & Stoddart, 2009 ; T. serans Lowry & Stoddart, 1983 ; T. sorell sp. nov.; T. tathra sp. nov.; T. toowoomba sp. nov.; T. tuckanarra sp. nov.; T. umbonatus ( Sars, 1883) ; T. wangaratta sp. nov.; T. wongada Lowry & Stoddart, 1995 .

Possible species. The following 24 taxa are currently placed in Tryphosella . For each taxon there is insufficient information about the gnathopod 1 coxa and/or the mouthparts to confirm or reject this placement. Although for many of them it is not possible to decide if they are tryphosines or uristids (because the mouthparts have not been described), they are probably mostly tryphosines. T. analogica (K.H. Barnard, 1932) ; T. barentsi ( Gurjanova, 1929) ; T. bispinosa ( Schellenberg, 1931) ; T. caecoides (J.L. Barnard, 1962) ; T. compressa ( Sars, 1895) ; T. coxalis (J.L. Barnard, 1962) ; T. groenlandica ( Schellenberg, 1935) ; T. index (J.L. Barnard, 1966) ; T. insignioides ( Stephensen, 1925) ; T. longichela ( Stephensen, 1925) ; T. macropareia ( Schellenberg, 1926) ; T. marri Thurston, 1974 ; T. nanoides ( Lilljeborg, 1865) ; T. orchomenoides ( Stephensen, 1925) ; T. oxystoma ( Stephensen, 1925) ; T. propinqua ( Chevreux, 1926) ; T. pusilla ( Sars, 1879) ; T. rotundata ( Stephensen, 1925) ; T. schneideri ( Stephensen, 1921) ; T. serrata ( Schellenberg, 1931) ; T. simillima Ruffo, 1985 ; T. spitzbergensis ( Chevreux, 1926) ; T. triangula ( Stephensen, 1925) ; T. triangularis (K.H. Barnard, 1932) .

Excluded species. Fifteen species are excluded:

Tryphosella castellata (K.H. Barnard, 1932) : coxa 1 is described as ‘distally widened’ (K.H. Barnard 1932: 53).

T. cicadopsis ( Schellenberg, 1926) : the setal teeth of maxilla 1 outer plate extend well down the face of the plate,

indicating a placement in Uristidae ( Schellenberg 1926: fig. 22e).

T. cucullata ( Walker, 1904) : coxa 1 is expanded anteroventrally ( Walker 1904: pl. 4, fig. 8).

T. erosa ( Meinert, 1890) : coxa 1 is expanded anteroventrally ( Meinert 1890: fig. 25).

T. gracilipes ( Stephensen, 1925) : coxa 1 is "rather broad, expanded toward the apex" ( Stephensen 1925: 115).

T. intermedia ( Schellenberg, 1926) : coxa 1 is not shortened or tapered ( Schellenberg 1926: 270, fig. 17d).

T. laevis ( Bonnier, 1896) : coxa 1 is not shortened or tapered; maxilla 2 inner plate is much shorter than outer plate;

molar appears to be a setose tongue ( Bonnier 1896: pl. 35 fig. 5). This species belongs in the family Uristidae . T. murrayi ( Walker, 1903) : based on examination of specimens in the Australian Museum collection (AM P.3190)

this taxon has maxilla 1 outer plate setal teeth in a 7/4 crown arrangement and maxilla 2 inner plate much shorter than the outer plate so belongs in the family Uristidae and the genus Uristes as Hurley (1965) indi-

cated.

T. paramoi ( Schellenberg, 1931) : coxa 1 is not shortened or tapered; maxilla 2 inner plate is much shorter than the outer plate ( Schellenberg 1931: figs 20, 21). This species belongs in the family Uristidae .

T. schellenbergi Lowry & Bullock, 1976 : coxa 1 is not shortened or tapered; the setal teeth of maxilla 1 outer plate extend well down the face of the plate, indicating a placement in Uristidae ( Schellenberg 1931: fig. 19, as Tmetonyx serratus ).

T. trigonica ( Stebbing, 1888) : the setal teeth of maxilla 1 outer plate extend well down the face of the plate and maxilla 2 inner plate is much shorter than the outer plate, indicating a placement in Uristidae ( Stebbing 1888: pl. 9).

T. trionyx ( Stephensen, 1925) : coxa 1 is "apically somewhat expanded" ( Stephensen 1925: 115).

T. triplans (J.L. Barnard, 1962) : coxa 1 is nearly as long as coxa 2 and very slightly tapered (J.L. Barnard, 1962: fig. 18).

T. tuberculimana ( Lagardère, 1968) : coxa 1 is nearly as long as coxa 2 and only slightly tapered, gnathopod 1 carpus and propodus not like that of Tryphosella ( Lagardère 1968: pls 1, 2).

T. uristesi Bellan-Santini, 1997 : coxa 1 is as large as coxa 2 and not tapering; maxilla 2 inner plate is much shorter than the outer plate ( Bellan-Santini 1997: fig. 11). This species belongs in the family Uristidae .

Remarks. Stebbing (1906) synonymised Pseudotryphosa Sars, 1891 with Uristes Dana, 1849 . Barnard & Karaman (1991) maintained Pseudotryphosa as a junior synonym of Uristes and it has remained that way until now. But the arrangement of the maxilla 1 setal-teeth, the relative lengths of the maxilla 2 plates and the strongly triturating mandibular molar are more similar to those of a tryphosine. The shortened, tapering first coxa puts Pseudotryphosa in the genus Tryphosella . We here transfer P. umbonata ( Sars, 1883) to Tryphosella and regard Pseudotryphosa as a synonym of Tryphosella . See Appendix 1 for an explanation of the reversal of precedence for these two names.

Three tryphosine genera ( Cedrosella Barnard & Karaman, 1987 , Thrombasia J.L. Barnard, 1966 and Tryphosella ) have molars with an asymmetrically reduced triturating column and a reduced, tapering gnathopod 1 coxae. Cedrosella differs from the other two genera, in among other things, the accessory flagellum which forms a cap and the weakly developed posteroventral lobe of the pereopod 4 coxa. Thrombasia and Tryphosella are very similar. They only differ in the mandibular palp which is attached distally in Thrombasia and midway in Tryphosella ; in the maxilla 1 ST7 which is cuspidate distally in Thrombasia and cuspidate along most of the sinsusoidal inner margin in Tryphosella ; and in the telson which is moderately cleft in Thrombasia and deeply cleft in Tryphosella . Currently Thrombasia is in synonymy with Schisturella Norman, 1900 (see Barnard & Karaman 1991: 526). We see no justification for this synonymy and re-establish the genus.

Tryphosella is a world-wide genus which often dominates scavenging guilds ( Lowry & Stoddart 1983; Lowry & Stoddart 1995; Lowry & Smith 2003; De Broyer et al. 2004). There are a number of distinctive characters, particularly in the Indo-West Pacific area, which are useful in recognising species groups. However, when a wider range of characters are considered, these "groups" are not mutually exclusive.

1. Species in which coxa 1 is small (length 1–1.4 x breadth) and subtriangular: T. ama , T. astrolabensis , T. betka , T. bicheno , T. fortescue , T. freycinet , T. martrudan , T. orana , T. rodondo , T. seasana , T. sorell , T. tathra , T. toowoomba .

2. Species with a long ischium on gnathopod 1: T. ama , T. astrolabensis , T. bicheno , T. seasana , T. wongada .

3. Species with robust setae on the callynophore and proximal articles of antenna 1: T. astrolabensis , T. bet , T. bicheno , T. chinchilla , T. cooee , T. wongada .

4. Species in which the basis of gnathopod 1 is densely setose: T. chinchilla , T. cooee , T. rodondo .

5. Species in which the male gnathopod 1 is simple (as opposed to subchelate): T. betka , T. martrudan , T. toowoomba , T. wangaratta .

6. Species in which some or all of the robust setae on the outer rami of uropods 1 and 2 are stout and striated: T. fortescue , T. freycinet , T. orana , T. sorell , T. tathra , T. tuckanarra .

7. Species in which the antenna 2 of the mature male is short (about as long as antenna 2, as opposed to the elongate antenna 2 of many mature lysianassoid males): T. betka , T. chinchilla , T. martrudan , T. wongada .

8. Species in which the proximal calceolus of male antenna 1 is very large compared to the subsequent calceoli: T. camela , T. fortescue , T. sorell .