What is the function of the jelly layer before the egg is fertilised?

Proteins in the jelly initiate the acrosome reaction in sperm so they are ready to fertilize the egg. It provides a sort of “shock absorber” to prevent injury to the egg from wave action.

What is the limiting factor for the sea urchin population?

The limiting factor for short term is oxygen use. Adding too many animals will reduce the oxygen level below survival level.

What is the significance of fertilisation?

Significance of fertilization: Fertilization maintains the diploid number of chromosomes in the newly formed zygote. It combines characters from two parents bringing about variation in the offspring. It determines the sex of the offspring. Fertilization introduces centrioles in the cell which are missing in the ovum.

What secondary consumer eats small fish?

The salt water food web begins with producers (plants, algae, phytoplankton) that create food from sunlight, and continues with primary consumers (zooplankton) that eat the producers, followed by secondary consumers (shrimp, crustaceans, small fish) that eat the primary consumers, then tertiary consumers (large …

What trophic level are seagulls?

Seabirds belong on the 4th trophic level in this community. They are tertiary consumers who prey on mussels, sea stars and fish.

Which event occurs during fertilization in both sea urchins and mammals?

The lysis of the vitelline envelope is followed by the fusion of the sperm plasma membrane with the plasma membrane of the egg. This membrane fusion is a common feature of fertilization in all animals.

Which organisms are top consumers in a marine food chain?

They are eaten by primary consumers like zooplankton, small fish, and crustaceans. Primary consumers are in turn eaten by fish, small sharks, corals, and baleen whales. Top ocean predators include large sharks, billfish, dolphins, toothed whales, and large seals.

Who are secondary producers?

Animals that feed on plants are called – secondary producers, since they produce the biomass (a renewable organic material) for their predators. Similarly, carnivores which are eaten by other species, are called ‘tertiary producers’. … A secondary producer is a herbivore, and is a food for a predator.

Who are the producers consumers and decomposers in the atlantic ocean?

Diatoms are a major group of algae, and are among the most common types of phytoplankton so are the producers, crustacean belongs to primary consumer, fish is secondary consumer, seal is tertiary and bacteria are decomposers.

Why are fishes heterotrophs?

Fish belong to the animal kingdom. Animals and fungi are heterotrophs—they are organisms that must obtain their food by feeding on other organisms.

Why are sea urchins multiplying?

Sea urchin populations have proliferated due to marine ecosystems being out of sync. They are destroying kelp forests, leaving large swathes of barren ocean. These kelp forests form part of a crucial carbon sink that helps in our battle against climate change.

Why do the sea urchins have a negative impact on the kelp population?

If their populations are left unchecked by predation, they can decimate kelp forests and prevent kelp from growing. That can transform a thriving community of kelp into an oceanic desert, known as an urchin barren. The relationships between predators and prey vary among communities.

Why is fish a secondary consumer?

Secondary Consumers. A fish, caught by a heron in Nokomis, Florida, has another fish in its mouth. These secondary consumers in the food chain prey on other organisms. Producers, such as plants, create their own nutrients, while primary consumers, also called herbivores, rely on producers for food.

Is a sea otter a producer or consumer?

Organisms in food webs are grouped into categories called trophic levels. Roughly speaking, these levels are divided into producers (first trophic level), consumers, and decomposers (last trophic level).

Are otters indicator species?

River otters are considered an indicator species and their presence is a hopeful sign of improving watershed conditions. These apex aquatic predators play an important role in ecosystem health, as they eat fish, crustaceans, invertebrates, birds, and amphibians.

Are river otters a keystone species?

Because they have a low tolerance for polluted water, river otters are considered by some naturalists to be a good indicator, or “keystone,” species of the quality of aquatic habitats.

Are sea animals producers?

They are the main producers of the carbon all ocean animals need to survive. They also produce more than half of the oxygen we breathe on Earth. The next level of the marine food chain is made up of plant-eaters, or herbivores. Many are microscopic animals known as zooplankton.

Are sea urchin producers or consumers?

Sea urchins are powerful primary consumers in kelp forests. These small herbivores eat dozens of kilograms (pounds) of giant kelp every day. Secondary consumers eat herbivores. They are at the third trophic level.

Are walruses primary consumer?

Secondary consumers include diving ducks such as eiders and walruses who both eat clams. They both live on the surface of the Bering Sea.