Voragonema tatsunoko, Lindsay, Dhugal & Pagès, Francesc, 2010

Lindsay, Dhugal & Pagès, Francesc, 2010, Voragonema tatsunoko (Trachymedusae: Rhopalonematidae), a new species of benthopelagic medusa, host to the hyperiid amphipod Mimonectes spandli (Physosomata: Mimonectidae), Zootaxa 2671, pp. 31-39 : 32-33

Voragonema tatsunoko sp. nov.

( Figs. 1 , 2 , 3 )

Synonymy. “ Voragonema sp.” in Lindsay & Miyake 2009, 2K1337SS 6g, 2K1337SS6h.

Type material. Two specimens collected immediately above the sea floor at 1967 m depth (temperature 2.17˚C, salinity 34.58, dissolved oxygen concentration 2.3 ml/L) at 15:18 and 15:24 by a suction sampler outfitted to the crewed submersible Shinkai 2000 on 7 April 2002 during dive number 1337 at 34˚ 43.21'N, 138˚ 35.06'E. The holotype [2K1337SS 6g] has been deposited at the Showa Memorial Institute, National Science Museum, Tokyo, under registration number NSMT-Co-1533. The paratype is deposited in the JAMSTEC biological sample collection under registration number 2K1337SS6h (048250).

Additional material examined. The holotype of V. l a c i n i a t a Bouillon, Pagès & Gili 2001, deposited in the Zoologisches Institut und Zoologisches Museum der Universität Hamburg ( Germany). One individual of V. laciniata [ NIWA 35989] sampled by the National Institute of Water and Atmospheric Research, New Zealand, in a non-closing Rough-bottom (orange roughy) trawl (ORH) that trawled the seafloor at 916–930 m depth on 12 February 2008 at Ross Sea Station TAN0802/41 (74.7˚S, 167.0˚E) as part of Oceans Survey 2020 for the International Polar Year and the Census of Antarctic Marine Life ( CAML).

Etymology. The specific epithet tatsunoko (Japanese) means “child of the dragon” and refers to the legendary dragon king, whose palace is at the bottom of the sea.

Figures

FIGURE 1. Specimen of Voragonema tatsunoko with the hyperiid amphipod Mimonectes spandli Stephensen and Pirlot, 1931 attached [paratype: 2 K 1337 SS 6 h]. Specimen collected at 15: 24: 36 above muddy sediment in Suruga Bay at 1967 m depth on 7 April 2002 and photographed in an aquarium on board ship. Voragonema tatsunoko: lateral (A), apicolateral (B), and oral (C) views; scale: 10 mm.

FIGURE 2. Lateral views of the holotype of Voragonema tatsunoko [2 K 1337 SS 6 g], collected at 15: 18: 15, under darkfield illumination (A) and transmitted light (B), and the paratype [2 K 1337 SS 6 h] under transmitted light after removal of the parasitoid amphipod (C). Note the striations on the external surface of the exumbrella (A), reminiscent of those in Crossota rufobrunnea (Kramp, 1913); scale: 10 mm.

FIGURE 3. (A) Lateral view of the holotype of Voragonema tatsunoko [2 K 1337 SS 6 g], collected at 15: 18: 15; scale: 1 mm. (B) detail of the bell margin of the paratype [2 K 1337 SS 6 h], from the external surface showing the proximal part of the autotomized marginal tentacles superimposed in several rows together; scale: 1 mm.