Marine Biology Exam 1 Questions and Answers |Complete Solutions Graded A+|100% Correct
Which is an example of a direct release reproductive strategy?
A. a snail that lays large eggs under rocks
B. a fish that releases thousands of larvae in the water column
C. a coral that broadcast spawns both eggs and sperm
D. a crab that undergoes two different pelagic larval phases A
_______ is NOT an example of a pelagic nekton -sea star, krill
Planktonic species should have _____ compared to direct release species?
A. higher genetic diversity at particular locations
B. lower early life mortality
C. higher reproductive success rates
D. lower numbers of offspring C
Direct Larval Release -involves a female laying eggs or brooding its young and the juveniles
crawling away
-larva travel shorter distances
-EX: live birth (viviparous)
Planktonic Larval Release -involves free floating larvae that can remain in the water column
for two weeks and can travel very long distances
-species tend to produce more larvae
Benefits of planktonic larvae -dispersal: pelagic larvae have the potential to disperse long
distances, colonize new territory, and/or escape crowded/unsuitable habitat
-food preference: larvae use a different food source than adults, which may decrease
competition between life stages
,-parasitic release: a long pelagic larval duration can help a species break its parasite cycles
-predator avoidance: pelagic larvae avoid benthic predators
What is NOT an advantage of planktonic larvae -if found at the surface of the water column
it will be exposed to UV rays
Lecithitrophic Larval Dispersal -female produces 100-1000 eggs
-can only survive in water column from hours to days
-cannot feed on plankton and must feed one yolk that they are produced with
Planktotrophic Larval Dispersal -female tends to produce larger quantities of eggs but
smaller than the lecithotrophic larvae
-feed on plankton and can survive in the water column for a longer period of time (weeks)
What is the benefit of planktotrophic larval dispersal when compared to lecithotrophic larval
dispersal? -the parents do not have to invest as much energy into each larva
Planktotrophic larva -is not capable of settlement throughout all of its planktonic life
Benthic species with planktotrophic larvae -have broader biogeographic ranges than species
with nonplanktonic larvae
Planktonic phrases are usually directly followed by what?
A. Reproduction
B. Fertilization
C. Settlement
D. Dispersal C
, Generalized life cycle of Planktonic marine organism -An adult reproduces and once
fertilization occurs, large are sent off into the water column for dispersal
-depending on type of larvae, it will feed off of plankton (planktotrophic) or yolk
(lecithotrophic) and remain in the water column until it finds a suitable destination to settle
based on chemical or geographic cues
-if the larvae run out of food or are subject to predation, they may die
-depending on larvae, as the larvae proceeds in the water column and once it settles, the larvae
will metamorphose gradually into an adult form
-prior to permanently settling, the adult may move a small distance
Costs of planktonic larvae -transport to unsuitable habitat
-predation
-environmental damage
Planktonic larvae have been shown to use all of the following cues to settle EXCEPT
A. chemical cues that indicate the presence of members of the same species
B. mechanical cues that indicate the presence of cracks in substrate
C. chemical cues that inmates that indicates the presence of members of the other species,
such as food species
D. visual cues that indicate the lack of predators D
Cues for larval settlement -substratum: cracks, shade
-gregarious settling: members of own species - chemical cues
-settling on other species
Settling problems -pre-settling problems: loss of inappropriate habitats, predation in
plankton, other damage
-post-settling problems: energetic cost of metamorphosis, predation, crowding
Which is an example of a direct release reproductive strategy?
A. a snail that lays large eggs under rocks
B. a fish that releases thousands of larvae in the water column
C. a coral that broadcast spawns both eggs and sperm
D. a crab that undergoes two different pelagic larval phases A
_______ is NOT an example of a pelagic nekton -sea star, krill
Planktonic species should have _____ compared to direct release species?
A. higher genetic diversity at particular locations
B. lower early life mortality
C. higher reproductive success rates
D. lower numbers of offspring C
Direct Larval Release -involves a female laying eggs or brooding its young and the juveniles
crawling away
-larva travel shorter distances
-EX: live birth (viviparous)
Planktonic Larval Release -involves free floating larvae that can remain in the water column
for two weeks and can travel very long distances
-species tend to produce more larvae
Benefits of planktonic larvae -dispersal: pelagic larvae have the potential to disperse long
distances, colonize new territory, and/or escape crowded/unsuitable habitat
-food preference: larvae use a different food source than adults, which may decrease
competition between life stages
,-parasitic release: a long pelagic larval duration can help a species break its parasite cycles
-predator avoidance: pelagic larvae avoid benthic predators
What is NOT an advantage of planktonic larvae -if found at the surface of the water column
it will be exposed to UV rays
Lecithitrophic Larval Dispersal -female produces 100-1000 eggs
-can only survive in water column from hours to days
-cannot feed on plankton and must feed one yolk that they are produced with
Planktotrophic Larval Dispersal -female tends to produce larger quantities of eggs but
smaller than the lecithotrophic larvae
-feed on plankton and can survive in the water column for a longer period of time (weeks)
What is the benefit of planktotrophic larval dispersal when compared to lecithotrophic larval
dispersal? -the parents do not have to invest as much energy into each larva
Planktotrophic larva -is not capable of settlement throughout all of its planktonic life
Benthic species with planktotrophic larvae -have broader biogeographic ranges than species
with nonplanktonic larvae
Planktonic phrases are usually directly followed by what?
A. Reproduction
B. Fertilization
C. Settlement
D. Dispersal C
, Generalized life cycle of Planktonic marine organism -An adult reproduces and once
fertilization occurs, large are sent off into the water column for dispersal
-depending on type of larvae, it will feed off of plankton (planktotrophic) or yolk
(lecithotrophic) and remain in the water column until it finds a suitable destination to settle
based on chemical or geographic cues
-if the larvae run out of food or are subject to predation, they may die
-depending on larvae, as the larvae proceeds in the water column and once it settles, the larvae
will metamorphose gradually into an adult form
-prior to permanently settling, the adult may move a small distance
Costs of planktonic larvae -transport to unsuitable habitat
-predation
-environmental damage
Planktonic larvae have been shown to use all of the following cues to settle EXCEPT
A. chemical cues that indicate the presence of members of the same species
B. mechanical cues that indicate the presence of cracks in substrate
C. chemical cues that inmates that indicates the presence of members of the other species,
such as food species
D. visual cues that indicate the lack of predators D
Cues for larval settlement -substratum: cracks, shade
-gregarious settling: members of own species - chemical cues
-settling on other species
Settling problems -pre-settling problems: loss of inappropriate habitats, predation in
plankton, other damage
-post-settling problems: energetic cost of metamorphosis, predation, crowding
