Polyplumaria G. O. Sars, 1874

Agís, José Ansín, Vervoort, Willem & Ramil, Fran, 2014, Hydroids of the families Kirchenpaueriidae Stechow, 1921 and Plumulariidae McCrady, 1859 (Cnidaria, Hydrozoa) collected in the Western Pacific Ocean by various French Expeditions, Zoosystema 36 (4), pp. 789-840 : 831-837

Genus Polyplumaria G. O. Sars, 1874

Polyplumaria cornuta ( Bale, 1884) ( Figs 27 , 28 ; Table 18)

Plumaria cornuta Bale, 1884: 132 , pl. XI, figs 1, 2. Polyplumaria cornuta – Billard 1913: 53, figs 65, 66, pl. III, fig. 33, pl. IV, figs 35, 36. — Watson 2000: 56, fig. 44A-F. — Schuchert 2003: 213, fig. 62A-E.

Polyplumaria cornuta var. longispina Billard, 1913: 56 , fig. 67.

MATERIAL EXAMINED. — New Caledonia. LAGON, stn 0615, 22°06.7’S, 166°57.0’E, 56-60 m, 05.VIII.1986: 120 mm high mutilated colony ; no gonothecae ( MNHN). — LAGON, stn 0745, 22°13.6’S, 167°02.8’E, 78-80 m, 13.VIII.1986: Several fragments of a large colony, no gonothecae ( MNHN). — Lagoon, Canal Woodin, 25-40 m, 13.IV.1995, leg. Dr Richer de Forges Noumea. Coelenterate 27624: Fragments with a few hydrocladia and without gonothecae ( RMNH) .

DISTRIBUTION. — Polyplumaria cornuta has been reported from Australia ( Bale 1884, Watson 2000) and Indonesia ( Billard 1913, Schuchert 2003), at depths between 6- 250 m.

Our material, from New Caledonia, was collected at depths of 25- 80 m.

DESCRIPTION

Hydrorhiza composed of a bundle of interwoven tubules adhering to shell sediment, from which rise polysyphonic and ramified hydrocauli. Stem with hydrocladia arranged in two lateral rows in the basal half, and three rows at the top that resembles a verticil. Branches monosiphonic, divided into internodes of varied length by oblique nodes. Apophyses with one mamelon and three nematothecae: two axillary and one above mamelon.

Hydrocladia formed by regular succession of hydrothecate internodes separated by oblique nodes.All internodes with one hydrotheca placed in the middle and three nematothecae: one mesial inferior and two laterals. Hydrotheca cup shaped, widening towards margin, adcauline wall completely adnate, abcauline wall slightly sinuous with distal part concave, margin with two rounded lateral lobes and adcauline side sligthly curved down, rim smooth. Mesial inferior nematotheca large, the margin reaching near half of the abcauline wall of hydrotheca, adcauline wall of upper chamber deeply scooped. Lateral nematotheca conical, movable and placed on small apophyses. Each internode with several perisarcal rings with a variable development; in basal internodes six internal thickenings have been observed: two under, three behind, and one above the hydrotheca.

Many apophyses with one normal hydrocladium and one modified hydrocladium, with a basal hydrotheca, one or two distal nematothecae, and tapering into pointed horn-like process.

Gonothecae not observed.

VARIABILITY

In some material from station 615, the top of a secondary hydrocladium developed a normal hydrocladium with several thecate internodes separated by oblique nodes.

REMARKS

The presence of horn-like modified secondary hydrocladia affirms the identity of this material as Polyplumaria cornuta . Cladacanthella scabra , considered a very similar species by Schuchert (2003), lacks such modified hydrocladia.

Polyplumaria kossowskae ( Billard, 1911) ( Fig. 29 ; Table 19)

Plumularia kossowskae Billard, 1911 : LXIV, fig. 5; 1913: 29, fig. XXVI, pl. I, fig. 19.

MATERIAL EXAMINED. — Vanuatu. MUSORSTOM 8, stn DW 966, 20º19’S, 169º52’E, 128-150 m, 21.IX.1994: one fragment 20 mm high, no gonothecae ( MNHN). — Stn CP 1001, 18º49’S, 169º00’E, 150-250 m, 25.IX.1994: three colonies 25-55 mm high with gonothecae ( MNHN).

DISTRIBUTION. — Plumularia kossowskae is known only from the type locality in Indonesia: station 166, Siboga Expedition, 2°28.5’S, 131°03.3’E, 118 m depth ( Billard 1911, 1913).

Our material, from Vanuatu, was collected between 129- 250 m.

DESCRIPTION

Hydrorhiza tubular, attached to substratum, supporting polysiphonic and branched hydrocauli. Branches develop from secondary tubes, arranged in opposite pairs, polysiphonic in lower zones of main axis. Original tube of axis and principal tube of branches divided into internodes of varied length by oblique nodes visible only in apical parts of main stem and branches.

Apophyses directed alternately left and right, each with a well developed mamelon on superior surface

Lagoon stn 745

Length thecate hydrocladial internodes 310-350

Diameter at node 90-125

Hydrotheca,

Length abcauline wall 130-155

Length adcauline wall 125-140

Diameter at rim 110-125

Mesial nematotheca, length 130-150

Diameter at rim 35-40

Lateral nematotheca, length 100-110

Diameter at rim 40-45

MUSORSTOM 8 stn CP 1001 Height of colony (in mm) 55

First hydrocladial internode, length 210-280 Length thecate hydrocladial 120-150 internodes

Length athecate hydrocladial 320-410 internodes

Diameter at node 25-35 Hydrotheca

Length abcauline wall 110-120 Diameter at rim 120-140 Length free part adcauline wall 50-60 Mesial nematotheca, length 40-50 Diameter at rim 25-30 Lateral nematotheca, length 80-100 Diameter at rim 40-50 Gonotheca, length 260* Greatest diameter 100*

and with one axillary nematotheca. One or two nematothecae between two consecutive apophyses.

Hydrocladia begin with an athecate internode having one nematotheca near the base. Remainder of hydrocladium formed by a succession of thecate and athecate internodes separated by oblique nodes. Thecate internodes with a conspicuous, strongly oblique basal node and a scarcely visible slightly oblique superior node; athecate internodes with reverse arrangement.

Each thecate internode with one hydrotheca in the middle and three nematothecae: one mesial inferior and a pair of laterals. Hydrotheca cup-shaped, deep, adcauline wall free about half its length, abcauline wall straight, walls nearly parallel, rim circular and smooth. Hydrothecal aperture forming an angle with hydrocladial axis of approximately 45 degrees.Mesial inferior nematotheca small, not reaching hydrothecal basis and with adcauline wall of superior chamber slightly reduced. Lateral nematothecae arising from well developed apophyses placed on both sides of the hydrotheca, surpassing the hydrothecal margin.

Athecate internodes with two nematothecae, one near the basal and other in the upper third. All nematothecae movable, bithalamic and conical. Lateral nematothecae larger than the others.

One gonotheca was found arising from an apophysis, small, tubular and with one internal thickening well marked, aperture circular and smooth.

Figures

FIG. 27. — Polyplumaria cornuta (Bale, 1884): A, LAGON, stn 0615, colony; B-E, LAGON, stn 0745: B, first internodes of hydrocladia and one modified hydrocladia on apophyses; C-E, internodes, lateral view. Scale bars: A, 1 cm; B-E, 0.1 mm.

FIG. 28. — Polyplumaria cornuta (Bale, 1884), LAGON, stn 0615: A, B, anomalous spine; C, detail spine. Scale bars: 0.1 mm.

FIG. 29. — Polyplumaria kossowskae (Billard, 1911), MUSORSTOM 8, stn CP 1001; A, colony; B, first internode of hydrocladia; C, internodes, lateral view; D, apophyses with first internode of hydrocladia; E, gonotheca. Scale bars: A, 1 cm; B-E, 0.1 mm.