Catablema multicirratum Kishinouye, 1910

Schuchert, Peter, 2018, DNA barcoding of some Pandeidae species (Cnidaria, Hydrozoa, Anthoathecata), Revue Suisse de Zoologie 125 (1), pp. 101-127 : 118-120

Catablema multicirratum Kishinouye, 1910

Figs 12-13

Catablema multicirrata Kishinouye, 1910: 24 .

Catablema multicirrata . ‒ Bigelow, 1913: 19, pl. 1 figs 4-7. ‒ Hartlaub, 1914: 321. ‒ Kramp, 1926: 91, pl. 2.‒ Uchida, 1927: 213. ‒ Uchida, 1933: 130 fig. 6. ‒ Uchida, 1940: 286. ‒ Uchida, 1969: 286. ‒ Arai & Brinckmann-Voss, 1980: 44, fig. 20. ‒ Wang et al., 2014: 99, fig. 12.

Catablema multicirratum . – Kramp, 1961: 96. – Kramp, 1968: 50, fig. 133

Perigonimus multicirratus . – Naumov, 1969: 204, fig. 71.

Perigonimus breviconis . – Naumov, 1969: 204, fig. 72. [not Neoturris breviconis ( Murbach & Shaerer, 1902) ]

a variant of C. vesicularium and named it Catablema vesicarium var. nodulosa . Bigelow observed tentacle numbers of 14-25 tentacles, but the numbers were often difficult to establish as there was a continuum of sizes from mere knobs to fully grown tentacles. Hartlaub (1914: 321), Foerster (1924), and Kramp (1926, 1968) regarded Catablema vesicarium var. nodulosa Bigelow, 1913 as a synonym of C. vesicarium .

Arai & Brinckmann-Voss (1980) did not agree and raised the variant to full species level. They distinguished Catablema nodulosum from C. vesicarium solely on account of the lower tentacle number, being only 8-16 instead of 32. The shape of the gonads as argued by Bigelow (1913) was deemed unsuitable to distinguish the two species and I concur. Arai & Brinckmann- Voss (1980) based their decision on medusae from the southern limit of this genus, thus perhaps with a suboptimal growth. This could perhaps also explain the lower tentacle number compared to C. vesicarium , which is an Arctic species. Bigelow (1913), who had medusae from cooler waters (Aleutian Islands), founded his variety on animals having up to 25 tentacles. It is therefore reasonable to follow Bigelow, Hartlaub, and Kramp and regard C. nodulosum only gradually different from C. vesicarium , representing a local variant only. Moreover, tentacle numbers in Pandeidae medusae vary considerably and are deemed mostly unsuitable to delimit

Type locality: Paramushir Island , Kuril Islands, Pacific Ocean .

Material examined: 1 specimen, not in permanent collection; USA, Friday Harbor Laboratories , floating docks, 48.54514° -123.01206°, 0.5 m depth; collection date 19.05.2011; depicted in Fig. 12; DNA isolate 868; GenBank numbers of sequences see Table 1. ‒ Tissue samples and photos of two medusae here identified as Catablema cf. multicirratum from north of Svalbard obtained from Aino Hosia (University Museum of Bergen); the rest of the medusae in the collections of the Bergen Museum. The collection data are given in Table 1 .

Diagnosis: Catablema medusa with umbrella height and diameter 30 to 65 mm including large dome-like apical projection corresponding to about half the total bell height. Manubrium with very broad, quadrangular base, long mesenteries, mouth margin variably folded, gonadal folds oblique to vertical, few or no pits. Mature animals with 80 to 160 tentacles, without or only few marginal bulbs between tentacles in adult specimens. Radial canals relatively short but very broad and with large, complex lateral outgrowths. No ocelli observed. Stomach and marginal bulbs light orange in living specimens.

Hydroid not known.

Remarks: Catablema multicirratum was somewhat inadequately described by Kishinouye (1910), with the sole diagnostic character distinguishing it from C. vesicarium being the tentacle number, given as “several hundreds.” This must certainly be erroneous. Bigelow (1913) then described and illustrated new material from the Bering Sea and the Gulf of Alaska. The species was subsequently also recorded from the west coast of Greenland by Kramp (1926). The Atlantic medusae were distinctly smaller, but had the same high number of tentacles. Although the species has been reported regularly (see Arai & Brinckmann- Voss, 1980; Wang et al., 2014), only a few specimens have been documented. It seems that it has sometimes also been confused with N. breviconis (e.g. Naumov, 1969). According to our current knowledge the tentacle number permits a reliable separation of C. vesicarium and C. multicirratum .

The Pacific specimen of Catablema multicirratum used for this study was identified based on Arai & Brinckmann- Voss (1980). The single animal was very large, reaching 6.5 cm in height ( Fig. 12) and had approximately 100 tentacles. It was thus easily separable from the Catablema vesicarium nodulosum ( Fig. 11) found at the same place. The two medusae from Svalbard ( Fig. 13) were smaller and had denser tissues with a darker orange colour than the Pacific specimen.

While morphologically separable, the status of the species remains somewhat problematic when using 16S, COI, and ITS sequence data. 16S and ITS sequences cannot be used to separate C. multicirratum from C. vesicarium ( Fig. 8; Table 2). COI has about three times higher divergence values than 16S and permits to discern somewhat more structure in the Catablema clade ( Fig. 9). The Pacific Catablema multicirratum separates from both, C. vesicarium and the Atlantic C. multicirratum . The Atlantic form is thus perhaps also an independent lineage and it was therefore named here C. cf. multicirratum .

The BOLD barcode database contains some additional COI sequences of Catablema samples, mostly identified as C. vesicarium . The origin of the material is from the Pacific and Atlantic coasts of Canada, but unfortunately the identifications are unreliable and the accompanying photos virtually useless. Due to the doubtful identities, Material examined: MHNG-INVE-97018; hydroid colony, young medusae, and medusae cultivated to maturity (31 days) by Takanori Suehiro; Japan, Mie, Honshu, Toba City, intertidal zone, 34.47806°N 136.8675°E; date collected 09.05.2014; DNA sample 1208; for GenBank number of sequences see Table 1.

Remarks: The material used to obtain the DNA sample and the details of the life cycle will be described by Suehiro & Kubota (2018).

The morphology of the adult medusa corresponds to Leuckartiara octonema , except for the presence of ocelli on the rudimentary bulbs. Therefore, the species was provisionally identified as Leuckartiara cf. octonema only, pending further sequence comparisons with specimens from near the type locality.

these sequences were therefore not included in the analyses of this study. Adding nevertheless these sequences to the ML-analysis (results not shown), the results remain similar to the one shown in Fig. 9. Catablema appears to be split into three clades with relatively low divergences: C. vesicarium , C. multicirratum , and Catablema from Svalbard.

However, it must be concluded that more Catablema samples with a thorough documentation and identification of the specimens are needed before any reliable conclusion is possible. Markers with more resolving power (e.g. microsatellites) might be necessary to settle the status of all nominal Catablema species. It is still possible that they all represent only different age groups and local variants.