Document Type

Report

Department/Program

Virginia Institute of Marine Science

Publication Date

1981

Series

Special papers in marine science; No. 6.

Abstract

Original literature on the super family Capsaloidea Price, 1936 published prior to May 1968 was examined for parasite-host locality records in order to study the host-specificity and zoo­geography of the super family. Complete locality records, synonyms, and references for 221 species of capsaloids belonging to 70 genera and five families and parasitizing over 260 natural hosts are given. New locality records are given for Dioncus agassizi, D. remora, and Caballerocotyla manteri. Host-specificity tables are given f or all species. The host names have been updated, and the host ranges documented. Comments are made on conf used and elroneous records. The level of host-specificity is discussed for all species. Aspects of physiological specificity, biological tags, host taxonomy, relative rates of evolution, organ-specifici­ty, and ecological specificity are discussed. Zoogeographical aspects are investigated. A list of recommendations is presented which, if followed, would ensure more meaningful parasite-host locality records in the future.

Capsaloids are shown to be presently primarily species-specific gill parasites of warm temperature Osteichthyes. At each level of host-specificity the majority of capsaloids were found to occur on the gills, with those occurring on the skin second in abundance. As the level of specificity decreases, there is a slight decrease in the percentage of capsaloids occurring on the gills, and a slight increase in the percentage occurring on the skin, an indication that gill forms are more species-specific than skin forms. More gill forms are species-specific than skin forms or capsaloids in any other organ. Capsaloids of Chondrichthyes are less gill-specific than those on Osteichthyes. The relative rates of evolution of Capsaloidea are shown to be slower than, coincident with, or f aster than their hosts. The slower evolving capsaloids are those that exhibit phylogenetic specificity and parasitize more than one host. The capsaloids whose rates of volution approximate those of their hosts are those species-specific ones which have no close relatives on the same host; if they had a close relative on the same host they would be evolving faster than the host. The occurrence of Benedeniinae on rays and Osteich­ thyes could indicate their evolution on ancestral jawed-fishes, if so, then they probably represent the oldest capsaloid subfamily. Their occurrence on a far larger number of host families than any other subfamily, and their cosmopolitan distribution are further indications of their antiquity. All host-specificity for species above the order-specific level may probably be attributed to ecological specificity. A majority of the capsaloid species (79.4 percent) are endemic to a single zoogeographical zone, while 6.7 percent are amphi-atlantic, 1.0 percent are amphi-Pacif ic, 1.4 percent are amphi-American, and 0.s percent are circumpolar. Several species approach a circumtropical distribution. There is a higher affinity among zones in the Atlantic than in the other oceans. Temperature appears to be a f actor in determining the distribution of capsaloids.

Issue

No. 6

DOI

http://doi.org/10.21220/V57G6N

Keywords

Trematoda > Geographical distribution. Platyhelminthes -- Geographical distribution. Brazil -- Commercial policy.

Creative Commons License

Creative Commons Attribution 3.0 License
This work is licensed under a Creative Commons Attribution 3.0 License.

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