Ammobaculites formosensis Nakamura, 1937

Lee, Somin Lee and Wonchoel, 2019, Three new records of recent benthic Foraminifera from Korea, Journal of Species Research 8 (4), pp. 389-394 : 390-392

1. Ammobaculites formosensis Nakamura, 1937

( Plate 1. 1a- d )

Ammobaculites formosensis Nakamura, 1937, p. 133 , pl. 10, figs. 1a-b (cited from Ellis and Messina, 1940); Scott et al., 2000, p. 5-6, figs. 1. 1-2; Debenay and Luan, 2006, p. 77, pl. 1, fig. 12; Garrett, 2010, p. 128, pl. 1, fig. 1; Wang et al., 2016, p. 4, pl. 2, fig. 20.

Material examined. 1 individual, Korea, East China Sea, station 16 (32°30ʹN, 124°00ʹE), 6 August 2019, by Smith-McIntyre grab, collected by Somin Lee and Nayeon Park, MABIK ID: MABIK PR00043230 .

Diagnosis. Test is free, elongated, and rounded shape in cross section. In early stage, chambers are closely, planispirally coiled, and compressed. Later stage is composed of five cylindrical chambers uniserially arranged. Chamber width and height gradually increase as added in later cylindrical stage. Sutures are indistinct in early coiled stage, and coiling axis slightly depressed. Wall is agglutinated with fine to coarse sediment particles. Aperture is at the terminal and rounded shape. Test length is about 550 μm.

Remarks. This species resembles Ammobaculites agglutinans in general shape but differs from it in the smaller size of early coiled portion. The width of coiled portion in A. formosensis is almost the same or smaller than that of the final chamber. While the width of the coiled portion in A. agglutinans is larger than that of the final chamber. Additionally, the chamber width in the later stage of A. formosensis tends to increase as added, whereas it is constant in A. agglutinans .

A total of 44 modern species belonging to the genus Ammobaculites have been recorded worldwide, and seven species have been recorded in Korea ( Hayward et al., 2018a; NIBR, 2019). Ammobaculites formosensis is originally reported from northern Taiwan ( Ellis and Messina, 1940) in the East China Sea and has been documented in the Bohai Sea ( Wang et al., 2016) and South China Sea: Mekong Delta ( Debenay and Luan, 2006) and Pearl River ( Garrett, 2010). This is the first report of A. formosensis from Korean waters.

Distribution. Korea and China.

Figures

Plate 1. 1. (a-d) Ammobaculites formosensis Nakamura, 1937; 1a. SEM image, side view; 1b. Digital camera image, side view; 1c. Frontal view; 1d. Apertural side view. 2. (a-d) Cylindroclavulina bradyi (Cushman, 1911); 2a-b. Side view; 2c-d. Apertural side view. 3. (a-d) Saracenaria hannoverana (Franke, 1936); 3a. Side view; 3b. Ventral view; 3c. Dorsal view; 3d. Apertural side view.