Comparative Studies on Furcocercous Cercariae
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^.-^.^^:1:;'^^:^: ^ -^ %-^':-/^ i>fci. w THE UNIVERSITY OF ILLINOIS LIBRARY XLL -m^ The person charging this material is re- from sponsible for its return to the library or before the which it was withdrawn on Latest Date stamped below. of books Theft, mutilation, and underlining may are reasons for disciplinary action and result in dismissal from the University. HAMPAIGN UNIVERSITY OF ILLINOIS LIBRARY AT URBANA C ILLINOIS BIOLOGICAL MONOGRAPHS PUBLISHED QUARTERLY UNDER THE AUSPICES OF THE GRADUATE SCHOOL BY THE UNIVERSITY OF ILLINOIS VOLUME X Urbana, Illinois 1926 Editorial CoMsnTTEE Stephen Alfred Forbes William Trelease Henry Baldwin Ward T / / TABLE OF CONTENTS VOLUME X NXTMBERS PAGES 1. Studies on the Avian Species of the Cestode Family H\ menolepididae. By R. L. Mayhew. With 9 plates and 2 text figures 1-126 2. Some North American Fish Trematodes. By H. W. Manter. With 6 plates, 2 charts, and 1 text figure 127-264 3. Comparative Studies on Furcocercous Cercariae. By H. M. Miller, Jr. With 8 plates and 2 text figures : 265-370 4. A Comparison of the Animal Communities of Coniferous and Deciduous Forests. By I. H. Blake. With 16 plates and 25 tables 371-520 Digitized by tine Internet Arciiive in 2011 witin funding from University of Illinois Urbana-Champaign http://www.archive.org/details/comparativestudi10mill COMPARATIVE STUDIES ON FURCOCERCOUS CERCARIAE WITH 8 PLATES AND 2 TEXTFIGURES BY HARRY MILTON MILLER, Jr. Contributions from the Zoological Laboratory of the University of Illinois imder the direction"of Henry B. Ward No." 2 90 THESIS SUBMITTED AS PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN ZOOLOGY IN THE GRADUATE SCHOOL OF THE UNIVERSITY OF ILLINOIS 1923 V, I tr' TABLE OF CONTENTS Introduction 7 Historical Review 8 Methods of Investigation 25 Nomenclature 25 Description of Species and Comparison with Related Forms 30 Apharyngeal Brevifurcate Distome Cercariae 30 Cercaria elvae Miller 1923 30 Cercaria ocellata LaVal. St. George 1855 30 Cercaria bombayensis no. 19 Soparkar 1921 30 Cercaria giganiea Faust 1924 30 Cercaria wardi MUler 1923 35 Cercaria bombayensis no. 13 Soparkar 1921 35 Cercaria indica XXV SeweU 1922 35 Pharyngeal Longifurcate Distome Cercariae 41 Cercaria burii Miller 1923 41 Cercaria doiiglasi Cort 1917 41 Cercaria tenuis MUler 1923 45 Cercaria chrysenterica Miller 1923 47 Cercaria emarginatae Cort 1917 47 Cercaria letijera Fuhrmann 1916 47 Pharyngeal Longifurcate Monostome Cercariae 50 Cercaria iniiUicellitlata MiUer 1923 50 Cercaria hamaia Miller 1923 55 Cercaria rhabdocaeca Faust 1919 55 Classification 59 Apharyngeal Cercariae 64 Apharyngeal Brevifurcate Cercariae 64 Apharyngeal Brevifurcate Distome Cercariae 64 Apharyngeal Brevifurcate Monostome Cercariae 68 Apharyngeal Longifurcate Cercariae 69 Apharyngeal Longifurcate Distome Cercariae 69 Apharyngeal Longifurcate Monostome Cercariae 69 Pharj-ngeal Cercariae 70 Pharyngeal Brevifurcate Distome Cercariae 70 Pharyngeal Brevifurcate Cercariae 70 Pharyngeal Brevifurcate Monostome Cercariae 70 Pharyngeal Longifurcate Cercariae . 70 Pharj'ngeal Longifurcate Distome Cercariae 71 Pharyngeal Longifurcate Monostome Cercariae 72 Furcocercous Cercariae of Uncertain Position 73 Check List of Furcocercous Cercariae 74 Fresh Water Species 74 Marine Species 77 S>Tionyms 77 Discussion of Life Histories 78 Incidence of Infection of Snails 81 Multiple Infections 81 Summary of Results 84 BibUography 85 Explanation of Plates 94 Index Ill 265] COMPARATIVE STUDIES ON FURCOCERCOUS CERCARIAE—MILLER INTRODUCTION Early in the study of larval trematodes, begun in 1920 at the suggestion of Professor Henry B. Ward, the author's interest became centered on the furcocercous cercariae, and exclusive attention was devoted to these forms. In this work all larvae which possess a tail with a bifurcated distal end have been considered, although the heterogeneity of the group is recognized and was, indeed, a reason for the present study; these forms are also of interest because of the relation of some of them to schistosomiasis. Collections of the common pulmonate snails, Planorbis and Physa, from the Drainage Ditch, Urbana, Illinois, as well as from small streams running into it, yielded furcocercous cercariae. Species of branchiate snails of the genera Goniobasis and Campeloma from several localities were also ex- amined, but no furcocercous infections were found. During the summer of 1921 the investigations were carried on at the University of Michigan Biologi- cal Station at Douglas Lake, Michigan; various species of pulmonate and branchiate snails were collected from the waters of this region. Complete collection and infection records are given in another part of this paper. As a result of this study seven new species of furcocercous cercariae are added to the fauna of North America; and the author is able, from a per- sonal knowledge of some partly described forms, and with the advantage of access to recent literature, to present a survey of this group of larval trema- todes. To Professor Henry B. Ward, under whose direction the investigations have been carried out, the author acknowledges indebtedness for sugges- tions and helpful criticisms, and for the use of his extensive private library. Thanks are also due to Dr. G. R. LaRue, Director of the Michigan Biologi- cal Station, for courtesies extended during the summer of 1921, and to Pro- fessor Frank Smith and Curator Frank C. Baker of the University of Ill- inois for the identification of snail hosts. ILLINOIS BIOLOGICAL MONOGRAPHS [266 HISTORICAL REVIEW Probably the first furcocercous cercaria to be described is included by O. F. Miiller (1773) in the Vermium Terrestrium et Fluviatilium; he placed it in the genus Vibrio, as Vibrio malleus. There is no figure, and the de- scription is short, containing the following significant words :"motu literam Y, quiete T simulat." This form was accepted by subsequent workers as a cercaria. In 1794 Abildgaard described a larval trematode from Denmark with a tail distally bifurcated to its middle, to which he gave the name Cer- caria varicans. This is the first record of a larva, recognized as a trematode, having this sort of tail. The original description is very scanty, and as no details of structure were added by the few subsequent workers who dis- cussed this form, it could not now be identified with certainty. No internal structures are either described or figured, which leaves in doubt the pres- ence or absence of a pharynx; no ventral sucker is shown. In the figures the furcae are about equal in length to the tail-stem. Nitzsch (1817) very briefly described C. fareata, a distome larva with relatively long furcae sharply delimited from the tail-stem; this form has been mentioned by a number of authors but no significant details have been added. Diesing (1850), in his Systema Helminthum, included Malleolus Jurcatns Ehrenberg (1838) as the only known species of distome furcocer- cous larva, and listed the following as synonyms: Vibrio malleus Miiller (1773), Zirkelthier of Eichhorn (1781), Histrionella fissa Bory (1825), Cer- caria furcata Nitzsch (1817), and Cercaria VI von Baer (1826). This syn- onymy, with the exception of Histrionella fissa, was accepted by Moulinie (1856), who did not recognize the genus Malleolus, but listed the synonyms under Cercaria furcata Nitzsch. The present author finds no evidence in the literature which would set aside the disposition of Moulinie; in every case the accounts are so meager, with an almost complete lack of description of internal structure, that the species could not be identified with certainty. Diesing, in the Systema Helminthum, placed Cercaria varicans Abildgaard in a new genus Cheilostomum, as Clieilostomum varicans, the type and sole species; Moulinie returned this species also to the genus Cercaria. La Valette St. George (1855) included in his monograph on larval tre- matodes brief descriptions of four new furcocercous forms, a brevifurcate monostome, Cercaria crisiata, and three distomes, C. fissicaiida, C. gracilis, and C. ocellata. He also figured C. dichotoma Joh. Miiller, said to have been found by Miiller in 1850 in the Mediterranean at Nice. This paper by Miiller does not contain any definite reference to a furcocercous larva, and 267] COMPA RA TIVE STUDIES ON FURCOCERCOUS CERCA RTA E—MILLER 9 the figure included by La Valette St. George has been accepted by sub- sequent workers. C. dichotoma is the first of the few marine furcocercous cercariae which have been described. Filippi (1857) questioned the valid- ity of C. cristata, as being distinct from C. varicans. The present author is of the opinion that they are distinct, because the dorsal body crest, prom- inent in C. cristata, was not mentioned or figured by Abildgaard for C. vari- cans; furthermore the latter species is a longifurcate larva, while the former is brevifurcate. Diesing (1858), in a further systematic treatise on cercariae, made a new genus Lophocercaria to contain only Lophocercariafissicauda, under which he put as a synonym Cercaria cristata La Val. St. George ; there is no reason, stated or apparent, for such a change of specific name. Two other species of La Valette St. George were placed in a new subgenus, Cercaria {Schizo- cerca) gracilis and C. {Schizocerca) fissicauda, as well as C. (Schizocerca) dichotoma Joh. Miiller. He also established the genus Histrionellina to con- tain only Cercaria oceUata La Val. St. George, which was designated His- trionellina fissicauda. No significant details of structure were