While investigating the species of Corallobothrium (Essex, 1928) I examined the intestinal parasites of 180 channel catfish (Ictalurus punctatus) taken in Rock River (Illinois). Only six of these fish harboured tapeworms that could not be assigned to the genus Corallobothrium. From the six fish, besides the species of Corallobothrium, I found fifteen adult Cestodes belonging to the genus Crepidobothrium. A study of these parasites has shown that they constitute a new species for which I propose the name Crepidobothrium fragile, because of the ease with which the strobila is broken. The members of this genus have been reported previously only from amphibians and reptiles. This is, so far as I am aware, the first recorded occurrence of a species of Crepidobothrium from a fish host. Nybelin (1917) has shown that the genus Ophiotaenia (La Rue, 1911) is synonymous with Crepidobothrium. It has been pointed out by Woodland (1925, 1925a) that the characters used by La Rue (1914) as the basis for the separation of the genera of Proteocephalids have been unreliable because of their inconstancy. He has proposed that all the genera of the family Proteocephalidae be placed in the genus Proteocephalus. Meggitt (1927) has indicated that this procedure is too sweeping and if followed would make “a most heterogeneous assemblage of some 100 species.” Therefore, he has placed all these species under four genera, namely, Corallobothrium, Crepidobothrium, Gangesia and Ichthyotaenia (= Proteocephalus), all of which have been well established for a number of years, and greater confusion of the literature may be avoided if they are retained until some worker, in the light of more complete knowledge, again makes a revision of the entire family. Since there yet remains some doubt as to the characters that will ultimately prove trustworthy in the classification of the Proteocephalids, descriptions of new species should be as complete as possible. Although there is much variability in the measurements of a given species of Cestode, yet the fact should not be overlooked that the range of size of the organism and its parts is of considerable aid in classification. It is admitted that there is great variability in size in a given species of Cestode, but if the extremes are known the size becomes of significant value.
Corrigendum to “Morphological and Molecular Identification of the New Species, Trichodina pseudoheterodentata
sp. n. (Ciliophora, Mobilida, Trichodinidae) from the Channel Catfish, Ictalurus punctatus
, in Chongqing China by Tang et al”