A bdelloid rotifer associated to the South American apple-snail Pomacea canaliculata.

HENRIQUEZ-CABALLERO M, GAMARRA-LUQUES C, CASTRO-VAZQUEZ A.

Mendoza

Congreso; XXIII Reunión Anual de la Sociedad de Biología de Cuyo.; 2005

Sociedad de Biología de Cuyo

A bdelloid rotifer associated to the South  American apple-snail Pomacea canaliculata.   Henriquez-Caballero M, Gamarra-Luques C, Castro-Vazquez A.  Lab. of Physiology, IHEM, UNCuyo-CONICET, C. de Correo  33, 5500 Mendoza. E-mail: henriquez.marcela@fcm.uncu.edu.ar   P. canaliculata has been reported to host a variety of eukaryotic organisms, such as ciliates, artrophods, platyhelmynths, nematods and annelids. We describe here a bdelloid rotifer inhabiting the lower gut (contorted gut and rectum) of cultured adult snails. The rotifers are eliminated in the feces and they are also found in the mantle cavity (but in much smaller numbers than in the gut system). They proliferate in feces from adult P. canaliculata individuals, but they are not found either in hatchlings or their feces. The rotifer has a corona with two large lateral trochal disks and a cingulum underlying them. A circular sulcus separates corona and trunk. The iloricate trunk is 2-segmented; the elongated cephalic segment bears a dorsal antenna, two ocelli above the ramate mastax, and a large stomach lumen which separates the bilateral germovitellaria; the caudal segment is much shorter and bears intestine, cloaca and anus. The foot is retractile and is 3-segmented; the longer first foot segment contains the pedal glands, whose ducts terminate at the junction of the second and third foot segment; the latter bears two lateral spurs at its origin and three toes at its end. The stomach and intestinal lumina are filled with a granular, brownish/greenish material, whose color is that of the putative cyanobionts inhabiting the snail’s midgut gland and which pass in large quantity into the lower gut. It is hypothesized that the granular material is made of the daughter cells of the putative cyanobiont and that the rotifer predates on them.