Tryphosinae

D’Acoz, Cedric D’Udekem & Havermans, Charlotte, 2012, Two new Pseudorchomene species from the Southern Ocean, with phylogenetic remarks on the genus and related species (Crustacea: Amphipoda: Lysianassoidea: Lysianassidae: Tryphosinae), Zootaxa 3310, pp. 1-50 : 3-4

Subfamily Tryphosinae Lowry and Stoddart, 1997

Type genus. Tryphosa Boeck, 1871 ; see Lowry & Stoddart, 1997.

Type species. Anonyx nanus Krøyer, 1846 ; designation by Boeck (1876: 180).

Remarks. Lowry & Stoddart (1997) designated Tryphosa as the type genus of their subfamily Tryphosinae , which includes the genus Pseudorchomene . However, for 140 years there was endless controversy concerning the type species of Tryphosa , and the validity and definition of that genus, resulting in extreme confusion. Since the identity of the subfamily Tryphosinae is based on its type genus ( Tryphosa ) and the type species of its type genus, a reconstruction of the ‘ Tryphosa saga’ is given herein, in order to solve this thorny problem.

Krøyer (1846) described Anonyx nanus in a long and precise description devoid of illustrations. When creating the genus Tryphosa Boeck, 1871 (the type genus of the subfamily Tryphosinae ), Boeck (1871) described four species without designating a type species, in the following order: T. nanus ( Krøyer, 1846) (original combination: Anonyx nanus ), T. Høringii Boeck, 1871, T. nanoides ( Lilljeborg, 1865) (original combination: Anonyx nanoides ) and T. longipes (Spence Bate1 & Westwood, 1861) (original combination: Anonyx longipes ). Five years later, Boeck (1876) formally designated Anonyx nanus Krøyer, 1846 as the type species of Tryphosa in repeating and expanding his earlier description. G. O. Sars (1883) redescribed Krøyer’s (1846) and Boeck’s (1871, 1876) species under the name Tryphosa ciliata G. O. Sars, 1883 , not realizing that his species had already been named earlier. G. O. Sars (1890) created the genus Orchomenella (with O. minuta as type genus) and described again Tryphosa nana sensu Krøyer & Boeck , this time as Orchomenella ciliata ( G. O. Sars, 1883) . G. O. Sars (1891) described as Tryphosa nana , a species which is not that of Krøyer (1846) and Boeck (1871, 1876), and which was still devoid of valid name at that time. Bonnier (1893) pointed out the mistakes of G. O. Sars (1890, 1891) and created the genus Tryphosella Bonnier, 1893 for the species fitting the definition of Tryphosa proposed by G. O. Sars (1891). He did not suggest a type species for Tryphosella but listed seven species, in the following order: T. sarsi Bonnier, 1893 (= Tryphosa nana sensu G. O. Sars, 1891 ), T. compressa (G. O. Sars, 1891) (original combination: Tryphosa compressa ), T. Hörringi ( Boeck, 1871) , T. angulata (G. O. Sars, 1891) (original combination: Tryphosa angulata ), T. nanoïdes ( Lilljeborg, 1865) (original combination: Anonyx nanoides ), T. antennipotens ( Stebbing, 1888) (original combination: Tryphosa antennipotens ) and T. barbatipes ( Stebbing, 1888) (original combination: Tryphosa barbatipes ). Bonnier (1893) restricted the genus Tryphosa to T. nana ( Krøyer, 1846) and T. pinguis ( Boeck, 1861) (original combination: Anonyx pinguis ). G. O. Sars (1895) accepted the conclusions of Bonnier (1893) concerning G. O. Sars’ (1891) misidentification of T. nana (thus accepting the specific epithet sarsi Bonnier, 1893 ) but rejected Bonnier’s (1893) generic changes, transferring Tryphosella sarsi to Tryphosa and transferring the true Tryphosa nana to Orchomenella . The resulting nomenclaturally invalid binomen Orchomenella nana ( Krøyer, 1846) has been accepted in all subsequent literature. Stebbing (1906) restricted Tryphosella to T. barbatipes and put T. sarsi and its satellite species in Tryphosa . On the other hand, Stephensen (1921, 1925 and 1935) accepted the definition of Tryphosa proposed by G. O. Sars (1891 – 95). Under the genus Tryphosa, Chevreux & Fage (1925) wrote without further comment: “ Type: Tr. hörringi, Boeck, 1871 ”. This statement is repeated by Gurjanova (1951). Barnard (1962) accepted Tryphosa horringi Boeck as the type species of the genus Tryphosa , without citing his sources, but probably referring to Chevreux & Fage (1925) and/or Gurjanova (1951). As far we know, there is no other reference to the action of Chevreux & Fage (1925) in more recent literature. Barnard (1967) considered ‘ Tryphosa ’ both as a useful concept and as an invalid synonym of Tryphosella . Barnard (1967) also designated T. sarsi as the type species of Tryphosella and Barnard (1969) reiterated this type designation. In recent literature, Tryphosa is implicitely considered as invalid ( Lincoln 1979; Ruffo 1985; Oleröd, 1987; Diviacco & Ruffo 1989; Palerud & Vader 1991; Kilgallen et al. 2006a; Lowry & Stoddart 2011b) or rejected on the basis of practical but nomenclaturally unsupported arguments ( Thurston 1974a), and its former components are assigned to the genera Orchomenella and Tryphosella , which have been created later than Tryphosa . Only Lowry & Stoddart (1995, 1997) recognized Tryphosa as valid and distinct from Tryphosella , although they did not indicate which species they considered as belonging to Tryphosa .

Finally, Lowry & Stoddart (1997) created the family Tryphosinae Lowry & Stoddart, 1997 with Tryphosa as type genus, without indicating the type species of that genus.

The conclusions of this account are that Tryphosa Boeck, 1871 is a nomenclaturally valid genus with Tryphosa nana ( Krøyer, 1846) as type species and that all subsequent alternative proposals concerning the type species of Tryphosa are irrelevant.

Whether the genus Orchomenella G. O. Sars, 1890 (type species: O. minuta G. O. Sars, 1890 ) is distinct from Tryphosa Boeck, 1871 (type species: T. nana (Krøyer, 1846)) or not, is a question, which falls out of the scope of the present paper.

1. See De Grave & Fransen (2011) for a discussion on the spelling of the name of that author.