Rhynchomonadidae

Rhynchomonas nasuta (rink-owe-moan-ass), a kinetoplastid flagellate. Arguably the most widespread heterotrophic flagellate - so fare found in northern and southern hemispheres, Atlantic and Pacific, surface waters and in deep sediments, coastal and oceanic, in water column and in sediments, in soils and freshwater habitats, in waters so salty the salt is crystallizing and from guaranteed anoxic habitats. There are two flagella, but the front one supports an expanded lobe of cytoplasm which includes the mouth and looks a bit like a nose or a proboscis. Posterior flagellum is acronematic - in that the posterior section is thinner than the bit nearer the body. Eats bacteria through its nose. Phase contrast.

Rhynchomonas, distinctive kinetoplastid flagellate, with swollen or bulbous ingestion apparatus that is supported by the anterior flagellum and has a waggling movement. Second flagellum trails behind the cell and is acronematic - the tip is thinner than the rest of the flagellum. Phase contrast micrograph.

Portrait of Rhynchomonas, a small, colorless bodonid flagellate. Two flagella, one short anterior and embedded in the mobile rostrum, the other about twice the body length trailing posteriorly. Bactivorous. Ingestion occurs via cytostome at the tip of the rostrum. The nucleus is seen anteriorly adjacent to the posterior flagellum in this image. Several digestive vacuoles are also seen. Collected from standing freshwater pond near Boise, Idaho. Phase contrast.

Portrait of Rhynchomonas, a small, colorless bodonid flagellate. Two flagella, one short anterior and embedded in the mobile rostrum, the other about twice the body length trailing posteriorly. Bactivorous. Ingestion occurs via cytostome at the tip of the rostrum. An anterior contractile vacuole is seen in this image. Collected from standing freshwater pond near Boise, Idaho. Phase contrast.

Rhynchomonas - the nosey flagellate. This organism eats bacteria that stick to particles of detritus. The mouth is in the 'nose' and it is pushed over bacteria and somehow they are detached and pulled into the flagellate for digestion.

Rhynchomonas nasuta (rink-owe-moan-ass), a kinetoplastid flagellate. Arguably the most widespread heterotrophic flagellate - so fare found in northern and southern hemispheres, Atlantic and Pacific, surface waters and in deep sediments, coastal and oceanic, in water column and in sediments, in soils and freshwater habitats, in waters so salty the salt is crystallizing and from guaranteed anoxic habitats. There are two flagella, but the front one supports an expanded lobe of cytoplasm which includes the mouth and looks a bit like a nose or a proboscis. Posterior flagellum is acronematic - in that the posterior section is thinner than the bit nearer the body. Eats bacteria through its nose. Phase contrast.

Rhynchomonas nasuta (rink-owe-moan-ass), a kinetoplastid flagellate. Arguably the most widespread heterotrophic flagellate - so fare found in northern and southern hemispheres, Atlantic and Pacific, surface waters and in deep sediments, coastal and oceanic, in water column and in sediments, in soils and freshwater habitats, in waters so salty the salt is crystallizing and from guaranteed anoxic habitats. There are two flagella, but the front one supports an expanded lobe of cytoplasm which includes the mouth and looks a bit like a nose or a proboscis. Eats bacteria through its nose. Phase contrast.

Rhynchomonas (rink-owe-moan-ass) one of these most widely distributed of all eukaryotes, having been found in marine and freshwater sites all round the world, in anoxic sites and in sites with so much salt that crystals form. Its tolerance for extremes now also illustrated by its occurrence in a thermal stream. This is a bodonid, the anterior nose contains a mouth with which it eats bacteria, and with one trailing flagellum which narrows towards the posterior end. Phase contrast. Material from Nymph Creek, thermal sites within Yellowstone National Park, photograph by Kathy Sheehan and David Patterson.

Rhynchomonas (rink-owe-moan-ass) nasuta Klebs, 1893. Cells are 3.5 to 6 microns long and flattened. The cells are flexible with a bulbous motile snout. The snout, which contains a mouth, beats slowly. The anterior flagellum lies alongside the snout and is hard to see, and the trailing flagellum is about 2 to 2.7 times the cell length, and is acronematic. The cells consume attached bacteria. The cells move by gliding. Commonly observed.

Rhynchomonas nasuta (Stokes, 1888) Klebs, 1893. Cells are 3.5 to 6 microns long and flattened. The cells are flexible with a bulbous motile snout. The snout, which contains a mouth, beats slowly. The anterior flagellum lies alongside the snout and is hard to see, and the trailing flagellum is about 2 to 2.7 times the cell length, and is acronematic. The cells consume attached bacteria. The cells move by gliding. Commonly observed.

Single Rgynchomonas nasuta gliding over a field of bacteria - its food. Phase contrasty micrograph.

Gliding cell, trailing flagellum just out of focus, snout is short and held close to the cell. 

This image was made from samples taken during a scientific cruise in the Pacific. Water was filtered to concentrate the organisms that were present, then dried onto a thin sheet of plastic and then shadowed with a fine layer of metal to provide contrast. The preparation was then observed with an electron-microscope. This technique has been used to document the diversity of marine microbes, especially, protists in the oceans.

Three profiles of Rhynchomonas isolated from Little Sippiwissett Marsh, Massachusetts. Phase contrast image by Banoo Malik.

Dimastigella (die-mast-ig-ella) is a plastid kinetoplastid flagellate, with two flagella inserting sub-apically, and with a slight anterior rostrum. Note that the posterior flagellum is acronematic (the tip is much thinner than the rest), and this characteristic is a useful general rule when distinguishing kinetoplastids from many other small flagellates. Phase contrast.