Sheina orri (Myodocopa: Cypridinidae), an ostracod parasitic on the gills of the epaulette shark, Hemiscyllium ocellatum (Elasmobranchii: Hemiscyllidae)

Bennett, M. B.; Heupel, Michelle R.; Bennett, SM; Parker, Andrew R.

doi:10.1016/s0020-7519(96)00201-9

Cited by 20 publications

(16 citation statements)

References 8 publications

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“…Harding, 1966), but Cohen (1983) considered that no myodocopids were truly parasitic and she suggested that these ostracods were scavengers on injured or unhealthy fish. Bennett et al (1997) examined S. orri on the gills of a shark and documented local distortion of gill lamellae accompanied by tissue damage at all sites of ostracod attachment, but they were unable to confirm that the ostracods had ingested shark tissue. The ostracods were typically found in small pockets between adjacent gill filaments.…”

Section: Ostracodamentioning

confidence: 99%

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Fossil Crustaceans as Parasites and Hosts

Klompmaker

Boxshall

2015

Fossil Parasites

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Section: Ostracodamentioning

confidence: 99%

“…The ostracods were typically found in small pockets between adjacent gill filaments. Bennett et al (1997) concluded that S. orri was parasitic, but such soft tissue features would have a low fossilization potential.…”

Section: Ostracodamentioning

confidence: 99%

Fossil Crustaceans as Parasites and Hosts

Klompmaker

Boxshall

2015

Fossil Parasites

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“…Ostracods fulfil an important role in aquatic food webs as basal species feeding on primary producers and detritus from plants and animals, and are themselves predated by larger invertebrates and vertebrates. Some myodocopid ostracods live as micro-predators of other invertebrates in the water column, as scavengers [21], and even live as parasites on the gills of sharks [22]. The basal position of ostracods in ancient food webs is suggested by their occurrence in coprolites [23].…”

Section: Resultsmentioning

confidence: 99%

Oxygen as a Driver of Early Arthropod Micro-Benthos Evolution

et al. 2011

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BackgroundWe examine the physiological and lifestyle adaptations which facilitated the emergence of ostracods as the numerically dominant Phanerozoic bivalve arthropod micro-benthos.Methodology/Principal FindingsThe PO2 of modern normoxic seawater is 21 kPa (air-equilibrated water), a level that would cause cellular damage if found in the tissues of ostracods and much other marine fauna. The PO2 of most aquatic breathers at the cellular level is much lower, between 1 and 3 kPa. Ostracods avoid oxygen toxicity by migrating to waters which are hypoxic, or by developing metabolisms which generate high consumption of O2. Interrogation of the Cambrian record of bivalve arthropod micro-benthos suggests a strong control on ecosystem evolution exerted by changing seawater O2 levels. The PO2 of air-equilibrated Cambrian-seawater is predicted to have varied between 10 and 30 kPa. Three groups of marine shelf-dwelling bivalve arthropods adopted different responses to Cambrian seawater O2. Bradoriida evolved cardiovascular systems that favoured colonization of oxygenated marine waters. Their biodiversity declined during intervals associated with black shale deposition and marine shelf anoxia and their diversity may also have been curtailed by elevated late Cambrian (Furongian) oxygen-levels that increased the PO2 gradient between seawater and bradoriid tissues. Phosphatocopida responded to Cambrian anoxia differently, reaching their peak during widespread seabed dysoxia of the SPICE event. They lacked a cardiovascular system and appear to have been adapted to seawater hypoxia. As latest Cambrian marine shelf waters became well oxygenated, phosphatocopids went extinct. Changing seawater oxygen-levels and the demise of much of the seabed bradoriid micro-benthos favoured a third group of arthropod micro-benthos, the ostracods. These animals adopted lifestyles that made them tolerant of changes in seawater O2. Ostracods became the numerically dominant arthropod micro-benthos of the Phanerozoic.Conclusions/SignificanceOur work has implications from an evolutionary context for understanding how oxygen-level in marine ecosystems drives behaviour.

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“…Masticatory processes associated with the lower lip form so-called food-rakes which assist the mandibles in breaking down food and passing it into the mouth (Meisch 2000). The parasitic form Sheina orri (Cypridinidae) uses its mandibular and maxillar claws to anchor itself to the gill tissues of its shark host (Bennett et al 1997;Vannier et al 1998).…”

Section: Feeding Strategymentioning

confidence: 99%

The Adaptations of the Foraminifera and Ostracoda to Fresh Water Colonisation

Iglikowska

Pawłowska

2015

GeoPlanet: Earth and Planetary Sciences

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In marine environments Ostracoda and Foraminifera have been very successful invaders. During the Phanerozoic they colonised the majority of shallow, marginal to deep water, fully marine habitats. Both groups had developed physiological adaptations which pre-adapted them to the invasion of new marine habitats. They adopted a broad range of feeding strategies and reproduction modes. The production of resting stages and brood care may also have contributed to them being efficient invaders. They are also both highly tolerant to variations in salinity. The first invasions of non-marine habitats by ostracods appear to have taken place at the turn of the Devonian and Carboniferous. It is estimated that there had been between 9 and 12 independent invasions of fresh waters by the ostracods. In contrast Foraminifera are typically marine organisms, and only a few species of agglutinated and organic-walled Foraminifera are to be found in brackish and freshwater environments. Agglutinated species build their test using ambient components but are not commonly regarded as calcifying organisms. An impact of salinity on foraminiferal calcification has been observed in several studies. It seems that Foraminifera are incapable of constructing a fully calcified test in low salinity regimes; they use sea water not only as a source of ions to construct shell, but also as a biomineralisation solution. Thus, the success of ostracods in invading freshwater habitats can be attributed to their development of a more effective mechanism of calcification in low mineralisation waters. The core question of this study is to examine possible causes for the differences in success between the two taxa.

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Sheina orri (Myodocopa: Cypridinidae), an ostracod parasitic on the gills of the epaulette shark, Hemiscyllium ocellatum (Elasmobranchii: Hemiscyllidae)

Cited by 20 publications

References 8 publications

Fossil Crustaceans as Parasites and Hosts

Fossil Crustaceans as Parasites and Hosts

Oxygen as a Driver of Early Arthropod Micro-Benthos Evolution

The Adaptations of the Foraminifera and Ostracoda to Fresh Water Colonisation

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