Lipkea stephensoni Carlgren, 1933

Miranda, Lucília S., Branch, George M., Collins, Allen G., Hirano, Yayoi M., Marques, Antonio C. & Griffiths, Charles L., 2017, Stalked jellyfishes (Cnidaria: Staurozoa) of South Africa, with the description of Calvadosia lewisi sp. nov., Zootaxa 4227 (3), pp. 369-389 : 384-386

Lipkea stephensoni Carlgren, 1933

( Fig. 11 )

Lipkea stephensoni Carlgren, 1933: 1 –15, figures 1–14; Carlgren 1935: 19, 23; Kramp 1961: 299; Grohmann et al. 1999: 386; Pisani et al. 2007: 7; Zagal et al. 2011: 652, 663, 664; Miranda et al. 2016b: 20, 26, 32, 38.

Material examined. Iziko South African Museum MB-A083794, 2 specimens, Onrust River, Overberg, Western Cape, South Africa (-34.4196, 19.1801), January 1992, intertidal pools, under rock, ethanol 70%, col. & det. C. Griffiths . Not kept, 2 specimens, Smitswinkel Bay , False Bay , Cape Town, Western Cape, South Africa (-34.2743, 18.4728), between 1990–2003, depth 3–4 m, observed by G. Spiby. Not kept, 3 specimens, False Bay (between Partridge Point and Castle Rocks), Cape Town, Western Cape, South Africa (-34.2457, 18.4795), April 2012, depth 23 m, observed and photographed by G. Jones.

Information on type material. The holotype is probably S185, from Still Bay, Eden, Western Cape, South Africa (type locality), found in pool under stones. The material is listed in the “University of Cape Town Ecological Survey” but could not be located in the Iziko South African Museum’s collection.

Description. (complemented with Carlgren 1933). Calyx elongated, funnel-shaped ( Fig. 11 ). Peduncle singlechambered, with four interradial longitudinal muscles. Four interradial septa visible in calyx ( Fig. 11 D, F, G). Variable number of marginal lappets (arms?), with reduced (rudimentary) tentacles in one row along their margin ( Fig. 11 A–C), although some specimens with smooth marginal lappets ( Fig. 11 D–G). Gastrovascular cavity not divided by claustrum. Manubrium with four perradial lips ( Fig. 11 B, D, G). Numerous gastric filaments in gastrovascular cavity. Gonads embedded in gastrovascular cavity of subumbrella, not extending into marginal lappets (confined to basal part of calyx) ( Fig. 11 B, D, G). Perradial and interradial anchors absent. Pad-like adhesive structures absent. Coronal muscle entire ( Fig. 11 D, E). White spots of nematocysts on subumbrellar surface, margin of calyx, and marginal lappets ( Fig. 11 ). General color of body pinkish white ( Fig. 11 ). Total body length about 8.0 to 16.0 mm.

Distribution and habitat. The type locality for L. stephensoni is Still Bay, Eden, Western Cape, South Africa ( Carlgren 1933). These new records are also in the Western Cape: Onrust River, Overberg; between Partridge Point and Castle Rocks, False Bay, Cape Town; Smitswinkel Bay, False Bay, Cape Town ( Fig. 5 F). The species was recorded from intertidal pools to 23 m deep, attached to rocks.

Remarks. There are three valid species in the genus Lipkea : Lipkea ruspoliana Vogt, 1886 , Lipkea sturdzii ( Antipa, 1893) , and Lipkea stephensoni Carlgren, 1933 . Lipkea ruspoliana was originally recorded from a single specimen from Alghero, on the Sardinian coast of the Mediterranean Sea ( Vogt 1886, 1887). The Sardinian specimen was defined by its peculiar morphology, with eight marginal lappets in the perradii and interradii with mucous glands, but without tentacles ( Vogt 1886, 1887). New specimens recently found in aquaria of the Oceanographic Museum of Monaco have 8–12 adradial lappets ( Pisani et al. 2007), raising questions about intraspecific variation and the homology of these structures with arms and primary tentacles/anchors ( Miranda et al. 2016b).

Capria sturdzii Antipa, 1893 was described based on one specimen from Capri Island, Gulf of Naples, Italy, being the only species of the genus Capria and the family Capriidae ( Antipa 1893). Carlgren (1933) synonymized Lipkea and Capria , proposing the name Lipkea sturdzii (see also Kramp 1961). Lipkea sturdzii has not been observed since its original description, but it differs from L. ruspoliana by the presence of a row of 16–20 toothlike or short finger-shaped rudimentary tentacles, which are fused one to another by a web ( Antipa 1893; Mayer 1910).

Finally, Lipkea stephensoni is the only formally described Lipkea species outside of Europe. The species was also described based on a single specimen from Still Bay, Eden, South Africa ( Carlgren 1933), characterized by eight adradial short lappets with 30–40 reduced tentacles in one row along their margin ( Fig. 11 A–C). However, the additional specimens that we observed show that the number of marginal lappets is variable in L. stephensoni ( Fig. 11 ; as seems to be common in Lipkea species, Pisani et al. 2007; Zagal et al. 2011), as is the presence of the rudimentary marginal tentacles ( Fig 11 C, E). The original description of L. stephensoni was based on a specimen found in the intertidal zone ( Carlgren 1933), but photographs of not-kept L. stephensoni stauromedusae revealed that specimens from deeper water (about 23 m deep) have rudimentary tentacles in the lappets ( Fig. 11 A–C), whereas intertidal and subtidal specimens ( Fig. 11 D–G) have smooth marginal lappets, similar to those of L. ruspoliana , indicating either an intraspecific variation in L. stephensoni or the existence of an additional (new) species, a hypothesis that cannot be tested until more specimens become available.

Indeed, the identification of Lipkea species is difficult ( Zagal et al. 2011), based on subtle differences (presence or absence, and number and distribution of reduced tentacle-like structures along the margin of each lappet, Zagal et al. 2011) that have never been tested in a phylogenetic context. In addition, there is little information on intraspecific variation ( Vogt 1886, 1887; Pisani et al. 2007) and no information on morphological changes during development. As a consequence, there are numerous unidentified records around the world, including specimens from Australia ( Zagal et al. 2011), New Zealand ( Cairns et al. 2009), and Japan ( Miranda et al. 2016b). Australian specimens seem to have a similar morphology to L. stephensoni , with a single row of 18–27 reduced tentacles along the margin of the lappets ( Carlgren 1933; Zagal et al. 2011), although, as discussed, it is equivocal whether the presence of rudimentary tentacles should be considered a diagnostic character ( Uchida 1929; Zagal et al. 2011). Therefore, the validity of described and possibly new Lipkea species remains to be vigorously tested in further investigations.

Figures

FIGURE 5. Geographic distribution of South African stauromedusae. A: Global distribution of Calvadosia capensis (South Africa and Brazil); B: Global distribution of Depastromorpha africana (South Africa, Australia, and New Zealand) *; C: Local distribution of C. lewisi sp. nov. (endemic from South Africa); D: Local distribution of C. capensis; E: Local distribution of D. africana; F: Local distribution of L. stephensoni (endemic from South Africa). Based on Carlgren (1933, 1935, 1938); Zagal et al. (2011); Miranda et al. (2012 b); and new records provided in this study. * Records of D. africana outside South Africa need confirmation of their identity (see text and Miranda et al. 2016 b).

FIGURE 11. Lipkea stephensoni Carlgren, 1933, living specimens in the field. A, B, D, F, G: Exumbrellar and subumbrellar views of different specimens; C: Detail of marginal lappet with rudimentary tentacles; E: Detail of marginal lappet without rudimentary tentacles. Abbreviations: cl, calyx; cm, coronal muscle; gd, gonad; isp, interradial septum; lp, marginal lappet; mn, manubrium; pe, peduncle; rt, rudimentary tentacles; ws, white spots of nematocysts. Photo credits: Georgina Jones (A – C); Geoff Spiby (D – F); Charles Griffiths (G; Iziko South African Museum MB-A 083794).