Haliclona (Flagellia) hiberniae, Van Soest, 2017

Van Soest, Rob W. M., 2017, Flagellia, a new subgenus of Haliclona (Porifera, Haplosclerida), European Journal of Taxonomy 351, pp. 1-48 : 29-32

Haliclona (Flagellia) hiberniae subgen. et sp. nov.

urn:lsid:zoobank.org:act:EAB80C5A-6259-4189-90D9-1715A83A3A2A

Fig. 14

Gellius flagellifer – Topsent 1904: 231, in part (only stat. 584). — Stephens 1916: 233; 1917: 5; 1921: 6. Haliclona (Gellius) flagellifera – Van Soest et al. 2007: 131.

non Gellius flagellifer Ridley & Dendy 1886: 323 ; 1887: 42, pl. XIII figs 5, 10.

Etymology

‘ Hibernia ’ is the Latin name of Ireland in Roman times, chosen here as a reference to the type locality.

Material examined

Holotype

NORTH ATLANTIC : SE Rockall Bank, W of Ireland, 55.4994° N, 15.8007° W, depth 560 m, boxcore, coll. R. W.M. Van Soest, BIOSYS2005 stat. BX66, 1 Jul. 2005 ( ZMA Por. 19596a).

Paratype

NORTH ATLANTIC: SE Rockall Bank, W of Ireland, 55.4444° N, 16.0756° W, depth 762 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX72, 4 Jul. 2005 ( ZMA Por. 19619).

Additional specimens examined

NORTH ATLANTIC: SE Rockall Bank, W of Ireland, 55.4991° N, 15.7967° W, depth 626 m, boxcore, coll. R.W.M. Van Soest, Moundforce 2004 stat. BX32, 2 Sep. 2004 ( ZMA Por. 18506, 18527d); SE Rockall Bank, W of Ireland, 55.5037° N, 15.7852° W, depth 673 m, boxcore, coll. R.W.M. Van Soest, Moundforce 2004 stat. BX33, 2 Sep. 2004 ( ZMA Por. 18536a); SE Rockall Bank, W of Ireland, 55.4359° N, 16.1158° W, depth 778 m, boxcore, coll. R.W.M. Van Soest, Moundforce 2004 stat. BX41B, 5 Sep. 2004 ( ZMA Por. 18551); SE Rockall Bank, W of Ireland, 55.4998° N, 15.7982° W, depth 602 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX10, 10 Jul. 2005 ( ZMA Por. 19407, 19412); SE Rockall Bank, W of Ireland, 55.4993° N, 15.7979° W, depth 587 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX12, 25 Jun. 2005 ( ZMA Por. 19421); SE Rockall Bank, W of Ireland, 55.5037° N, 15.7869° W, depth 614 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX28, 27 Jun. 2005 ( ZMA Por. 19476a); SE Rockall Bank, W of Ireland, 55.4440° N, 16.0752° W, depth 785 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX38, 28 Jun. 2005 ( ZMA Por. 19517); SE Rockall Bank, W of Ireland, 55.5011° N, 15.7887° W, depth 577 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX96, 6 Jul. 2005 ( ZMA Por. 19690); SE Rockall Bank, W of Ireland, 55.4429° N, 16.0974° W, depth 644 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX115, 9 Jul. 2005 ( ZMA Por. 19745, 19752); SE Rockall Bank, W of Ireland, 55.4907° N, 15.8013° W, depth 573 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX153, 11 Jul. 2005 ( ZMA Por. 19985); SE Rockall Bank, W of Ireland, 55.5012° N, 15.7885° W, depth 585 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX160, 11 Jul. 2005 ( ZMA Por. 20023); Porcupine Bank, W of Ireland, 53.77° N, 13.9472° W, depth 683–749 m, dredge, coll. R.W.M. Van Soest, HERMES2005 stat. DR190, 14 Jul. 2005 ( ZMA Por. 20099); Porcupine Bank, W of Ireland, 53.7701° N, 13.9457° W, depth 745–754 m, dredge, coll. R.W.M. Van Soest, HERMES2005 stat. DR215, 17 Jul. 2005 ( ZMA Por. 20123).

Unregistered slides examined

NORTH ATLANTIC: W of Ireland, SE Rockall Bank, 55.5007° N, 15.7893° W, depth 586 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX71, 4 Jul. 2005; W of Ireland, SE Rockall Bank, 55.4441° N, 16.0756° W, depth 767 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX78,

4 Jul. 2005; W of Ireland, SE Rockall Bank, 55.4428° N, 16.0975° W, depth 644 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX114, 9 Jul. 2005; W of Ireland, SE Rockall Bank, 55.5011° N, 15.7884° W, depth 585 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX161, 11 Jul. 2005; W of Ireland, SE Rockall Bank, 55.4443° N, 16.0756° W, depth 691 m, boxcore, coll. R.W.M. Van Soest, BIOSYS2005 stat. BX168, 12 Jul. 2005.

Description

Small dirty white to greyish brown or greyish beige encrustations ( Fig. 14A holotype, A 1 paratype), often forming thick cushions or small globular masses, occasionally pear-shaped (grey in alcohol). Color remains unchanged in alcohol. Size variable from tiny, <2 mm individuals up to 2.5 × 1.6 × 1 cm. Surface undulating to shaggy, sometimes ‘hairy’ due to protruding spicule tracts, and also appearing clathrate. There may be one or two oscules, only apparent in larger, thicker specimens. Consistency soft.

SKELETON. Confused reticulation, consisting of ascending paucispicular spicule tracts connected by single spicules, spongin present only at the nodes.

OXEAS ( Fig. 14 B–B1). Slightly curved to almost straight, 288– 367 –419 × 6– 11. 1 –14 μm.

FLAGELLOSIGMAS ( Fig. 14 C–G). Similar to those of Haliclona (Flagellia) flagellifera , ovoid, larger spicules strongly asymmetrical, smaller less so, curvature of long ending shortly rounded ( Fig. 14C 1 ), no upturned hook, curvature of short ending shallow ( Fig. 14C 2 ). Found in a wide size range, suggesting two overlapping size categories, but this depends on individual sponges. Larger spicules (I) ( Fig. 14 C– E) with length of long ending 64– 104 –159 μm, length of short ending 48– 69 –106 μm, width 51– 73 – 102 μm, thickness 1.5– 2. 6 –4 μm. Smaller (II) ( Fig. 14 F–G), length of long ending 13– 29. 5 –55 μm, length of short ending 10– 27 –39 μm, width 12– 27 –45 μm, thickness 0.5– 1. 05 –2 μm.

NORMAL SIGMAS ( Fig. 14 H–I). Numerous, in two distinct size categories, larger (I) ( Fig. 14H ) robust, with more shallow curve, 53– 76 –92 × 2.5– 3. 3 –5 μm, smaller (II) ( Fig. 14I ) thin, deeper curve, with more distinct incurved endings, 28– 33. 5 –39 × 1– 1. 6 –2.5 μm.

Distribution and ecology

Rockall and Porcupine Banks, W of Ireland (Marine Ecoregion Celtic Seas). Known predominantly from deep-water coral banks. Depth range: 560–785 m ( Stephens (1921) mentions 90–1328 m).

Remarks

The present deep-water North Atlantic specimens are overall very similar to the type of Gellius flagellifer . The one major difference is the occurrence of two distinct size categories of normal sigmas. Minor differences are thinner oxeas and larger size range of the two flagellosigmas’ size categories in the present specimens.

Topsent (1904) reported Gellius flagellifer from the Azores (845–1360 m). Oxea size ranges were from 335–345 × 8–10 μm in the more shallow station, to 620–680 × 18–20 μm at the deeper stations, suggesting a relationship between oxea size and depth. In the Azores material flagellosigmas reached sizes of up to 118 μm, and normal sigmas occurred in a large size range of 30–80 μm, suggesting the presence of size categories in both. It is possible that the Azores specimens conform to the Irish material, at least the shallower sample (but there is some doubt over the identity of the deeper sample, see below).

Conspecificity is also likely for Irish material reported by Stephens (1921). She described specimens from the Porcupine Bank (698–1145 m depth) with oxeas up to 400 × 13 μm, flagellosigmas of up to 120 μm (width 60–90 μm), and sigmas in a large size range of 35–90 μm.

Remarkably, Topsent (1928: 314) took the erroneous view that his earlier reports on Gellius flagellifer were part of what he considered to be Gellius vagabundus ( Schmidt, 1870) , referring to Vosmaer as the inspiration for this change. In fact, Topsent’s (1928) description of ‘ Gellius vagabundus ’ from 1378 m near São Miguel, Azores, is likely to be a different species from his other described specimens as the sigmas appear dissimilar to the flagellosigmas discussed here. Possibly, it is a Haliclona (Gellius) species, but it is not the present species.

Lundbeck (1902) (and other authors such as Rezvoi 1928 and Koltun 1959) assigned specimens from Arctic waters to Gellius flagellifer , which could perhaps be members of the present species because Lundbeck’s drawing (pl. XIV fig. 1d) of the normal sigmas shows a large size range. However, without the original material this cannot be decided for certain.

Mediterranean records of Gellius vagabundus (cf. Babič 1922), Gellius flagellifer (cf. Vacelet 1969; Pulitzer-Finali 1978, 1983; Pansini 1987) and Haliclona (Gellius) flagellifera (cf. Longo et al. 2005; Sitjà & Maldonado 2014) could be conspecific with the present species. The depth range of the combined records is 20– 809 m. Babič (1922: 228, text-fig. H) provides detailed spicule data that appear to conform to those of the present material, except the upper size of the oxeas (222–480 × 2–12 μm) and the normal sigmas (15–125 μm) which are in excess of the North Atlantic material. The other Mediterranean records do not provide details of size categories of normal sigmas, so the conspecificity remains doubtful.

Figures

Fig. 14. Haliclona (Flagellia) hiberniae subgen. et sp. nov., from the deep water of the Rockall Bank, W of Ireland. A. Habitus (arrow) of holotype (ZMA Por. 19596a), encrusting a dead coral. A 1. Habitus (paratype ZMA Por. 19619), encrusting a hydrocoral. B–I. SEM images of the spicules. B. Oxeas. B 1. Detail of one of the apices. C–E. Large category of flagellosigmas (I). C 1. Detail of long ending of large flagellosigma. C 2. Detail of short ending of large flagellosigma. F–G. Small category of flagellosigmas (II). H. Large category of sigmas (I). I. Small category of sigmas (II).

Fig. 1. Flagellosigma, the characteristic feature of Haliclona (Flagellia) subgen. nov., showing meristic and descriptive features used in this study.

Fig. 2. ‘Flagellated’ sigma of Mycale (Naviculina) diversisigmata Van Soest, 1984, a sigma type superficially similar to a flagellosigma, but the morphology is considered non-homologous due to the lack of a strong asymmetry in the longer and shorter endings.