Acidostoma obesum ( Bate & Westwood, 1861 )

Stoddart, H. E. & Lowry, J. K., 2012, Revision of the lysianassoid genera Acidostoma and Shackletonia (Crustacea: Amphipoda: Acidostomatidae fam. nov.), Zootaxa 3307 (1), pp. 1-34 : 22-25

Acidostoma obesum ( Bate & Westwood, 1861)

( Figs 18–22 )

Anonyx obesus Bate & Westwood, 1861: 98 , un-numbered fig. ― Bate, 1862: 74, pl. 12, fig. 1. ― Robertson, 1888: 21. ― Walker, 1892: 136.

Acidostoma obesum . Lilljeborg, 1865a: 34, pl. 5. ― Lilljeborg, 1865b: 24. ― Bate, 1866: 333. ― Norman, 1869: 276. ― Boeck, 1871: 121. ― M'Intosh, 1874: 266. ― Metzger, 1875: 283. ― Boeck, 1876: 193. ― Stebbing, 1876: 75. ― Meinert, 1890: 157 (in part, part = A. neglectum ). ― Sars, 1890: 38, pl. 14 fig. ― Della Valle, 1893: 784. ― Norman, 1895: 479. ― Sars, 1895: 675. ― Chevreux, 1898: 476. ― Norman, 1900: 141. ― Scott, 1901: 258. ― Scott, 1904: 257. ― Reibisch, 1905: 151. ― Stebbing, 1906: 14. ― Stephensen, 1923b: 9. ― Chevreux & Fage, 1925: 32, fig. 9. ― Stephensen, 1926: 7. ― Stephensen, 1929: 52, fig. 14/13. ― Molander, 1930: 82. ―Anon. [Plymouth Marine Fauna], 1931: 188. ― Stephensen, 1932: 353 (in part). ― Stephensen, 1935: 31 (key), 32. ― Raitt, 1937: 249, 251. ― Stephensen, 1942: 470. ― Dahl, 1946: 4. ― Jones, 1948: 404. ― Enequist, 1949: 387, 400. ― Gurjanova, 1951: 158, fig. 32. ―J.L. Barnard, 1958: 88. ― Oldevig, 1959: 5. ― Gurjanova, 1962: 55 (key). ― Dahl, 1964: 50, figs 1–3.

?not Acidostoma obesum . Reid, 1951: 195 (possibly an unknown species).

Acidostoma laticorne . Meinert, 1890: 157.

Acidostoma nodiferum Stephensen, 1923a: 40 , fig. 1. ― Stephensen, 1923b: 10. ― Stephensen, 1929: 52. ― Dahl, 1946: 4. ― Enequist, 1949: 387, 400. ― Gurjanova, 1951: 158 (key). ―J.L. Barnard, 1958: 88. ― Oldevig, 1959: 5. ― Gurjanova, 1962: 55 (key). ― Dahl, 1964: 50 (key), 51, figs 4–7. ― Vader, 1967: 283, fig. 1 (map). ― Ledoyer, 1977: 372. ― Vader, 1984: 144. ― Bellan-Santini, 1985: 274. ― Costello et al., 1990: 32. ― Barnard & Karaman, 1991: 457. ― Palerud & Vader, 1991: 32. ― Miskov-Nodland et al., 1999: 154. ― Pinn & Robertson, 2003: 442.

Acidostoma sarsi Lincoln, 1979: 56 (key), 58, figs 19a–d, 20g –m. ― Diviacco & Ruffo, 1989: 472, fig. 319. ― Kunitzer, 1990: 203 (list). ― Barnard & Karaman, 1991: 457. ― Buhl-Jensen & Fosså, 1991: 248 (table 2). ―Dauvin & Sorbe, 1996: 456. ― Krapp-Schickel & Zavodnik, 1996: 459. ― Cartes et al., 2003: 748.

not Acidostoma obesum . Sars, 1886: 43 (= A. laticorne ).

not Acidostoma obesum . K.H. Barnard, 1925: 322. ―K.H. Barnard, 1940: 514 (list). ―Griffiths, 1975: 143. ― Griffiths, 1976: 56 (key), fig. 31I (= A. namibiensis ).

not Acidostoma obesum . Thurston & Allen, 1969: 353. ― Lincoln, 1979: 56 (key), 58, figs 19e–g, 20a–f. ― Vader, 1984: 144. ― Diviacco & Ruffo, 1989: 471, fig. 318. ― Barnard & Karaman, 1991: 457. ― Palerud & Vader, 1991: 32 (= A. neglectum ).

?not Acidostoma obesum . Poxton et al., 1983: 323, table 2. ― Moore, 1984: 32. ― Holmes, 1985: 23. ― Keegan et al., 1987: 13 (list). ―Costello et al., 1989: 32. ― Dauvin & Gentil, 1990: 127 (table 2). ― Vallet & Dauvin, 1996: 481. (prob. = A. neglectum ).

Material examined. NEOTYPE, here designated, female with setose oostegites, 5.5 mm, [part of BMNH 1911.11.8:12534-546], Scotland, A.M. Norman collection [remainder of this sample, 12 males, = A. neglectum ]. — Female, with non-setose oostegites, BMNH 1911.11.8:12547, Trondhjeimfjord, Norway, 20–40 fms [36–73 m], 1893, A.M. Norman collection. —Female, non-ovigerous, 6 mm, AM P.33635, Skagerrak-Kattegat, North Sea, 26 May 1891, ex ZMC. —Female, ZMO F13154, Karmø [= Karmöy Island, western Norway, approx. 59°15’N 5°15’E], Boeck collection. —One small female, ZMO F13189, unknown locality, Boeck collection. — 3 females, ZMO F13363a, western Norway, G.O. Sars collection [2 males from this collection = A. neglectum ]. —Female, ZMO F14282a, Christiansand, Norway, [approx. 58°10’N 8°00’E]. —Male, 5 mm, HOLOTYPE of Acidostoma nodiferum, ZMC CRU- 2311, south-west of the Faeroes, North Atlantic Ocean, 61°07'N 9°30'W, 835 m, 12 March 1904, Thor station 78. —Male, ZMC CRU- 2312, east of Shetlands, eastern North Atlantic Ocean, 61°14'N 1°19'E, 160 m, Thor station 120 [material recorded by Stephensen 1923a as A. nodiferum ]. —Male, 4.5 mm, ZMC CRU- 2313, 6 miles north-east of Skagen, [Skagerrak], clay with fine sand, 132 m, Hauch station 58 [material recorded by Meinert 1890 as A. laticorne and by Stephensen 1923a as A. nodiferum ].

Diagnostic description. Mandible molar absent. Maxilla 1 palp vestigial, 1-articulate, without apical setae.

Maxilliped inner plate well developed; outer plate with subapical notch. Gnathopod 2 dactylus vestigial. Pereopods

5 and 6 merus about as long as broad. Epimeron 3 posteroventral corner produced, rounded. Uropod 1 peduncle dorsolateral margin with less than 10 robust setae. Uropod 2 peduncle dorsolateral margin not castellate, without setae. Uropod 3 reaching to about the end of uropod 2; rami longer than peduncle, without plumose setae; outer ramus article 2 vestigial. Telson about as long as broad, deeply cleft (about 66%).

Distribution. Norwegian Sea, North Sea, eastern North Atlantic Ocean, Mediterranean Sea, in 0–1200 m depth.

Figures

FIGURE 18. Acidostoma obesum (Bate & Westwood), neotype, female, 5.5 mm, BMNH, Scotland.

FIGURE 19. Acidostoma obesum (Bate & Westwood), neotype, female, 5.5 mm, BMNH, Scotland. Scales represent 0.1 mm.

FIGURE 20. Acidostoma obesum (Bate & Westwood), neotype, female, 5.5 mm, BMNH, Scotland. Scales for U1–3, T represent 0.1 mm; remainder represent 0.2 mm.

FIGURE 21. Acidostoma obesum (Bate & Westwood), male, 5 mm, holotype of A. nodiferum Stephensen, ZMC CRU2311, south-west of the Faeroes.

FIGURE 22. Acidostoma obesum (Bate & Westwood), male, 5 mm, holotype of A. nodiferum Stephensen, ZMC CRU2311, south-west of the Faeroes. Scales for G1, 2 represent 0.2 mm; remainder represent 0.1 mm.