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Notes on the Species of Capillaria Zeder, 1800 Known from Gallinaceous Birds

1951; American Society of Parasitologists; Volume: 37; Issue: 3 Linguagem: Inglês

10.2307/3273197

1937-2345

Holger Madsen,

Animal Ecology and Behavior Studies

The species of the nematode genus, Capillaria Zeder, 1800, present many taxonomic difficulties. The most important of more recent studies regarding species in birds are those of Orosz (1931), Morgan (1932), Freitas & Almeida (1935a-b), Cram (1936) and Read (1949). Based upon large collections from gallinaceous and anatine game birds the present author (1945) tried to clear up the difficulties and confusions in the very scattered literature on these species. Since then I have found several new features especially concerning the species in gallinaceous birds. I consider it, therefore, of some use to summarize the results, and give a revised list of the species from these birds. The genus Capillaria comprises a large number of species. It would, therefore, be useful if it could be split into several genera. Some attempts have been made in this respect, beginning with Dujardin (1845). Baylis (1931) showed that the attempts up to that time had been futile, and this point of view was accepted by the above mentioned authors. Recently, L6pex-Neyra (1947), in a very comprehensive paper, revived some of the genera discarded by Baylis (1931), and erected some new ones. As principal characters for segregating the genera he used the ratio between the length of the esophagus, and of the entire body, and the presence or absence of spines on the spicule sheath. It is already doubtful to use differences in size, and even more ratios taxonomically. This is the more objectionable since he did not compute this ratio on the individual ratios, but took the first and last figure in the range of the length of the esophagus and of the posterior part of the body, respectively, computing the range of the ratio on these figures. For instance, in a table, p. 43, quoting measurements by Wehr (1939), on Capillaria obsignata, he found a range of the said ratio of 1.23-1.59; whereas the range, computed on the indivudal measurements is actually 1.20-1.88. For the main grouping in his key, p. 46-47, he used the feature, whether the esophagus constitutes less or more than one-third of the total length, and as subgrouping in both groups, spiny or non-spiny spicule sheath. If this key is strictly followed it should be possible to place, e.g. my specimens of Capillaria caudinflata in no less than four of his genera! (cf. Holger Madsen (1945, p. 15 and fig. 4)). I cannot, therefore, find an attempt at erecting subgenera or genera justified, when based upon the characters known at present, and prefer to adopt the opinion of Baylis. In the synopsis given by L6pez-Neyra, and by me in 1945, species described by Yamaguti (1941) and Johnston & Mawson (1941, 1945) are not included. In the following list the new points of view will be given under the heading of the individual species.