Filellum contortum Nutting 1905

<i>Filellum contortum</i> (Nutting, 1905) <p>(Figure 6 A–D)</p> <p> <i>Lafoea contorta</i> Nutting, 1905: 945, pl. 3, fig. 6, pl. 9, figs. 8–9.</p> <p> ? <i>Filellum contortum</i>: Peña Cantero <i>et al.</i> 1998: 301.</p> <p> Non <i>Filellum contortum</i>: Peña Cantero and Gili 2006: 766 [= <i>Filellum bouvetensis</i> <b>sp. nov.</b>].</p> <p> <b>Type series.</b> Lectotype— <i>Lafoea contorta</i> Nutting, 1905; alcohol specimen on Aglaopheniidae (USNM 70715; specimen represented by Nutting 1905, pl. 3, fig. 6, pl. 9, figs. 8–9). Paralectotype— <i>Lafoea contorta</i> Nutting 1905; alcohol specimen (USNM 68984).</p> <p> <b>Type locality.</b> From the lectotype, “Albatross R/V” Expedition, Hawaiian Explorations, Stn. 3949, north Pacific Ocean, Hawaii, north of Laysan Island, 27o47’45’’N; 171o52’35’’W, 108–238 m, 21 May 1902, leg. Albatross R/V. Paralectotype: “Albatross R/V” Expedition, Hawaiian Explorations, Stn. 4102, north Pacific Ocean, Hawaii, Pailolo Channel, between Maui and Molokai Islands, 21o03’10’’N; 156o45’20’’W, 223–241 m, 23 September 1902, leg. Albatross R/V.</p> <p> <b>Material examined.</b> Lectotype USNM 70715 and paralectotype USNM 68984.</p> <p> <b>Description of lectotype.</b> Colony stolonal, with a filiform and creeping hydrorhiza growing over some 7 mm at base of an aglaopheniid hydroid; hydrorhizal tubes 0.10–0.14 mm wide, with few anastomosed perisarc. Hydrothecae sessile, arising with no definite pattern from hydrorhiza, less than half of their total length partially adnate to substratum parallel to hydrorhizal stolon, free part emerging from substrate plane at angles wide than 60o, usually 90o.</p> <p>Adnate portion of hydrothecae tubular or maximally slightly flattened, 0.41–0.73 mm (0.58 ±0.11, n=10) long, perisarc with many striae on abaxial hydrothecal surface of adnate part, striae extend up to curvature of hydrothecae; free part cylindrical, smooth, 0.84–1.40 mm (1.22 ±0.15, n=10) long; perisarc moderately thin; hydrothecae slightly widening distally, margin even and smooth, with up to two renovations, tenuous flaring; hydrothecal orifice circular, 0.21–0.27 mm (0.24±0.02, n=10) wide, perpendicular to axis of free part of hydrotheca. Hydranths badly preserved, with ca. 14 tentacles, hypostome conical. Hydranths, when retracted, lying at the adnate space of the hydrothecae. Gonothecae absent.</p> <p>Nematocysts of one category, heterotrichous microbasic?mastigophores (not seen discharged), 5.0–6.0 X 2.0– 2.5 µm (5.60 ± 0.39 X 2.35 ± 0.24, n = 10), rice-shaped, common.</p> <p> <b>Distribution.</b> <i>Filellum contortum</i> was recorded for the coast of Japan (Stechow 1913b).</p> <p> <b>Remarks.</b> <i>Filellum contortum</i> was originally described as <i>Lafoea contorta</i> Nutting, 1905, and diagnosed as a “colony parasitic, growing from a twisted rootstock” with hydrothecae “sessile, tubular, very long, and often bent and twisted in various ways”. The specimens described by Nutting (1905: 945) were sterile.</p> <p> This species is different from most of the species of <i>Filellum</i> in its morphometry (e.g., larger dimension of the free part of hydrotheca). The cnidome of <i>F. contortum</i> is also different, comprising a single type of nematocyst (heterotrichous microbasic mastigophore), comparatively smaller than those found in other species. Although these differences could characterize the species, they may be variable or dependent on the quality of specimen preservation. Besides, Nutting’s (1905) material lacks coppinia, so the crucial information concerning the reproductive structure, necessary to properly assign new material to this species, is unknown. The only coppiniae assigned to <i>F. contortum</i> was described by Peña Cantero and Gili (2006) from Bouvet Island, herein redescribed as <i>Filellum bouvetensis</i> <b>sp. nov.</b> Therefore, a reliable diagnosis of the species is difficult, and its validity remains dubious (Peña Cantero <i>et al.</i> 1998) until its reproductive parts are described. We consider <i>F. contortum</i> as a <i>species inquirenda</i>.</p>Published as part of <i>Marques, Antonio C., Peña, Álvaro L., Miranda, Thaís P. & Migotto, Alvaro E., 2011, Revision of the genus Filellum Hincks, 1868 (Lafoeidae, Leptothecata, Hydrozoa), pp. 1-28 in Zootaxa 3129</i> on pages 22-24, DOI: <a href="http://zenodo.org/record/206783">10.5281/zenodo.206783</a&gt

Filellum serpens Hassall 1848

<i>Filellum serpens</i> (Hassall, 1848) <p> <i>Sertularia arcta</i> Dalyell, 1847: 224 –226, pl. 42, figs. 1–15.</p> <p> <i>Campanularia serpens</i> Hassall, 1848: 2223; Hassall and Coppin, 1852: 163, pl. 21, fig. 4.</p> <p> <i>Capsularia serpens</i>: Gray 1848: 151.</p> <p> <i>Coppinia mirabilis</i> Hassall, 1848: 2223.</p> <p> <i>Reticularia immersa</i> Thomson, 1853: 443, pl. 16a, figs. 2–3.</p> <p> <i>Filellum serpens</i>: Hincks 1868: 214 –215, pl. 41, figs. 4a–b (synonym of <i>Reticularia immersa</i> Thomson, 1853); Fraser 1944: 215 – 216, pl. 44, figs. 198a–d; Naumov 1960: 281, figs. 47, 170, 171; Naumov 1969: 303, figs. 47, 170, 171; Vervoort 1972: 49 – 50; Cornelius 1975: 378 –381, fig. 2; Peña Cantero <i>et al.</i> 1998: 302 –304.</p> <p> <i>?</i> <i>Filellum tubiforme</i> Schydlowsky, 1902: 168, pl. 3, fig. 29.</p> <p> <i>Lafoea serpens</i>: Vanhöffen 1910: 311.</p> <p> <i>Grammaria serpens:</i> Vervoort 1946: 194 –196, fig. 82.</p> <p> <i>Filellum serpens serpens</i>: Naumov 1969: 303, figs. 170–171.</p> <p> ? <i>Filellum serpens tubiforme</i>: Naumov 1969: 303, fig. 172.</p> <p> <i>Reticularia serpens</i>: Rees and Thursfield 1965: 87 –88.</p> <p> [More complete synonymy in Peña Cantero <i>et al.</i> 1998: 302–303]</p> <p> <b>Type series.</b> Holotype—“Dublin, 1842, infertile colony on herbarium specimen of <i>Abietinaria abietina</i> (Linnaeus, 1758), coll. A.H. Hassall, 1973.10.8.4; mentioned Gray, 1848: 151” (Cornelius 1975: 379).</p> <p> <b>Type locality.</b> From the holotype, Dublin, Ireland (Cornelius 1975: 379).</p> <p> <b>Description after literature data.</b> (Trophosome after Peña Cantero & García Carrascosa 1995: 20, translated; coppinia after Hassall 1848: 2223): Colony with barely visible stolonal hydrorhiza. Hydrothecae arising from hydrorhiza; about half of hydrotheca adnate to substratum. Adnate portion of hydrothecae 0.26–0.28 mm long; free part 0.10–0.22 mm long. Hydrotheca bearing circular aperture, 0,08– 0.10 mm wide, rim even, slightly flared, without renovations. Coppinia—“Polypidom parasitic, massive, hirsute; polype cells elongated, tubular, often curved, arising at irregular distances (and generally at the angles of junction) out of a cellular basis, the apertures of the cells or spaces of which are often themselves covered in by a lid perforated by a small tubular orifice”.</p> <p> <b>Distribution.</b> Eurybathic species, living as an epibiont mainly other species of hydroids (Peña Cantero <i>et al.</i> 1998). It has been recorded around the world, but records are mainly based on infertile material. According to records based on fertile material, the species seems to have a temperate-cold boreal distribution (cf. Peña Cantero <i>et al.</i> 1998).</p> <p> <b>Remarks.</b> Following the general decision concerning the generic name <i>Filellum</i> after application of case by Cornelius and Calder (1986), the ICZN (Opinion 1485, ICZN 1988) also ruled in favor of the conservation of the specific name <i>serpens</i> Hassall, 1848, as published in the binomen <i>Campanularia serpens</i> Hassall, 1848, the type species of the genus <i>Filellum</i>.</p> <p> The identity of the species <i>Campanularia intertexta</i> Couch, 1844 was questioned by Cornelius and Calder (1986), because the specimens analysed by Couch (1844) were growing on <i>Lafoea dumosa</i> and <i>Sertularella polyzonias</i>, the latter being a typical substrate for <i>Filellum serpens.</i> The authors consider that it is possible that the type material of <i>Campanularia intertexta</i> Couch, 1844, includes <i>F. serpens,</i> besides <i>L. dumosa</i> and <i>Orthopyxis integra,</i> as proposed by Cornelius (1982).</p> <p> Hassall (1848) described the trophosome and gonosome of <i>F. s e r p e n s</i> as two different species, <i>Campanularia serpens</i> and <i>Coppinia mirabilis</i>, respectively. The first author who united them was Hincks (1868), and the name “coppiniae” since then refers to the peculiar reproductive structures found in some genera of the family Lafoeidae. <i>Coppinia mirabilis</i> Hassall, 1848 is considered a junior synonym of <i>Sertularia arcta</i> Dalyell, 1847, as evidenced by Hincks (1868) and reviewed by Cornelius and Calder (1986).</p> <p> <i>Reticularia immersa</i> Thomson, 1853 is considered a synonym of <i>Filellum serpens</i> (Hassall, 1848) and its conspecificity was corroborated by Cornelius (1975) through the analyses of its type material.</p> <p> Although data on the coppinia of the species is sketchy (e.g., “Coppinia of typical structure”, Naumov 1969: 303; “…coppiniae typical of the sub-family”, Cornelius 1975: 380) the trophosome of <i>F. s e r p e n s</i> may be differentiated from that of most species of the genus (viz. <i>F. antarcticum</i>, <i>F. magnificum</i>, <i>F. nitidum</i>, and <i>F. serratum</i>), but it is similar to those of <i>F. adhaerens</i> and <i>F. disaggregatum</i>, with more than half of the hydrothecae adnate to the substrate. However, the hydrothecae and hydrorhiza of <i>F. adhaerens</i> form a mesh laying on the substrate, which is also found in <i>F. parasiticum.</i></p> <p> Concerning the sexual structures, <i>F. disaggregatum</i> has a completely different coppinia, whereas <i>F. serpens</i>, <i>F. parasiticum</i> and <i>F. adhaerens</i> have similar coppiniae, with gonothecae having juxtaposed walls and a distal neck, and curved protective tubes arising among the gonothecae. However, there are some differences in the gonothecal morphology, polygonal in <i>F. adhaerens</i> (Nutting 1901: 178, pl. 21, fig. 4) and <i>F. parasiticum</i>, and fusiform in <i>F. serpens</i> (Dalyell 1847, pl. 42, fig. 6, also in Peña Cantero <i>et al.</i> 1998: 304).</p> <p> The taxonomic status of <i>F. s e r p e n s</i> is dubious, because of the imprecise morphological descriptions associated with the species. It is likely that a group of different species may be confused and incorrectly assigned to the species under discussion. However, since <i>F. serpens</i> is the type species of the genus, it is by definition the senior synonym, although other congeners appear to be much more clearly described. Therefore, dismissing the name <i>serpens</i> would demand major nomenclatural acts at the genus level that we would prefer to avoid at this time.</p>Published as part of <i>Marques, Antonio C., Peña, Álvaro L., Miranda, Thaís P. & Migotto, Alvaro E., 2011, Revision of the genus Filellum Hincks, 1868 (Lafoeidae, Leptothecata, Hydrozoa), pp. 1-28 in Zootaxa 3129</i> on pages 18-19, DOI: <a href="http://zenodo.org/record/206783">10.5281/zenodo.206783</a&gt

Filellum conopeum Watson 2003

<i>Filellum conopeum</i> Watson, 2003 <p> <i>Filellum conopeum</i> Watson, 2003: 159 –160, figs. 9a–c.</p> <p> <b>Type series.</b> Holotype— <i>Filellum conopeum</i> Watson, 2003, malinol-mounted microslide, sparse fertile colony on stem of <i>Acryptolaria patagonica</i> (NMV F91342) (Watson 2003: 159).</p> <p> <b>Type locality.</b> From the holotype, off Macquarie Island (53˚55.8´S–53˚55.7´S; 159˚5.5´E–159˚4.7´E), 453 m, (Watson 2003).</p> <p> <b>Description.</b> See Watson (2003: 159–160).</p> <p> <b>Distribution.</b> <i>Filellum conopeum</i> is known only from its original description, off Macquarie Island (53˚55.8´– 53˚55.7´S; 159˚5.5´–159˚4.7´E) (Watson 2003).</p> <p> <b>Remarks.</b> <i>Filellum conopeum</i> was described by Watson (2003: 159) as bearing “Hydrothecae stolonal […]. Proximal quarter to one third of hydrotheca adnate to stolon, dorsal abcauline wall furrowed by many close, sharpedged ridges with minute ragged frill of perisarc; ridges fading on adnate wall. Adnate wall becoming free at a sharp upward bend, free part cylindrical or weakly expanding from bend to margin, free part straight to broadly curved, walls smooth, occasionally with several regenerations. Margin circular, transverse, with smooth, distinctly everted rim. Perisarc of walls fairly thick, thinning distally. Hydranth with c. 12 tentacles and clavate hypostome”. Trophosome features of <i>F. conopeum</i> are found in other species of the genus, such as <i>F. serratum</i>, <i>F. a n t a rc t i c u m</i> or <i>F. magnificum</i>, so they alone do not allow a proper identification of the species, although <i>F. mangnificum</i> differs from Watson’s species by the distinctly larger hydrothecae, particularly in relation to the diameter of the hydrothecal aperture.</p> <p> As with other species of the genus, truly diagnostic characters of <i>F. conopeum</i> are based on features of the coppiniae: “Coppinia bud-shaped, c. 1 mm wide and 1 mm high, comprising many tightly packed gonothecae enclosed within a cone of protective nematophorous tubules. Gonotheca flask-shaped (lateral view), base rounded, body expanding a little from base to shoulder then narrowing into a short straight or slightly curved neck tapering to a circular aperture; in transverse view gonothecae polygonal. Nematophorous tubules similar in length, not forked, conjoined just above gonothecae then becoming free, most narrowing distally and inwardly curved to meet above gonotheca; terminal orifice circular. Perisarc of gonothecae and tubes moderately thick; perisarc of tubes somewhat roughened. Planulae enclosed in gonothecae small, spherical.” (Watson 2003: 160). The general structure of the coppinia of this species resembles that of <i>F. a n t a rc t i c u m</i> and <i>F. magnificum</i>, in which the defensive tubes are situated on the periphery of the mass of gonothecae, like a fence, arching over the gonothecae (in <i>F. magnificum</i> the defensive tubes also arise among the gonothecae). They are different, however, because the gonothecae lack a distal neck in <i>F. antarcticum</i>, and have a short, clearly differentiated distal neck with an everted rim in <i>F. magnificum</i>. In Watson’s species, however, the “body expanding a little from base to shoulder then narrowing into a short straight or slightly curved neck tapering to a circular aperture”. Although Watson did not give measurements of the gonothecal neck, this seems distinctly longer in general and variable in shape. The cnidome of <i>F. conopeum</i> is unknown and, therefore, no comparison concerning this character can be made.</p>Published as part of <i>Marques, Antonio C., Peña, Álvaro L., Miranda, Thaís P. & Migotto, Alvaro E., 2011, Revision of the genus Filellum Hincks, 1868 (Lafoeidae, Leptothecata, Hydrozoa), pp. 1-28 in Zootaxa 3129</i> on pages 11-12, DOI: <a href="http://zenodo.org/record/206783">10.5281/zenodo.206783</a&gt

Filellum magnificum Pena Cantero, Svoboda and Vervoort 2004

<i>Filellum magnificum</i> Peña Cantero, Svoboda and Vervoort, 2004b <p> <i>Filellum magnificum</i> Peña Cantero <i>et al.</i>, 2004b: 2287 –2289, figs. 2g –h, 5a–c; Peña Cantero 2010: 765, figs. 3d, e.</p> <p> <b>Type series.</b> Holotype— <i>Filellum magnificum</i> Peña Cantero <i>et al.</i>, 2004b, several hydrothecae on <i>Billardia subrufa</i>, with coppinia (RMNH-Coel. 30789) (Peña Cantero <i>et al.</i> 2004b: 2271, 2287).</p> <p> <b>Type locality.</b> From the holotype, Weddell Sea, Antarctic, ANT II-4 Stn 502, 21 February 1984, several hydrothecae on <i>Billardia subrufa</i>, with coppinia (Peña Cantero <i>et al.</i> 2004b: 2271).</p> <p> <b>Material examined.</b> German Polarstern Antarctic Cruises: ANT I-2 Stn 135, off Riiser-Larsen Ice Shelf, Princess Martha Coast, Weddell Sea (73° 41.6’S; 20° 55.3’W, 205m, 8 February 1983), on <i>Stegella lobata</i> (RMNH- Coel. 30779); ANT II-4 Stn 474, off Ronne Ice Shelf, Weddell Sea (76° 56.7’S; 49° 44.0’W, 220m, 14 February 1984), on <i>Billardia subrufa</i> (RMNH-Coel. 30788); ANT II-4 Stn 502, Weddell Sea (21 February 1984), on <i>B. subrufa</i>, with coppinia (holotype, RMNH-Coel. 30789); ANT VIII-5 Stn 16-481 (74.74° S; 61.13° W, off Ronne Ice Shelf, Weddell Sea, 620–640m, 15 February 1990), on spicules of a sponge (RMNH-Coel. 30802); ANT IX-3 Stn 158 (72° 21.8’S; 16° 42.1’W, off Cape Norvegia, Princess Martha Coast, Weddell Sea, 623m, 13 February 1991), on <i>B. subrufa</i> (RMNH-Coel. 30806). Spanish Bentart 2003 Expedition: Stn 5A, south of Peter I Island (68°56’37’’– 68°56’43’’S; 90°35’50’’– 90°35’19’’W, 124 m, 4 February 2003), on the ascidian <i>Cnemidocarpa verrucosa</i>, with coppiniae; Stn 8A, east of Peter I Island (68°50’05’’– 68°50’16’’S; 90°21’15’’– 90°21’16’’W, 85–86 m, 6 February 2003), on <i>Schizotricha vervoorti</i>, <i>Symplectoscyphus glacialis</i> and? <i>Tubularia</i> stem, with coppinia; Stn 8T, east of Peter I Island (68°50’08’’S; 90°21’17’’W, 87 m, 6 February 2003), on <i>Schizotricha vervoorti</i>, with coppiniae.</p> <p> <b>Description.</b> (After Peña Cantero <i>et al.</i> 2004b: 2287): Colony stolonal, composed of creeping stolons giving rise to partially sessile hydrothecae. Hydrotheca tubular, sock-shaped, and adnate to substratum for just a tiny portion. Hydrothecal aperture circular, 169–208 µm wide; rim even and smooth, though indistinctly everted. Free part of hydrotheca, 436–670 µm long, directed upwards at varied degrees, frequently with few, long renovations. Adnate part of hydrothecae, 208–300 µm long, provided with a few striae on dorsal side. Cnidome consisting of two size-classes of nematocysts (e.g. ANT II-4 Stn 502): small (6.5–7.2 X 2.9 µm) and occasionally large (18.2 X 5.2 µm) capsules. In material from ANT VIII-5 Stn 16-481 only the small nematocysts were observed (5.9–7.2 X 2.6–3.3 µm).</p> <p>Coppinia consisting of firmly adpressed gonothecae with defensive tubes. Gonothecae 423–455 µm long, 98– 111 µm wide, aperture circular, 52–58 µm wide, on a short and distinctly everted distal neck. Defensive tubes situated on periphery of the group of gonothecae, but also arising amongst them, and provided with large, distal, circular aperture.</p> <p> <b>Distribution.</b> <i>Filellum magnificum</i> has been recorded only for the Antarctic, “at depths from 205 to 640 m […] south and east coasts of the Weddell Sea (off Ronne Ice Shelf, off Riiser-Larsen Ice Shelf and off Cape Norvegia, Princess Martha Coast)” (Peña Cantero <i>et al.</i> 2004b: 2289) and the south and east coast of Peter I Island, in the Bellingshausen Sea (Peña Cantero 2010).</p> <p> <b>Remarks.</b> See Peña Cantero <i>et al.</i> (2004b: 2288–2289).</p>Published as part of <i>Marques, Antonio C., Peña, Álvaro L., Miranda, Thaís P. & Migotto, Alvaro E., 2011, Revision of the genus Filellum Hincks, 1868 (Lafoeidae, Leptothecata, Hydrozoa), pp. 1-28 in Zootaxa 3129</i> on page 14, DOI: <a href="http://zenodo.org/record/206783">10.5281/zenodo.206783</a&gt

Filellum plicatum Hartlaub 1904

<i>Filellum plicatum</i> (Hartlaub, 1904) <p> <i>Lafoea plicata</i> Hartlaub, 1904: 12, pl. 2, fig. 3.</p> <p> <b>Type series.</b> Holotype—“the material … is lost” (Peña Cantero <i>et al.</i> 2004b: 2287).</p> <p> <b>Type locality.</b> From the original description, “Schwabber VIII”, “N° 923”, Antarctic, 70°00’S; 80°48’W, 55 m, 18 October 1898 (Hartlaub 1904: 12).</p> <p> <b>Remarks.</b> <i>Lafoea plicata</i> was originally described by Hartlaub (1904), who remarked on the resemblance of his species with <i>F. serratum</i> based on the adnate part of the hydrotheca being surrounded by a thin membrane provided with fine pleats resembling indentations in lateral view (see also Peña Cantero <i>et al.</i> 2004b: 2287). The type material was infertile and is reportedly lost. According to Peña Cantero <i>et al.</i> (2004b: 2287) “the size of the hydrothecae in <i>L. plicata</i> is closer to that of the material here considered as <i>F. antarcticum</i> (e.g. 104–111 mm diameter at the aperture)”. However, based on the lack of diagnostic characters of the trophosome, we decided to consider this taxon as <i>species inquirenda</i>.</p>Published as part of <i>Marques, Antonio C., Peña, Álvaro L., Miranda, Thaís P. & Migotto, Alvaro E., 2011, Revision of the genus Filellum Hincks, 1868 (Lafoeidae, Leptothecata, Hydrozoa), pp. 1-28 in Zootaxa 3129</i> on page 24, DOI: <a href="http://zenodo.org/record/206783">10.5281/zenodo.206783</a&gt

Filellum antarcticum Hartlaub 1904

<i>Filellum antarcticum</i> (Hartlaub, 1904) <p> <i>Lafoea antarctica</i> Hartlaub, 1904: 11, pl. 2, fig. 2; Vanhöffen 1910: 311 –312, figs. 31a–c.</p> <p> <i>Reticularia antarctica</i>: Totton 1930: 160 –161, fig. 17.</p> <p> <i>Filellum antarcticum</i>: Millard 1964: 10; 1975: 177, figs. 58g –h; 1978: 171, 172, 192; Peña Cantero <i>et al.</i> 1998: 300; 2004b: 2283–2287, figs. 2c–f, 3, 4; Vervoort and Watson 2003: 57 –58; Peña Cantero 2008: 453; 2010: 764–765, figs. 3a–c.</p> <p> <b>Type series.</b> The type specimen of <i>Filellum antarcticum</i> is lost (Peña Cantero <i>et al.</i> 2004b: 2285). Neotype— <i>Lafoea antarctica</i> Vanhöffen, 1910; specimens on <i>Symplectocyphus</i> sp. (ZMB Cni 14222) (Peña Cantero <i>et al.</i> 2004b: 2285– 2286).</p> <p> <b>Type locality.</b> From the original description of <i>Lafoea antarctica</i> Hartlaub, 1904, it would be “S. Y. Belgica ” Expedition, Antarctic, Schwabber VII (70°23’S; 82°47’W, ca. 500 m, 8 October 1898), specimens on bryozoan (Hartlaub 1904: 5). From neotype designation it is “Deutschen Southpolar Expedition”, Gauss Station, 65°21’S; 86°06’E, 385 m (Peña Cantero <i>et al.</i> 2004b: 2285).</p> <p> <b>Material studied.</b> ANTARCTIC: German <i>Polarstern</i> expedition–ANT II-4 Stn 310, Ronne Ice Shelf, Weddell Sea (76°52.0’S; 50°40.4’W, 252 m, 20 January 1984), “on <i>Billardia subrufa</i>, with coppinia” (RMNH-Coel. 30782); ANT II-4 Stn 341, Ronne Ice Shelf, Weddell Sea (76°39.2’S; 52°09.0’W, 297 m, 26 January 1984), “on <i>B. subrufa</i> and <i>Stegella lobata</i>, with coppinia” (RMNH-Coel. 30783); ANT II-4 Stn 438, Larsen Ice Shelf, Antarctic Peninsula, Weddell Sea (67°09.7’S; 54°21.4’W, 423 m, 7 February 1984), “on <i>B. subrufa</i>, with coppinia” (RMNH- Coel. 30785); ANT II-4 Stn 474, Ronne Ice Shelf, Weddell Sea (76°56.7’S; 49°44.0’W, 220 m, 14 February 1984), “on <i>B. subrufa</i>, with coppinia” (RMNH-Coel. 30788);?ANT II-4 Stn 524, Cape Norvegia, Princess Martha Coast, Weddell Sea (71°23.9’S; 13°58.8’W, 325 m, 25 February 1984), “on <i>Halecium</i> sp., with coppinia” (RMNH-Coel. 30790); ANT VIII-5 Stn 16-399, Riiser-Larsen Ice Shelf, Princess Martha Coast, Weddell Sea (72.86°S; 19.30°W, 380–390 m, 30 December 1989), “Bottom: large rocks”, “on <i>B. subrufa</i>, with coppinia” (RMNHCoel. 30794); ANT VIII-5 Stn 16-405, Ronne Ice Shelf, Weddell Sea, (76.52°S; 52.63°W, 330 m, 7 January 1990), “Bottom: mud”, “on <i>B. subrufa</i>,? <i>Opercularella belgicae</i>, and axis of gorgonian, with coppinia” (RMNH-Coel. 30796); ANT VIII-5 Stn 16-456, Cape Norvegia, Princess Martha Coast, Weddell Sea (71.25°S; 12.01°W, 200 m, 26 January 1990), “on <i>B. subrufa</i>, with coppinia” (RMNH-Coel. 30816); ANT VIII-5 Stn 16-459, Cape Norvegia, Princess Martha Coast, Weddell Sea (70.96°S; 11.19°W, 350–380 m, 28 January 1990), “on <i>B. subrufa</i>, with coppinia” (RMNH-Coel. 30799); ANT VIII-5 Stn 16-486, Ronne Ice Shelf, Weddell Sea (76.50°S; 52.15°W, 330–340 m, 17 February 1990), “on <i>B. subrufa</i>, with coppinia” (RMNH-Coel. 30803); ANT IX-3 Stn 135, McDonald Ice Rumples, Caird Coast, Weddell Sea (75°27.9’S; 26°45.4’W, 221 m, 4 February 1991), “on <i>B. subrufa</i>, with coppinia” (RMNH-Coel. 30805). Deutsche Südpolar Expedition–Gauss Station (65°21’S; 86°06’E, 385 m), Museum für Naturkunde der Humboldt-Universität zu Berlin (neotype, ZMB Cni 14222) (Peña Cantero et al., 2004b: 2284– 2285). Spanish Bentart 95 Expedition–Stn 3A, south of Livingston Island (62°37.7018’S; 60°22.8167'W, 92 m, 17 January 1995), on polychaete tube, with coppinia. Spanish Bentart 2003 Expedition–Stn 5A, south of Peter I Island (68°56’37’’– 68°56’43’’S; 90°35’50’’– 90°35’19’’W, 124 m, 4 February 2003), on <i>Stegella lobata</i> and the ascidian <i>Cnemidocarpa verrucosa</i>, with coppinia.</p> <p> <b>Description of neotype.</b> (Complementing the description by Peña Cantero et al. 2004b: 2285): Colony stolonal, growing on monosiphonic stems of <i>Symplectoscyphus</i> sp., stolons creeping on substratum, hydrorhiza ca. 0.72–0.80 mm wide. Hydrothecae sessile, sock-shaped, arising with no definite pattern from hydrorhiza, varying in form, from about half of hydrotheca adnate to substratum to some completely free. Hydrothecae irregularly curved in diverse patterns, emerging from substrate plane at various angles. Adnate portion of hydrothecae tubular or maximally slightly flattened, 0.24–0.35 mm long, with numerous external transverse ridges on exposed side; free part cylindrical, smooth, 0.30–0.35 mm long; total adcauline wall 0.59–0.65 mm long, abcauline wall 0.55–0.63 mm long; hydrothecae slightly widening distally, margin even and smooth, with up to four renovations, slightly flaring; hydrothecal aperture circular, 0.104–0.130 mm wide. Hydranths not seen.</p> <p>Gonothecae arranged in coppinia, ca. 2.4 mm wide. Gonothecae closely set, juxtaposed, their limits almost distinct in dorsal view, general shape tubular. Gonothecae 0.48 mm high, 0.11 mm wide, distally truncated with unraised circular aperture, 0.055 mm wide, rim even, not flared, without renovations. Protective tubes present, long, hollow, either forked or unforked, with distal circular aperture. Protective tubes usually curved towards center of gonothecal mass and merged to each other over gonothecae, forming a nest or corbula acting as an incubatory chamber. In one case, disk-shaped coppinia with defensive tubes forming two fused and disk-shaped structures, protecting gonothecae and eggs; in another case, coppinia as a semicircular structure. Eggs remaining inside gonothecae, immersed in a tissue mass presumed to be nourishing. Cnidome composed of two types of nematocysts, small (5.5– 6.5 X 2.6 µm) and large ones (10.4–12.4 X 4.2–5.2 µm).</p> <p> <b>Distribution.</b> <i>Filellum antarcticum</i> seems to be “a shelf species” (Peña Cantero <i>et al.</i> 1998: 300), being recorded from 13.5 m (Millard 1964, 1975) to 423 m (Peña Cantero <i>et al.</i> 2004b). The species has always been recorded epibiotic, on hydroids (Vanhöffen 1910; Totton 1930; Peña Cantero <i>et al.</i> 2004b; Peña Cantero 2010), gorgonians (Peña Cantero <i>et al.</i> 2004b), bryozoans (Vanhöffen 1910; Millard 1964, 1975), cidarid spines (Vanhöffen 1910), polychaete tubes (Peña Cantero 2008), and ascidians (Peña Cantero 2010). Coppinia found in austral summer (Peña Cantero <i>et al.</i> 2004b: 2297). It is known from South Africa (Millard 1964, 1975) and Antarctica, in the Davis Sea (Vanhöffen 1910), Ross Sea (Totton 1930), Weddell Sea (Peña Cantero <i>et al.</i> 2004b), the South Shetland Islands (Peña Cantero 2008), and off Peter I Island, in the Bellingshausen Sea (Peña Cantero 2010).</p> <p> <b>Remarks.</b> <i>Filellum antarcticum</i> was originally described as <i>Lafoea antarctica</i> by Hartlaub (1904) who, according to Peña Cantero <i>et al.</i> (1998: 300), diagnosed it as “sessile hydrothecae, with a short portion adnate to the substratum, followed by a long part directed upwards (this part being longer than in <i>Filellum serpens),</i> and by the presence of numerous renovations of the hydrothecal rim”. However, these features are not sufficient to characterize a species of the genus.</p> <p> The first solution in adequately describing <i>Filellum antarcticum</i> would be to study the type specimen. However, the type material of <i>Lafoea antarctica</i> Hartlaub, 1904 is reportedly lost (Peña Cantero <i>et al.</i> 2004b: 2285). Therefore, Peña Cantero <i>et al.</i> (2004b) proposed the material described by Vanhöffen (1910) as the neotype of the species, since this specimen was the basis for the first description of the coppinia. Vanhöffen’s (1910) material was diagnosed by Peña Cantero <i>et al.</i> (2004b: 2286) as having “several coppiniae […] of varied shape […] all have in common a set of gonothecae surrounded by a fence of forked or unforked, defensive tubes provided with a distal circular aperture”. Peña Cantero <i>et al.</i> (2004b: 2286) emphasize that “this variability seems related to the nature of the substratum where the colony was growing” and when “there is enough surface for attachment of the stolonal tubes […] the coppinia is like a nest with the gonothecae surrounded by a fence of defensive tubes which arch over the gonothecae, whereas when there is not so much space, […] the coppinia has a disk or semicircular shape”. This plasticity is corroborated by several authors (Totton 1930: 160; Millard 1975: 177) and calls attention to the difficulty in identifying boundaries of species in the genus <i>Filellum</i>.</p> <p> Concerning the trophosome, as many other species congeners (viz. <i>F. magnificum</i>, <i>F. nitidum</i>, <i>F. serratum</i>), <i>F. antarcticum</i> has striations on the outer part of the adnate wall and, therefore, the morphology of the coppinia is essential for the identification of the species. <i>Filellum antarcticum</i> has characteristic coppiniae with tubular gonothecae without distal neck and with bent protective tubes at the periphery of the coppinia, forming a structure that calls to mind a corbula. Differently, the gonothecae of <i>F. magnificum</i> are provided with a distal neck and the protective tubes may be either at the periphery or arise amongst gonothecae in the central area of the coppinia. Also, in <i>F. nitidum</i>, the coppinia has the surface covered by a thin, perforated, tissue layer; in addition, the hydrothecae of <i>F. nitidum</i> are spread on the coppinia together with the thin inverted, occasionally bifid, protective tubes. Finally, Peña Cantero <i>et al.</i> (2004b: 2286–2287) remarked that the differences between <i>F. antarcticum</i> and <i>F. serratum</i> are as follows: “the distally closed defensive tubes arise from amongst the gonothecae and curve over them forming a protective structure like a canopy” in <i>F. serratum</i>, whilst “the gonothecae are surrounded by a fence of distally open defensive tubes usually bent towards the centre of the gonothecal mass, constituting a nest or corbula” in <i>F. antarcticum</i>. Additionally, the gonothecae of <i>F. serratum</i> are “bottle-shaped, provided with a short and everted distal neck bearing the aperture, and are slightly shorter and wider”. The similarities in the trophosome of <i>F. antarcticum</i> and <i>F. serratum</i> led Peña Cantero <i>et al.</i> (2004b) to disregard the previous records of <i>Filellum antarcticum</i> not based on fertile specimens.</p>Published as part of <i>Marques, Antonio C., Peña, Álvaro L., Miranda, Thaís P. & Migotto, Alvaro E., 2011, Revision of the genus Filellum Hincks, 1868 (Lafoeidae, Leptothecata, Hydrozoa), pp. 1-28 in Zootaxa 3129</i> on pages 8-9, DOI: <a href="http://zenodo.org/record/206783">10.5281/zenodo.206783</a&gt

Filellum

Key for the identification of the fertile specimens of <i>Filellum</i> <p>1 Abcauline wall of the adnate part of the hydrotheca with transverse striae........................................ 2</p> <p>- Abcauline wall of the adnate part of the hydrotheca without transverse striae....................................... 7</p> <p>2 Defensive tubes of the coppinia forming a protective structure over the gonothecae................................. 3</p> <p> - Defensive tubes of the coppinia not forming a protective structure over the gonothecae........... <i>F. nitidum</i> Watson, 2005</p> <p>3 Defensive tubes arising amongst the gonothecae. Gonotheca with short distal neck with everted rim.................... 4</p> <p>- Defensive tubes exclusively on the periphery of the gonothecal mass and arching over the gonothecae................. 5</p> <p> 4 Defensive tubes forming a shield-shaped structure (canopy)............................... <i>F. serratum</i> (Clarke, 1879)</p> <p> - Defensive tubes simply arching over gonothecae............................. <i>F. magnificum</i> Peña Cantero <i>et al.</i>, 2004b</p> <p> 5 Gonothecae without distal neck................................................. <i>F. antarcticum</i> (Hartlaub, 1904)</p> <p>- Gonothecae with distal neck............................................................................. 6</p> <p> 6 Coppinia bud-shaped. Gonothecae flask-shaped. Hydrothecal aperture 140–168 µm. Hydrothecal free part 320–420 µm.................................................................................... <i>F. conopeum</i> Watson, 2003</p> <p> - Coppinia corbula-shaped. Gonothecae irregular. Adnate hydrothecal part short or absent. Hydrothecal aperture 180–250 µm. Hydrothecal free part 650–1875 µm..................................................... <i>F. bouvetensis</i> <b>sp. nov.</b></p> <p> 7 Gonothecae without juxtaposed walls. Defensive tubes absent................ <i>F. disaggregatum</i> Peña Cantero <i>et al.</i>, 1998</p> <p>- Gonothecae with juxtaposed walls. Defensive tubes present.................................................... 8</p> <p>8 Hydrothecae and hydrorhiza forming a continuous layer on the substrate.......................................... 9</p> <p> - Hydrothecae and hydrorhiza spaced and distinct from each other............................ <i>F. serpens</i> (Hassall, 1848)</p> <p> 9 Gonothecae fusiform............................................................. <i>F. adhaerens</i> (Nutting, 1901)</p> <p> - Gonothecae polygonal....................................................... <i>F. parasiticum</i> (Antsulevich, 1987)</p>Published as part of <i>Marques, Antonio C., Peña, Álvaro L., Miranda, Thaís P. & Migotto, Alvaro E., 2011, Revision of the genus Filellum Hincks, 1868 (Lafoeidae, Leptothecata, Hydrozoa), pp. 1-28 in Zootaxa 3129</i> on page 24, DOI: <a href="http://zenodo.org/record/206783">10.5281/zenodo.206783</a&gt

Filellum annulatum Watson 1973

<i>Filellum annulatum</i> (Watson, 1973) <p> <i>Reticularia annulata</i> Watson, 1973: 164, figs. 5–6.</p> <p> <i>Filellum annulatum</i>: El Beshbeeshy 1991: 71 –73, figs. 15a–b; Peña Cantero <i>et al.</i> 1998: 299. Non <i>Corystolona annulata</i>: Watson 2002: 334 –335, figs. 1a–e.</p> <p> <b>Type series.</b> Holotype—“ NMV G1922, microslide; G2091, preserved material, remainder of holotype colony–S [denoting the sheltered side of Pearson Island], 17 m, on a small calcareous bryozoa” (Watson 1973: 164). Type material was not examined.</p> <p> <b>Type locality.</b> From the holotype, sheltered side of Pearson Island, Great Australian Bight (Watson 1973).</p> <p> <b>Remarks.</b> Watson (1973) described and figured <i>Reticularia annulata</i> as a new species assigned to the family Lafoeidae. When <i>Reticularia</i> was recognized as a preoccupied name for a brachiopod, the species referred to this genus were assigned to the genus <i>Filellum</i> by Peña Cantero <i>et al.</i> (1998) (see discussion above). Watson (1973: 164) characterized her species “by the close thecal rings […] of uniform size, and the distance between them varies little along the entire length of the hydrotheca. They have developed by continuous apical reduplication during growth of the hydrotheca, the flange of each rib being a relict margin”.</p> <p> Peña Cantero <i>et al.</i> (1998: 299) considered <i>Reticularia annulata</i> Watson, 1973 actually to belong to the pterobranch hemichordate genus <i>Rhabdopleura</i>, but the authors gave no arguments supporting their conclusion. <i>Filellum annulatum</i> was subsequently recorded from Patagonia and redescribed in the dissertation of El Beshbeeshy (1991), including details and figure of the hydranth. El Beshbeeshy’s data undoubtedly refer to a hydroid and, most likely, to a species of <i>Filellum</i>. Whether the specimens assigned to <i>F. annulatum</i> by El Beshbeeshy are conspecific to the geographically distant material originally described by Watson is open to question.</p> <p> Watson (2002) proposed the new hydroid genus <i>Corystolona,</i> assigned it to the family Clavidae, and mistakenly placed it in “Leptothecatae”. The holotype of the type species of <i>Corystolona annulata</i> (Watson, 1973) is NMV G1922, as described by her in 1973. However, Watson (2002: 333) also collected “Abundant colonies of a hydroid previously described as <i>Reticularia annulata</i> Watson, 1973 ” and, based on this new material [(see Watson 2002: 334: “Description (of Tasmanian material)”], redescribed and provided illustrations (her Figure 1) of a specimen that is undoubtedly a member of “ Clavidae ” (today considered part of family Oceaniidae, see Schuchert 2009). The rationale of the redescription and new assignment was that “the small sample of <i>Reticularia annulata</i> from Pearson Island in the eastern Great Australian Bight had deeply withdrawn, partly decomposed, sterile hydranths and disposition of the specimen on the bryozoan host was such that the bases of the hydrocauli were obscured; the specimen was thus mistakenly referred to <i>Reticularia</i> Thomson, 1853 (junior synonym, <i>Filellum</i> Hincks, 1868). The smaller dimension of the type compared with those of the present specimens is almost certainly due [to] its being a young, infertile colony while the Tasmanian material ranges from young to aged” (Watson 2002: 334). The dimensions of perisarc of the two specimens are obviously different, as well as their trophosomal morphology. Watson (2002) neither remarked about the reassignment of her species made by Peña Cantero <i>et al.</i> (1998) as a hemichordate, nor its subsequent redescription by El Beshbeeshy (1991).</p> <p> We believe that the two papers by Watson describe different species; the 1973 one being a <i>Filellum</i>, and the 2002 one being a species of Anthoathecata and indeed a new species of Oceaniidae.</p> <p> However, once Watson (2002) explicitly considered <i>Corystolona annulata</i> as linked to the holotype NMV G1922, both the species and generic name shall not be considered for nomenclatural purposes, because the holotype was intended to be a <i>Filellum</i>, not an oceaniid. Therefore, we consider <i>F. annulatum</i> a valid name based on the holotype material NMV G1922 (a microslide, and the remainder preserved material of the holotype colony NMV G2091). The Tasmanian material NMV F91280 (malinol mounted microslide, female colony, Port of Launceston, Tasmania, colonies from bryozoans on wharf pilings 1–4 m, Aquenal Pty Ltd, May, 2001, see Watson 2002: 334) undoubtedly represents a species of Corydendriinae (sensu Schuchert, 2004), and perhaps even the genus <i>Corydendrium</i> van Beneden, 1844, whose description was emended as “erect, branching or stolonal hydroid colonies […]” (Schuchert, 2004: 335), therefore encompassing the diagnostic character “strictly stolonal colonies” (Watson, 2002: 334) presented by <i>Corystolona</i>.</p>Published as part of <i>Marques, Antonio C., Peña, Álvaro L., Miranda, Thaís P. & Migotto, Alvaro E., 2011, Revision of the genus Filellum Hincks, 1868 (Lafoeidae, Leptothecata, Hydrozoa), pp. 1-28 in Zootaxa 3129</i> on pages 7-8, DOI: <a href="http://zenodo.org/record/206783">10.5281/zenodo.206783</a&gt