Tintinnid Distribution from the Frontal Zone in the Southern Waters of Korea and a Brief Description of Metacylis-Like Species

Abstract

As the frontal zone of coastal waters has potentiality of high primary productivity, planktonic predators including tintinnids can be flourished in the zone. Seasonality of tintinnid distribution was investigated via the frontal zone survey of the South Sea in 2016 and 2017. Higher diversity of tintinnid species was recorded in summer (August 2016). Vertical profile of tintinnid distribution in the frontal zone was matched well with the distribution of its prey sources of chlorophyll-a and bacteria. High abundance of a neritic species, Tintinnopsis beroidea (15,000 cells L-1), was detected in the surface chlorophyll maximum (SCM) layer at A-5 station of a western frontal zone. A patch distribution of Metacylis-like species (1,800 cells L-1) was found in the water mass of high temperature and low salinity at the B-3 station of an eastern frontal zone, which coincided with the bacterial distribution. The morphological and molecular features of Metacylis-like species are as follows: (1) stout lorica consists of short collar with two annular lines, cup-shaped with subapical bulge and broad bowl (2) inconspicuous and blunt aboral horn (3) existence of reticulate ridges and pores on lorica surface (4) lorica length of 86.4 ± 6.4