Five New Spathidiids (Ciliophora: Haptoria) from Caribbean Tank Bromeliads

Abstract

There is a widespread belief that spathidiids have few morphological features. In contrast, we show a rich morphological diversity in five new species discovered in tank bromeliads from the Caribbean, using live observation; protargol impregnation; morphometry; scanning electron microscopy; and resting cyst morphology, demonstrating lepidosomes (organic scales) for the first time in spathidiid haptoria. Arcuospathidium bromelicola nov. spec. is very similar to the previously described A. muscorum but its resting cyst has conspicuous, pillar-shaped lepidosomes on the surface. Protospathidium lepidosomatum nov. spec. is very similar to the previously described P. muscicola but has outstanding, nipple-shaped (vs. conical) lepidosomes on the cyst surface. Spathidium bromeliophilum nov. spec., whose ontogenesis is highly similar to that of S. turgitorum, differs from similar species by the body length: width ratio, the number of ciliary rows, the shape of the oral bulge, and details of the ciliary pattern. Spathidium bromelicola nov. spec. is similar to S. muscicola (extrusomes bluntly fusiform and 4 mu m long vs. rod-shaped and > 15 mu m long) and S. stammeri (resting cyst wall smooth vs. spinous). Spathidium wolfi nov. spec. has an anterior and a posterior contractile vacuole. It differs from the supposed nearest relative, S. faurefremieti, by body size (on average 135 x 25 mu m vs. 240 x 17 mu m), the shape of the macronucleus (moniliform vs. a long, tortuous strand), and the total number of dorsal brush bristles (on average 47 vs. 72). The bent oral bulge of Arcuospathidium bromelicola and Spathidium bromeliophilum as well as the occurrence of lepidosomes on the cyst surface of Arcuospathidium bromelicola and Protospathidium lepidosomatum are discussed.