Ergasilus (Copepoda: Cyclopoida): Revision and Key to Species in North America

Abstract

JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact support@jstor.org. Species reduced to synonymy are E. osburni Tidd and Bangham, 1945 (with E. celestis); E. nigritus Wilson, 1916 (with E. centrarchidarum); E. confusus Bere, 1931 (with E. luciopercarum); and E. skriabini Mueller, 1936 (with E. luciopercarum). A key to the species in the genus based on characteristics of the adult females is presented. A generic diagnosis, specific diagnoses, and some comments relative to each species are included.The genus Ergasilus has not received comprehensive attention in the United States since Wilson (1911), although its importance is attested by the numerous reports in fish parasite surveys since then (see Hoffman 1967). In addition, there have been several new species described since Wilson's monograph (). Some of these new species have been synonymized with previously described species (Mueller 1936b), and some of the synonyms have been redescribed as distinct (Roberts 1 This study was supported in part by NIH grants AI-06153 and 5 TOI-AI-226. I am indebted to the following persons for the loan or gift of specimens: 135 1969a). Many of the earlier descriptions are either incomplete, inaccurate, or both, and partly for this reason there have been numerous errors in the survey reports. Other reasons for these errors were expressed succinctly by Pennak (1963) in reference to other cyclopoids. Therefore, it appeared desirable to restudy all known species of the genus occurring in North America. It is not anticipated that the present treatment will be definitive, but it will be of value as a basis for further work.Methods and terminology are as used previously (Roberts 1969a,b). The key relies chiefly on characteristics which can be observed with a minimum of dissection. The reader is referred also to the dissection and preparation instructions given by Pennak (1963) for the free-swimming cyclopoids, most of which can be applied to Ergasilus. For identification, it is usually necessary to mount at least one specimen whole, dorsal side up, under a supported cover slip, and to perform at least some dissection on one specimen, ventral side up, i.e., to remove the antennal area (including antennae and antennules) and the genital segment plus abdomen (including the 4th free thoracic segment bearing the 5th legs). The egg sacs, if any, should be separated from the genital segment before that segment is removed from the rest of the thorax.In collecting Ergasilus specimens, it is generally preferable to excise and preserve the fish gill arches entire. The specimens mav be removed from the gill filaments later under a dissecting microscope to avoid damaging the antennae.Considerable emphasis is placed in the kev and diaenoses on the prehensile antennae. Functioning to h...

The Parasitic Crustaceans of Fishes From the Brazilian Amazon. 5. Brasergasilus Gen. Nov. (Copepoda: Cyclopidea), a "Three-Legged" Ergasilid, With Two New Species and the Proposal of Abergasilinae Subfam. Nov.

“…Al though Hewitt (1978) did not discuss the matter, it should be admitted that neither of these ge nera conforms to the definitions of Ergasilidae currently in use (ie. Yamaguti, 1963& Roberts, 1970. These definitions indicate that fe males should have four pairs of swimming legs and a fifth pair of vestigial legs.…”

Os crustáceos parásitos de peixes da Amazonia Brasileira. I-Ergasilus bryconis n. sp. (Copepoda: Cyclopoidea) da matrinchã (Brycon melanopterus (Cope))

“…Por exemplo, Yamaguti (1963) conside rou que a anterra 11 tem 5 segmentos, mas outros autores mais recent· es (Roberts, 1970;Burris & Miller , 1972) só contaram 4 segmentos. Segundo Roberts (1970), o primeiro endopódito tém 2 ou …”

Ergasilus coatiarus Sp. N. (Copepoda, Poecilostomatoida, Ergasilidae) parasita dos filamentos branquiais de Cichla monoculus spix, 1831 (Perciforme: Cichlidae) da Amazônia Brasileira

“…luciopercarum Henderson, 1926;E. arthrosis Roberts, 1969 (sinonímia E. versicolor); E. lanceolatus Wilson, 1916; E. nerkae Roberts, 1963e E. caeruleus Wilson, 1911(Roberts, 1970.…”