Talitrus saltator ( Montagu, 1808 ), 2019

Lowry, J. K. & Myers, A. A., 2019, Talitrus saltator (Montagu, 1808), a species complex (Amphipoda, Senticaudata Talitroidea, Talitridae), Zootaxa 4664 (4), pp. 451-480 : 461-464

Talitrus saltator ( Montagu, 1808)

( Figs 2C , 9–10 )

Oniscus locusta Pallas, 1766: 191 , pl. 14, fig.15 [homonym of Cancer locusta Linnaeus, 1758 = Gammarus locusta ( Linnaeus, 1758 )].? Cancer locusta .— Pennant, 1777: 21. Cancer (Gammarellus) locusta Herbst, 1793: 127 pl. 36, fig. 1. Gammarus locusta , Talitrus (part) Latreille, 1802: 39. Cancer (Gammarus) saltator Montagu, 1808: 94 pl. 4, fig. 3. Talitrus littoralis Leach, 1814: 402 . Talitrus saltator .—Milne-Edwards, 1830, 364.— Lucas, 1840: 226.— Brandt, 1851: 137.— Della Valle, 1893: 492, 947, fig. 57.— Stebbing, 1906, 525.— Stephensen, 1929, 14, fig. 10.— Schellenberg, 1942, 138, figs 114, 115.— Bulycheva, 1957, 129, fig. 48.— Lincoln, 1979, 226, figs 96, 104.— Chevreux & Fage, 1925 (in part), 271, fig. 282 (in part).— Bousfield, 1982. 45.— Zettler & Zettler, 2017: 349, figs 245–247. Talitrus locusta .— Spence Bate, 1862: 5.— Spence Bate & Westwood, 1863: 16.—G.O. Sars, 1890, 23, fig. 9.

Type material. Neotype, male, 17 mm, NHMUK 2018.1539 , beach on small spit near top of Ringabella Bay , Ireland (51°46.259’N 8°19.192’E), J.K. Lowry, L. Fanini and R. Lowry, 6 June 2017).

Other material examined (all NHMUK). 5 males 7 females, Ringabella Bay, J.K. Lowry, L. Fanini and R. Lowry, 6 June 2017; 3 unsexed, Kent, England, 1969, D.J. Wildish; 12 unsexed, Sandwich Bay, Kent, England, 1988; 3 unsexed, Channel Tunnel Reclamation site, Dover, England, 2000; 12 unsexed, Plymouth, Devon, England, 1908; 4 unsexed, Porthcothan and Harlyn Bay, Cornwall, England, 1915; 1 male, South Devon, T.R.R. Stebbing; 1 male, Swanage, Dorset, England, 1911, A.M. Norman; 1 male, 1 female, Colwyn Bay, Wales, 1925, A. Walker; 7 unsexed, Dale Flats, Pembrokeshire, Wales, 1967; 4 unsexed, Whiteford Burrows, Glamorgan, Wales, 1967, M. Thurston; 8 juveniles, Aberdaron Bay, Glamorganshire, Wales, 1967, M. Thurston; 34 unsexed, West Angle, Pembrokeshire, Wales, 1980, J. Ellis; 7 unsexed, Niarbyl, Isle of Man, 1939; 22 unsexed, Poolewe, Rosshire, Scotland, 1955; 4 unsexed, Cap Ferret, France, 1969, D.J. Wildish; 2 unsexed, Monarch Isles, Outer Hebrides, Scotland, 1970, R.J. Lincoln; 76 unsexed, Garloch golf course, Ross and Cromarty, Scotland, 1971, R.J. Lincoln; 25 unsexed, Gainearnh Smo., Ross and Cromarty, Scotland, 1971, R.J. Lincoln; 12 unsexed, Shetland Islands, Scotland, 1974, R.J. Lincoln; 40 unsexed, St Andrews, Scotland, 1911, A.M. Norman; 10 unsexed, Woolacombe Sands, North Devon, England, 1911, A.M. Norman; 2 unsexed, St. Cyrus, Kincardine, Scotland, 1949, C.H. Otto; 2 unsexed, Tangier, Morocco, 1928, T.R.R. Stebbing.

Type locality. Beach on small spit near the top of Ringabella Bay, Ireland (51°46.259’N 8°19.192’E) .

Diagnosis (male). Antenna 1 peduncular articles 2 and 3 short, 1.2 × as long as broad. Antenna 2 slightly incrassate, quite variable in length in similar sized individuals between populations. Gnathopod 1 merus posterior margin unexpanded; carpus: propodus length = 1:0.5; dactylus short, one third length of propodus. Pereopod 6 basis expanded, posterior margin weakly convex Pereopod 7 basis expanded, posterior margin convex, propodus 5 × as long as broad; dactylus short and stout. Uropods short. Uropod 1 rami shorter than peduncle (1:0.7), endopod slightly longer than exopod. Uropod 2 exopod 0.8 × length of endopod. endopod:peduncle ratio = 1:1.3. Uropod 3 peduncle about as broad as long; ramus short, broad, not markedly tapering distally, with 4 or 5 marginal setae.

Description of neotype. Male 17 mm.

Head. Eyes round, medium size. Antenna 1 short, reaching end of antenna 2 article 4; peduncular articles 2 and 3 about 2 × as long as broad; flagellum with 5 articles. Antenna 2 slightly incrassate, peduncular articles of variable length; flagellum with 22 articles. Maxilla 1 inner plate slender with 2 terminal setae. Maxilla 2 without oblique setal row. Maxilliped palp article 4 fused with article 3.

Pereon. Gnathopod 1 coxa subtriangular; basis stout, anterior margin straight; merus posterior margin unexpanded; carpus stout, parallel-sided; propodus a little over half length of carpus; dactylus short, one third length of propodus. Gnathopod 2 mitten-shaped; basis sub-ovoid; carpus longer than propodus; posterior margin of propodus with lobe covered in palmate setae; propodus palm obtuse; dactylus short, distally acute, shorter than posterior margin of propodus. Pereopods 3–7 bicuspidactylate. Pereopod 4 dactylus thickened proximally with notch midway along posterior margin. Pereopod 5 short, less than 2/3 length of pereopod 6; basis with large posterior lobe. Pereopod 6 subequal in length with pereopod 7; basis with margin of posterior lobe weakly convex. Pereopod 7 basis expanded, with margin of posterior lobe convex; propodus 5 × as long as broad.

Pleon. Epimeron 3 posterior margin weakly scalloped. Uropod 1 rami shorter than peduncle (1:0.7); endopod slightly longer than exopod; Uropod 2 exopod 0.8 × length of endopod. endopod:peduncle ratio = 1:1.3.. Uropod 3 peduncle about as broad as long; ramus short, broad, not markedly tapering distally, with 4-5 marginal setae. Telson with 9–10 setae per lobe.

Female (sexually dimorphic characters). Not significantly different from male.

Remarks. Type material of T. saltato r ( Montagu, 1808) cannot be traced in the collections of the British Museum and is considered lost (Lauren Hughes pers. com.). Given the historical ambiguity in the identity of T. saltator , we therefore establish a neotype for this species in order to stabilize the species.

Talitrus saltator differs from both T. cloquetii and T. platycheles in its more robust build, in particular its shorter and stouter pereopods 6–7. It differs from T. cloquetii in the shape of the posterior margin of the basis of pereopod 7 that is evenly convex in T. saltator but flattened in T. cloquetii . It differs from T. platycheles in having a short uropod 3 with the ramus not markedly tapering and an unswollen merus on the male gnathopod 1.

Distribution. This species is widely distributed along European coasts, from Norway and the Baltic Sea in the North, around British and Irish coasts, the coast of France and northern Spain and the Azores in the south. There are no records of Talitrus along the south coast of Spain.

Figures

FIGURE 2. Talitrus cloquetii Audouin, Gournes, Crete; B. Talitrus platycheles Guérin, Cagliari, Italy; C. Talitrus saltator Montagu, Ringabella Bay, Cork, Ireland.

FIGURE 9. Talitrus saltator Montagu, male neotype, 17 mm, Ringabella Bay, Cork, Ireland.

FIGURE 10. Talitrus saltator Montagu, male neotype, 17 mm, Ringabella Bay, Cork, Ireland.