Chrysaora kynthia, Gershwin, Lisa-Ann & Zeidler, Wolfgang, 2008

Gershwin, Lisa-Ann & Zeidler, Wolfgang, 2008, Some new and previously unrecorded Scyphomedusae (Cnidaria: Scyphozoa) from southern Australian coastal waters, Zootaxa 1744, pp. 1-18 : 4-7

Chrysaora kynthia , sp. nov.

(Plates 1, 2)

Chrysaora sp.— Marsh & Slack-Smith 1986: 35 –36, 38–39, fig. 27; Perth region, WA. – Williamson et al. 1996: 226. — Gershwin & Collins 2002: 129 , 130, 133; as C. sp. #1 (morphological phylogenetic comparison with congeners).

Material examined. Holotype: WAM Z9944, South Mole, Fremantle, WA, coll. K. Usher, at surface, 7.ii.2000; male (BD 86.1 mm).

Paratypes: WAM Z4749, Hall Bank, Fremantle, WA, 30–40 feet, dead coral bank, 25.i.1980; fragmented immature specimen (BD 47.5 mm). WAM Z4750, Cockburn Sound, WA, coll. D. Parker, 25.ii.1971; female (BD 112.1 mm). WAM Z4751, City Beach, Perth area, WA, coll. D. Curry, 16.iii.1985; 3 specimens in poor condition (BD 53.9, 72.4 & 83.7 mm). WAM Z4752, washed ashore in shallows near Palm Beach, Cockburn Sound, WA, coll. A. Paterson, 27.xii.1970; immature specimen (BD 70.5 mm). WAM Z4753 & Z4757, Woodman’s Groin, Cockburn Sound, WA, depth 1 m, coll. N. Coleman, 4.iii.1972; two males (BD 106.4 & 95.5 mm). WAM Z4754, Applecross, in Swan River Estuary, WA, coll. S. De la Hunty, 30.i.1975; immature?male (BD 54.5 mm). WAM Z4755, near Kwinana wreck, Cockburn Sound, WA, coll. L. Marsh, 16.i.1980; male (BD 78.4 mm). WAM Z4756, Woodman’s Point, Cockburn Sound, WA, coll. Science Teacher’s Association, 18.iii.1972; male (BD 91.4 mm). WAM Z4758, Palm Beach, Rockingham, Cockburn Sound, WA, coll. A. Paterson, Jan. 1971; female (BD 111.7 mm).

Diagnosis. Chrysaora with 24 tentacles, with inner core sometimes pleated; exumbrellar rhopalial cone wide, tapering, not open to rhopalium; radial gastric septa bent, not S-shaped; gonads delicate and inverted Wshaped; lacking any pigmentation or star pattern.

Description. Bell flatter than a hemisphere, retained specimens to 112 mm BD, but reported to 200 mm ( Marsh 1986). Exumbrella finely granulated with microscopic transparent warts throughout and extending onto lappets, or concentrated in center, lacking peripherally, appearing smooth to naked eye. Subumbrella smooth over radial gastric pouches, possessing microscopic, scattered, transparent warts over manubrium and oral arms.

PLATE 1. Chrysaora kynthia , sp. nov., in life.

Tentacles 24 (reported variable to 32 by Marsh and Slack-Smith 1986), in eight groups of three between adjacent rhopalia (Plate 2A), laterally flattened throughout length; hollow, with inner core simple and ribbonlike, or pleated, resembling a non-enclosing row of honeycomb.

Radial gastric pouches 16, of equal width at stomach, but tentacular pouches approximately twice as wide as rhopaliar pouches at margin (Plate 2B). Gastric cirri attached to floor of stomach within looping of gonad. Radial gastric septa with smooth or jagged edges; with simple to elongated teardrop-shaped proximal terminus; straight throughout most of length, widening in outer quarter toward rhopalium, with distal terminus at midpoint of lappet between rhopalium and nearest tentacle.

Rhopalia eight, four perradial and four interradial, on the end of long, finger-like base (Plate 2C), within niche formed by adjacent lappets, open on the subumbrellar side; exumbrellar rhopalial cone wide, tapering, blind-ending over rhopalium. Marginal lappets 32, of equal size, evenly rounded.

Oral arms four, perradial, approximately 1– 2 x BD in length; simple, folded in half, with loosely crenulated margins. Manubrium short, approximately half BD in life. Subgenital ostia oblong, longer than width of corresponding radial gastric pouch. Gonads four, interradial, contained within subgenital ostia; delicate and lacy, lacking robustness; inverted W-shape, with ends looping back towards center of bell; serving as a partition between gastric and genital cavities.

Color in life ghostly bluish-whitish, transparent to translucent, lacking any pigmentation or star pattern; preserved specimens colorless, slightly translucent, with pinkish gonads.

PLATE 2. Chrysaora kynthia , sp. nov., holotype. A, subumbrellar view, in preserved state. (Scale = 5 mm). B, subumbrellar margin. C, rhopalium. (Scale = 0.5 mm).

Etymology. From the Greek “ Kynthia ,” the goddess of the moon (feminine, noun in apposition), in recognition of its lunar appearance.

Stinging ability. According to Marsh and Slack-Smith (1986) this species is a severe stinger, producing general as well as local symptoms.

Distribution. Chrysaora kynthia has been found from Rockingham to Perth, Western Australia, including, occasionally, the Swan River estuary, but it seems to be most commonly found near Woodman’s Point, Cockburn Sound, in the summertime. It is intriguing that, as a pelagic animal, it has not been reported farther north or south.

Remarks. Chrysaora kynthia can easily be distinguished from its congeners by a total lack of pigmentation, by its delicate and lacy W-shaped gonads, easily visible through the body, and its blind-ending exumbrellar rhopaliar pits.

The genus Chrysaora was recently reviewed by Gershwin and Collins (2002), in which C. kynthia was included as Chrysaora sp. #1. Based on analysis of 20 characters, C. kynthia was part of an unresolved clade of 24-tentacled species which grouped separately from those species with 40 tentacles, the latter often historically referred to the genus Dactylometra .