Cladocarpus integer (G. O . Sars, 1874)

Altuna, Álvaro, Murillo, Francisco J. & Calder, Dale R., 2013, Aglaopheniid hydroids (Cnidaria: Hydrozoa: Aglaopheniidae) from bathyal waters of the Flemish Cap, Flemish Pass, and Grand Banks of Newfoundland (NW Atlantic), Zootaxa 3737 (5), pp. 501-537 : 516-519

Cladocarpus integer (G. O. Sars, 1874)

( Figs. 1 D, 5A–F, tables 1, 6, 9, 11–12)

Aglaophenia integra G. O. Sars, 1874: 100 , pl. 2, fig. 11–15.—Hincks 1874: 128.—Kirchenpauer 1876: 25.—Storm 1879: 24.—Storm 1880: 122.—Storm 1882: 23.—Marktanner-Turneretscher 1890: 277.—Bonnevie 1898: 14.—Bonnevie 1899: 93.—Nutting 1900: 117.—Bonnevie 1901: 13.

Aglaophenia Moebii Schulze, 1875: 134 , pl. 2, figs. 3–5.—Kirchenpauer 1876: 25.

Cladocarpus Pourtalesii Verrill, 1879: 309 .—Whiteaves 1901: 28.

Cladocarpus Holmii Levinsen, 1893: 209 , pl. 8, fig. 15–18.—Saemundsson 1902: 70.

Cladocarpus Holmi : Vanhöffen 1897: 246.—Hartlaub 1900: 181.—Jäderholm 1909: 110.—Broch 1910: 207.—Kramp 1914: 1059.

? Aglaophenia pourtalesii: Bonnevie 1898: 13 , pl. 1, fig. 11, 11a–b.—Bonnevie 1899: 93.

Aglaophenia cladocarpa G. O. Sars , in Bonnevie, 1898: 14 (nomen nudum).

Cladocarpus pourtalesii: Bonnevie 1898: 14 .—Nutting 1900: 116, pl. 29, fig. 1–2.—Ritchie 1912: 230.—Kindle & Whittaker 1917: 233.—Cairns et al. 2002: 56.

Cladocarpus pourtalesius: Nutting 1900: 35 .

Cladocarpus holmii: Hartlaub 1905: 675 .—Linko 1912: 29, fig. 5.—Jäderholm 1919: 10.

Halicornaria integra: Jäderholm 1909: 109 .—Ritchie 1912: 228, fig. 6.

Cladocarpus Pourtalesi : Jäderholm 1909: 110.—Fraser 1918: 361.

Aglaophenia moebiusi: Bedot 1916: 44 .—Stechow 1919: 135.

Cladocarpus holmi: Hartlaub & Scheuring 1916: 82 .—Vervoort 1966: 149.—Naumov 1969: 523, pl. 19, fig. 5, fig. 376A–B.

Aglaophenia moebieusi: Bedot 1918: 61 .

Cladocarpus integer: Jäderholm 1919: 10 .—Kramp 1932a: 62.—Kramp 1935: 169, figs. 70, 71.—Kramp 1938: 39.—Kramp 1943: 44.—Vervoort 1966: 149.—Calder 1970: 1540, pl. 8.—Jägerskiöld 1971: 61.—Stepanjants 1989: 416.—Cornelius 1995: 208, fig. 49A–F.—Calder 1997b: 89.—Schuchert 2000: 413 (table 1).—Schuchert 2001: 140, fig. 120A–D.—Cairns et al. 2002: 22, 56.—Buhl-Mortensen & Mortensen 2005: 865.—Bouillon et al. 2006: 283.—Calder 2012: 63.—Moura et al. 2012: 721.

Cladocarpus pourtalesi: Fraser 1931: 7 .—Fraser 1944: 407, pl. 89, fig. 395a–c.—Fraser 1946: 414.—Vervoort 1966: 149.— Bouillon et al. 2006: 283.

Cladocarpus pourtelessii: Stepanjants 1989: 416 .

Material examined. FN3L06 L51, one fertile colony 56.0 cm high; FN3L06 L86, one fertile colony 62.0 cm high; PLA07 L61, one fertile colony 17.0 cm high; PLA07 L73, one sterile colony 13.2 cm high; PLA07 L75, one fertile colony 78.0 cm high; PLA07 L76, one sterile colony 45.0 cm high; PLA07 L77, one sterile colony 10.2 cm high; PLA07 L78, one fertile colony 10.0 cm high; PLA07 L80, one fertile colony 18.0 cm high; FC07 L23, one sterile colony 8.9 cm high; FC07 L123, one fertile colony 30.5 cm high; FN3L09 L80, one fertile colony 38.0 cm high; NEREIDA0509 RD7, one sterile colony 10.5 cm high; NEREIDA0509 RD9, one sterile colony 20.2 cm high; NEREIDA0610 RD62, one fertile fragment 1.7 cm high; NEREIDA0610 RD67, one fertile colony 8.0 cm high; NEREIDA0710 RD80, one sterile colony 4.7 cm high; NEREIDA0710 RD87, 2 sterile colonies, largest one 22.3 cm high; NEREIDA0710 RD88, 5 colonies, largest 41.8 cm high, 2 fertile; NEREIDA0710 RD89, 5 sterile colonies, largest one 25.3 cm high; NEREIDA0810 RD97, one sterile fragment 11.5 cm high; NEREIDA0810 RD98, one fertile colony 12.2 cm high; NEREIDA0810 RD99, 8 sterile colonies, up to 12.0 cm high; NEREIDA0810 RD100, one sterile colony 44.6 cm high.

Description. Colonies large, plumose, ramified, up to 78.0 cm high, arising from a hydrorhiza consisting of a network of tubules, supporting the stems. Stem polysiphonic basally (up to 4.0 mm wide), thinning out to monosiphonic distally. Ramification in one plane, up to the second order. Branches arising at acute angles, up to 40.0 cm long in large colonies, polysiphonic for most of their length. Stem and branches brown to yellowish in alcohol.

Main tube in front of stem and branches, divided into 820–890 µm long internodes by straight nodes.

Accessory tubes parallel, not jointed, without hydrothecae, but with numerous nematothecae. Internodes with one apophysis located almost in middle, directed alternately left and right, and two nematothecae: one frontal at base of apophysis, and another axillar.

Hydrocladia up to 3.5 cm long, abundant over entire colony, closely set, given off frontally at acute angles from apophyses of main tube, formed by up to 35 short internodes with 3–7 internal septa (normally 5–6) of varied length; perisarc thick. All internodes thecate, separated by more or less transverse nodes. Internodes with one hydrotheca and three nematothecae, all one-chambered and on frontal surface. Hydrothecae totally adnate to internode, inserting slightly obliquely, with walls almost parallel in side view and bulging deeply into lumen of hydrocladium. A small but stout intrathecal ridge arising from behind hydrotheca and pointing forwards. Margin even, with abaxial side slightly tilted downwards. Distal end of hydrothecae almost circular in cross section.

Nematothecae: one mesial and two laterals. Mesial adnate to hydrotheca except on first internode, not tapering distally in front view, with even to slightly crenulated margin, two internal septa, extending 1/3–1.2/3 up abcauline wall of hydrotheca. Laterals mostly adnate to internode and hydrotheca, with distal end free; aperture adcaulinar, with margin finely crenulated to almost smooth.

Phylactocarps up to 5.5 mm long, arising slightly laterally on first cormidium, one per hydrocladium, between hydrotheca and mesial nematotheca. Not ramified, jointed, formed by a first small internode, and a series of up to 8 similar internodes, 550–700 µm long and 180–250 µm wide, separated by more or less transverse nodes, with a short apophysis and two nematothecae. Nematothecae consisting of one basal and two distal ones on either side of apophysis; margin finely crenulated. Each phylactocarp with up to 8 gonothecae; gonothecae obovate, curved towards phylactocarp with lateral aperture near distal end. Sex indeterminable.

Remarks. Cladocarpus pourtalesii Verrill, 1879 and C. holmii Levinsen, 1893 are generally considered synonyms of C. integer (Broch 1918; Schuchert 2001). Hydroids of all three nominal species have the basal regions of the hydrothecae bulging into the lumen of the hydrocladium (see Naumov 1969, fig. 376), and the shape of the thecate internodes is much alike ( Figure 5 C). Putative differences include the development and position of the mesial nematotheca on the thecate internodes, as well as the shape of the hydrothecae. Illustrations of C. holmii from Davis Strait by Levinsen (1893), in his original description of the species, leave no doubt about its synonymy with C. integer . However, the basal regions of the hydrothecae of “ Aglaophenia pourtalesii ” from Norway, as illustrated by Bonnevie (1898), do not bulge into the internode, although the hydrothecal margin is clearly entire. If C. holmii and C. pourtalesii are indeed conspecific with C. integer , then the position of the mesial nematotheca is decidedly variable. According to Naumov (1969), it may be attached posterior to the base of the hydrotheca (as in C. pourtalesii ), or it can be fused to the abcauline wall of the hydrotheca (as in C. holmii ). No colonies belonging to the type of the former nominal species were seen during our study.

Due to the occasional absence of phylactocarps, or their development as simple, unbranched phylactogonia, C. integer has been considered a primitive species of the genus (Broch 1918). Cladocarpus pourtalesii has sometimes been distinguished from C. integer in having unbranched phylactocarps rather than unprotected gonangia (Nutting 1900). Otherwise, Nutting’s description of the species fully agrees with material of C. integer as first described by G. O. Sars (1874, pl. 2, fig. 12). Phylactocarps were present in all of the material we have seen, although we found some fertile colonies of Aglaophenopsis cornuta and Cladocarpus formosus lacking phylactocarps.

The size of the colony collected at station PLA07 L75, attaining 78.0 cm high, is considered exceptionally large. In previous reports, Nutting (1900) mentioned colonies of up to ca. 46.0 cm, Kramp (1932a) 23.0 cm high, and Schuchert (2001) 20.0 cm high.

Cladocarpus integer was recorded growing on Primnoa resedaeformis off Atlantic Canada by Buhl-Mortensen & Mortensen (2005), although no specific location was given.

Observed depth range: 119–1339 m. This is the deepest record of the species. A neritic-bathyal species according to Calder (1997b).

Fertile material. Collected in August 2006 (240–617 m depth), June and July 2007 (300–957 m depth), August 2009 (425–426 m depth), and from June to August 2010 (600–1100 m depth).

Distribution. Kramp (1938) considered C. integer as an Atlantic species, penetrating to some extent into arctic regions. It is known from the Barents Sea (Naumov 1969), Norway (Bonnevie 1898; Jäderholm 1909, ca. 183–365 m), Skagerrak (Kramp 1935, 80– 90 m), Iceland (Broch 1918, ca. 254–260 m; Kramp 1938, 190– 260 m; Schuchert 2001, 86– 748 m), the east (Broch 1918, ca. 384 m) and west (Broch 1918, ca. 740–1096 m; Jäderholm 1919, 63°47’N – 52°26’W, ca. 64 m; Kramp 1932a, 66º17’N – 54º36’W, 97 m; Schuchert 2001, 191– 195 m) coasts of Greenland, Davis Strait (Levinsen 1893, ca. 150–188 m; Broch 1918, ca. 150 m), Port Burwell (Ungava Bay) (Fraser 1931, 1944, no depth given), off northeast Newfoundland (Calder 1970, 457 m), eastern Canada (Kindle & Whittaker 1917, ca. 205–548 m, based on literature records), Atlantic Canada, no specific location (Buhl- Mortensen & Mortensen 2005, no depth given), Flemish Cap and Grand Banks (present study), three stations southeast of Cape Canso (Fraser 1944, ca. 164–243 m), Banquereau and southwest of Cape Sable (Nova Scotia) (Verrill 1879, ca. 205–548 m; Nutting 1900; Whiteaves 1901; Fraser 1918, 1944), and from off northern Florida to southwest of Cape Sable (Nutting 1900, ca. 164–548 m, Albatross stations 2474, 2479, 2666, 2698; Fraser 1944).

Figures

FIGURE 1. Distribution of the five aglaopheniid species in the study area. A) Aglaophenopsis cornuta (Verrill, 1879). B) Cladocarpus diana Broch, 1918. C) Cladocarpus formosus Allman, 1874. D) Cladocarpus integer (G. O. Sars, 1874). E) Nematocarpus ramuliferus (Allman, 1874). FC, Flemish Cap; FP, Flemish Pass; GB, Grand Banks.

FIGURE 5. Cladocarpus integer (G. O. Sars, 1874). A) Colony. B) Detail of a hydrocladium. C, D) Hydrothecae; D corresponds to the distalmost cormoid. Note distinctive bulging into lumen of hydrocladium. E, F) Phylactocarps with gonothecae; note on the first thecate internode that there is a distinct gap between distal end of nematotheca and hydrothecal base. Scale bar: A = 5.0 cm; B, D, F = 500 µm; C = 200 µm; E = 1000 µm. A = PLA 07 L 75; B – F = PLA 07 L 61.