Pygidiopsoides spindalis n. gen., n. sp., (Heterophyidae; Trematoda), and Its Second Intermediate Host

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org.. The American Society of Parasitologists is collaborating with JSTOR to digitize, preserve and extend access to The Journal of Parasitology.Naturally infected brackish-water fishes, Fundulus parvipinnis parvipinnis (Girard), were collected at Newport Bay, California and fed to cats and to newlyhatched chicks. After a lapse of four to six days the cats and chicks were found to harbor small trematodes in the small intestine which do not fit any of the existing genera although they obviously are heterophyids. MATERIALS AND METHODS Living specimens and material fixed inBouin's solution and stained with paracarmine were studied. OBSERVATIONS Pygidiopsoides n. gen. Diagnosis: Small, oval to spindle-shaped trematodes. Mouth surrounded by a single row of large spines. Oral sucker oval in lateral view not tapering posteriorly into a cone. Prepharynx, pharynx, and esophagus well-developed, ceca terminating near posterior border of ventral sucker. Ventral sucker near mid-body level, well-developed, and enclosed in a ventrogenital sac. Single testis in posterior one-third of body. Large seminal vesicle bipartite; "prostate" well-developed; cirrus and cirrus sac lacking. Ovary between testis and acetabulum; Laurer's canal present; uterus in mature specimens filling most of posterior half of body; eggs oval, operculate, relatively large; vitellaria transverse between testis and ovary. Large, muscular, common genital ejector present. Ventro-genital sac contains two, lateral, lenticular gonotyls. Excretory bladder simple, spindle-shaped to tubular; excretory pattern of the "mesostoma" type. Remnants of eyespots may be present. Genotype: Pygidiopsoides spindalis. Pygidiopsoides spindalis n. sp. (Figs. 1-3) Diagnosis: With characters of the genus. Body spindle-shaped to oval and measuring 0.223-0.429 mm. (av. 0.314 mm.) in length and 0.066-0.095 mm. (av. 0.081 mm.) in maximum width. Cuticula moderately thick and covered with spines which decrease in size at both ends of the body. Fourteen spines ranging from 0.010 mm. to 0.012 mm. in length and 0.003 mm. in width surround the mouth. Circular muscles lie immediately mediad to circum-oral spines. Remnants of eyespots occur between pharynx and acetabulum. Oral sucker oval in lateral view and averaging 0.028 mm. wide and 0.049 mm. long. Prepharynx approximately as long as pharynx. Pharynx muscular, varying from spherical to oval, and measuring 0.016 mm. in diameter when spherical. Esophagus two to three times the length of the pharynx. Cecal bifurcation anterior to acetabulum, ceca terminate at or near the posterior margin of acetabulum. Acetabulum in mid-body region, enclosed in ventro-genital sac, and measuring 0.028-0.033 mm. (av. 0.030 mm.) in leng...