DISTRIBUTION AND ABUNDANCE OF CHOANOFLAGELLATES IN GREAT-WALL BAY, KING GEORGE ISLAND, ANTARCTICA TN AUSTRAL SUMMER (15th Symposium on Polar Biology)

• Main Author: Bo CHEN
• Format: Report
• Language: English
• Published: Proceeding 1994
• Subjects: Antarctic; Austral; King George Island; West Antarctica; Wall Bay; Antarc*; Antarctica; Polar Biology; Proceedings of the NIPR Symposium on Polar Biology
• Online Access: https://nipr.repo.nii.ac.jp/?action=repository_uri&item_id=5215; http://id.nii.ac.jp/1291/00005215/; https://nipr.repo.nii.ac.jp/?action=repository_action_common_download&item_id=5215&item_no=1&attribute_id=18&file_no=1

Eleven species of seven genera of loricate choanoflagellates were found in Great-Wall Bay, King George Island, west Antarctica during the sampling period from January 22 to February 8, 1991. Among them, Pleurasiga orculaeformis aff. was a new record in Antarctic waters. Choanoflagellates was an abundant taxa in Great-Wall Bay. Their total abundance ranged from 5.1 × 10^3 to 5.3 × 10^4 cells/l. The spatial distribution of choanoflagellate species and abundance showed heterogeneous patterns. The maximum concentration of chlorophyll a and the highest abundance of choanoflagellates were located at depths of 20 m and 30 m respectively. Choanoflagellates usually showed a tendency to follow the variations of chlorophyll a concentration in their vertical abundance. Regression analysis on the basis of 40 data sets showed that there was a positive correlation between abundance of choanoflagellates and chlorophyll a concentration in this season. The four dominant species of choanoflagellates, Bicosta spinifera, Crinolina aperta, Diaphanoeca multiannulata and Parvicorbicula circularis, were distributed widely from the surface to the bottom in Great-Wall Bay. They were counted for more than 90% of total choanoflagellates in all layers. B. spinifera was up to about 41% of the mean value of surface abundance of total choanoflagellates. D. multiannulata reached the highest abundance of 2.2 × 10^4 cells/l at 20 m depth on January 25.