Growth:

Question 1

What are five ways in determining growth in marine invertebrates?

Answer 1

1. Lab rearing
2. Tag/recapture
3. Growth rings
4. Radiocarbon dating
5. Size/frequency

Question 2

Describe lab rearing:

Answer 2

Raising marine invertebrates in controlled laboratory conditions to observe growth rates and establish age through direct observations

Question 3

Describe growth rings:

Answer 3

Many marine invertebrates form growth rings in their hard structures (like shells or statoliths) due to seasonl changes in environmental condtions. Counting these growth rings can provide age estimates

Question 4

Descirbe size/frequency analysis:

Answer 4

This method estimates age distribution within a population by analysing size frequency data. It relies on the assumption that size correlates with age.

Question 5

Describe radiocarbon dating:

Answer 5

This technique meausres the decay of carbon-14 isotopes in biological materials to estimate age, which is particulalry useful for long-lived species.

Question 6

Describe tag/recapture:

Answer 6

Involves marking individuals and recapturing them later to measure growth and estimate age. This can be done through physical, chemical, or DNA tagging

Question 7

What are examples of a marine invertebrate group that has been aged using each technique?

Answer 7

1. Growth rings: bivalves (cockles, oytsers, etc
2. Tag/recapture: crustaceans (lobsters, crabs)
3. Radiocarbon dating: black coral
4. Size/frequency analysis:
5. Laboratory rearing: sea urchins