\u3ci\u3eFessisentis\u3c/i\u3e, a Genus of Acanthocephalans Parasitic in North American Poikilotherms

Thirteen of 16 Siren intermedia collected in Union County, Illinois, were infected with from two to 49 specimens of Fessisentis fessus Van Cleave, 1931. There are no previous reports of identified specimens of Acanthocephala from Siren. This is also the first report of F. fessus since the original description and represents new host and locality records. Old siren harbor more and larger specimens than do young siren. Intensity of infection and host age do not, however, relate to variability of other morphological features. Two paratypes, the original description, and specimens from siren form the basis for redescription of Fessisentis fessus. It is now realized that the trunk of females may be up to 52 mm long and unlike all other species of the genus it possesses a subterminal genital pore. It is also known that lemnisci of males seldom reach the anterior testis and that proboscis hooks may be in as many as 21 longitudinal rows. Contrary to the original description, F. fessus possesses two retinacula. The proboscis receptacle departs from usual acanthocephalan morphology in consisting of two muscular layers of tubular bundles with contractile fibers at the periphery enclosing a central area of noncontractile cytoplasm. Fessisentis necturorum Nickol, 1967, and F. vancleavei Haley and Bullock, 1953, also possess two retinacula and have proboscis receptacles identical in construction to those of F. fessus. Fessisentis and Fessisentidae are redescribed to conform to this additional information. Acanthocephalus vancleavei Hughes and Moore, 1943, agrees with Fessisentis as redescribed with the exception of cement gland number. One male specimen was reported to have a cement gland number atypical of both Acanthocephalus and Fessisentis. It is felt that this deviation should not be emphasized to the point of obscuring unique features shared with species of Fessisentis. Because of transfer of this species to Fessisentis, a new name, F. friedi, is proposed for F. vancleavei Haley and Bullock, 1953. Richard Heard has collected Fessisentis necturorum near Athens, Georgia, from larval Ambystoma opacum. This represents additional knowledge of host and geographical distribution

Epizootiology: [Chapter 9 in \u3ci\u3eBiology of the Acanthocephala\u3c/i\u3e]

In practice, epizootiology deals with how parasites spread through host populations, how rapidly the spread occurs and whether or not epizootics result. Prevalence, incidence, factors that permit establishment of infection, host response to infection, parasite fecundity and methods of transfer are, therefore, aspects of epizootiology. Indeed, most aspects of a parasite could be related in sorne way to epizootiology, but many of these topics are best considered in other contexts. General patterns of transmission, adaptations that facilitate transmission, establishment of infection and occurrence of epizootics are discussed in this chapter. When life cycles are unknown, little progress can be made in understanding the epizootiological aspects of any group of parasites. At the time Meyer\u27s monograph was completed (1933), intermediate hosts were known for only 17 species of Acanthocephala, and existing descriptions are not sufficient to permit identification of two of those. Laboratory infections of intermediate hosts had apparently been produced for only two species. Study at that time was primarily devoted to species descriptions, host and geographical distribution, structure and ontogeny. Little or nothing was known about adaptations that promote transmission and the concept of paratenic hosts was unclear. In spite of the paucity of information, Meyer (1932) summarized pathways of transmission among principal groups of hosts, visualized the relationships among life cycle patterns for the major groups of Acanthocephala, and devised models for the hypothetical origin of terrestrial life cycles from aquatic ones. Nevertheless, most of our knowledge regarding epizootiology has been recently acquired

\u3ci\u3eFessisentis necturorum\u3c/i\u3e sp. n. (Acanthocephala: Fessisentidae), a Parasite of the Gulf Coast Waterdog, \u3ci\u3eNecturus beyeri\u3c/i\u3e

Specimens of a previously undescribed species of the genus Fessisentis were taken from the Gulf Coast waterdog, Necturus beyeri beyeri, in southeastern Louisiana. This is the third species of the genus to be described and the first published record of Fessisentis from an amphibian. The new species as a shorter body, smaller proboscis hooks, and a proportionately larger proboscis than F. fessus. The species from Necturus has more longitudinal rows of proboscis hooks each with fewer hooks, relatively smaller male genitalia, and proportionately longer lemnisci than F. vancleavei

A Possible Function of the Fibrillar Coat in \u3ci\u3eAcanthocephalus jacksoni\u3c/i\u3e Eggs

Discusses a possible function of the fibrillar coat in Acanthocephalus jacksoni eggs

\u3ci\u3eOligacanthorhynchus lamasi\u3c/i\u3e (Freitas and Costa, 1964) comb. n. from Domestic Cats of Brazil

Freitas and Costa (1964, Arq. Esc. Vet. Univ. Fed. Minas Gerais 16:231-234) described a new species, Echinopardalis lamasi, from two acanthocephalans (1 male, 1 female) of a cat, Felis domestica (=F. catus), captured in Belo Horizonte, Minas Gerais. These specimens have been lost (Freitas, 1975, personal communication). Until two of 127 domestic cats, F. catus, from Porto Alegre, Rio Grande do SuI, captured between October 1973 and July 1976, were found to harbor respectively two and nine acanthocephalans conspecific with those described by Freitas and Costa, no additional specimens of this species were available for study. These new specimens assist in clarifying the generic affinities of E. lamasi and permit additions to the species description

\u3ci\u3eOligacanthorhynchus lamasi\u3c/i\u3e (Freitas and Costa, 1964) comb. n. from Domestic Cats of Brazil

Freitas and Costa (1964, Arq. Esc. Vet. Univ. Fed. Minas Gerais 16:231-234) described a new species, Echinopardalis lamasi, from two acanthocephalans (1 male, 1 female) of a cat, Felis domestica (=F. catus), captured in Belo Horizonte, Minas Gerais. These specimens have been lost (Freitas, 1975, personal communication). Until two of 127 domestic cats, F. catus, from Porto Alegre, Rio Grande do SuI, captured between October 1973 and July 1976, were found to harbor respectively two and nine acanthocephalans conspecific with those described by Freitas and Costa, no additional specimens of this species were available for study. These new specimens assist in clarifying the generic affinities of E. lamasi and permit additions to the species description

Dedication in \u3ci\u3eHost-Parasite Interfaces\u3c/i\u3e, edited by Brent B. Nickol

Dedication in Host-Parasite Interfaces, edited by Brent B. Nickol, proceedings of a symposium held at the University of Nebraska-Lincoln, Lincoln, Nebraska, U.S.A., October 5-7, 1977

Two Species of Acanthocephala from Australian Fishes with Description of \u3ci\u3eArhythmacanthus paraplagusiarum\u3c/i\u3e sp. n.

Two South Australian garfish, Hemirhamphus melanochir, collected near Adelaide, South Australia, harbored 14 and 15 specimens of Micracanthorhynchina hemirhamphi. Arhythmacanthus paraplagusiarum sp. n. is described from 10 specimens collected from Paraplagusia guttata taken from Moreton Bay, Brisbane, Queensland. A. paraplagusiarum differs from other species of the genus in length of the enlarged subapical proboscis hooks. These hooks are 120 to 132 μm long in females and 113 to 120 μm long in males of A. paraplagusiarum, 188 to 210 μm long in A. fusiformis, and 60 μm long in A. septacanthus. Males of A. paraplagusiarum have proboscides 182 to 206 μm long compared to proboscides 340 to 430 μm long in A. fusiformis

Life History and Host Specificity of \u3ci\u3eMediorhynchus centurorum\u3c/i\u3e Nickol 1969 (Acanthocephala: Gigantorhynchidae)

Examination of 1905 arthropods from a swamp and surrounding pasture in southern Louisiana revealed larval specimens of Mediorhynchus centurorum in 8 of 228 woodroaches, Parcoblatta pensylvanica, but in no other species. The life cycle was confirmed by feeding eggs of M. centurorum to laboratory-reared woodroaches. Cystacanths later recovered from the woodroaches developed into mature worms when pipetted into esophaguses of red-bellied woodpeckers, Centurus carolinus; redheaded woodpeckers, Melanerpes erythrocephalus; yellow-shafted flickers, Colaptes auratus; and a hairy woodpecker, Dendrocopos villosus. Infection was achieved in all woodpeckers fed cystacanths at least 47 days old and the mean prepatent period was 35 days. Cystacanths fed starlings, Sturnus vulgaris, and red-winged blackbirds, Agelaius phoeniceus, did not produce infections although cystacanths from the same pool were infective to control woodpeckers. Larval development of Mediorhynchus centurorum in woodroaches did not differ significantly from that of M. grandis in grasshoppers. M. centurorum is the only species of the Gigantorhynchidae for which the life cycle has been confirmed by laboratory infections using an intermediate host species known infected in nature