Trochammina inflata ( Montagu, 1808 )

Camacho, S, Moura, D, Connor, S, Scott, DB & Boski, T, 2015, Taxonomy, ecology and biogeographical trends of dominant benthic foraminifera species from an Atlantic-Mediterranean estuary (the Guadiana, southeast Portugal), Palaeontologia Electronica 52 (4), pp. 1-37 : 21

Trochammina inflata ( Montagu, 1808)

Figure 3.17-3.21

1808 Nautilus inflatus Montagu : p. 81, pl. 18, fig. 3.

1858 Rotalina inflata (Montagu) ; Williamson, p. 50, pl. 4, figs. 93, 94.

1952 Trochammina inflata (Montagu) ; Parker, p. 459, pl. 3, fig. 1.

1957 Siphotrochammina lobata Saunders : p. 9, pl. 3, figs. 1, 2.

1977 Siphotrochammina elegans Zaninetti, Brönnimann, Beurlen and Moura : pl. 2, figs. 8, 10, 11.

1990 Trochammina inflata (Montagu) ; Scott, Schnack, Ferrero, Espinosa and Barbosa, p. 733, pl. 1, fig. 3.

2005 Trochammina inflata (Montagu) ; Horton, Whittaker, Thomson, Hardbattle, Kemp, Woodroffe and Wright, p. 3, pl. 1, fig 4.

Morphological description. Agglutinated test, trochospirally enrolled, chambers rather inflated, increasing in size gradually; aperture a low arch with a bordering lip; smoothly agglutinated.

Occurrence. Dominant in the living assemblages of the modern estuary; closely related to J. macrescens , occurring together in almost all the samples, although it has higher abundances in middle elevations (0.2 to 0.8 m above MSL at samples E1, LG2 and FB2) where J. macrescens abundance starts to decrease and species diversity starts to increase; like J. macrescens , it is more common in winter.

Remarks. This taxon is the type species of the genus Trochammina ; perhaps the best known and most distinctive of all the endemic marsh species, as well as being one of the earliest species ever described (Scott et al., 2001); the specimens found in Guadiana often present a proteinaceous umbilical tube ( Figure 3.18 ), covered with fine sediment, the purpose of which is unknown.

Figures

FIGURE 3. Scanning electron and light microscope micrographs of the foraminifera specimens. Scale bar equals 100 µm except where noted otherwhise; 1-2- Jadammina macrescens (Brady, 1870); 1- supplementary apertures view; 2- detail of supplementary apertures (scale bar = 50 µm); 3-4- Lepidodeuterammina plymouthensis Brönnimann and Whittaker, 1990; 3- dorsal view; 4- ventral view; 5-8- Lepidodeuterammina ochracea (Williamson, 1858); 5- dorsal view; 6- ventral view; 7- dorsal view of a smaller specimen; 8- ventral view of a smaller specimen; 9-10- Portatrochammina sp.; 9- dorsal view; 10- ventral view; 11-13- Siphotrochammina sp.; 11- dorsal side with inter-cameral foramen view; 12- dorsal view of a smaller specimen, also with inter-cameral foramen; 13- ventral view of a smaller specimen; 14-16- Tiphotrocha comprimata Saunders, 1957; 14- dorsal view; 15- ventral view; 16- individual strongly attached to a sea-grass leaf; detail of a Pinus pollen grain at the center of the leaf; 17-21- Trochammina inflata (Montagu, 1808); 17- dorsal view; 18- ventral view; 19- ventral view with umbilical tube detail; 20- microspheric form dorsal view; 21- microspheric form ventral view; 22- Eggerelloides scaber (Williamson, 1858); 23-25- Textularia earlandi Parker, 1952; 23- apertural view; 24- lateral view; 25- profile view with aperture in detail; 26-29- Discorinopsis aguayoi (Bermúdez, 1935); 26- scanning electron dorsal view; 27- scanning electron ventral view; 28- light microscope dorsal view; 29- light microscope ventral view.