Plumularia pseudocontraria, Agís & Vervoort & Ramil, 2014

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 : 821-830

Plumularia pseudocontraria n. sp. ( Figs 20 , 21 ; Table 12)

MATERIAL EXAMINED. — Philippines. MUSORSTOM 3, stn DR 117, 12°31.2’- 12°31.3’N, 120°39.3’- 120°39.5’E, 92-97 m, 03. VI.1985: a branched fragment 30 mm high without gonothecae, holotype (MNHN-IK-2012-14254).

ETYMOLOGY. — The specific name pseudocontraria has been chosen because of the resemblance of this new species to Plumularia contraria n. sp.

DISTRIBUTION. — Plumularia pseudocontraria n. sp. is known only from a single locality in the Philippines (type locality), at a depth of 92- 97 m.

DESCRIPTION

Apical part of colony with monosiphonic axis, branched. Branches arising from axil of a closed apophysis and one small secondary tube born from the axils of each branch but it does not continue its growth towards top of colony.

Apophyses alternately directed left and right almost frontally, each with one well developed mamelon on superior surface and two axillary nematothecae, two or four nematothecae between consecutive apophyses.

Hydrocladia formed by regular succession of hydrothecate internodes separated by slightly oblique nodes not very marked; each internode with one hydrotheca and four nematothecae: one median infracalycine, two laterals and one median distal. Hydrotheca tubular, deep, adcauline wall fully adnate, abcauline wall practically straight, hydrothecal rim smooth and with adcauline side curved down. Median inferior and distal nematothecae placed at an elevation, with adcauline wall of superior chamber scooped. Lateral nematothecae placed near hydrothecal margin and with adcauline wall of upper chamber clearly scooped. All nematothecae movable, bithalamic and conical.

Internodes with a variable number of internal thickenings, until eight in basal internodes of hydrocladium: one below, four behind and three above the hydrotheca. The development and number of perisarcal rings is lower in distal internodes of a given hydrocladium.

MUSORSTOM 3 stn DR 117

Height of colony (in mm) 30

Length thecate hydrocladial 480-560

internodes

Diameter at node 55-65

Hydrotheca

Length abcauline wall 230-270

Length adcauline wall 160-210

Diameter at rim 70-100

Mesial nematotheca, length 65-70

Diameter at rim 25

Lateral nematotheca, length 70-80

Diameter at rim 30

Supracalycine nematotheca, length 65-70

Diameter at rim 20-25

Gonothecae not observed.

VARIABILITY

The presence of two suprahydrothecal nematothecae normally present after damage and subsequent regeneration.

In the distal parts of hydrocladia, sometimes there are no signs of injury when there are two suprahydrothecal nematothecae.

REMARKS

Plumularia pseudocontraria n. sp. resembles P. contraria n. sp. in its spiral colony structure and in the number and arrangement of nematothecae on the thecate internodes. The two nevertheless differ in the morphology of their hydrothecae, with P. pseudocontraria n. sp. lacking an adcaulinar intrathecal septum, in having a hydrothecal orifice that is directed upwards, and in having a hydrothecal rim that is sinuous: it is straight on the abcauline side and curved downwards on the adcauline side.

In the absence of an intrathecal septum and in the form of the hydrothecal margin, this species is similar to P. habereri . However, it clearly differs in the morphology and ramification pattern of the colony, and in the number of nematothecae on hydrocladial internodes.

MUSORSTOM 4 CC 201

Height of colony (in mm) 33

Stem internode, length 520-750 Diameter at node 160-240

First hydrocladial internode, length 60-100 Diameter at node 60-80 Length thecate hydrocladial 480-650 internodes

Length athecate hydrocladial 270-360 internodes

Diameter at node 45-70 Hydrotheca

Length abcauline wall 70-90 Length adcauline wall 80-100 Diameter at rim 90-105 Mesial nematotheca, length 70-80 Diameter at rim 25-35 Lateral nematotheca, length 70-85 Diameter at rim 30-35

Plumularia setacea ( Linnaeus, 1758) ( Fig. 22 ; Table 13)

Sertularia setacea Linnaeus, 1758: 813 .

Plumularia setacea – Vervoort 1966: 142, fig. 43a- e. — Ramil & Vervoort 1992: 191, fig. 47f-i. — Hirohito 1995: 278, fig. 95c, d. — Ansín Agís, Ramil & Vervoort 2001: 238, fig. 91a-j. — Vervoort & Watson 2003: 398, figs 96G, 97A-G, 98A. — Schuchert 2013a: 105 , figs 4-6; 2014a: 1, figs 1, 2.

Plumularia corrugata Nutting, 1900: 64 , pl. VI, figs 1-3.

Plumularia diploptera Totton, 1930: 222 , fig. 59a, b. — Ralph 1961: 32, fig. 3f-j. — Rees & Vervoort 1987: 137-139, fig. 29.

Plumularia setacea var. setacea Ralph, 1961: 33 , figs 3e, 4a, 4c, d.

Not Plumularia corrugata – Bennitt, 1922: 255. — Fraser 1944: 341. — Morris & Mogelberg 1973: 19. — Defenbaugh 1974: 101, fig. 14 (records included in Plumularia strictocarpa Pictet, 1893 ).

MATERIAL EXAMINED. — New Caledonia. MUSOR- STOM 4, stn CP 169, 18°54.3’S, 163°11.2’E, 590 m, 17.IX.1985: several colonies 50-60 mm high rising from rampant stolon. No gonothecae ( MNHN) ( RMNH, two slides). — Stn CC 201, 18°55.80’S, 163°13.80’E, 500 m, 20.IX.1985: many 70 mm high plumes rising from stolon on worm-tube. One gonotheca observed ( MNHN) ( RMNH, one slide).

Norfolk Ridge. SMIB 5, stn DW 101, 23°21.2’S, 168°04.9’E, 270 m, 14.IX.1989: one colony 25 mm high with several stems on coral fragment and some fragments. No gonothecae ( MNHN).

BATHUS 3, stn CP 833, 23º03’S, 166º58’E, 441-444 m, 30.XI.1993: two colonies 10-33 mm high without gonothecae (MNHN).

Marquesas Islands. MUSORSTOM 9, stn DW 1170, 08º45.1’S, 140º13.1’W, 104-109 m, 25.VIII.1997: six colonies 10-25 mm high with damaged gonothecae (MNHN).

DISTRIBUTION. — Many authors (Vannucci-Mendes 1946, Leloup 1947, Picard 1958, Ralph 1961, Millard 1975, Boero & Bouillon 1993, Blanco 1994) consider Plumularia setacea as a cosmopolitan species, although it has not been reported from Antarctic waters ( Peña Cantero 2004). Schuchert (2013a) ascribe the species a circumglobal distribution in warm and temperate waters.

REMARKS

The current status of the Plumularia lagenifera Allman, 1885 is considered as problematic and difficult to separate from P. setacea by Schuchert (2013a). In his opinion, the only operational character to distinguish both species is the morphology of the hydrothecal abcauline wall, convex in the former and straight or even concave in the last one. Our material showed a straight abcauline wall and, therefore it was included in P. setacea . In addition, Schuchert (2014a), after molecular analyses of different populations of P. setacea , concluded that the current concept of this species could include either a species complex or a single near-cosmopolitan species with a strong population stratification.

Plumularia spiralis Billard, 1911 ( Fig. 23 ; Table 14)

Plumularia spiralis Billard, 1911 : LXIX, fig. 12; 1913: 49, fig. 54, pl. II, figs 26, 27. — Jäderholm 1919: 22, pl. V, fig. 5. — Stechow 1923a: 18. — Rho 1969: 167, pl. I, figs 4, 5, pl. II, fig. 7. — Millard & Bouillon 1973: 87, fig. 11D. — Rho 1977: 282, pl. XCVI, fig.97. — Hirohito 1995: 280, fig. 96d-e. — Kirkendale & Calder 2003: 167.

Not Plumularia spiralis Milstein, 1976: 82 , figs. 17, 21, 22, 34, 37 (synonym of Plumularia milsteinae n. nom.)

MATERIAL EXAMINED. — NE Mozambique Channel, NE Geyser Bank. BENTHEDI, stn CH 13, 12º12.7’S, 46º40.8’E, 2300-2500 m, 20.III.1997: three ramified fragments, 20-25 m high, without gonothecae ( MNHN).

DISTRIBUTION. — Plumularia spiralis is known from the Seychelles, Indonesia, Korea, Japan ( Hirohito 1995), Guam and the Northern Marianas Islands ( Kirkendale & Calder 2003) and American Samoa ( Coles et al. 2003); its bathymetrical range extends from 1 to 400 m depth. Our material comes from a single station in the Mozambique Channel (NE Geyser Bank), located at 2300- 2500 m.

DESCRIPTION

Axis monosiphonic, branched,in zigzag(according to Billard 1913: 49); branches originating from zig-zag corners of main axis alternately in different planes; main stem and branches divided into internodes of varied length by oblique nodes.

Apophyses alternately directed right and left with a small mamelon on superior surface and three nematothecae: two axillary and one frontal near of mamelon. Arrangement of apophyses in one plane, but slightly frontally.

Hydrocladia homomerously segmented, hydrocladial internodes separated by oblique nodes. Each thecate internode with one hydrotheca and four nematothecae: one mesial inferior, two laterals and one suprahydrothecal. Hydrotheca cup-shaped, small, adcauline wall completely adnate, abcauline wall straight and slightly higher than adcauline wall; rim smooth, circular and slightly tilted towards adcauline side.

Mesial inferior and suprahydrothecal nematothecae above an elevation. Lateral nematothecae arising from a small apophysis on each side of hydrotheca. All nematothecae bithalamic, movable and conical. Internodes with several perisarcal rings with a variable development.

Gonothecae not observed.

REMARKS

Our material agrees well with the description of this species given by Billard (1913), and we have no doubt about its identification. The locality falls within its geographical distribution but the sampling depth (2300-2500 m) is far away from its known bathymetrical range (1-400 m). The possibility of

BENTHEDI stn CH 13

Height of colony (in mm) 20-25

Length thecate hydrocladial internodes 490-560

Diameter at node 40-50

Hydrotheca

Length abcauline wall 55-70

Length adcauline wall 35-40

Diameter at rim 65-80

Mesial nematotheca, length 70-80

Diameter at rim 30-40

Lateral nematotheca, length 80-85

Diameter at rim 30-35

MUSORSTOM 3 stn CP 121 Height of colony (in mm) 21

Stem internode, length 290-380 Diameter at node 45-100

First hydrocladial internode, length 100-150 Length thecate hydrocladial 240-280 internodes

Length athecate hydrocladial 225-290 internodes

Diameter at node 25-35 Hydrotheca

Length abcauline wall 40-50 Length adcauline wall 50-70 Diameter at rim 60-75 Mesial nematotheca, length 40-55 Diameter at rim 20-25 Lateral nematotheca, length 60-70 Diameter at rim 30-35

detached colonies subsequently collected by the trawl can not be excluded; in consequence the depth record should be regarded with caution and the presence of P. spiralis in the lower bathyal must be confirmed with new data.

Plumularia spiralis Milstein, 1976 , described from Uruguay, is a permanently invalid junior primary homonym of P. spiralis Billard, 1911 , and must be replaced.We propose the name Plumularia milsteinae n. nom. for it. The species from South America is quite different in morphology, having (1) erect and straight monosiphonic axes with some lateral ramifications in large colonies, (2) hydrocladia alternately arranged in one plane at the base but in a spiral elsewhere, (3) heteronomous segmentation of hydrocladia, with thecate internodes having one hydrotheca and three nematothecae (one mesial inferior and two laterals) and (4) small athecate internodes without nematothecae.

Plumularia strobilophora Billard, 1913 ( Fig. 24 ; Table 15)

Plumularia strobilophora Billard, 1913: 35 , fig.26. — Vervoort & Vasseur 1977: 79, fig. 33a, b. — Schuchert 2013b: 410 , fig. 3.

Plumularia strobilifera – Billard 1933: 23, fig. 9. — Schmidt 1972: 43 (incorrect subsequent spelling).

Plumularia strobilophora – Vannucci Mendes 1951: 87, pl. 3, figs 17, 18. – Grohmann et al. 2011: 195, fig. 2h (doubtful records).

Not Plumularia strobilophora – Ryland & Gibbons 1991: 536, fig. 8A, B (included in Plumularia mooreana Schuchert, 2013 ).

MATERIAL EXAMINED. — Philippines. MUSORSTOM 3, stn CP 121, 12°08.3’N, 121°17.3’E, 73-84 m, 03. VI.1985: one colony 22 mm high without gonothecae ( MNHN).

DISTRIBUTION. — Plumularia strobilophora is an Indo- Pacific species, known from the Gulf of Suez ( Billard, 1933) and Aqaba ( Schmidt, 1972), Key Islands ( Billard, 1913; Schuchert, 2013b), French Polynesia and the Philippines ( Vervoort & Vasseur 1977) and American Samoa ( Coles et al, 2003). The bathymetrical distribution extends from the littoral zone to 60 m.

Our material was collected in the Philippines at a depth of 73- 84 m.

Brazilian records ( Vannucci Mendes 1951; Grohmann et al. 2011) are here considered doubtful.

DESCRIPTION

Stem monosiphonic, divided into internodes by straight nodes. Each internode with a distal apophysis and one nematotheca on its basal half, inserting on wall opposite the apophysis. Apophyses alternately directed left and right, each with three nematothecae: two paired axillary and one unpaired above a small and scarcely visible mamelon; one internal septum close to node. First internode of hydrocladium athecate and without nematothecae; remainder of hydrocladium

A

A

D

a succession of thecate and athecate internodes separated by oblique and straight nodes; thecate internodes with basal oblique and distal straight node; athecate internodes the reverse; thecate and athecate internodes with a pair of perisarcal rings, with one at each end; thecate internodes with one hydrotheca and three nematothecae: one mesial inferior and two lateral. Hydrotheca in middle of internode, cup-shaped, low, abcauline wall lower than adcauline wall; hydrothecal aperture circular, quite oblique and tilted to abcauline side, rim smooth. Mesial inferior nematotheca conical, with adcauline wall of upper chamber slightly scooped. Lateral nematothecae conical. Athecate internodes each with one nematotheca, located towards the middle; all nematothecae bithalamic and movable. Gonothecae not observed.

VARIABILITY

One branch given off instead of one hydrocladia in basal part of colony.

REMARKS

This species is characterized by the morphology of its hydrothecae, which are very shallow and with the plane of its aperture quite oblique ( Vervoort & Vasseur 1977). Material described by Vannucci Mendes (1951) and Grohmann et al. (2011), the only records of this species in the Atlantic, shows a different hydrothecal morphology and probably belongs to another species.

Plumularia fragilia Watson, 2012 very much resembles this species in morphology, including measurements and height of colonies. The only objective difference is the everted hydrothecal rim in P. fragilia . Revision of type material is needed before reaching a conclusion about their relationship.

Figures

FIG. 20.— Plumularia pseudocontraria n. sp.,MUSORSTOM 3, stn DR 117 (holotype):A, colony;B, detail of branch;C, two consecutive apophyses. Scale bars: A, 1 cm; B, C, 0.1 mm.

FIG. 21. — Plumularia pseudocontraria n. sp., MUSORSTOM 3, stn DR 117 (holotype): A, first hydrocladial internodes, lateral view; B, distal hydrocladial internodes, lateral view; C, D, internodes, frontal view. Scale bars: 0.1 mm.

FIG. 22.— Plumularia setacea (Linnaeus,1758),MUSORSTOM 4, stn CC 201,basal partof hydrocladia,lateralview.Scale bar:0.1 mm.

FIG. 23.— Plumularia spiralis Billard,1911,BENTHEDI,stn CH 13:A, colony;B, internode,lateral view;C, apophyses and first internode of hydrocladia; D, internode, lateral view. Scale bars: A, 1 cm; B-D, 0.1 mm.

FIG. 24. — Plumularia strobilophora Billard, 1913, MUSORSTOM 3, stn CP 121: A, colony; B, branch arising instead hydrocladia; C, internodes from distal part of hydrocladia, lateral view; D, internode, lateral view. Scale bars: A, 1 cm; B-D, 0.1 mm.