Arrangement Of Male Caudal Papillae Research Articles

SKRJABINURA GNEDINA, 1933 (NEMATODA: SEURATOIDEA: SEURATIDAE), IN BIRDS FROM THE AREA DE CONSERVACION GUANACASTE, COSTA RICA WITH DESCRIPTION OF A NEW SPECIES

Two species of Skrjabinura Gnedina, 1933, were collected in the intestines of birds from the Area de Conservación Guanacaste (ACG), Costa Rica. Skrjabinura mesoamericana n. sp. inhabits Dendrocincla homochroa, Calocitta formosa, Dendrocolaptes certhia, Basileuterus rufifrons, and Chordeiles acutipennis. The new species differs from all species of the genus by having dissimilar spicules, the right having a distinctive thin and bent handle on the proximal end. The new species can be further distinguished from Skrjabinura pomatostomi and Skrjabinura brevicaudatum by having subequal versus equal spicules. Skrjabinura mesoamericana resembles S. brevicaudatum in the number and arrangement of male caudal papillae but differs in the vulva position and in having smaller eggs. The new species differs from S. potamostomi in having 6 versus 8 pairs of postcloacal papillae. Among those species having subequal spicules, the new species further differs from Skrjabinura spiralis in having 1 pair of paracloacal papillae and 6 pairs of postcloacal papillae, versus no paracloacal papillae and 4 pairs of postcloacal papillae, and in the vulva position. The new species is perhaps most similar to Skrjabinura vali, from which it further differs by having 3 pairs of precloacal, 1 pair of paracloacal, and 6 pairs of postcloacal versus 2 pairs of precloacal, 2 pairs of paracloacal, and 6 pairs of postcloacal papillae in the vulva position and in the shape of the eggs. Skrjabinura vali (Guerrero, 1971) Chabaud, 1978, originally described in Piaya cayana from Venezuela, occurs in the small intestine of P. cayana, as well as the new hosts, Crotophaga sulcirostris and Myiarchus tyrannulus, in the ACG, a new locality. Our specimens differ from the original description in the body length of the female, the numbers of postanal papillae of male tail, and the size of eggs.

Redescription of Dracunculus globocephalus Mackin, 1927 (Nematoda: Dracunculidae), a parasite of the snapping turtle, Chelydra serpentina

Dracunculus globocephalus Mackin, 1927 (Nematoda: Dracunculoidea) is redescribed from specimens collected from the mesentery of the snapping turtle, Chelydra serpentina (L.), in Louisiana, USA. The use of scanning electron microscopy, applied for the first time in this species, made it possible to study details in the structure of the cephalic end and the arrangement of male caudal papillae that are difficult to observe under the light microscope. This species markedly differs from all other species of Dracunculus in having the spicules greatly unequal in size and shape, in the absence of a gubernaculum, and in the disposition of male caudal papillae. The validity of D. globocephalus is confirmed, but the above mentioned morphological differences are not sufficient for listing it in a separate genus. This is the first record of D. globocephalus in Louisiana.

First Record of the Acuarioid Nematode Paracuaria adunca from South America, with New Morphological Details and Discussion of Cordons

Abstract The acuarioid nematode Paracuaria adunca (Creplin, 1846) was found in 7 of 13 (54%) Larus dominicanus (Aves: Laridae) examined from several locations along the Argentine coast. It was only present in specimens from Patagonia; the intensity of infection ranged from 1 to 14 (mean = 5.4). This is the first record of P. adunca from South America and as a parasite of L. dominicanus. Using both light and scanning electron microscopy (SEM), the complexity of the left spicule and the number and arrangement of male caudal papillae were observed. Although P. adunca is parasitic in several unrelated bird families and has a wide geographical distribution, the dimensions of our specimens fully agree with previous reports. The genus Paracuaria was characterized by the presence of rudimentary cordons; thus, it was considered the most primitive acuarioid. The cordons appear as finger-like structures within shallow grooves held tightly against the surface and extend posteriorly from the ends of the mouth and for ...

Micropleura australiensis n. sp. (Nematoda: Micropleuridae) from the body cavity of Crocodylus johnsoni in Western Australia.

A new nematode species, Micropleura australiensis n. sp., is described on the basis of specimens found in the peritoneal cavity of the Australian freshwater crocodile, Crocodylus johnsoni Krefft, from the Ord River area, Western Australia. The new species is mainly characterized by the length of spicules (0.360-0.366 mm) and gubernaculum (0.096-0.105 mm), the number and arrangement of male caudal papillae (4 preanal and 6 postanal pairs), and the postequatorial vulva. To date, it is the first species of Micropleura reported from Australia. Micropleura trionyxi Agrawal, 1966, and M. lissemysia Chattervati, 1985, are considered junior synonyms of M. indica Khera, 1951.