Acanthatrium umbraculatum sp. n. (Digenea: Lecithodendriidae) from the Little Brown Bat, Myotis lucifugus

Abstract

The new species is described from the intestine of bats collected at Columbus, Ohio. It differs from all other species of Acanthatrium in having spines in the genital atrium arranged in the outline of an umbrella with a curved handle. This report is based on specimens from the intestine of little brown bats, Myotis lucifugus, caught at Ohio State University, Columbus, Ohio, during the summer of 1968. Because of the unique arrangement of spines in the genital atrium and the form of the atrial partition in these trematodes, they are described as Acanthatrium umbraculatum sp. n. for the umbrellalike pattern of the spines. Trematodes were killed without flattening in hot AFA solution, stained with Semichon's carmine, and mounted in balsam. Drawings were made with the aid of a camera lucida and a microprojector. All measurements are in microns unless otherwise indicated. Acanthatrium umbraculatum sp. n. (Figs. 1-3) Description (based on 20 mature specimens): Body broadly oval to pyriform; 610 to 660 long, 390 to 455 wide at posterior level of testes. Tegument aspinose. Oral sucker terminal to slightly subterminal, 75 to 90 in diameter; ventral sucker 56 to 75. Prepharynx absent; pharynx 31 to 40 in diameter; esophagus 45 to 78 long; ceca short, widespread, with slightly inflated ends. Testes entire, symmetrical, at ends of ceca on either side of acetabulum, slightly oblong to spherical, 112 to 135 long by 110 to 130 wide. Prostate mass mesial, 130 to 160 in diameter, extending from intestinal bifurcation almost to posterior edge of acetabulum dorsally. Genital atrium and pore ventral, in anterior portion of prostate mass; atrium with 2 chambers armed with groups of facing spines and joined by a connecting channel armed with 1 row (sometimes 2 rows) of spines; spines sharp, 12 to 14 long; anterior chamber about 3 times as large as posterior chamber. Atrial spines arranged in shape of umbrella with curved handle. Seminal vesicle sometimes inconspicuous, located dorsally within prostate mass, between genital atrium and acetabulum. Ovary unevenly oval to Received for publication 18 January 1972. pyriform, 63 to 98 long by 54 to 85 wide, at acetabular level and partially overlapping right testis posteriorly. Seminal receptaculum usually obscured by eggs, immediately postacetabular and posterolateral to ovary. Uterus occupying most of hindbody, filled with yellowish and brownish operculate eggs 26 to 28 long by 15 to 17 wide. Vitelline follicles in forebody on each side anterior to testes, sometimes overlapping posterior half of esophagus and ceca but never intracecal; vitelline ducts extend posteriorly from vitellaria to unite just anterior to ootype and enter it. Excretory vesicle V-shaped, with terminal pore. Type host: Little brown bat, Myotis lucifugus. Location: Small intestine. Type locality: Columbus, Ohio. Holotype: USNM Helm. Coll. No. 72011, paratypes (3)-USNM Helm. Coll. No. 72012.