How do sea urchins reproduce sexually or asexually?
Although Purple Sea Urchins are dioecious, meaning they have separate male and female sexes, it is hard to distinguish the two because they are very similar. Instead, they spawn, meaning that they release their eggs and sperm into the water, reproducing sexually. …
Why are sea urchins used to study fertilization and development?
Sea urchins have been used for many years by scientists to study developmental processes such as fertilization. Because they have lots of relatively big eggs, they’re ideal animals to study. Scientists can mix the eggs from a female with the sperm from a male in sea water.
What are the factors that might affect the fertilization of the sea urchin?
Our results indicated that sperm concentration, sperm-egg contact time, sperm age, and individual variability were sequentially the most important factors influencing fertilization success.
What does Polyspermy lead to?
The entrance of multiple sperm—polyspermy—leads to disastrous consequences in most organisms. In the sea urchin, fertilization by two sperm results in a triploid nucleus, in which each chromosome is represented three times rather than twice.
What is the relationship between temperature and urchin survival?
Explanation: Although the sea urchins live in sea water in cold temperature, they require a temperature of around 23 degrees to cleave for fertilisation if this temperature is reduced the process of cleavage slows down eventually depleting the urchin population.
What is the effect of temperature on sea urchins?
Effect of temperature on sea urchin cleavage. Results: Temperature had an effect on the cleavage rates of developing sea urchin embryos. Generally, the higher the environmental temperature, the faster the embryo divided.
What is the relationship between sea urchin survival and water clarity?
Explanation: The higher the water clarity, the lower/or negligible is the number of urchin found in that particular water body. It is so because sea urchins prefer to stay in water bodies with proximity to rock pools and mud. Most commonly they are found on coral reefs of kelp forest or sea grass bed.
What water temperature do sea urchins live in?
The purple sea urchin can tolerate temperatures of 41o to 74oF (5o-23.5oC). Water temperatures above about 79oF (26oC) cause massive die-offs.