Terebrasabella

Murray, Anna & Rouse, Greg W., 2007, Two new species of Terebrasabella (Annelida: Sabellidae: Sabellinae) from Australia, Zootaxa 1434, pp. 51-68 : 62

Comparison of Terebrasabella spp.

The characters that distinguish the two species described here are as follows:

Thoracic uncini form: Terebrasabella hutchingsae sp. nov., has two forms of acicular uncini (“palmate” and heterodont-crested uncini) both of which are different to the single type present in Terebrasabella fitzhughi sp. nov., (homodont-crested uncini). Terebrasabella heterouncinata possesses only heterodontcrested acicular uncini.

Abdominal uncini form: T. hutchingsae sp. nov., has acicular uncini that are a smaller version of the longhandled “palmate” uncini of chaetiger 1, whereas those of T. fitzhughi sp. nov., are homodont-crested with a series of many fine teeth. T. heterouncinata possesses long-handled heterodont-crested acicular uncini.

Ventral peristomial lappets: anteriorly elongate on specimens of T. fitzhughi sp. nov., and relatively shorter and distally-rounded on T. hutchingsae sp. nov. T. heterouncinata has small, triangular, distallyrounded ventral collar lappets.

The number of rasp-shaped avicular uncini per row: on chaetiger 7, is greater in T. hutchingsae sp. nov., (~50) than in T. fitzhughi sp. nov., (<24). T. heterouncinata has fewer uncini in chaetiger 7 (~23 per row), but more uncini in chaetiger 8 (~19 per row) than either of the other 2 species (both <15).

The faecal tracks of T. hutchingsae sp. nov., and T.fitzhughi sp. nov., bifurcate in the 8th chaetiger, not the in the 10th chaetiger as in T. heterouncinata .

The main characters that distinguish all three species of Terebrasabella are the different types of uncini. These are summarised in Table 1 .

Uncini number and type in thorax and abdomen of:

Chaetiger Terebrasabella heterouncinata Terebrasabella hutchingsae sp. Terebrasabella fitzhughi

nov. sp. nov.