Upgrade to remove ads
Only $2.99/month

Marine Animal Reproduction Behavior

Terms in this set (18)

Describe the life cycle of salmon. [6]
1. salmon eggs are spawned, fertilized, and buried in fresh-water rivers in gravel beds called redds in the autumn
2. eggs develop over winter and hatch into alevins w/ an attached yolk sac used for food
3. As the yolk sac depletes, the salmon become fry and must swim to the surface to fill their swim bladders with air to swim freely in the river (avoid predators)
4. fry develop parr marks on their sides for camouflage and become parr and remain in the river for 1-4 years
5. parr move into estuaries and lose their markings, become more elongated and silver, now smolts
6. smolts move in shoals into the sea and become sexually mature and breed
Describe the life cycle of oysters. [6]
1. a synchronizing pheromone triggers the release of sperm and eggs that get fertilized in the water
2. the fertilized egg floats to the surface and hatches and develops into the first swimming larval stage trochophore. they have cilia on their head to move through the water and feed on plankton
3. As trochophores develop a shell and a vellum, they keep the cilia all over and are now veligers
4. Veligers then develop a foot that can attach to a substrate and are now called pediveligers
5. pediveligers then sink to the bottom and use their foot to find a suitable place to attach. They secrete a material known as the byssus thread to keep them attached
6. oysters morph into small oysters, or spats, that will eventually reach sexual maturity
Describe the life cycle of the giant clam. [6]
1. giant clams are hermaphrodites, so they first release a stream of sperm and then eggs sometime later to prevent self-fertilization
2. within 12 hours of fertilization, a trochophore larva hatches with cilia to swim and feed on plankton and rises to the surface
3. the trochophore then develops a shell and a vellum and is now considered a veliger larva
4. the veliger develops a foot and is now considered a pediveliger
5. the pediveliger sinks to the seabed and uses its sensitive foot to find a suitable substrate
6. once the pediveliger attaches, it becomes a spat and then will eventually mature into giant clam
Describe the life cycle of tuna. [5]
1. adult tuna swim to their spawning grounds and release sperm and eggs into the water (broadcast spawning)
2. larvae hatch after about 2 days and feed on the larvae of other species, have disproportionately large heads and jaws
3. these larvae remain in the spawning grounds until they move out into the open ocean and become juveniles
4. Juvenile tuna tend to stick together in schools to avoid predators
5. Tuna then reach sexual maturity and will migrate to the spawning grounds
Describe the life cycle of shrimp. [7]
1. Individuals mate with each other. The male attaches a sac of sperm (spermatocyst) to the underside of the female, who will release the sperm with the eggs, still external fertilization
2. a nauplius larva hatches from the egg, floats to the surface, and feeds on plankton. They have appendages on their heads to aid in swimming and one single eye
3. Nauplius larva metamorphoses into protozoea, feeding on plankton and molting their exoskeletons
4. the larva becomes more shrimp-like and is now called a mysis, carried towards the coast where they settle in nutrient-rich areas
5. They metamorphose into post larva, that settle in estuaries, feed on detritus and small organisms
6. Juveniles move into deeper estuary waters to find prey, less susceptible to predation
7. Adults live in deep ocean waters in benthic zones, feed on detritus
Describe the life cycle of grouper. [6]
1. Most species change into males. If there are no males in the area, the largest female will spontaneously change into a male
2. Fertilization: Adults migrate into offshore waters and broadcast spawn
3. Larvae for 80 days, planktonic, surface waters
4. Fry still have an attached yolk sac
-Move in currents to mangroves and seabeds, current may not cary all larvae
-Higher predation in open sea than salmon
5. Juveniles migrate to mangroves then out to coral reefs
6. Adults live in coral reefs and mature as females
State one way in which the life cycle of oysters differs from that of giant clams. [1]
Giant clams have two different sexes, while giant clams are hermaphrodites
State two ways in which the life cycle of oysters is similar to that of giant clams.[2]
1. Free-swimming planktonic Larvae
2. The development of a foot to sense and attach to a substrate
State two similarities between the life cycles of shrimp and groupers. [2]
1. Larvae migrate to mangroves
2. Larvae dispersed by ocean currents
State two differences between the life cycles of shrimp and groupers. [2]
1. Groupers use broadcast spawning while shrimp do not
2. Adult groupers live in coral reefs while adult shrimp live in the open ocean
List two advantages and two disadvantages of having a larval stage in a life cycle. [4]
Disadvantage: Larvae are more susceptible to prey, many larvae don't survive past the first couple days
Advantage: good distribution, less competition for resources
Suggest and explain one advantage and one disadvantage of broadcast spawning. [2]
Disadvantage: many eggs do not become fertilized, high risk of predation and mortality
Advantage: genetic variation, mother does not use energy carrying eggs
Why is it important for salmon fry to live in moving river water and what happens if the water flow is too slow or too fast. [3]
1. moving water keeps a steady flow of Oxygen and nutrients
2. Too fast, the gravel and eggs will be washed away
3. Too slow, the embryos do not receive enough oxygen
Explain how building hydroelectric damns across a river can affect the population of bears. [4]
1. dams make it difficult for salmon to reach the river and reproduce
2. Bears mostly feed on salmon coming upstream from the ocean
3. less salmon means less food for bears
4. less food for bears means less bears
Explain why replanting of mangroves is important for the conservation of groupers and shrimps. [3]
1. Grouper and shrimp larvae live in mangrove estuaries
2. less mangroves means less habitat for shrimp and grouper
3. less habitat means less shrimp and grouper
Suggest and explain why it is beneficial to the salmon to have life cycles stages in both rivers and oceans. [3]
1. rivers and oceans provide different food sources
2. Younger fish would die in the ocean due to predation
3. Salmon at different ages won't be competing with each other, less cannibalism
Discuss the advantages and disadvantages of external fertilization. [6]
Disadvantage: require large number of eggs and sperm to increase chances of fertilization, many eggs are not fertilized = waste of energy, few offspring survive
Advantage: useful for sessile animals that don't move, less energy for parental care (i.e. producing milk or embryo development), increase in genetic variation
Discuss the advantages and disadvantages of internal fertilization. [8]
Disadvantage: energy used for maternal care, requires means of transferring sperm, must find and attract mate, often require complex behaviors/competition with others, long periods of pregnancy before birth
Advantages: Increased chance of survival, young learn skills (social, survival, etc.) from parents, may liv

e in groups, which are more successful at finding food
YOU MIGHT ALSO LIKE...