Parasite communities are arranged into hierarchical levels of organization, covering various spatial and temporal scales. These range from all parasites within an individual host to all parasites exploiting a host species across its geographic range. This arrangement provides an opportunity for the study of patterns and structuring processes operating at different scales. Across the parasite faunas of various host species, several species-area relationships have been published, emphasizing the key role of factors such as host size or host geographical range in determining parasite species richness. When corrections are made for unequal sampling effort or phylogenetic influences, however, the strength of these relationships is greatly reduced, casting a doubt over their validity. Component parasite communities, or the parasites found in a host population, are subsets of the parasite fauna of the host species. They often form saturated communities, such that their richness is not always a reflection of that of the entire parasite fauna. The species richness of component communities is instead influenced by the local availability of parasite species and their probability of colonization. At the lowest level, infracommunities in individual hosts are subsets of the species occurring in the component community. Generally, their structure does not differ from that expected from a random assembly of available species, although comparisons with precise null models are still few. Overall studies of parasite communities suggest that the action of processes determining species richness of parasite assemblages becomes less detectable as focus shifts from parasite faunas to infracommunities.

SPECIES RICHNESS OF PARASITE ASSEMBLAGES: Evolution and Patterns

Whereas terminological recommendations require authors to use mean intensity or mean abundance to quantify parasites in a sample of hosts, awkward statistical limitations also force them to use either the median or the geometric mean of these measures when making comparisons across different samples. Here, we propose to reconsider this inconsistent practice by giving priority to biological realism in the interpretation of different statistical descriptors and choosing the statistical tools appropriate to our decisions. Prevalence, mean intensity, and indices of parasite distribution (such as median intensity) are suitable descriptors to quantify parasites in a sample of hosts. These measures have different biological interpretations and need different statistical methods to be compared between samples.

/pdf/quantifying-parasites-in-samples-of-hosts-3mbxkolxq1.pdf

Quantifying parasites in samples of hosts

As the number of fish reproduction studies has proliferated, so has the number of gonadal classification schemes and terms. This has made it difficult for both scientists and resource managers to communicate and for comparisons to be made among studies. We propose the adoption of a simple, universal terminology for the phases in the reproductive cycle, which can be applied to all male and female elasmobranch and teleost fishes. These phases were chosen because they define key milestones in the reproductive cycle; the phases include immature, developing, spawning capable, regressing, and regenerating. Although the temporal sequence of events during gamete development in each phase may vary among species, each phase has specific histological and physiological markers and is conceptually universal. The immature phase can occur only once. The developing phase signals entry into the gonadotropin-dependent stage of oogenesis and spermatogenesis and ultimately results in gonadal growth. The spawning cap...

https://afspubs.onlinelibrary.wiley.com/doi/pdf/10.1080/19425120.2011.555724

A Standardized Terminology for Describing Reproductive Development in Fishes

Parasites can have strong impacts but are thought to contribute little biomass to ecosystems. We quantified the biomass of free-living and parasitic species in three estuaries on the Pacific coast of California and Baja California. Here we show that parasites have substantial biomass in these ecosystems. We found that parasite biomass exceeded that of top predators. The biomass of trematodes was particularly high, being comparable to that of the abundant birds, fishes, burrowing shrimps and polychaetes. Trophically transmitted parasites and parasitic castrators subsumed more biomass than did other parasitic functional groups. The extended phenotype biomass controlled by parasitic castrators sometimes exceeded that of their uninfected hosts. The annual production of free-swimming trematode transmission stages was greater than the combined biomass of all quantified parasites and was also greater than bird biomass. This biomass and productivity of parasites implies a profound role for infectious processes in these estuaries.

Ecosystem energetic implications of parasite and free-living biomass in three estuaries

https://www.esf.edu/efb/mitchell/Marcogliese2005-Parasites_of_the_superorganism.pdf

Parasites of the superorganism: Are they indicators of ecosystem health?

We consider 27 population and community terms used frequently by parasitologists when describing the ecology of parasites. We provide suggestions for various terms in an attempt to foster consistent use and to make terms used in parasite ecology easier to interpret for those who study free-living organisms. We suggest strongly that authors, whether they agree or disagree with us, provide complete and unambiguous definitions for all parameters of their studies.

/pdf/parasitology-meets-ecology-on-its-own-terms-margolis-et-al-4c6w2pahe6.pdf

Parasitology meets ecology on its own terms: Margolis et al. revisited.

This paper reports patterns of similarity and overlap in species presence and patterns of linear distribution of intestinal helminths in 22 avocets from 4 populations. Avocets collected from ephemeral bodies of water in Alberta and Manitoba had communities composed largely of species that are avocet specialists plus some that are host generalists. The composition of helminth communities in these hosts was similar to that reported in earlier surveys of avocet helminths. There was little evidence for competition between helminth species in these communities. In contrast, avocets collected from permanent bodies of water in Alberta had communities composed largely of species that are specialists in various duck species, particularly lesser scaup. These helminths were superimposed on the normal community, fitting into linear gaps along the intestine but also overlapping the distributions of avocet specialists. These lesser scaup specialists exhibit interactive patterns amongst themselves and, to some extent, with avocet specialists. Helminth communities in avocets from ephemeral bodies of water have vacant niches and are largely isolationist in nature. Those in avocets from permanent bodies of water are saturated and are more interactive in nature.

Helminth communities in avocets: importance of the compound community.

Tetrameres williamsi sp. n. is described from the white ibis in Florida and Louisiana. The new species is placed in the subgenus Gynaecophila and is characterized by the absence of a gubernaculum, dorsolateral projections on the right spicule, very minute cuticular spines, and 3 (occasionally 2) pairs of postanal papillae. Tetrameres (T.) grusi Shumakovich, 1946, is reported for the first time from North America in a new host, the sandhill crane. The male of this species is redescribed and the female is described for the first time. Seventy of 140 white ibis, Eudocimus albus, collected in Florida between February 1970 and August 1972, and 13 of 37 white ibis collected in Louisiana between June 1970 and August 1971, were found infected with Tetrameres (Gynaecophila) williamsi sp. n. Infected birds harbored one to 111 worms. This species is named in honor of Lovett E. Williams, Jr., Biologist, Florida Game and Fresh Water Fish Commission. In addition, Tetrameres (Tetrameres) grusi Shumakovich was recovered from the proventriculus in 23 of 45 sandhill cranes, Grus canadensis, collected in Florida between February 1970 and May 1972, thus establishing a new host and locality record for this parasite. Infected birds harbored one to 79 worms. A description of female T. (T.) grusi is presented for the first time and the male is re-

Tetrameres (Gynaecophila) williamsi sp. n. (Nematoda: Tetrameridae) from the White Ibis, Eudocimus albus, with Notes on Tetrameres (Tetrameres) grusi Shumakovich from the Sandhill Crane, Grus canadensis

http://phthiraptera.info/sites/phthiraptera.info/files/39734.pdf

Albert O. Bush

Papers

Parasitology meets ecology on its own terms: Margolis et al. revisited.

Helminth communities in avocets: importance of the compound community.

Tetrameres (Gynaecophila) williamsi sp. n. (Nematoda: Tetrameridae) from the White Ibis, Eudocimus albus, with Notes on Tetrameres (Tetrameres) grusi Shumakovich from the Sandhill Crane, Grus canadensis

Parasites of Florida Sandhill Cranes, Grus canadensis pratensis

Parasitology meets ecology: definitions, clarifications, examples and Margolis et al. revisited