Cirrhitiara superba ( Mayer, 1900 )

Schuchert, Peter & Collins, Richard, 2021, Hydromedusae observed during night dives in the Gulf Stream, Revue suisse de Zoologie 128 (2), pp. 237-356 : 244-247

Cirrhitiara superba ( Mayer, 1900)

Figs 4 A-D, 5

Tiara superba Mayer, 1900: 34 , pl. 16 fig. 39.

Tiara pileata var. superba . – Mayer, 1910: 126, pl. 27 fig. 8, pl. 28 figs 3-4.

Tiara pileata f. superba . – Vanhöffen, 1913a: 416.

Cirrhitiara superba . – Hartlaub, 1914: 284, fig. 237. – Kramp, 1959a: 121, fig. 122. – Kramp, 1961: 97. – Kramp, 1968: 39, fig. 101.

not Cirrhitiara superba . – Thiel, 1938: 296, fig. 2. – Kramp, 1953: 267. – Van der Spoel & Bleeker, 1988: 167, fig. 8.

Examined material: BFLA4087 ; 1 specimen; 07 -MAY-2019; preserved in ethanol for DNA extraction; 16S sequence MW528672 . – 30-JUL-2018; 1 specimen photographed; not collected.

Observations: Pandeid medusa 7 mm high and 5 mm wide, bright pink manubrium and tentacle bulbs, apical process of variable size present, apical exumbrella with perradial furrows. Manubrium filling more than half of the volume of the subumbrella, mouth rim complexly folded. Gonads on stomach forming folds diverging from interradial, in each quadrant two adradial series of folds that are connected interradially by a transverse fold. Four broad radial canals, connected to stomach via funnel-like widenings. Four long, tapering, perradial tentacles, base laterally compressed and clasping bell margin, no abaxial spur, large red abaxial ocellus near abaxial end. Alternating with the tentacles three small bulbs, each with an abaxial ocellus and a thin cirrus usually originating laterally from bulb. All small bulbs of equal size.

16S Data: The partial 16S gene sequence ( MW528672 ) obtained was used to search for similar sequences in GenBank using the blastn function. Similar sequences found were mostly from Leuckartiara species and other Pandeidae , giving sequence identities in the 90% range. However, there was also one sequence ( MH361354 ) which had only a single mismatch in 599 aligned bases (99.8% identity, = 0.2 % divergence), a value which certainly represents intraspecific variation (reference values for Pandeidae acc. Schuchert, 2018, table 2). The matching sequence was obtained from a hydroid originating from Caribbean Sea close to Panama and identified as Thecocodium spec. ( Miglietta et al., 2018b). The hydroid is described and depicted in the supplementary material of Miglietta et al. (2018b) It is a polyp lacking tentacles. The typical capitate dactylozooids of the genus Thecocodium were not observed, which means that it could also belong to other genera with hydroids lacking tentacles, e.g. Hydrichthys ( Pandeidae , see Schuchert, 2007).

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The obtained 16S sequence did not cluster with any other genus of Pandeidae for which there were sequences available ( Fig. 8 ), but this is due to the poor resolving power of the 16S marker above the genus level.

Remarks: Cirrhitiara superba has only rarely been reported. The identity of the present material is beyond doubt as it matches very well the descriptions in Mayer (1900, 1910). Moreover, it comes from the same region and the same continental shelf region as the type material.

Thiel (1938) identified a small (1 mm) juvenile medusa from Brazil as C. superba . His specimen had eight tentacles, the interradial ones being less developed. There were also 8 to (?) 16 rudimentary bulbs, each with a lateral cirrus. The presence of interradial tentacles – even less developed – argues against this being C. superba . Neither Mayer (1900, 1910) nor we observed interradial tentacles in C. superba . Vanhöffen (1913a), who had mostly young medusae obtained from Mayer, speaks of 8 tentacles in his largest medusae, but he was likely referring to both types of tentacles, viz. four large ones and four cirri.

Kramp (1953) thought that two medusae collected near the eastern coast of Australia belonged to C. superba despite they lacked cirri. Additionally, the interradial bulbs were larger than the adradial ones and no ocelli were observed. This makes the identification rather doubtful. The medusae are perhaps referable to Leuckartiara fujianensis Huang, Xu, Lin & Qiu, 2008 or Leuckartiara neustona Xu & Huang, 2004 .

The medusa shown in Van der Spoel & Bleeker (1988: fig. 8) originating from Indonesia had thick cirri and 8 long tentacles and thus unlikely belong to the present species.

Distribution: Florida, Bahamas ( Mayer, 1910). Records from Brazil ( Thiel, 1938), north-eastern Australia ( Kramp, 1953), and Indonesia ( Van der Spoel & Bleeker, 1988) are likely misidentifications (see above). Type locality: USA, Florida, Dry Tortugas archipelago.

Figures

Fig. 4. Cirrhitiara superba, specimen BFLA4087, bell height 7 mm. (A-B) Lateral view. (C-D) Close up of bell margin, note cirri (arrow in C).

Fig. 8. 16S rRNA maximum likelihood phylogenetic tree of Pandeidae species obtained with PhyML (GTR+G+I model) and based