Marine Ecology Study Guide
Marine Ecology Final Exam Review
Difference between broadcast spawners, brooders, direct developers, lecithotrophic and planktotrophic larvae
* Many marine organisms have a dispersal phase in their life history * Dispersal can occur as eggs, sperms, fertilized eggs, larvae, juveniles or adults * Many species only disperse as juveniles or adults * Other species take advantage of high density of water to disperse during very early life stages: eggs/sperm/fertilized eggs/larvae 1. Broadcast spawners: parent release eggs/sperm/young fertilized eggs into water; developing young is on its own in the water column long time
2. Brooders: parent retains fertilized egg in body and releases young at a more developed stage; developing young spends less time in water column
3. Direct developers: parent retains fertilized egg in its body or in a large egg case until it hatches as a small version of an adult
* Larvae: independent, morphologically different stages developing from fertilized eggs and going through metamorphosis before reaching final adult stage.
* Are usually fundamentally unlike the adult stage morphologically, behaviorally, Physiologically
* Two basic types of larval production strategies:
1. Produce huge number of small eggs with little to no yolk that hatch quickly into feeding, free-swimming larvae: planktotrophic larvae 2. Produce smaller number of larger eggs with some yolk that hatch into non-feeding, free-swimming larvae: lecithotrophic larvae 3. In general, time in spent in plankton decreases as egg size increases
Pros and cons of different larval dispersal strategies; why all of them persist over time
* Planktotrophs:
Advantages: 1. Can produce more offspring with less parental investment (yolk) 2. Greater dispersal (longer time in water column)
Disadvantage: 1. Larvae might not find enough food in plankton 2. Long time in water column
Difference between broadcast spawners, brooders, direct developers, lecithotrophic and planktotrophic larvae
* Many marine organisms have a dispersal phase in their life history * Dispersal can occur as eggs, sperms, fertilized eggs, larvae, juveniles or adults * Many species only disperse as juveniles or adults * Other species take advantage of high density of water to disperse during very early life stages: eggs/sperm/fertilized eggs/larvae 1. Broadcast spawners: parent release eggs/sperm/young fertilized eggs into water; developing young is on its own in the water column long time
2. Brooders: parent retains fertilized egg in body and releases young at a more developed stage; developing young spends less time in water column
3. Direct developers: parent retains fertilized egg in its body or in a large egg case until it hatches as a small version of an adult
* Larvae: independent, morphologically different stages developing from fertilized eggs and going through metamorphosis before reaching final adult stage.
* Are usually fundamentally unlike the adult stage morphologically, behaviorally, Physiologically
* Two basic types of larval production strategies:
1. Produce huge number of small eggs with little to no yolk that hatch quickly into feeding, free-swimming larvae: planktotrophic larvae 2. Produce smaller number of larger eggs with some yolk that hatch into non-feeding, free-swimming larvae: lecithotrophic larvae 3. In general, time in spent in plankton decreases as egg size increases
Pros and cons of different larval dispersal strategies; why all of them persist over time
* Planktotrophs:
Advantages: 1. Can produce more offspring with less parental investment (yolk) 2. Greater dispersal (longer time in water column)
Disadvantage: 1. Larvae might not find enough food in plankton 2. Long time in water column