Sarsia tubulosa, M. Sars, 1835

Wang, Xiao, Chen, Xiao-Yin & Xu, Zhen-Zu, 2022, Two new species and four new records of the Sarsia tubulosa group of Sarsia (Cnidaria, Corynidae) from the Bohai Sea of China, Zootaxa 5189 (1), pp. 243-254 : 251-253

Sarsia tubulosa (M. sars, 1835) ( Fig. 8 )

Oceania tubulosa M. Sars, 1835: 25 , pl. 5 Fig. 11.

Syncoryne decipiens Dujardin, 1845: 275 , pl. 14~15.

Sarsia mirabilis L. Agassiz, 1849: 224 , pl. 4~5.

Sarsia litorea Hartlaub, 1907: 32 , Figs. 23~24; Mayer, 1910: 53, Fig. 13.

Sarsia pulchella Hartlaub, 1907: 34 , Fig. 27.

Sarsia reticulata Hartlaub, 1907: 45 , Figs. 41~43: Kramp, 1961: 31.

Sarsia tubulosa Forbes, 1848: 55 , pl. 6 Fig. 2 ; Hartlaub, 1907: 19, Figs. 10~14; Mayer, 1910: 53, pl. 3 Figs. 2 ~5, pl. 4, Figs. 1 ~2; Russell, 1953: 55, Figs. 21~23; Kramp, 1959: 78, Fig. 10; Kramp, 1961: 32; Kramp. 1968: 6, Fig. 2 ; Calder, 1972: 223, pl. 1, Fig. 8 ; Edwards, 1978: 301, Figs. 4 ~5; Arai & Brinckmann-Voss, 1980: 25, Fig. 12; Schuchert, 2001: 813, Fig. 29 A-F; Bouillon et. al., 2004: 100, Fig. 53 A-J;Sheng et al. 2018;1418.fig1~5.

Material examined: Holotype ( FIO-HCCS06 ), paratypes ( FIO-HCCS07 ), two samples from Station 5-1 (39°51’20.09”N, 119°31’42.20”E, depth 2.2 m) and 4-3 (119°34' 19.52”N, 39°53' 16.54”E, depth 9.5 m) in the Bohai Sea of China. April 2020, collected by Wang Xiao.

Description. Holotype. Umbrella is bell-shaped, about 4~ 5 mm in width and height, jelly moderately thick, thicker at apex, with interradial exumbrellar furrows. The manubrium very extensive, can extend beyond the bell orifice when completely contracted ( Fig. 8A, B ), reaching 2~3 times as long as the bell when fully extended ( Fig. 8C ). Apical knob of variable shape is usually present, apical canal usually absent. Manubrium consists of a long slender tubular proximal part and a capacious distal stomach terminating in a round tubular thick-walled oral part armed with nematocysts. Gonad encircles the long thin part, leaving the proximal part of manubrium uncovered (less than 1/5 of bell height in mature animals), and gonad ends distally at beginning of stomach. Radial canals enter gastrodermal chambers of bulbs on abaxial side and pass through mesogloea. Tentacle bulbs large, gastrodermal chambers high, arching-shaped, epidermal nematocyst ring incomplete, with abaxial black or red ocelli. Each bulb has a very long tentacle, covered by nematocyst clusters or spiral rings, terminal cluster of nematocysts spherical, but not enlarged. Preserved medusa are mostly pale orange to reddish.

Biology: This medusa is known to feed on mesoplankton and macroplankton such as copepods, mysids, amphipods, euphausiids and occasionally other medusae such as Aurelia (Aral & Brinckmann-Voss, 1980) . Daan (1986) investigated its food intake, growth, and ecology and Van (1985) and Purcell (1986) focused on its ecological and potential economic impact on commercially important fish larvae.

Distribution:The Bohai Sea and northern Yellow Sea of China. It is a circumpolar boreal neritic species and has been recorded in the Atlantic, Indo-Pacific, and Mediterranean.

Remarks. The life cycle of Sarsia tubulosa has been examined several times, commencing with Schulze (1873), but Edwards (1978) provided a particularly detailed and valuable account.

Sarsia tubulosa is a variable species with a complicated synonymy which has been widely discussed ( Hartlaub,1907; Kramp,1926; Russell,1953; Edwards,1978, 1983; Aral & Brinckmann-Voss, 1980), even two or three species with different life cycles has been accounted into S. mirabilis which is confusing ( Edwards, 1978). While we do not discuss them here, some ambiguities in distinguishing this species remain, particularly in relation to the different color morphs of the medusa stage.

While Sarsia mirabilis is regarded as a subjective synonym of Sarsia tubulosa (Schushert, 2001) . The specific characteristics of Sarsia tubulosa are similar to that of Sarsia viridis Brinckmann-Voss, 1980 , which also has a distinct proximal part of the manubrium that is <1/2 the subumbrella height. Despite the similarities, Sarsia tubulosa can be differentiated from similar species by: 1) its short gonad-free portion of the manubrium, about 1/6 of manubrium; 2) exumbrella with interradial furrows; and 3) the highly variable colors of bulbs and apical knob (see Table 1).

Figures

FIG. 8 Sarsia tubulosa (M. sars, 1835) A. and B. Lateral view, after preserved specimen from the Bohai sea of China; C. tentacular bulbs in frontal view; D. tentacle bulbs in lateral view; (C–D after Edwards, 1978).

FIG. 2 Sarsia bohaiensis Xu, Wang, & Chen sp. nov. A and B.lateral view; C. tentacle bulbs in frontal view.; D. tentacle bulbs in lateral view.

FIG. 1 Map of the study area

FIG. 4 Sarsia apicula Murbach & Shearer, 1902 A. and B. lateral view; C.Tentacle bulbs in frontal view; D.Tentacle bulbs in lateral view.(C.D. after Murback & Shearer, 1902)