Zygophylax lighti, Gu & Ruthensteiner & Moura & Liu & Zhang & Song, 2022

Gu, Zhangjie, Ruthensteiner, Bernhard, Moura, Carlos J., Liu, Lihua, Zhang, Rui & Song, Xikun, 2022, Systematic affinities of Zygophylacidae (Cnidaria: Hydrozoa: Macrocolonia) with descriptions of 15 deep-sea species, Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 196, pp. 52-87 : 68-70

ZYGOPHYLAX LIGHTI GU & SONG SP. NOV.

( FIGS 12 , 13A, B , 14A )

Z o o b a n k r e g i s t r a t i o n: urn: lsid: zoobank. org:act: 536BAF1F-9924-41D1-AF33-6612D85F206A.

Type locality: South China Sea ; 921–1816 m.

Etymology: The specific name honours Professor Sol Felty Light (1886–1947) who served as the chairman of the Department of Zoology at Xiamen University from 1922 to 1924, and memorizes the centenary celebration of the biological disciplines in Xiamen University. Light’s systematic studies on marine invertebrates initiated the early development of marine science at the Xiamen University.

Type material: Holotype, XUMB7904 , fertile; paratype, XUMB7905 , fertile; see Supporting Information, Table S1 .

Other material: Thirty-five infertile colonies deposited separately, each specimen containing one colony (XMUB7863, XMUB7869, XMUB7906– XMUB7938), also collected from South China Sea. See details in Supporting Information, Table S1 .

Figures

Figure 12. Type material of Zygophylax lighti sp. nov.A, a colony; B, hydrothecal arrangement; C, two axillary hydrothecae and four gonothecae; D, magnification of an axillary hydrotheca; E, magnification of nematothecae (arrow); F, I, hydrotheca, the arrow in I indicates a nematotheca; G, J, magnification of the indentation (arrows); H, magnification of an oblique hydrothecal diaphragm (arrow); K–M, gonothecae; N, gonotheca with dichotomous defensive tubes; O, magnification of a node (arrow) on the defensive tubes. A–O: XMUB7904, holotype, South China Sea. A–H, K, L, light microscope images; I, J, M–O, SEM images. Scale bars:A = 5 mm; B, C = 1 mm, D, F, I, M, N = 200 µm; E, G, H = 100 µm; J, O = 50 µm; K, L = 500 µm.

Figure 13. Hydrothecal arrangement and gonothecae of three new species. A, B, Zygophylax lighti sp. nov.; C, D, Z. pseudosibogae sp. nov.; E, F, Z. tankahkeei sp. nov. A, C, E, hydrothecal arrangement, the bases of hydrothecal pedicels are unilateral arranged, and the distal hydrothecal ends alternately turn left and right, respectively; B, D, F, gonothecae (with defensive tubes). Scale bars: A–F = 500 µm.

Figure 14. Morphological comparisons of selected zygophylacids with curved hydrothecae. A, Zygophylax lighti sp. nov.; B, Z. tankahkeei sp. nov.; C, Z. pseudosibogae sp. nov.; D, E, Z. sibogae Billard, 1918; F, Z. unilateralis Totton, 1930; G, Z. convallaria (Allman, 1877); H, Z. infundibulum Millard, 1958; I, Z. concinna (Ritchie, 1911); J, Z. reflexa (Fraser, 1948); K, Z. adhaerens (Fraser, 1938), hydrothecal basal portion is adherent on the hydrocladium; L, Z. tizardensis Kirkpatrick, 1890; M, Z. kakaiba Campos, Marques, Puce & Pérez, 2016; N, Z. curvitheca Stechow, 1913; O, Cryptolaria prima Busk, 1858, the hydrotheca is almost completely immersed in the hydrocladium. A, XMUB7904, holotype; B, XMUB6200-1, holotype; C, ZSM 20220300, holotype; N, ZSM 20043572, paralectotype. The following images were redrawn from the related original descriptions: D, Schuchert (2003); E, Billard (1918); F, Totton (1930); G, Allman (1877); H, Millard (1958); I, Ritchie (1911); J, Fraser (1948); K, Fraser (1938); L, Kirkpatrick (1890), Hirohito (1995); M, Campos et al. (2016); O, Busk (1858), Ralph (1958). All arrows indicate hydrothecal indentations. Scale bars: A–D, F–I, L–O = 500 µm; E, J, K, unknown.