Ichthyology Ch. 9 Flashcards

These flashcards cover key concepts related to age and growth in fish, including growth patterns, factors affecting growth, and methods for age determination.

What is meant by indeterminate growth in fish?

Indeterminate growth refers to the continual increase in length and volume that occurs in most fishes throughout their lives.

How is age defined in biological terms?

Age is defined as the length of time an organism has lived.

What is a major factor influencing the growth and 'size at age' of fish?

Factors include temperature, food availability, nutrient availability, light regime, oxygen, salinity, pollutants, predator density, intraspecific social interactions, and genetics.

What does maturation refer to in the context of fish?

Maturation refers to the 'age at first reproduction,' and involves a shift from somatic to gonadal growth.

What is the significance of the von Bertalanffy growth curve?

The von Bertalanffy growth curve describes the growth of an organism and relates total length at age to theoretical maximum size and growth coefficients.

What structures are commonly used for age determination in fish?

Common structures for age determination include otoliths, fin spines, and scales.

Describe how temperature affects metabolic rate and growth in fish.

Temperature significantly influences metabolic rate; a thermal increase of 10 °C can increase metabolic rates by about twofold, affecting growth rates.

What is meant by the term 'ontogenetic niche partitioning'?

Ontogenetic niche partitioning refers to the phenomenon where different age groups of fish occupy different habitats and use different types of food.

What challenges are associated with using scales for age determination in fish?

Challenges include the potential for crowding near the distal margin, accuracy issues in older fish, and false annuli that may misrepresent true age.

What is the significance of identifying annuli in age determination?

Annuli are crucial for estimating growth rates and age, as they reflect periods of fast and slow growth in fish.