Tryphosella Bonnier, 1893

Lowry, J. K. & Stoddart, H. E., 2009, Lysianassidae *, Zootaxa 2260 (1), pp. 561-597 : 581

Tryphosella Bonnier, 1893

Remarks. There is considerable variation within the genus Tryphosella as defined by Lowry & Stoddart (1995). One of the main defining characters of Tryphosella is the morphology of gnathopod 1 in which the coxa is reduced (slightly shorter than coxa 2) and tapering and the ischium is short, as evidenced in the type species T. sarsi Bonnier, 1893 . Within the genus, especially in Australasian species, there is a tendency towards shortening the coxa to a point where it becomes about as long as broad and the ischium becomes at least twice as long as broad, as evidenced in the new species T. seasana . Given the two extremes there appears to be a case for establishing a second genus, but both characters are gradational so that in the case of T. flynnana and T. seasana , which are very similar, T. flynnana would remain in Tryphosella and T. seasana would move to a new genus.

Another set of defining characters is the prominent ridge on the coxae of pereopods 4 and 5 and an apparent ‘photophore’ on the basis of pereopod 5. Several species ( T. charlotteae sp. nov., T. miersi ( Stebbing, 1888) , T. mucronata ( Pirlot, 1936)) known from Australia and New Guinea share these apomorphic characters. In other respects they cannot be separated from the genus Tryphosella and appear to form a species complex within it. At this stage we prefer to maintain all species in Tryphosella .