Dipetalonema barbascalensis sp. n. (Nematoda: Filarioidea) from the Owl Monkey, Aotus trivirgatus, with a Consideration of the Status of Parlitomosa zakii Nagaty, 1935

Abstract

Dipetalonema barbascalensis sp. n. recovered from the abdominal cavity of owl monkeys, Aotus trivirgatus, from Colombia is described. This filarioid belongs to the Tetrapetalonema group and most closely resembles the nematode previously known as Parlitomosa zakii Nagaty, 1935, from the pectoral muscles of a Brazilian marmoset. It is concluded that the monotypic genus Parlitomosa falls into synonymy with Dipetalonema Diesing, 1911, sensu Chabaud, 1952, the species thus becoming Dipetalonema zakii (Nagaty, 1935) comb. n. These 2 worms resemble each other in the presence of a terminal caudal digitiform process in the male, in the similarity of the left spicule, and in the position of the vulva. They differ markedly in size, D. zakii adults and microfilariae being approximately twice as long as those of D. barbascalensis. D. zakii lacks the prominent subterminal caudal papillae and ventrolateral striae in the coiled portion of the tail of the male and the right spicule is smaller than and of a different shape from that of D. barbascalensis. In the course of an investigation of the filarial parasites of Neotropical primates certain worms were recovered from the abdominal cavity of owl monkeys (Aotus trivirgatus) collected at Barbascal, Meta, Colombia. Subsequently identical nematodes were obtained from several individuals of the same host species provided by Dr. Leon Schmidt of the Southern Research Institute, Birmingham, Alabama. Following an examination of all the specimens recovered, it was concluded that these worms represented members of a previously undescribed species of the genus Dipetalonema Diesing, 1861, sensu Chabaud, 1952. MATERIALS AND METHODS A total of 8 infected owl monkeys (2 from Barbascal and 6 from unspecified regions of Colombia) provided the filarial worms upon which the present description is based. After matching the microfilariae in the blood with those from the ovejector of several specimens, adult worms were fixed in glacial acetic acid, transferred to 70% alcohol containing 5% glycerine, and ultimately studied in pure glycerine or glycerine jelly. Microfilariae were examined in thick blood films and in films of blood concentrated in 2% aqueous formalin, all subsequently stained with hematoxylin Received for publication 27 June 1974. * Supported by the Tulane University ICMRT, Grant TW-00143, Grant AI-08099-04 from the Office of International Research, NIH, U. S. Public Health Service, NSF Grant GB-30824 and Grant AI-00002-14 from NIAID, NIH. t Tulane University Medical Center, 1430 Tulane Avenue, New Orleans, La. 70112. and eosin. Illustrations were made with the aid of a Wild drawing apparatus. Measurements were made with an ocular micrometer. In the following descriptions, all measurements (ranges, with the mean in parentheses), unless otherwise stated, are in microns. The term width at anus refers to the dorsoventral thickness of the body at the level of the anus. Locations of structures in the microfilariae are given as the distance from the anterior extremity.