Compass orientation of sockeye salmon fry from a complex river system

1981 ◽  
Vol 59 (8) ◽  
pp. 1548-1553 ◽  
Author(s):  
Ernest L. Brannon ◽  
Thomas P. Quinn ◽  
Gino L. Lucchetti ◽  
Brian D. Ross

Sockeye salmon (Oncorhynchus nerka) fry from the Weaver Creek – Harrison Lake population were tested to determine whether they exhibited directional orientation in the absence of water flow. The fry oriented in a generally north-northeast direction. The presence of the moon greatly enhanced the strength of the northward orientation response, and the moon may have provided the fry with guidance information. Tests with newly emerged fry indicated little or no response to a directionally altered magnetic field. Both the passage of time and exposure to Harrison River – Harrison Lake water enhanced the compass orientation response, implying that an inherited response is triggered by environmental and temporal cues.

2014 ◽  
Vol 11 (99) ◽  
pp. 20140542 ◽  
Author(s):  
Nathan F. Putman ◽  
Erica S. Jenkins ◽  
Catherine G. J. Michielsens ◽  
David L. G. Noakes

Animals navigate using a variety of sensory cues, but how each is weighted during different phases of movement (e.g. dispersal, foraging, homing) is controversial. Here, we examine the geomagnetic and olfactory imprinting hypotheses of natal homing with datasets that recorded variation in the migratory routes of sockeye ( Oncorhynchus nerka ) and pink ( Oncorhynchus gorbuscha ) salmon returning from the Pacific Ocean to the Fraser River, British Columbia. Drift of the magnetic field (i.e. geomagnetic imprinting) uniquely accounted for 23.2% and 44.0% of the variation in migration routes for sockeye and pink salmon, respectively. Ocean circulation (i.e. olfactory imprinting) predicted 6.1% and 0.1% of the variation in sockeye and pink migration routes, respectively. Sea surface temperature (a variable influencing salmon distribution but not navigation, directly) accounted for 13.0% of the variation in sockeye migration but was unrelated to pink migration. These findings suggest that geomagnetic navigation plays an important role in long-distance homing in salmon and that consideration of navigation mechanisms can aid in the management of migratory fishes by better predicting movement patterns. Finally, given the diversity of animals that use the Earth's magnetic field for navigation, geomagnetic drift may provide a unifying explanation for spatio-temporal variation in the movement patterns of many species.


1967 ◽  
Vol 24 (11) ◽  
pp. 2321-2338 ◽  
Author(s):  
M. C. Healey

During May and June 1966, the migration of pink salmon fry from the Bella Coola River was studied in Burke Channel, British Columbia. The movement of pink fry down Burke Channel was saltatory. Short periods of active migration were interspersed with longer periods when the fry did not migrate and accumulated in bays. Fry were sampled from these accumulations and their ability to orient using celestial cues was examined. During the early morning, fry tended to prefer directions at right angles to their direction of migration, but at other times of the day preferred the direction of migration. The preference for the direction of migration was strongest at midday. Fry were better oriented on clear days than on cloudy days. These data indicate that fry may use celestial cues to find directions during their oceanic migrations.


2021 ◽  
Vol 7 (32) ◽  
pp. eabi7647
Author(s):  
John A. Tarduno ◽  
Rory D. Cottrell ◽  
Kristin Lawrence ◽  
Richard K. Bono ◽  
Wentao Huang ◽  
...  

Determining the presence or absence of a past long-lived lunar magnetic field is crucial for understanding how the Moon’s interior and surface evolved. Here, we show that Apollo impact glass associated with a young 2 million–year–old crater records a strong Earth-like magnetization, providing evidence that impacts can impart intense signals to samples recovered from the Moon and other planetary bodies. Moreover, we show that silicate crystals bearing magnetic inclusions from Apollo samples formed at ∼3.9, 3.6, 3.3, and 3.2 billion years ago are capable of recording strong core dynamo–like fields but do not. Together, these data indicate that the Moon did not have a long-lived core dynamo. As a result, the Moon was not sheltered by a sustained paleomagnetosphere, and the lunar regolith should hold buried 3He, water, and other volatile resources acquired from solar winds and Earth’s magnetosphere over some 4 billion years.


Nature ◽  
1948 ◽  
Vol 161 (4095) ◽  
pp. 646-647 ◽  
Author(s):  
M. S. VALLARTA

2021 ◽  
Vol 55 (6) ◽  
pp. 50-55
Author(s):  
S.A. Pineguin ◽  
◽  
O.A. Dadasheva ◽  
E.I. Mednikova ◽  
O.A. Grushina ◽  
...  

Expectation of remote space missions and long-term stay and work on the Moon with the magnetic field 1,000 times weaker than on Earth sets the researchers the formidable task to investigate effects of the hypomagnetic environment on living organisms. The paper reports data about the liver and spleen development in Japanese quail embryos of various age exposed in a modeled lunar magnetic field. Retardation of hemopoiesis was observed as in the first generation embryos (F1), so in sequential embryo generations developed in the ordinary magnetic environment (F2).


2021 ◽  
Author(s):  
Marine Lasbleis

<div> <p>Growth of the solid inner core is generally considered to power the Earth's present geodynamo. Cristallisation of a solid central inner core has also been proposed to drive the lunar dynamo and to generate a magnetic field in smaller bodies. In a previous work, we estimated the compaction of planetary cores for different scenarios of growth (with or without supercooling) and different sizes of the inner core. Our main results indicated that small inner cores are unlikely to compact efficiently the liquid trapped during the first steps of the growth.</p> <p>This is especially true for small bodies for which the typical size of the core is similar to the compaction length. The light elements are thus trapped during the cristallisation, reducing the release of latent heat and of light elements. We present here a model to include the effect of an inefficient compaction in the energy budget of a planetary core and investigate the implications for the dynamo evolution in small bodies. We apply this model for the evolution of the core of the Moon. </p> </div>


2020 ◽  
Vol 6 (40) ◽  
pp. eabb1475
Author(s):  
Rona Oran ◽  
Benjamin P. Weiss ◽  
Yuri Shprits ◽  
Katarina Miljković ◽  
Gábor Tóth

The crusts of the Moon, Mercury, and many meteorite parent bodies are magnetized. Although the magnetizing field is commonly attributed to that of an ancient core dynamo, a longstanding hypothesized alternative is amplification of the interplanetary magnetic field and induced crustal field by plasmas generated by meteoroid impacts. Here, we use magnetohydrodynamic and impact simulations and analytic relationships to demonstrate that although impact plasmas can transiently enhance the field inside the Moon, the resulting fields are at least three orders of magnitude too weak to explain lunar crustal magnetic anomalies. This leaves a core dynamo as the only plausible source of most magnetization on the Moon.


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