ABSTRACT
Divergence of biological performance of a laboratory-reared population of Moniliformis moniliformis (Acanthocephala) was investigated after 31 yr, or approximately 60 generations, of genetic isolation. An isolate of the laboratory-reared population and isolates of 2 wild populations were used to begin 3 independent life cycles that were maintained for 1 generation for interbreeding and life history trait comparison. Both wild population isolates represented populations with open gene flow. One wild population isolate represented a present-day sample of descendants of the parent population of the laboratory isolate. All 3 populations hybridized, and egg production occurred in all mixed-sex pairs of different populations. The 3 populations did not differ significantly in prepatent period, mean daily egg production, or establishment within the definitive host Rattus norvegicus. The 3 populations varied in patent period, but the laboratory-isolated worms differed from the 2 wild population isolates no more than they did from each other. A positive correlation between mean daily egg production and duration of patent period resulted in different cumulative egg productions. A 31-yr period of isolation did not produce greater divergence in a laboratory population of M. moniliformis than occurs between wild populations with respect to the biological parameters measured.
Subject(s)
Cockroaches/parasitology , Helminthiasis, Animal/parasitology , Moniliformis/pathogenicity , Rats/parasitology , Rodent Diseases/parasitology , Animals , Evolution, Molecular , Female , Fertility , Host-Parasite Interactions , Male , Moniliformis/genetics , Moniliformis/physiology , Parasite Egg Count/veterinaryABSTRACT
Three hundred and seventy-five acanthocephalans, Moniliformis clarki, were removed from the small and large intestines of a gray squirrel from Arkansas County, Arkansas (USA). This is the first report of M. clarki from Arkansas. Enteric lesions, including distension, perforating ulcers, enteritis, crypt hypertrophy, goblet cell hyperplasia, and occlusions of the intestinal tract were observed, indicating the pathogenic potential of this parasite.
Subject(s)
Helminthiasis, Animal , Intestinal Diseases, Parasitic/veterinary , Moniliformis/isolation & purification , Rodent Diseases/parasitology , Sciuridae/parasitology , Animals , Arkansas , Female , Helminthiasis/parasitology , Helminthiasis/pathology , Intestinal Diseases, Parasitic/parasitology , Intestinal Diseases, Parasitic/pathology , Intestines/parasitology , Intestines/pathology , Male , Moniliformis/pathogenicity , Rodent Diseases/pathologyABSTRACT
The acanthocephalan Moniliformis moniliformis is surrounded by a membranous envelope that protects the parasite from hemocytic attack in the cockroach host. If injected into a cockroach infected with M. moniliformis, hatched oncospheres of the tapeworm Hymenolepis diminuta are able to penetrate this envelope and, once inside, utilize its protective function in order to develop. These "double parasites" were infective to rats.
