Capnea georgiana (Carlgren, 1927)

Rodríguez, Estefanía & López-González, Pablo J., 2013, <strong> New records of Antarctic and Sub-Antarctic sea anemones (Cnidaria, Anthozoa, Actiniaria and Corallimorpharia) from the Weddell Sea, Antarctic Peninsula, and Scotia Arc </ strong>, Zootaxa 3624 (1), pp. 1-100 : 30-36

Capnea georgiana (Carlgren, 1927)

( Figs. 14–17 ; Table 7; Appx. 1, 2)

non Actinia nymphaea Dana, 1846 .

Leiotealia nymphaea Hertwig, 1882a , b.

Aureliana [sic] georgiana Carlgren, 1927 : Carlgren 1949.

Aureliania tricirrata Carlgren & Stephenson, 1929 .

Condylanthus aucklandicus Carlgren, 1924 : Grebelny 1975.

Capnea georgiana: Dunn 1983 .

TABLE 7. Size ranges of the cnidae of Capnea georgiana (Carlgren, 1927) ; for comparative cnidae data of the species see Dunn (1983). Χ: mean. SD: standard deviation. S: ratio of number of specimens in which each cnidae was found to number of specimens examined. N: total number of capsules measured. F: Frequency, +++ = very common, ++ = common, + = rather common, --- = sporadic. Abbreviations: Mc, Microbasic. (*) Mean values based in fewer than 40 capsules.

(1) Named as basitrichs by Dunn (1983).

MATERIAL EXAMINED

Polarstern ANT XV/3: stn. PS48/027 (AMNH-4339, 1 specimen); stn. PS48/058 ( BEIM: ANT-4320, 1 specimen) ; stn. PS48/071 ( BEIM: ANT-4397, 1 specimen) ; stn. PS48/167 ( BEIM: ANT-4365, 2 specimens) .

Polarstern ANT XVII/3 : stn. PS56/166-1 (AMNH-4463, 1 specimen) ; stn. PS56/178-2 ( BEIM: ANT-4364, 1 specimen; AMNH-4583, 4 specimens; BEIM: ANT-4464, 3 specimens; AMNH-4466, 1 specimen); stn. PS56/ 183-1 ( BEIM: ANT-4363, 1 specimen; AMNH-4456, 1 specimen); stn. PS56/184-1 (AMNH-4362, 15 specimens) .

Polarstern ANT XIX/3 : stn. PS61/98-1 ( BEIM: ANT-4060, 3 specimens); stn. PS61/105-1 (AMNH-4138, 1 specimen) .

Polarstern ANT XXI/2 : stn. PS65/019-1 ( BEIM: ANT-4967, 1 specimen); stn. PS65/274-1 (AMNH-4941, 1 specimen) .

DIAGNOSIS

Pedal disc well developed, diameter to 50 mm. Column smooth, firm to delicate, to 50 mm diameter and 54 mm height in preserved specimens. Column usually pyramidal in contracted specimens, often contracted in the middle also in relaxed specimens, divided into scapus and short capitulum. Fosse well developed. Living specimens with whitish to light orange proximal column, with periderm marginally; column orange distally, with orange spots; tentacles light orange with darker orange longitudinal stripes. Delicate preserved specimens light purple whereas tough specimens are beige in colour. Tentacles distinct, very short and lobate, to 192; tentacles distinctly arranged in six cycles, forming rows of four or more tentacles per endocoel alternated with rows of two tentacles per exocoel. Marginal sphincter muscle endodermal, strong and circumscribed, with wide central mesogleal lamella. More mesenteries proximally than distally. Mesenteries arranged to five cycles, first four cycles perfect and fertile, fifth cycle sterile and asynchronic. Only one siphonoglyph. Retractor muscles strong, circumscribed, with mesogleal pennon; parietobasilar muscles well developed, with long mesogleal pennon extending to the base of retractor muscles. Cnidom: Spirocysts, basitrichs, and microbasic p -mastigophores. For a complete description of Capnea georgiana , see Dunn (1983).

GEOGRAPHIC AND BATHYMETRIC DISTRIBUTION

Capnea georgiana is distributed in Antarctica in the Ross Sea and the Drake Passage , although its type locality is in the sub-Antarctic region, in the Kerguelen Islands (Hertwig 1882a, b). The depth range of C. georgiana is 421– 2,186 m, although most records are between 500– 1,200 m depth ( Dunn 1983) .

The new material of this study confirms the species in the Drake Passage and the South Shetland Islands, and extends its geographic and bathymetric distribution to the eastern Weddell Sea and Bouvet Island, between 182– 2,228 m depth.

Capnea georgiana is a circumpolar Antarctic and sub-Antarctic species, inhabiting continental shelf and bathyal depths ( Fig. 14b ).

REMARKS

Capnea georgiana is a very distinct species because of its short and lobate tentacles. It usually lives burrowed in the sediment, showing only the extended oral disc. Based on a survey using underwater photography in the eastern Weddell Sea (Rodríguez unpubl. data), this species is more abundant than expected from collected specimens.

Family HALOCLAVIDAE Verrill, 1899

Genus Stephanthus Rodríguez & López-González, 2003

Figures

FIGURE 14. Distribution map of species. a) Isotealia antarctica Carlgren, 1899. b) Capnea georgiana (Carlgren, 1927). c) Stephanthus antarcticus Rodríguez & López-González, 2003. d) Liponema multiporum Hertwig, 1882. e) Dactylanthus antarcticus (Clubb, 1908). f) Actinostola crassicornis (Hertwig, 1882). Green triangles, type locality; green circles, previous localities; red circles, localities from this study; yellow circles, localities from this study from underwater photography survey; dark line, Subtropical Front; light line, Polar Front.

FIGURE 15. External anatomy of Capnea georgiana (Carlgren, 1927). a–d) Underwater photographs of specimens in situ; note that C. georgiana lives burrowed in the sediment and only the most distal part of the body is visible. e) Oral view of living specimen [BEIM(ANT-4363)]. f) Detail of the oral disc of living and semi-contracted specimen [AMNH-4941]. g) Oral view of the distal margin of the column in a living specimen [AMNH-4941]. h) Lateral view of living specimen [AMNH-4941]. Scale bars: a, f, h, 20 cm; b, d, 50 mm; c, 10 cm; e, 30 mm; g, 25 mm.

FIGURE 16. External anatomy of Capnea georgiana (Carlgren, 1927). a) Lateral, oral, and basal view of preserved specimens [AMNH-4362]. b) Detail of lateral view of preserved specimen [AMNH-4362]. c) Oral view of preserved specimen [AMNH- 4362)]. d) Detail of the pedal disc of preserved specimen [AMNH-4941]. e–f) View of the oral disc of a preserved specimen showing the distinct tentacles and their arrangement [AMNH-4941]. Scale bars: a, c–e, 20 mm; b, f, 10 mm.

FIGURE 17. Cnidae of Capnea georgiana (Carlgren, 1927). a–d, f–i, k) Basitrichs. e) Spirocyst. j, l, m) Microbasic p- mastigophores.