Leuckartiara longicalcar, Schuchert, 2018

Schuchert, Peter, 2018, DNA barcoding of some Pandeidae species (Cnidaria, Hydrozoa, Anthoathecata), Revue suisse de Zoologie 125 (1), pp. 101-127 : 120-123

Leuckartiara longicalcar n. spec.

Figs 14 , 15 A-C, 16

in part Leuckartiara octona . ‒ Mackie & Mackie, 1963: 68. [not L. octona ( Fleming, 1823) ]

Leuckartiara species. ‒ Arai & Brinckmann-Voss, 1980: 56, fig. 30.

Holotype: MHNG-INVE-98638; female; USA, San Juan Island , Friday Harbor, 48.54514° -123.01206°, depth 0.5 m; collection date 20.05.2011; preserved in formalin, subsequently transferred to ethanol.

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Paratypes: MHNG-INVE-78922, 9 specimens; USA, San Juan Island, Friday Harbor , 48.54514° -123.01206°, depth 0.5 m ; collection date 20.05.2011; one specimen used to isolate DNA 869; for GenBank numbers of sequences see Table 1 . ‒ MHNG-INVE-82312, 2 specimens; Canada, British Columbia, Salish Sea , 49.2505° -123.74867°, depth 0-50 m; collected by Moria Galbraith ; preserved in formalin, subsequently transferred to ethanol.

Additional data: Several photographs of living medusae taken by Kevin Lee off the coast of Palos Verdes, California, USA, 33.8211° -118.4569°, one of the photos is reproduced here in Fig. 16 .

Etymology: From the Latin longus, long, and calcar, spur, referring to the long abaxial spurs of the tentacle bulbs.

Type locality: USA, San Juan Island , Friday Harbor, 48.54514°N 123.01206°W .

Diagnosis: Leuckartiara medusa 15-20 mm total height, with large pointed apical process of about 1/3 to 2/5 of total bell height, umbrella higher than wide; up to 16-24 tentacles, between each tentacle pair 1-3 small, rudimentary bulbs, perradial and interradial tentacles with conspicuous, long, pointed abaxial spurs reaching up to 1/6 of the bell height; tentacles and bulbs lacking tentacles usually with small red abaxial ocelli. Manubrium about 1/2 of subumbrellar height, paleorange, with long mesenteries, mouth cruciform, mouth margin moderately ruffled. Gonads in adradial series of horizontal folds, distinct interradial connecting fold absent.

Description: Leuckartiara medusa up to 15-20 mm in height and about 10 mm in diameter when mature, with a large, pointed apical process of about 1/3 to 2/5 of total bell height, umbrella higher than wide. Interradial, subumbrellar pockets of variable size present.

Manubrium about half the height of the subumbrellar height, shaped like inverted vase, connected to radial canals via long mesenteries (about 1/3 of manubrium height). Manubrium base and mouth opening cruciform, mouth rim moderately ruffled.

Gonad tissue in 8 series of broad, adradial, horizontal folds, 8-12 folds in an adradial series, many folds with a central depression and resembling a loop or simply bifurcated ( Fig. 15A ). The two series of gonad folds of one quadrant usually not connected by a fold across the interradial region as in other congeners (thus without the H-form of the gonad folds, often described as “horse-shoe shape” in older publications, comp. Fig. 17C ). Sometimes an inconspicuous interradial connection of the two rows of folds may be present at the aboral end of the manubrium. No gonadal pits. Egg size about 0.1 mm. Radial canals slightly jagged and broad. Ring canal smooth, broad.

Tentacles usually 16, sometimes up to 24, between each tentacle pair 1-3 small, rudimentary bulbs without tentacles. Bases of tentacles laterally compressed, clasping bell margin. Perradial and interradial tentacle bases (oldest tentacles) with long, pointed abaxial spurs, reaching up to 1/6 of the bell height ( Fig. 15B ), shorter (younger) tentacles with short spur or no spur. Spurs appear solid, without internal canal. A small red ocellus present on most tentacles and also rudimentary bulbs, situated on abaxial side at interface of tentacle to exumbrella, in tentacles with long abaxial spurs ocelli at end of spur.

Colour: Manubrium pale orange, proximal parts of tentacles pale orange to yellowish, ocelli orange-red.

Nematocysts of tentacles microbasic heteronemes, ca. 4 x 7 μm.

Distribution: North-eastern Pacific, from Vancouver Island to Southern California.

Remarks: This species was described by Arai & Brinckmann-Voss (1980: 56) as Leuckartiara species distinct from L. octona . Dr Anita Brinckmann-Voss (pers. com., 2013) told me that she initially intended to name it in a subsequent publication, but was now unable to do it and encouraged me to do it myself.

Leuckartiara longicalcar does not match any of the known species ( Kramp, 1968; Pages et al., 1992; Xu & Huang, 2004; Schuchert, 2017). It has previously been misidentified as L. octona ( Fleming, 1823) and been considered related to L. zacae Bigelow, 1940 (see Arai & Brinckmann-Voss, 1980).

Leuckartiara octona is indeed similar in appearance, but lacks the long abaxial spurs and regularly has a fold across the interradial region connecting the adradial series of folds. The 16S and COI sequence data ( Figs 8-9 ) clearly separated L. longicalcar from the Atlantic L. octona , although they are closely related.

Leuckartiara zacae Bigelow, 1940 is a rare species first found in the Gulf of Panama. It is somewhat larger than L. longicalcar and has about the same number of tentacles. The most prominent difference is the length of the tentacle spurs: they are much longer and extend up to 2/3 of the bell height. Bigelow (1940) described them as exumbrellar ribs containing a thin gastrodermal canal. Additionally, L. zacae has no apical process (but Kramp (1965) observed a small process in a juvenile specimen from Indonesia, the identity of this material is perhaps questionable), the umbrella without the process is larger (21 versus 12 mm), the manubrium is more voluminous and has more gonadal folds. It is only known to occur in tropical seas ( Kramp, 1965).

Other Leuckartiara species with tentacle spurs are L. gardineri Browne, 1916 , L. acuta Brinckmann-Voss, Arai & Nagasawa, 2005 , and L. fujianensis Huang, Xu, Lin & Qiu, 2008 . All three have only four fully formed tentacles.

Kevin Lee (2017) published a series of magnificent photos of Leuckartiara medusae observed off Los Angeles, California. One of them is reproduced here ( Fig. 17 ). These medusae must clearly be referred to L. longicalcar n. spec. Some of the individuals are almost identical to the ones shown here, while others ( Fig. 17 ) appear somewhat larger, with up to 24 tentacles, and a more voluminous stomach. Some of the individuals have a more intense colour, appearing more reddish, and also the tentacle bases show some reddish pigments. The distribution of the species extends thus from Vancouver Island to Southern California.

Figures

Fig. 14. Leuckartiara longicalcar, n. spec., living animal (paratype), total height about 15 mm.

Fig. 15. Leuckartiara longicalcar, n. spec., living animal. (A) Details of manubrium with gonad folds. (B) Lateral view of a perradial tentacle with the characteristic, long, abaxial spur. (C) Adradial tentacles and rudimentary bulbs, note red ocelli.

Fig. 16. Leuckartiara longicalcar, n. spec., living animal, height 13-18 mm, photographed by Kevin Lee off Los Angeles, California, USA. Note, this photograph is copyright protected and permission to use it here has been obtained by paying a royalty fee to the author and copyright holder Kevin Lee (www.diverkevin.com).

Fig. 17. Leuckartiara spec., living animal. (A) Whole medusa. (B) Bell margin with tentacle bases. (C) Details of manubrium with gonad folds (immature?).

Fig. 8. 16S maximum likelihood phylogenetic tree of Pandeidae species obtained with PhyML (GTR+G+I model) and based on 595 bp positions of the mitochondrial 16S gene. Node-support values are bootstrap values of 100 pseudoreplicates (shown only if > 70%). For more details see text and Table 1. Samples based on the polyp stage are indicated, all others are medusa samples.

Fig. 9. COI maximum likelihood phylogenetic tree of Pandeidae species obtained with PhyML (GTR+G+I model) and based on 664 bp positions of the mitochondrial COI gene. Node-support values are bootstrap values of 100 pseudoreplicates (shown only if> 70%). For more details see text and Table 1. Samples based on the polyp stage are indicated, all others are medusa samples.