Can a terrestrial ectoparasite disperse with its marine host?

Katherine L. Moon, Ian J. Aitkenhead, Ceridwen I. Fraser, Steven L. Chown

Research output: Contribution to journalArticleResearchpeer-review

1 Citation (Scopus)

Abstract

One of the most extreme examples of parasite adaptation comes from terrestrial ectoparasites exploiting marine hosts. Despite the ubiquity of such ectoparasitism and its ecological and evolutionary importance, investigations of the responses of ectoparasites to conditions encountered on their hosts are rare. In the case of penguins and their ticks, current understanding suggests that ticks freely parasitize their hosts on land but are incapable of surviving extended oceanic journeys. We examined this conjecture by assessing the physiological capacity of little penguin ticks to endure at-sea foraging and dispersal events of their hosts. Survival in penguins ticks was not significantly compromised by exposure to depths commonly associated with host dives (40 and 60 m), repeated seawater exposure relevant to the most common(30 s) andlongest (120 s) recorded host dives, or extended (48 h) exposure to seawater. Mean (±SD) closed-phase durations in adult and nymphal ticks exhibiting discontinuous gas exchange (339 ± 237 and 240 ± 295 s, respectively) exceeded that of the maximum recorded host dive duration (120 s). Normoxic-anoxic-normoxic respirometry also confirmed spiracle closure. Mean metabolic rates (0:354 ± 0:220 and 4:853 ± 4:930 µL/h at 25°C for unfed and fed adult females, respectively) were significantly influenced by temperature; optimal and LT50 temperatures for adult ticks and fed nymphal ticks were typically higher than swimming penguinbody temperatures. These findings suggest that marine host dispersal is unlikely to present an insurmountable barrier to long-distance tick dispersal. Such dispersal has important implications for evolutionary theory, conservation, and epidemiology.

Original languageEnglish
Pages (from-to)163-176
Number of pages14
JournalPhysiological and Biochemical Zoology
Volume92
Issue number2
DOIs
Publication statusPublished - 1 Mar 2019

Keywords

  • Depth tolerance
  • Metabolic rate
  • Penguins
  • Salinity tolerance
  • Ticks
  • Underwater survival

Cite this

Moon, Katherine L. ; Aitkenhead, Ian J. ; Fraser, Ceridwen I. ; Chown, Steven L. / Can a terrestrial ectoparasite disperse with its marine host?. In: Physiological and Biochemical Zoology. 2019 ; Vol. 92, No. 2. pp. 163-176.
@article{d5b1ca0b226c462489c08ae3e0da17d2,
title = "Can a terrestrial ectoparasite disperse with its marine host?",
abstract = "One of the most extreme examples of parasite adaptation comes from terrestrial ectoparasites exploiting marine hosts. Despite the ubiquity of such ectoparasitism and its ecological and evolutionary importance, investigations of the responses of ectoparasites to conditions encountered on their hosts are rare. In the case of penguins and their ticks, current understanding suggests that ticks freely parasitize their hosts on land but are incapable of surviving extended oceanic journeys. We examined this conjecture by assessing the physiological capacity of little penguin ticks to endure at-sea foraging and dispersal events of their hosts. Survival in penguins ticks was not significantly compromised by exposure to depths commonly associated with host dives (40 and 60 m), repeated seawater exposure relevant to the most common(30 s) andlongest (120 s) recorded host dives, or extended (48 h) exposure to seawater. Mean (±SD) closed-phase durations in adult and nymphal ticks exhibiting discontinuous gas exchange (339 ± 237 and 240 ± 295 s, respectively) exceeded that of the maximum recorded host dive duration (120 s). Normoxic-anoxic-normoxic respirometry also confirmed spiracle closure. Mean metabolic rates (0:354 ± 0:220 and 4:853 ± 4:930 µL/h at 25°C for unfed and fed adult females, respectively) were significantly influenced by temperature; optimal and LT50 temperatures for adult ticks and fed nymphal ticks were typically higher than swimming penguinbody temperatures. These findings suggest that marine host dispersal is unlikely to present an insurmountable barrier to long-distance tick dispersal. Such dispersal has important implications for evolutionary theory, conservation, and epidemiology.",
keywords = "Depth tolerance, Metabolic rate, Penguins, Salinity tolerance, Ticks, Underwater survival",
author = "Moon, {Katherine L.} and Aitkenhead, {Ian J.} and Fraser, {Ceridwen I.} and Chown, {Steven L.}",
year = "2019",
month = "3",
day = "1",
doi = "10.1086/701726",
language = "English",
volume = "92",
pages = "163--176",
journal = "Physiological and Biochemical Zoology",
issn = "1522-2152",
publisher = "The University of Chicago Press",
number = "2",

}

Can a terrestrial ectoparasite disperse with its marine host? / Moon, Katherine L.; Aitkenhead, Ian J.; Fraser, Ceridwen I.; Chown, Steven L.

In: Physiological and Biochemical Zoology, Vol. 92, No. 2, 01.03.2019, p. 163-176.

Research output: Contribution to journalArticleResearchpeer-review

TY - JOUR

T1 - Can a terrestrial ectoparasite disperse with its marine host?

AU - Moon, Katherine L.

AU - Aitkenhead, Ian J.

AU - Fraser, Ceridwen I.

AU - Chown, Steven L.

PY - 2019/3/1

Y1 - 2019/3/1

N2 - One of the most extreme examples of parasite adaptation comes from terrestrial ectoparasites exploiting marine hosts. Despite the ubiquity of such ectoparasitism and its ecological and evolutionary importance, investigations of the responses of ectoparasites to conditions encountered on their hosts are rare. In the case of penguins and their ticks, current understanding suggests that ticks freely parasitize their hosts on land but are incapable of surviving extended oceanic journeys. We examined this conjecture by assessing the physiological capacity of little penguin ticks to endure at-sea foraging and dispersal events of their hosts. Survival in penguins ticks was not significantly compromised by exposure to depths commonly associated with host dives (40 and 60 m), repeated seawater exposure relevant to the most common(30 s) andlongest (120 s) recorded host dives, or extended (48 h) exposure to seawater. Mean (±SD) closed-phase durations in adult and nymphal ticks exhibiting discontinuous gas exchange (339 ± 237 and 240 ± 295 s, respectively) exceeded that of the maximum recorded host dive duration (120 s). Normoxic-anoxic-normoxic respirometry also confirmed spiracle closure. Mean metabolic rates (0:354 ± 0:220 and 4:853 ± 4:930 µL/h at 25°C for unfed and fed adult females, respectively) were significantly influenced by temperature; optimal and LT50 temperatures for adult ticks and fed nymphal ticks were typically higher than swimming penguinbody temperatures. These findings suggest that marine host dispersal is unlikely to present an insurmountable barrier to long-distance tick dispersal. Such dispersal has important implications for evolutionary theory, conservation, and epidemiology.

AB - One of the most extreme examples of parasite adaptation comes from terrestrial ectoparasites exploiting marine hosts. Despite the ubiquity of such ectoparasitism and its ecological and evolutionary importance, investigations of the responses of ectoparasites to conditions encountered on their hosts are rare. In the case of penguins and their ticks, current understanding suggests that ticks freely parasitize their hosts on land but are incapable of surviving extended oceanic journeys. We examined this conjecture by assessing the physiological capacity of little penguin ticks to endure at-sea foraging and dispersal events of their hosts. Survival in penguins ticks was not significantly compromised by exposure to depths commonly associated with host dives (40 and 60 m), repeated seawater exposure relevant to the most common(30 s) andlongest (120 s) recorded host dives, or extended (48 h) exposure to seawater. Mean (±SD) closed-phase durations in adult and nymphal ticks exhibiting discontinuous gas exchange (339 ± 237 and 240 ± 295 s, respectively) exceeded that of the maximum recorded host dive duration (120 s). Normoxic-anoxic-normoxic respirometry also confirmed spiracle closure. Mean metabolic rates (0:354 ± 0:220 and 4:853 ± 4:930 µL/h at 25°C for unfed and fed adult females, respectively) were significantly influenced by temperature; optimal and LT50 temperatures for adult ticks and fed nymphal ticks were typically higher than swimming penguinbody temperatures. These findings suggest that marine host dispersal is unlikely to present an insurmountable barrier to long-distance tick dispersal. Such dispersal has important implications for evolutionary theory, conservation, and epidemiology.

KW - Depth tolerance

KW - Metabolic rate

KW - Penguins

KW - Salinity tolerance

KW - Ticks

KW - Underwater survival

UR - http://www.scopus.com/inward/record.url?scp=85060569544&partnerID=8YFLogxK

U2 - 10.1086/701726

DO - 10.1086/701726

M3 - Article

VL - 92

SP - 163

EP - 176

JO - Physiological and Biochemical Zoology

JF - Physiological and Biochemical Zoology

SN - 1522-2152

IS - 2

ER -