Bolocera kerguelensis Studer, 1879

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 : 14-18

Bolocera kerguelensis Studer, 1879

( Figs. 3 , 6–7 ; Table 3; Appx. 1, 2)

Bolocera kerguelensis: Studer 1879 ; Andres 1883; Kwietniewski 1896; Carlgren 1928; Carlgren 1949; Dunn 1983. Polystomidium patens Hertwig, 1882a , b.

Bolocera occidua McMurrich, 1893 ; Carlgren 1949; Carlgren 1959.

Bolocera longicornis Stephenson, 1918a ; non Carlgren 1891; Carlgren 1893; non Stephenson 1918b.

Bolocera capensis Carlgren, 1928 ; Carlgren 1938.

Bolocera patens Carlgren 1949 .

Bolocera tuediae occidua: Riemann-Zürneck 1980 ; Riemann-Zürneck 1991 b.

Bolocera paucicornis Dunn 1983 .

Bolocera tuediae kerguelensis: Riemann-Zürneck 1986a ; Riemann-Zürneck 1990.

MATERIAL EXAMINED

Polarstern ANT XV/3: stn. PS48/141 ( BEIM: ANT-4280, 2 specimens) ; stn. PS48/167 (AMNH-4448, 1 specimen); stn. PS48/338 (AMNH-4236, 2 specimens).

Polarstern ANT XVII/3 : stn. PS56/150 (AMNH-4518, 1 specimen; AMNH-4519, 1 specimen); stn. PS56/ 165 (AMNH-4542, 1 specimen; BEIM: ANT-4631, 19 specimens; AMNH-4632, 8 specimens; AMNH-4541, 1 specimen); stn. PS56/166-1 (AMNH-4476, 5 specimens) ; stn. PS56/178-2 ( BEIM: ANT-4633, 30 specimens; AMNH-4634, 15 specimens; AMNH-4635, 15 specimens; AMNH-4636, 25 specimens; AMNH-4637, 25 specimens; BEIM: ANT-4638, 25 specimens; BEIM: ANT-4639, 20 specimens); stn. PS56/183-1 (AMNH-4467, 3 specimens) ; stn. PS56/184-1 (AMNH-4509, 1 specimen).

Polarstern ANT XIX/3 : stn. PS61/98-1 (AMNH-4023, 1 specimen) ; stn. PS61/114-1 (AMNH-4129, 12 specimens); stn. PS61/121-1 (AMNH-4107, 1 specimen).

Polarstern ANT XIX/4 : stn. PS61/132-3 ( BEIM: ANT-4048, 1 specimen); stn. PS61/139-5 (AMNH-4199, 3 specimens) .

Polarstern ANT XIX/5 : stn. PS61/145 ( BEIM: ANT-4669, 1 specimen) ; stn. PS61/150 (AMNH-4653, 5 specimens); stn. PS61/153 (AMNH-4658, 5 specimens).

Polarstern ANT XXI/2 : stn. PS65/109-1 (AMNH-4910, 1 specimen; AMNH-4911, 1 specimen; AMNH- 4912, 1 specimen; AMNH-4913, 1 specimen) .

DIAGNOSIS

Pedal disc circular, to 40 mm diameter. Column short, to 30 mm height, funnel shaped, with very large, slightly convex oral disc to 104 mm, partially to completed covered by about 160 tentacles. Tentacles deciduous, with marginal endodermal sphincter in base, in six cycles. Column and tentacles dark pink to orange in living specimens, yellowish to tan when preserved. To five cycles of thin mesenteries equally developed along column, first cycles perfect and fertile (plus some pairs of third cycle) except directives; no oral or marginal stomata. Retractor muscles diffuse, parietobasilar muscles with large detached pennons. Basitrichs of mesenterial filaments to 69 µm long. Cnidom: spirocysts, basitrichs, and microbasic p -mastigophores. For a complete description of Bolocera kerguelensis , see Riemann-Zürneck (1980) and Dunn (1983).

GEOGRAPHIC AND BATHYMETRIC DISTRIBUTION

Bolocera kerguelensis is distributed around the Southern Ocean. Records are concentrated in areas where sampling effort has been higher: both sides of South America under 35ºS, Scotia Arc and Antarctic Peninsula, Ross Sea, Kerguelen Islands and South Africa (?). The depth range of the species is broad, from 45– 3,500 m, although is more abundant between 100– 1,000 m ( Dunn 1983).

The examined specimens occur within the previously known range, Scotia Sea and Antarctic Peninsula, but also in the eastern Weddell Sea, between 200– 3,947 m. Specimens from the Weddell Sea represent the first record of this species in the area and the deepest bathymetric collection extending the range to almost 4,000 m.

Bolocera kerguelensis is considered a Southern Ocean wide spread species from continental shelf and bathyal depths ( Fig. 3d ).

TABLE 3. Size ranges of the cnidae of Bolocera kerguelensis Studer, 1879 ; 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.

REMARKS

Dunn (1983) describes Bolocera paucicornis as a sympatric species of B. kerguelensis based mainly on the different size classes of basitrichs in the tentacles ( B. paucicornis has two sizes classes whereas B. kerguelensis has only one). Dunn (1983) provides additional differential characters for B. paucicornis : lack of microbasic p - mastigophores in the actinopharynx, tentacles covering the entire oral disc up to the mouth, and a convex oral disc. According to Dunn (1983), B. kerguelensis has microbasic p -mastigophores in the actinopharynx, tentacles are restricted to the margin of the oral disc, and the oral disc is flat. The specimens examined in this study show the above characters without any of the consistency expected for indicating different species. All examined specimens have the two size classes of basitrichs in the tentacles described for B. paucicornis , however, they all also simultaneously have microbasic p -mastigophores in the actinopharynx (although in low frequency: three specimens only had six of these capsules). Among specimens from one collection event we found specimens with tentacles restricted to the margin and others with the tentacles covering the entire oral disc; in the latter, we found, although in very low numbers, microbasic p -mastigophores in the actinopharynx.

Genus Epiactis Verrill, 1869

Figures

FIGURE 3. Distribution map of species. a) Overview. b) Actinernus antarcticus (Carlgren, 1914). c) Aulactinia sulcata (Clubb, 1902). d) Bolocera kerguelensis Studer, 1879. e) Epiactis georgiana Carlgren, 1927. f) Glyphoperidium bursa Roule, 1909. Green triangles, type locality; green circles, previous localities; red circles, localities from this study; dark line, Subtropical Front; light line, Polar Front. AP, Antarctic Peninsula; DP, Drake Passage; RS, Ross Sea; SS, Scotia Sea; WD, Weddell Sea.

FIGURE 6. External anatomy of Bolocera kerguelensis Studer, 1879. a–c) Oral view of preserved specimen [AMNN-4911], [AMNH-4910], [AMNH-4913]. d) Detail of the oral disc with marks of autotomized tentacles [AMNH-4910]. e) View of distal margin of the column in preserved specimen [BEIM(ANT-4008)]. f) Detail of the pedal disc in preserved specimen [AMNH- 4913]. Scale bars: a, 30 mm; b, e, 25 mm; c, d, 20 mm; f, 45 mm.

FIGURE 7. Cnidae of Bolocera kerguelensis Studer, 1879. a–d, f–i, k, l) Basitrich. e) Spirocyst. j, m) Microbasic p- mastigophore.