Growth Flashcards
What are 2 advantages and 2 disadvantages of using Lab rearing to measure growth?
Advantages:
Allows for precise control of environmental conditions, enabling researchers to study the effects of specific variables on growth.
Permits continuous monitoring and measurement of individuals throughout their life cycle.
Disadvantages:
May not accurately represent natural growth conditions, potentially leading to differences in growth rates compared to wild populations.
Can be labor-intensive and costly, especially for long-lived species or those with complex life cycles.
What are 2 advantages and 2 disadvantages of using Tag/recapture to measure growth?
Advantages:
Provides data on growth in natural environments, reflecting realistic conditions.
Allows for the study of individual growth rates over time in wild populations.
Disadvantages:
Can be challenging to recapture sufficient numbers of tagged individuals, especially in marine environments.
Tagging may affect the animal’s behavior or growth, potentially biasing results.
What are 2 advantages and 2 disadvantages of using Growth Rings to measure growth?
Advantages:
Offers a non-invasive method to estimate age and growth rates in species with calcified structures.
Can provide long-term growth records, including information on past environmental conditions.
Disadvantages:
Not all marine invertebrates produce clear growth rings, limiting the applicability of this method.
Interpretation of growth rings can be subjective and may require validation through other methods.
What are 2 advantages and 2 disadvantages of using Size/Frequency to measure growth?
Advantages:
Allows for rapid assessment of population growth patterns without the need for long-term studies.
Can be applied to large samples, providing a broad overview of population dynamics.
Disadvantages:
May not accurately represent individual growth rates, as it relies on population-level data.
Can be confounded by factors such as size-selective mortality or recruitment variability.
Briefly desire 5 methods that can be used to determine age in marine invertebrates. For each method give an example of a marine invertebrate group that has been ages using the technique.
1) growth rings - rings on their shells, exoskeletons that can be counted to determine their age (Bivalves such as cocks, oysters, clams)
2) size-frequency analysis - measuring size of individuals in a population and analysing their distribution of these sizes to inner age classes, it is assumes larger individuals are older (squid)
3) tag/recapture - individuals are marked with a. tag or natural marker and released, then recaptured later and time between marking and recapture provides information on growth rates (Crab, lobsters)
4) chemical tagging - chemicals incorporated into sites of calcium deposition, usually a fluorescent tag, marks laid down indicate size of animal at tagging and later recover and see growth (sea urchin, abalone)
5) isotope analysis - ratios of certain isotopes such as oxygen or carbon change over time in the hard parts of marine invertebrates, this change can be used to estimate age (black corals)
