On the consortium of the tintinnid Eutintinnus and the diatom Chaetoceros in the Pacific Ocean
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The morphology and distribution of the diatoms Chaetoceros tetrastichon and Ch. dadayi as epiphytes on the loricae of the tintinnids Eutintinnus apertus and E. pinguis investigated in the open waters of the Pacific Ocean. The Eutintinnus–Chaetoceros consortia was encountered in 38 of the 52 sampling stations from 34°N to 33°S, and together were among represented the most wide-spread species. The abundance was low with a maximum of 32 consortia l−1 and E. apertus was often the most abundant species of the genus. The free-living Eutintinnus congeneric species showed a wider vertical distribution, whereas E. apertus–Chaetoceros tended to be near the surface. The success of E. apertus in consortium with Chaetoceros may be due to increase of the clearance rate and/or the lower susceptibility to predation. Chaetoceros modifies its morphology to adapt the epiphytic life, especially Ch. dadayi. The shorter curved setae may facilitate the transfer to the lorica of the daughter tintinnid after the cell division. The free-living Ch. tetrastichon and Ch. dadayi are very rare and Chaetoceros remained attached to empty loricae or encysted tintinnid cells. This suggests that the Eutintinnus–Chaetoceros consortium is obligate for the success of the diatom and renders the tintinnid more competitive versus congeneric species.
KeywordsKuroshio Current Congeneric Species Prochlorococcus Oral Diameter Oligotrophic Water
The studies in the NE and equatorial Pacific were supported by a fellowship of the European Commission (ICB2-CT−2001-80002) held at the University of Tokyo with K. Furuya as host. I am grateful to the scientists and crew of R/V Soyo Maru (Nat. Res. Inst. Fish. Sci.), R/V Hakuho Maru (ORI, Tokyo University), R/V Mirai (JAMSTEC) and R/V L’Atalante (IFREMER). I thank to H. Claustre for the seawater samples and J. Ras for collecting assistance. I thank S. Coale for improving on the manuscript. This is a contribution to a Grant-in-aid for Creative Basic Research (12NP0201, DOBIS) from the MEXT, Japan; BIOSOPE of the LEFE-CYBER and the French IFB ‘Biodiversité et Changement Global’ programs.
- Balech E (1962) Tintinnoinea y dinoflagellata del Pacífico. Revista del Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”. Ciencia Zool 8:1–249Google Scholar
- Froneman PW, Pakhomov EA, Meaton V (1998) Observations on the association between the diatom, Fragilariopsis doliolus Wallich, and the tintinnid, Salpingella subconica Kofoid. South Afr J Sci 94:202Google Scholar
- Hada Y (1938) Studies on the tintinnoinea from the western tropical Pacific. J Fac Sci Hokkaido Imp Univ ser Zool VI 2:87–190Google Scholar
- Kofoid CA, Campbell AS (1929) A conspectus of the marine and fresh-water Ciliata belonging to the suborder Tintinnoinea, with descriptions of new species principally from the Agassiz expedition to the Eastern Tropical Pacific 1904–1905. Univ California Publ Zool 34:1–403Google Scholar
- Kofoid CA, Campbell AS (1939) The Ciliata: the Tintinnoinea. Bull Mus Comp Zool Harvard Coll 84:1–473Google Scholar
- Paranjape MA, Gold K (1982) Cultivation of marine pelagic protozoa. Ann Inst océanogr (Paris) 58(S):143–150Google Scholar
- Pavillard J (1935) Péridiniens et Diatomées pélagiques recueillis par Alain Gerbault entre les îles Marquises et les îles Galapagos. Bull Inst océanogr (Monaco) 669:1–8Google Scholar
- Pierce RW, Turner JT (1992) Ecology of planktonic ciliates in marine food webs. Rev Aquat Sci 6:139–181Google Scholar
- Rampi L (1952) Ricerche sul Microplancton di superficie del Pacifico tropicale. Bull Inst océanogr (Monaco) 1014:1–16Google Scholar
- Spittler P (1973) Feeding experiments with tintinnids. Oikos 15:128–132Google Scholar
- Taylor FJR (1982) Symbioses in marine microplankton. Ann Inst océanogr (Paris) 58(S):61–90Google Scholar