Tintinnopsis estuariensis Zhang, Feng & Yu, 2014

Zhang, Wu-Chang, Feng, Mei-Ping, Yu, Ying, Chen, Xu-Miao & Xiao, Tian, 2014, A new tintinnid ciliate (Ciliophora: Spirotrichea) from Yangtze River Estuary, with notes on its habitat, Zoological Systematics 39 (3), pp. 372-379 : 375-378

Tintinnopsis estuariensis Zhang, Feng & Yu , sp. nov. ( Figs 2–3 , Tables 1–2)

Diagnosis. The species is distinguished from other species by: cylindro-conical shaped lorica with a lateral flattened posterior portion ( Fig. 2 ).

Note. Min, minimum; Mean, arithmetic mean; Max, maximum; SD, standard deviation; CV, coefficient of variation in %. © Zoological Systematics, 39(3): 372–379 Note. Min, minimum; Mean, arithmetic mean; Max, maximum; SD, standard deviation; CV, coefficient of variation in %.

Description. Lorica 124–176 μm long and 55–72 μm wide orally (measured in this paper), totally covered with flakes of mineral particles ( Figs 2–3 ); cylindro-conical shaped with a lateral flattened posterior portion and open at both ends ( Fig. 2 ); the upper 44%–71% of the lorica cylindrical and the lower 29%–56% flattened; flare 6–26 μm long at the oral end and no collar; aboral opening diameter along the major axis 13–37 μm, aboral opening diameter along the minor axis 7–23 μm ( Table 1); oral rim round and the aboral end ragged ( Fig. 3 ).

Holotype, China, Yangtze River Estury (31.5°N, 122.2°E), September 2005, Wu-Chang Zhang , deposited in the Key Laboratory of Marine Ecology and Environmental Sciences , Institute of Oceanology, Chinese Academy of Sciences . Paratypes 20 individuals, same data as holotype.

Habitat. The species is found in the estuary of Yangtze River, China. Temporally, T. estuariensis Zhang, Feng & Yu , sp. nov. was most abundant in September, 32 410 ind./m 3 in max. The species also occurred in May and November with maximum abundance of 17 070 ind./m 3 and 1 357 ind./m 3 respectively. No individuals were found in February. T. estuariensis Zhang, Feng & Yu , sp. nov. occurred in waters with a surface temperature of 14–27°C ( Fig. 5 ).

By analyzing surface salinity of 40 stations ( Figs 4–5 ), T. estuariensis Zhang, Feng & Yu , sp. nov. can be alive in water with a surface salinity of 3.9‰–29.8‰, especially water with surface salinity below 21‰, which has abundance larger than 800 ind./m 3.

Etymology. The species name estuariensis reflects its the typical location.

Comparison. The new species is similar with several species of Tintinnopsis on the tube shape and lorica size, a comparison is provided (Table 3, Fig. 6 ). The new species differed from its congeners due to the lateral flattened posterior portion, the vertical aboral opening and the wider oral opening.

© Zoological Systematics, 39(3): 372–379

Remarks. Although most taxonomic studies on tintinnids have been based on the lorica, there are reports of large variations in the shape of loricae in the same species in the genera Favella , Parafavella and Ptychocylis (Laval-Peuto, 1981; Davis, 1978, 1981). Therefore, modern taxonomy of tintinnid requires cytological characteristics such as infraciliature. However, there are no reports on a large variation in lorica shape in the genus Tintinnopsis . These data should be added in future research.

Funding This study was supported by the National Basic Research Program of China (973 Program) (2011CB409804) and the National Natural Science Foundation of China (U1406403).

Figures

Fig. 2. Tintinnopsis estuariensis Zhang, Feng & Yu, sp. nov., six different individuals with same scale. Scale bar=50μm.

Fig. 3. SEM images of major axis in Tintinnopsis estuariensis Zhang, Feng & Yu, sp. nov. Scale bars: A=100μm; B – C=10 μm.

Fig. 5. Surface water temperature (T, C) and salinity (S, ‰) in the sampling sites during four cruises in the estuary of Yangtze River in 2005. Different sizes of circles indicates different abundances (ind./ m3) of Tintinnopsis estuariensis Zhang, Feng & Yu, sp. nov. in the sampling site, and the solid dots means no individual were found in the according site.

Fig. 4. Distribution of surface temperature (T, C), salinity (S, ‰) and abundance (Abun, ind./ m3) in May, September and November of 2005.

Fig. 6. Tintinnopsis estuariensis sp. nov. and its allied species. A. T. estuariensis; B. T. akkeshiensis; C. T. sufflata; D. T. kofoidi; E. T. radix; F. T. cylindrical. B and C after Hada (1937); D after Hada (1932a, b, 1937), Balech (1948), Alder (1999) and Zhang et al. (2012b); E after Kofoid and Campbell (1929), Xu and Song (2005); F after Kofoid and Campbell (1929) and Zhang et al. (2012a). Scale bar=50μm.