A bisected Pelosina rejoined!

Abstract. INTRODUCTION

During a NIVA (Norwegian Institute for Water Research) environmental monitoring cruise along the Norwegian Skagerrak coast, a 16 mm long specimen of the foraminifer Pelosina arborescens Pearcey, 1914, was found in light brown, bioturbated, soft muddy sediment collected with a Gemini corer on 29 May 2008, in 350 m water depth SE of Arendal, Norway (58° 24.177′ N, 9° 01.648′ E). In an effort to pull the individual out of the sediment with forceps, it was accidentally cut into two separate parts (the ‘root’ and the dendritic part). The two pieces were isolated in a 180 ml, 72 mm diameter, plastic container with about 1 cm of sea water and stored in a fridge at near-ambient temperature (about 7°C). On return to the lab four days later (2 June), the two test-pieces had rejoined in their original position and were photographed using a Nikon Coolpix 990 digital camera attached to a Nikon SMZ1000 binocular microscope. The mended fracture (where the two pieces had rejoined) was clearly visible (Fig. 1). The individual was kept in a fridge at 9–10°C and, two days later (4 June), it was still in one piece, even when the water in the container was carefully swirled. The plan was to cut the individual one more time (this time deliberately) to see if the process of rejoining the two pieces would be repeated. However, when manipulating the test to take a new picture, it broke at the old fracture. The test looked worn and the . . .