Candelabrum valdiviensis Galea & Schories

Galea, Horia R., Schories, Dirk, Försterra, Günter & Häussermann, Verena, 2014, New species and new records of hydroids (Cnidaria: Hydrozoa) from Chile, Zootaxa 3852 (1), pp. 1-50 : 2-6

Candelabrum valdiviensis Galea & Schories , sp. nov.

(Plate 1, Table 1)

Material examined. Corral, Chaihuin/Huiro, lat. -39.95000, long. -73.61667, 30.xi.2011, 6 m, sample 01: a 2.2 cm high, relaxed specimen with gonophores (holotype: MHNG-INVE-86204); 06.vi.2012, 8 m, sample 07: a 1 cm high, contracted specimen, without gonophores (paratype: MHNG-INVE-86203).

Description. Largest polyp (holotype) ca. 2.2 cm long in preserved state, more extended in life, reaching at least 4.5 cm in height (Pl. 1 Fig. C). Foot partly damaged due to removal from substrate, although there are remains of a few brownish, chitinous structures limited to several pads. Basal part, ca. 4 mm long, covered with about 50 knobs crowded with large nematocysts (Pl. 1 Fig. F); young blastostyles overlap the distal half of this region and occupy a total of about 1.2 cm of body length (Pl. 1 Fig. D), the nematocyst knobs disappearing from the major part of the blastostyle region. Blastostyles, as many as 70, shorter proximally, and of a nearly uniform length (up to 5 mm long) above; blastostyles unbranched, tapering distally, where they carry up to ca. 12 short tentacles with large terminal knobs, the distalmost bearing the largest capitation. Shorter tentacles, slightly fewer in number and with no distinct stalks, are scattered throughout the blastostyles down to their bases; basally, 2–8 spherical (up to 0.25 mm in diameter), sessile gonophores, presumably female, in 1–3 whorls, basalmost the youngest (Pl. 1 Fig. E). A cluster of about 30 embryos, packed in two alternating rows, is held by several neighbouring blastostyles (Pl. 1 Figs D, G, H). Similarly, a clump of juvenile polyps, is held by another group of blastostyles (Pl. 1 Figs C, D, I). Clasper tentacles absent. Distal 8 mm of polyp covered with hundreds of densely packed, short (ca. 0.5 mm long) tentacles, all directed upright (Pl. 1 Figs A, B); mouth terminal, hidden by distalmost tentacles. Cnidome (Pl. 1, Fig. J): stenoteles, microbasic euryteles, small and large desmonemes (see Table 1). Colors in life: capitula of most of the body tentacles purple brown, others white; body creamy, blastostyles and gonophores creamy-white with brownish cores.

Remarks. Polyps of this species were found living attached to pebbles. One of the gathered specimens was fertile and seemed able to brood: a cluster of embryos (Pl. 1 Figs D, G, H), as well as a clump of juveniles (Pl. 1 Figs C, D, I), both held by groups of several blastostyles, could be observed. The sticky foots of the juveniles had accumulated various particles and attached to them, thus providing a support for the blastostyles to maintain a grip on the whole group. The nematocyst knobs at the base of the polyp may represent the capitations of the future distalmost tentacles on very incipient blastostyles.

PLATE 1. Candelabrum valdiviensis sp. nov. —Living specimen, in situ (A); the same, preserved (B); fertile, living specimen (holotype) (C); the same, preserved (D); details of the blastostyle region (E, G), and of the basal part of the polyp (F); cluster of embryos (H) and clump of juveniles (I), both attached to groups of blastostyles; cnidome (J), scale bar 10 µm. Photos by D.S. (A‒D, F, I) and H.R.G. (E, G, H, J).

Species Reference(s) Polyp Body tentacles Blastostyles Blastostyle Gonophores Cnidome Distribution

tentacles

. australe Briggs 2–6 cm, Above Crowded on 6–10 distally on Up to 15, ca. - small desmonemes, (10–12) × (7–9) Μm; Australia, New Briggs, 1928) ( 1928), pale blastostyle- lower body, ca. blastostyle; 1 mm in - large desmonemes, (18–20) × (12–15) Μm Zealand

Watson flesh– bearing region 4 mm long, capitulum apically diameter, - small stenoteles, ca. 12 × 10 Μm;

(2007) pink unbranched flattened with a ring of - ovoid, medium-sized stenoteles, ca. 15 × 11 Μm;

dark brown - rounded, medium-sized stenoteles, ca. 15 × 13

pigment Μm;

granules - large stenoteles, ca. 21 × 13 Μm;

- large merotrichous isorhizas, (19–22) × (14–16)

Μm;

- small? merotrichous isorhizas, (8–9) × (5–6)

Μm;

- mesoteles, (18–21) × (7–9) Μm

. austro- Jäderholm <30 Covering Unbranched, 3 One distally, 6–10, up to Undescribed South-Georgia, georgiae (1905), own cm, whole body, mm long occasionally 1.5–2 mm in Antarctica Jäderholm, observations orange including the additional ones diameter

1905) blastostyle-

bearing region

. capensis Manton <2.5 Above Ca. 20, 1.5–4.0 4–7 distally 4–9, 0.8–0.9 - heteronemes, (11.7–19.2) × (3.6–6.0) Μm; South Africa Manton, (1940), cm blastostyle- mm long, in a mm in - small desmonemes, ca. 7.8 × 5.4 Μm; 1940) Millard bearing region single whorl, diameter, - large desmonemes, ca. 16.8 × 12.6 Μm;

(1975) unbranched with several - stenoteles, (9.9–11.4) × (7.2–8.1) Μm;

longitudinal - haplonemes, ca. 10.8 × 9.9 Μm;

purple-brown -? atrichous isorhizas, ca. 18.0 × 6.0 Μm

stripes and 2

apical rings

. harrisoni Briggs 1.2 cm, Above Irregularly 1 distally, with 1–3, ca. 0.8 At least: Australia Briggs, 1928) ( 1928, 1930, pinkish- blastostyle- lobed base, flattened mm in - microbasic euryteles, (15–21) × 6–9) Μm;

1931), white bearing region with a short, capitulum diameter, - large desmonemes, (10–12) × (8–9) Μm

Watson narrow, distal apically

(1997) portion flattened,

with 4 small

processes

……continued on the next page Species Reference(s) Polyp Body tentacles Blastostyles Blastostyle Gonophores Cnidome Distribution

tentacles

Briggs <3 cm Above Many closely- Absent 3–10, up to - microbasic euryteles, (14.9–16.1) × (5.7–6.1) Macquarie Is.,

meridianum (1938), blastostyle- set at base of 1.1–1.3 mm Μm; Marion Is.

Briggs, 1938) Millard bearing region hydranth; up long, with a - small desmonemes, ca. 6.5 × 5.2 Μm; (1971), to 9 mm long, terminal - large desmonemes, (11.3–14.9) × (8.7–11.3) Μm; Stepanjants branched pigmented - stenoteles, (10.4–10.8) × (6.2–7.2) Μm (1979) spot and a

ring around it

penola Manton <85 Above Ca. 300, up to On lobes or main 7–10 per - small heteronemes; Antarctica

Manton, (1940), cm, blastostyle- 25 mm long, axes of blastostyle, - large heteronemes, ca. 20 × (5–6) Μm;

) Galea & creamy- bearing region irregularly blastostyles ca. 8 mm in - small desmonemes, ca. 9 Μm long; Schories white lobed or diameter - large desmonemes, ca. 18 Μm long; (2012b) branched - stenoteles, (10–18) × (7–13) Μm; - haplonemes, ca. 13 × 9 Μm

Millard 2.5–3.1 Above Ca. 17, up to 2 Several amongst 4–8 per - heteronemes, (44.1–45.9) × 8.1 Μm; South Africa

tentaculatum (1966a, cm blastostyle- cm long, in a the gonophores blastostyle, - small desmonemes, (10.2–10.8) × (7.2–7.7) Μm;

Millard, 1975) bearing region single whorl, and ca. 25 up to 2 mm - large desmonemes, (17.1–18.0) × (12.6–14.4)

a) unbranched, scattered over in diameter, Μm;

tapering from distal part of with 8–10 - stenoteles, ca. 14.4 × 10.8 Μm; base to tip blastostyle pigmented - atrichous isorhizas, (15.3–19.8) × (4.0–7.2) Μm spots apically

valdiviensis Present Up to Above Ca. 70, Up to 12 distally, Up to 8 in 1– - small desmonemes, (7.7–8.6) × (5.2–5.6) Μm; Chile

Galea & study 4.5 cm blastostyle- scattered, some others 3 rows, ca. - large desmonemes, (11.8–12.3) × (7.5–9.2) Μm;

Schories, sp. in life bearing region unbranched, scattered down to 0.25 mm in - stenoteles, (11.2–12.0) × (8.6–9.8) Μm;

. tapering from base diameter - microbasic euryteles, (15.8–17.8) × 6.0–6.6) Μm base to tip

The distinguishing features between Candelabrum valdiviensis and its congeners from the southern hemisphere are summarized in Table 1. This species exhibits some similarities with the European C. cocksii (Cocks, 1854) , viz. its general appearance, the scattered blastostyles, and the cnidome composition. However, the latter species possesses claspers involved in carrying the fertilized eggs and developing embryos, a very contractile tentacle region, and a characteristic, exceedingly long foot region (the whole animal reaching up to 12 cm in length) ( Schuchert 2006).

Etymology. The specific name is taken from the type locality, Valdivia.

Distribution in Chile. Only known from Corral, near Valdivia.

World records. Not reported from elsewhere.