Euphysora luoyuanensis Xu, Huang & Yang, 2022

Liu, Zhiyong, Yang, Yanyan, Xu, Zhenzu & Huang, Jiaqi, 2022, A new species of medusae from Luoyuan Bay, Fujian, China, Zoological Systematics 47 (4), pp. 345-348 : 346-348

Euphysora luoyuanensis Xu, Huang & Yang , sp. nov. ( Fig. 1 )

Material examined. Holotype NMR-LY2001, Luoyuan Bay , Fujian, Station G 12 (26°23′59.11″N, 119°47′1.98″E), 7 August 2019, depth 40 m, coll. Zhiyong Liu. Paratypes. NMR-LY2002–2003, Luoyuan Bay , Station G 14 (26°24′55.76″N, 119°48′15.228″E), 7 August 2019, depth 49 m, coll. Zhiyong Liu.

Description. Umbrella 2.3 mm height (including apical projection), 1.3 mm width, nearly high bell-shaped, with a welldeveloped blunt solid apical projection, umbrella lateral walls thin, exumbrella surface smooth; manubrium large, with base wide, nearly flask-shaped, slightly exceeding beyond velar opening, without apical chamber, but with mouth tubular long, about 1/3 of length of manubrium; gonad almost encircling whole manubrium; mouth simply circular; 4 radial canals thick and broad, with vacuolated endodermal cells in radial canals; principal tentacle short and stiff, with 6–7 adaxial nematocyst knobs and with a large terminal nematocyst knob, three other perradial bulbs large, nearly oval-shaped, each with a small and short papilla-like tentacle; velum moderately wide.

Distribution. China Sea (Luoyuan Bay).

Etymology. The specific name is referring to the type locality, Luoyuan Bay, Fujian, China.

Remarks. At the present time, 27 valid species of Euphysora have been reported ( Bouillon, 1978; Huang, 1999; Bouillon & Boero, 2000; Xu & Huang, 2003, 2006; Bouillon et al., 2006; Du et al., 2010, 2013; Gershwin et al., 2010; Lin et al., 2013; Xu et al., 2014). The new species is similar to E. bigelowi , E. meijiensis and their congeners by having 3 rudimentary tentacles and 1 long principal tentacle, but different from E. bigelowi and E. meijiensis by the terminal of the principal tentacle short and inflexible, with 6–7 adaxial nematocyst knobs; another three perradial bulbs large, each with a short, papilla-like tentacle; manubrium flask-shaped with mouth tubular. It can also be distinguished from other species of Euphysora by: 1) exumbrella smooth, bell margin without medusa buds; 2) the terminal of principal tentacle without bifurcated branches; 3) the row of nematocyst knobs on principal tentacle adaxial; 4) umbrella with apical projection rather than apical chamber.

Key to worldwide species of the genus Euphysora .

1. Umbrella margin with medusa buds...................................................................................................... E. gemmifera Bouillon, 1978 * Umbrella margin without medusa buds................................................................................................................................................2

2. Exumbrella with wart processes or scattered nematocysts ...................................................................................................................3 Exumbrella without wart processes or scattered nematocysts.............................................................................................................. 4

3. Exumbrella with wart processes and brown pigment, three rudimentary tentacular bulbs with pigment ............................................... ............................................................................................................................................................... E. verrucosa Bouillon, 1978 * Exumbrella with dense scattered nematocysts clusters rather than wart processes and brown pigment, three rudimentary tentacular bulbs without pigment..................................................................................................................................... E. knides Huang, 1999 *

4. Only with one long and thin principal tentacle, with several bifurcated branches, without rudimentary tentacular bulbs ..................... .................................................................................................................................................................... E. gigentea Kramp, 1957 With one long tentacle and three small or rudimentary tentacular bulbs..............................................................................................5

5. Terminal of principal tentacle bifurcated twice ....................................................................................................................................6 Terminal of principal tentacle not bifurcated ....................................................................................................................................... 7

6. Principal tentacle long, each of four terminal branches with a nematocyst knob; opposite tentacle filiform, longer than another two tentacles ........................................................................................................................................................ E. furcata Kramp, 1948 * Principal tentacle short, four terminal branches without nematocyst knobs; other three tentacles short, conical-shaped ...................... ............................................................................................................................................................... E. valdiviae Vanhöffen, 1911

7. Principal tentacle moniliform, with numerous rings of nematocysts....................................................................................................8 Principal tentacle with a single row of nematocyst knobs..................................................................................................................15

8. Moniliform tentacle with number of prominent swelling knobs at irregular array..................................... E. gracilis (Brooks, 1882) * Moniliform tentacle without prominent swelling knobs.......................................................................................................................9

9. Moniliform tentacle with base thick and present 4–5 rings of nematocysts; rest part with over 16 spherical nematocyst knobs........... ..................................................................................................................................................... E. fujianensis Xu & Huang, 2006 * Moniliform pincipal tentacle with either a single row of nematocyst knobs or rings of nematocysts................................................ 10

10. Moniliform principal tentacle only with a single row of nematocyst knobs....................................................................................... 11 Moniliform principal tentacle only with rings of nematocysts........................................................................................................... 12

11. Moniliform principal tentacle with 9 spherical nematocyst knobs, opposite tentacle rudimentary, bulb-shaped, another two lateral tentacles long, filiform ................................................................................................................................. E. russelli Hamond, 1974 Moniliferm principal tentacle with over 16 nearly elliptic-like nematocyst knobs, other three tentacles rudimentary, four tentacular bulbs nearly cone-shaped ............................................................................................................. E. taiwanensis Xu & Huang, 2003 *

12. Umbrella without apical projection or apical canal; principal tentacle with a large spherical terminal nematocyst knob, opposite tentacle rudimentary, another two lateral tentacles cone-shaped, all tentacle bulbs extending to both lateral side ................................ ............................................................................................................................................................... E. solidonema Huang, 1999 * Umbrella with apical projection and apical canal .............................................................................................................................. 13

13. Moniliform principal tentacle without terminal nematocyst knob, other three tentacles cone-shaped, opposite tentacle longer than another two lateral tentacles...................................................................................................................... E. annulata Kramp, 1928 * Moniliform principal tentacle with terminal nematocyst knob........................................................................................................... 14

14. Principal tentacle with 3–10 rings and an elliptic-shaped terminal knob; opposite tentacle short and thick, another tentacles short clubshaped.............................................................................................................................................................. E. bitungensis Xu, Huang & Guo, 2013 Principal tentacle long and thin, with 10 distinct swellings and a terminal teardrop-shaped knob; other three tentacles simple, opposite tentacle about twice as long as another two ......................................................... E. juliephillipsi Gershwin, Zeidler & Davie, 2010

15. Principal tentacle with an abaxial row of nematocyst knob ...............................................................................................................16 Principal tentacle with adaxial or lateral row of nematocyst knobs ................................................................................................... 23

16. Manubrium thick and long, about half extends beyond velar opening, with broad base covering compact vacuolated endodermal cells; principal tentacle thin and long, with 30–40 abaxial nematocyst knobs and without terminal knob, other three rudimentary perradial bulbs very small with abaxial spurs .......................................................................................... E. vacuola Xu, Huang & Guo, 2012 * Manubrium shorter than bell cavity, base without vacuolated cells ...................................................................................................17

17. Principal tentacle with both hemicyclic nematocyst knobs and normal nematocyst knobs................................................................ 18 Principal tentacle only with normal nematocyst knobs, without hemicyclic nematocyst knobs ........................................................21

18. Umbrella with apical chamber ...........................................................................................................................................................19 Umbrella without apical chamber ...................................................................................................................................................... 20

19. Umbrella with apical projection; manubrium very large, filling in bell cavity; base of principal tentacle swollen on inner side, nearly round; marginal bulb opposite of main tentacle larger than another two.................................. E. apiciloculifera Xu & Huang, 2003 * Umbrella without apical projection; manubrium hat-shaped, connected to oval apical chamber by a short canal; 4 equal perradial marginal bulbs, swollen in inner side ................................................................................... E. pileiformis Xu, Huang & Guo, 2014 *

20. Principal tentacle thin and long, with over 100 abaxial nematocyst knobs; principal tentacle with elongated conical base and with 5– 6 hemicyclic cnidocysts cluster along their abaxial surface, other three perradial marginal bulbs smaller, short cone-shaped and bulbs extending as spurs slight up exumbrella surface .................................................................. E. multiknoba Xu, Huang & Guo, 2014 * Principal tentacle short, with 6 abaxial hemicyclic cnidocyst clusters and with a large spherical terminal nematocyst knob; main tentacular bulb large, nearly elliptical, other three rudimentary tentacular bulbs small ............................. E. abaxialis Kramp, 1962 *

21. Gonads on interradial side of manubrium, principal tentacle very long, with over 60 nematocyst knobs in abaxial side; other three marginal knobs rudimentary, very small, same size ....................................................................... E. interogona Xu & Huang, 2003 * Gonads surrounding manubrium wall ................................................................................................................................................22

22. Principal tentacle long, with 50–60 abaxial nematocyst knobs; other three rudimentary tentacular bulbs with 6–8 brown pigment spots on their abaxial clusters....................................................................................................................... E. brunnescentis Huang, 1999 * Principal tentacle short, with 12 abaxial nematocyst knobs; other three rudimentary bulbs without brown pigment spots ................... ........................................................................................................................................................ E. pseudobaxialis Bouillon, 1978

23. Umbrella without apical projection.................................................................................................................................................... 24 Umbrella with apical projection .........................................................................................................................................................25

24. Four radial canals thick and broad, with vacuolated endodermal cells in radial canals............. E. crassocanalis Xu & Huang, 2003 * Four radial canals narrow, without vacuolated endodermal cells in radial canal; principal tentacle with a large oval bulb and 3–6 adaxial nematocyst knobs, and end with a very large nearly oval terminal nematocyst knob, opposite tentacle very small, nearly papilla-shaped, another two filiform tentacles with lateral, cone-shaped bulbs ......................... E. macrobulbus Xu & Huang, 2003 *

25. Umbrella with apical chamber; principal tentacle with a long, hollow, sac-like basal bulb, and terminating with a large globular ball containing nematocysts and also three other globular clusters nematocysts uanilaterally arranged, three other marginal bulbs rudimeatary ............................................................................................................................................... E. normani (Browne, 1916) Umbrella without apical chamber ...................................................................................................................................................... 26

26. Principal tentacle long, with a small spherical bulb and over 10 adaxial nematocyst knobs, other three perradial tentacles long cone pointed, without filiform tentacles ............................................................................................................. E. bigelowi Maas, 1905 * Principal tentacle short and stiff, with several adaxial knobs ............................................................................................................. 27

27. Manubrium nearly globular, almost filling in bell cavity; principal tentacle with 4 adaxial nematocyst knobs and a spherical terminal knob, bulb of opposite tentacle long cone-shaped, as long as main tentacle, terminating with a large terminal red pigment patch, another two bulbs rudimentary, papilla-like, without filiform tentacle ...................................................... E. meijiensis Xu, Huang & Guo, 2013 * Manubrium nearly flask-shaped, with mouth tubular about 1/3 length of manubrium; principal tentacle with 6–7 adaxial nematocyst knobs and a large terminal knob, other three perradial bulbs large, oval-shaped, each with a short, papilla-like tentacle ..................... ................................................................................................................................... E. luoyuanensis Xu, Huang & Yang , sp. nov. *

Funding This work is suppoted by the Global Climate Change and Ocean Atmosphere Interation Research: Marine Biological Sample Museum (GASI-02-YPK-SW) and Study of Seagrass Resources and Environments Along Coastline of Fuqing (MEMRT202104).

Zhiyong Liu1, Yanyan Yang2 *, Zhenzu Xu3, Jiaqi Huang3 1Xiamen Ocean Center, Ministry of Natural Resources, Xiamen 361008, China

2 Third Institude of Oceanography, Ministry of Nature Resoures, Xiamen 361105, China

3 College of Ocean and Earth Science, Xiamen University, Xiamen 361102, China

* Corresponding author, E-mail: [e-mail]

Figures

Figure 1. Euphysora luoyuanensis Xu, Huang & Yang, sp. nov., lateral view, photo (A) and line-drawing (B). Scale bars=0.5 mm.