Filellum

Marques, Antonio C., Peña, Álvaro L., Miranda, Thaís P. & Migotto, Alvaro E., 2011, Revision of the genus Filellum Hincks, 1868 (Lafoeidae, Leptothecata, Hydrozoa), Zootaxa 3129, pp. 1-28 : 24

Key for the identification of the fertile specimens of Filellum

1 Abcauline wall of the adnate part of the hydrotheca with transverse striae........................................ 2

- Abcauline wall of the adnate part of the hydrotheca without transverse striae....................................... 7

2 Defensive tubes of the coppinia forming a protective structure over the gonothecae................................. 3

- Defensive tubes of the coppinia not forming a protective structure over the gonothecae........... F. nitidum Watson, 2005

3 Defensive tubes arising amongst the gonothecae. Gonotheca with short distal neck with everted rim.................... 4

- Defensive tubes exclusively on the periphery of the gonothecal mass and arching over the gonothecae................. 5

4 Defensive tubes forming a shield-shaped structure (canopy)............................... F. serratum ( Clarke, 1879)

- Defensive tubes simply arching over gonothecae............................. F. magnificum Peña Cantero et al., 2004b

5 Gonothecae without distal neck................................................. F. antarcticum ( Hartlaub, 1904)

- Gonothecae with distal neck............................................................................. 6

6 Coppinia bud-shaped. Gonothecae flask-shaped. Hydrothecal aperture 140–168 µm. Hydrothecal free part 320–420 µm.................................................................................... F. conopeum Watson, 2003

- Coppinia corbula-shaped. Gonothecae irregular. Adnate hydrothecal part short or absent. Hydrothecal aperture 180–250 µm. Hydrothecal free part 650–1875 µm..................................................... F. bouvetensis sp. nov.

7 Gonothecae without juxtaposed walls. Defensive tubes absent................ F. disaggregatum Peña Cantero et al., 1998

- Gonothecae with juxtaposed walls. Defensive tubes present.................................................... 8

8 Hydrothecae and hydrorhiza forming a continuous layer on the substrate.......................................... 9

- Hydrothecae and hydrorhiza spaced and distinct from each other............................ F. serpens ( Hassall, 1848)

9 Gonothecae fusiform............................................................. F. adhaerens ( Nutting, 1901)

- Gonothecae polygonal....................................................... F. parasiticum ( Antsulevich, 1987)