The Importance Of Navigational And Migratory Behaviors

1100 Words 5 Pages
Both navigational and migratory behaviors are seen in a large variety of vertebrates across all spheres of life. The ability to navigate and knowing when to migrate is, at least in part, genetic (Lee et al. 2013 and Smith 1985). This means that some organisms can have birth defects that will hinder their navigational and/or migratory behaviors (Lee et al. 2013). Migration is defined as a mass leaving of one place for another, pre-determined one, on a repeating basis (Merriam-Webster 2018). In mature fishes it often, but not always, involves returning to the birthplace at a later point in life (Merriam-Webster 2018 and Morais and Daverat 2016). Merriam-Webster defines navigation as the act of moving from place to place by determining relative …show more content…
It can be done passively, by going with the current, or actively, by going against the current (Jonsson 1991). Passive migration is often the method employed by juvenile fishes. These fishes are, for example, born into rivers and upon reaching a certain age, they will allow themselves to be moved downstream along with the current. This stream would, eventually, empty into a larger body of water, for example, the ocean, for juvenile salmon, or a lake, as is the case for lake sturgeons (Chmielewski and Whelan 1997 and Putman et al. 2014). Active migration is used by adult pacific salmon and Chinook salmon, for example, who migrate upriver in order to lay their eggs (Putman et al. 2014). This movement against the downward flow of water is considered active because it requires significantly more energy. The migration of salmons is widely known because of the feats they preform as they expend all of their energy getting up waterfalls and past predators in the name of laying eggs only to die shortly thereafter in many …show more content…
It is worth noting that there are many other types of migration but for the purposes of this paper, only the three main categories were chosen. Potamodromous migration occurs in fishes who migrate but never leave freshwater (Cooper 2000). Lake sturgeons are good examples of this (Chmielewski and Whelan 1997). Eggs are laid in the upstream portion of a river and they eventually hatch, grow and, upon reaching juvenile age, will migrate down the stream and into a lake environment (Chmielewski and Whelan 1997). The benefits of this migration is increased variety and size of food, more shelter, space and mates (Chmielewski and Whelan 1997) When the juveniles reach maturity and it comes time for them to lay their eggs, they will usually migrate back up the stream they originally came from (Chmielewski and Whelan 1997). In this manner, they never leave the freshwater environment during their migrations (Chmielewski and Whelan 1997 and Cooper 2000). Contrarily, oceanodromous fishes never leave the saltwater and a good example are the bluefin tuna (Morais and Daverat 2016 and Kitagawa et al. 2002). According to Morais and Daverat, oceanodromic fishes need to be endothermic (2016). This is because they possess the ability to warm themselves without having to rely on the surrounding environment and therefore are capable of fully utilizing their muscles at all times. This means they are

Related Documents