The habitat of the foraminifer Paratrochammina (Lepidoparatrochammina) haynesi

Abstract. INTRODUCTION

Trochammina haynesi Atkinson, 1969, the type species of Paratrochammina (Lepidoparatrochammina) haynesi (Atkinson), was described from the holdfasts of Laminaria from the shallow sublittoral zone (18.3m) of Cardigan Bay, Wales. After collection, the algae were placed in a bucket in a solution of one part formalin to ten parts seawater and agitated to free the foraminifera. Some 16 specimens of P. (L.) haynesi were recovered out of a total assemblage for two samples of 2787 individuals. Because of the method of preparation, nothing could be said of the mode of life other than that all the foraminifera were associated with algae. Brönnimann and Whittaker (1986) also recorded this species from off Plymouth.

In their remarks on the subgenus Paratrochammina (Lepidoparatrochammina), Brönniman and Whittaker (1986) suggested that the form of the test is ‘better adapted to fixation than the higher spired Paratrochammina s.s.’.

NEW OBSERVATIONS

In the course of a broader study of the Hamble estuary, a tributary of Southampton Water, we collected sediment samples from the intertidal and subtidal areas. These were preserved in alcohol, stained with rose Bengal, and washed on a 63μm sieve. The foraminifera were concentrated by flotation using trichloroethylene.

One coarse grained sandy gravel from the margin of the channel contained an abundance of rose Bengal stained (living) P. (L.) haynesi in the flotation. These formed 53% of the living and 6% of the dead assemblage >63μm. However, examination of the coarse material in the sediment fraction revealed that this species lives in sheltered microhabitats. For . . .