Branchiomma curtum ( Ehlers, 1901 )

Keppel, Erica, Tovar, Maria Ana & Ruiz, Gregory, 2015, First record and establishment of Branchiomma coheni (Polychaeta: Sabellidae) in the Atlantic Ocean and review of non – indigenous species of the genus, Zootaxa 4058 (4), pp. 499-518 : 508

Branchiomma curtum ( Ehlers, 1901)

This species was described from Juan Fernández Island ( Chile) in 1901, and it was recorded in New Zealand, Cape Verde Islands and the Mexican Caribbean ( Tovar-Hernández & Knight-Jones, 2006). In the latter area, it was reported as abundant living in gregarious clumps among algae and was thought to be introduced by ballast water from ships ( Tovar-Hernández & Knight-Jones 2006).

There are no new records of B. curtum elsewhere; however, the record by Tovar-Hernández & Knight-Jones (2006) from Caribbean may be erroneous, requiring further sampling, because both syntypes of B. curtum and Caribbean specimens were juveniles produced by fission with a low number of thoracic segments (4–6). This is a common reproductive phenomena in species of Branchiomma ( Tovar-Hernández & Dean 2014) .

Materials examined and compared by Tovar-Hernández & Knight-Jones (2006) do not show significant morphological differences with Ehlers syntypes because juveniles of different species can look all similar. Shape and size of stylodes in juveniles of many species of Branchiomma change in adult stages. Additionally, the original description and drawings by Ehlers (1901) emphasized important differences among the nominal species B. curtum and specimens reported in from the Mexican Caribbean. The thoracic uncini has one row of teeth, covering 1/4 of the main fang length in B. curtum ( Ehlers 1901: plate 25, Fig. 13) versus three rows covering 1/2 of the main fang length in Caribbean material. Thus, the status of B. curtum as NIS in the Mexican Caribbean, New Zealand and Cape Verde demands a further morphological study using adult forms as well as molecular markers at juvenileadult stages.