Complex life-cycles in trophically transmitted helminths: Do the benefits of increased growth and transmission outweigh generalism and complexity costs?
Why do so many parasitic worms have complex life-cycles? A complex life-cycle has at least two hypothesized costs: (i) worms with longer life-cycles, i.e. more successive hosts, must be generalists at the species level, which might reduce lifetime survival or growth, and (ii) each required host tran...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2022-01-01
|
| Series: | Current Research in Parasitology and Vector-Borne Diseases |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2667114X22000115 |
| _version_ | 1797980792010309632 |
|---|---|
| author | Daniel P. Benesh James C. Chubb Kevin D. Lafferty Geoff A. Parker |
| author_facet | Daniel P. Benesh James C. Chubb Kevin D. Lafferty Geoff A. Parker |
| author_sort | Daniel P. Benesh |
| collection | DOAJ |
| description | Why do so many parasitic worms have complex life-cycles? A complex life-cycle has at least two hypothesized costs: (i) worms with longer life-cycles, i.e. more successive hosts, must be generalists at the species level, which might reduce lifetime survival or growth, and (ii) each required host transition adds to the risk that a worm will fail to complete its life-cycle. Comparing hundreds of trophically transmitted acanthocephalan, cestode, and nematode species with different life-cycles suggests these costs are weaker than expected. Helminths with longer cycles exhibit higher species-level generalism without impaired lifetime growth. Further, risk in complex life-cycles is mitigated by increasing establishment rates in each successive host. Two benefits of longer cycles are transmission and production. Longer cycles normally include smaller (and thus more abundant) first hosts that are likely to consume parasite propagules, as well as bigger (and longer-lived) definitive hosts, in which adult worms grow to larger and presumably more fecund reproductive sizes. Additional factors, like host immunity or dispersal, may also play a role, but are harder to address. Given the ubiquity of complex life-cycles, the benefits of incorporating or retaining hosts in a cycle must often exceed the costs. |
| first_indexed | 2024-04-11T06:00:34Z |
| format | Article |
| id | doaj.art-1b4d3ab04a4d44d9be51801a2f68e0f0 |
| institution | Directory Open Access Journal |
| issn | 2667-114X |
| language | English |
| last_indexed | 2024-04-11T06:00:34Z |
| publishDate | 2022-01-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Current Research in Parasitology and Vector-Borne Diseases |
| spelling | doaj.art-1b4d3ab04a4d44d9be51801a2f68e0f02022-12-22T04:41:43ZengElsevierCurrent Research in Parasitology and Vector-Borne Diseases2667-114X2022-01-012100085Complex life-cycles in trophically transmitted helminths: Do the benefits of increased growth and transmission outweigh generalism and complexity costs?Daniel P. Benesh0James C. Chubb1Kevin D. Lafferty2Geoff A. Parker3Humboldt University of Berlin, Molecular Parasitology, Philippstr. 13, Haus 14, 10115, Berlin, Germany; Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), Müggelseedamm 310, 12587, Berlin, Germany; Corresponding author. Humboldt University of Berlin, Molecular Parasitology, Philippstr. 13, Haus 14, 10115, Berlin, Germany.Department of Evolution, Ecology and Behaviour, University of Liverpool, Liverpool, L69 7ZB, UKWestern Ecological Research Center, U.S. Geological Survey, at Marine Science Institute, University of California, Santa Barbara, CA, 93106, USADepartment of Evolution, Ecology and Behaviour, University of Liverpool, Liverpool, L69 7ZB, UKWhy do so many parasitic worms have complex life-cycles? A complex life-cycle has at least two hypothesized costs: (i) worms with longer life-cycles, i.e. more successive hosts, must be generalists at the species level, which might reduce lifetime survival or growth, and (ii) each required host transition adds to the risk that a worm will fail to complete its life-cycle. Comparing hundreds of trophically transmitted acanthocephalan, cestode, and nematode species with different life-cycles suggests these costs are weaker than expected. Helminths with longer cycles exhibit higher species-level generalism without impaired lifetime growth. Further, risk in complex life-cycles is mitigated by increasing establishment rates in each successive host. Two benefits of longer cycles are transmission and production. Longer cycles normally include smaller (and thus more abundant) first hosts that are likely to consume parasite propagules, as well as bigger (and longer-lived) definitive hosts, in which adult worms grow to larger and presumably more fecund reproductive sizes. Additional factors, like host immunity or dispersal, may also play a role, but are harder to address. Given the ubiquity of complex life-cycles, the benefits of incorporating or retaining hosts in a cycle must often exceed the costs.http://www.sciencedirect.com/science/article/pii/S2667114X22000115AdaptationComparative analysisComplex life-cycleHost specificityLife-history strategyTrophic transmission |
| spellingShingle | Daniel P. Benesh James C. Chubb Kevin D. Lafferty Geoff A. Parker Complex life-cycles in trophically transmitted helminths: Do the benefits of increased growth and transmission outweigh generalism and complexity costs? Current Research in Parasitology and Vector-Borne Diseases Adaptation Comparative analysis Complex life-cycle Host specificity Life-history strategy Trophic transmission |
| title | Complex life-cycles in trophically transmitted helminths: Do the benefits of increased growth and transmission outweigh generalism and complexity costs? |
| title_full | Complex life-cycles in trophically transmitted helminths: Do the benefits of increased growth and transmission outweigh generalism and complexity costs? |
| title_fullStr | Complex life-cycles in trophically transmitted helminths: Do the benefits of increased growth and transmission outweigh generalism and complexity costs? |
| title_full_unstemmed | Complex life-cycles in trophically transmitted helminths: Do the benefits of increased growth and transmission outweigh generalism and complexity costs? |
| title_short | Complex life-cycles in trophically transmitted helminths: Do the benefits of increased growth and transmission outweigh generalism and complexity costs? |
| title_sort | complex life cycles in trophically transmitted helminths do the benefits of increased growth and transmission outweigh generalism and complexity costs |
| topic | Adaptation Comparative analysis Complex life-cycle Host specificity Life-history strategy Trophic transmission |
| url | http://www.sciencedirect.com/science/article/pii/S2667114X22000115 |
| work_keys_str_mv | AT danielpbenesh complexlifecyclesintrophicallytransmittedhelminthsdothebenefitsofincreasedgrowthandtransmissionoutweighgeneralismandcomplexitycosts AT jamescchubb complexlifecyclesintrophicallytransmittedhelminthsdothebenefitsofincreasedgrowthandtransmissionoutweighgeneralismandcomplexitycosts AT kevindlafferty complexlifecyclesintrophicallytransmittedhelminthsdothebenefitsofincreasedgrowthandtransmissionoutweighgeneralismandcomplexitycosts AT geoffaparker complexlifecyclesintrophicallytransmittedhelminthsdothebenefitsofincreasedgrowthandtransmissionoutweighgeneralismandcomplexitycosts |