Onisimus normani Sars, 1891

Vader, Wim, Johnsen, Jan Roger & Tandberg, Anne Helene S., 2020, Onisimus turgidus (Sars, 1879) (Amphipoda, Uristidae), an overlooked amphipod from sea anemones in Northern Norway, European Journal of Taxonomy 724, pp. 34-50 : 36-40

Onisimus normani Sars, 1891

Figs 1–3

Onesimus normani (Schneider ms) Sars, 1891: figs on pl. 36–2.

Onesimus normani – Sars, 1895: 105.

Onisimus normani – Stephensen 1923: 48; 1935: 38. — Vader 1967: 286, figs 2–3; 1975: 38; 1983: 144. — Vader & Lønning 1973: 29. — Lowry & Stoddart 1993: 169. — Johnsen 2001: 49, fig. 17.

non O. normani – Stephensen 1923: 48. — Shoemaker 1930: 11. — Vader 1975: 38. – Moore et al. 1994: 206. — Vader & Krapp-Schickel 1995: 65. — Bryazgin 1997: 99. — Lyubina et al. 2014: 246. (All these references = O. turgidus ( Sars, 1879) .)

Material examined

NORWAY • 1 ♀ (10 mm); Korsfjorden; 680 m depth; 1968; Wim Vader leg.; from Bolocera tuediae ; TSZCr8659 ( Figs 1–3 ) • 1 ♀ immature (8 mm); same collection data as for preceding; TSZCr8659 • 1 spec.; Raunefjorden; 240 m depth; 1968; Wim Vader leg.; from Bolocera tuediae ; TSZCr8628 • 1 spec.; Korsfjorden; 680 m depth; 1968; Wim Vader leg.; from Bolocera tuediae ; TSZCr8623 • 1 spec.; same collection data as for preceding; TSZCr8624 • 2 specs; same collection data as for preceding; TSZCr9320 • 7 specs; Andfjorden; 69°18′42″ N, 16°23′24″ E; 498 m depth; 1 Jul. 1997; Wim Vader leg.; from Bolocera tuediae ; TSZCr12962

Distribution

Although there are many records of O. normani in the amphipod literature, all except those from Southern Norway in reality are either O. turgidus or taxa very closely related to that species ( Johnsen 2001). Johnsen mentions a record from Andsfjorden at 69° N (material in Tromsø Museum): otherwise this species has only been recorded from the Oslofjord and a number of localities in W Norway ( Vader 1967). Onisimus normani appears to be an obligate associate of the sea anemone Bolocera tuediae , and it has only exceptionally been found in other sea anemones ( Vader 1967, 1975), although it is well able to survive also in other sea anemone hosts in the laboratory ( Vader & Lønning 1973).

Figures

Fig. 1. Onisimus normani Sars, 1890, ♀, 10 mm, Korsfjorden, Norway (TSZCr8659). Head, mouthparts (l mandible, lower lip, maxilla 1, maxilla 2, maxilliped), telson.Abbreviations: see Material and methods. Scale bars = 0.1 mm.

Fig. 2. Onisimus normani Sars, 1890, ♀, 10 mm, Korsfjorden, Norway (TSZCr8659). Pereopods 2, 3 and 4, uropods 1, 2 and 3, antenna 1 and 2. Abbreviations: see Material and methods. Scale bars = 0.1 mm.

Fig. 3. Onisimus normani Sars, 1890, ♀, 10 mm, Korsfjorden, Norway (TSZCr8659). Pereopods 1, 5, 6 and 7, uropod 2, epimeral plates 1–3. Abbreviations: see Material and methods. Scale bars = 0.1 mm.