Taxonomy of Ammonia catesbyana (d'Orbigny, 1839) revisited: evidence on the intraspecific DNA sequences from the intertidal sediments of the southwestern Yellow Sea

Ammonia is one of the dominant foraminiferal species in the intertidal zone and the late Quaternary delta stratigraphy, which has been popularly used as a key micropaleontological indicator for the past environment.  However, its classification has been battled since 19^th century.  The development of molecular analysis has shed a new light on the taxonomy and phylogeny of foraminifers over the last several decades.

Ammonia confertitesta Zheng 1978, taxonomically erected and adopted in the microfossil study for the Shangdong peninsula, China, is the most dominant species in the surface sediments of shallow water of the Yellow Sea.  This species was reported recently in the European ocean environment (harbor), regarding as a non-indigenous species.  Ammonia aomoriensis (Asano, 1951) has also been adopted in some recent publications.  For a better understanding of its taxonomy and distribution, in this study, living Ammonia specimens were collected from the muddy sediments at the Haimen inter-tidal zone of the southwestern Yellow Sea, and performed molecular analyses on their SSU rDNA sequences.

A large number of the inter- and intra-specific SSU rDNA sequences were obtained for Ammonia confertitesta specimens of the southwestern Yellow Sea. These sequences were conducted phylogenetic analysis together with other related Ammonia sequences from the GenBank.

The phylogenetic tree shows that Ammonia catesbyana (d'Orbigny, 1839), Ammonia aomoriensis (Asano,1951), Ammonia confertitesta Zheng 1978 and Ammonia sp. T6 (Hayward et al. 2004) form one distinct group (Clade A), and suggests that A. confertitesta, A. catesbyana and A. aomoriensis be synonymous.  Ammonia catesbyana, was first reported and described from the shallow waters off Cuba (D'Orbigny, 1839).  Therefore, instead of others, we propose that Ammonia catesbyana (D'Orbigny, 1839) be a valid nomination for the distinct group; and the worldwide distribution of Ammonia catesbyana implies that Ammonia confertitesta Zheng 1978 in Europe is probably not a non-indigenous species from the East Asia marine waters.

 

This work is supported by the CAS Strategic Priority Project (XDB XDB26000000) and the National Natural Science Foundation of China (Grants 41776073).