Reef fish study
Read Reef fish study and check the IELTS Reading answers. It is a widely held belief among those who study animals that larger size conveys some form of advantage throughout life. The idea that certain body characteristics may influence a prey's ability to survive when being attacked by a predator…
Passage preview
It is a widely held belief among those who study animals that larger size conveys some form of advantage throughout life. The idea that certain body characteristics may influence a prey's ability to survive when being attacked by a predator has received considerable attention in the past, and has been applied to a wide range of both animals and habitats. Body size, weight, growth rate, overall condition, sensory development and escape speed have all been linked to survival. Of these, body size has received the most attention from researchers, which has subsequently led to the development of a number of theories on how this characteristic may influence the predator-prey relationship. One of the most popular of these is known as the 'bigger is better' hypothesis. This theory predicts that larger body size should increase an individual's ability to escape from a predator due to the characteristics associated with this, such as overall strength and visual development. Bigger is thought to be better, but is this always the case?
Vocabulary from this passage
10 words worth learning before you sit the test, each with the sentence it appears in.
- abundant adjective
Existing or available in large quantities; plentiful and easily found within a specific habitat
Algae are abundant in shallow tropical waters, providing a primary food source for numerous reef species.
- convey verb
To communicate or impart a quality or benefit; to provide or grant a specific advantage in a context
Genetic researchers believe that certain hereditary traits convey a significant survival advantage to offspring.
- daunting task noun
A responsibility or project that is perceived as extremely difficult, intimidating, or overwhelming in scope
Mapping the entire floor of the deep ocean remains a daunting task for modern marine researchers.
- juvenile stage noun
The period of an organism's life following the larval phase but before reaching full sexual maturity
During the juvenile stage, reef fish must quickly adapt to complex social hierarchies and environmental pressures.
- larval phase noun
The early, immature stage in the life cycle of many animals, occurring after hatching and before adult form
Many marine species are highly vulnerable to predation during the initial larval phase of their development.
- mortality noun
The state of being subject to death; the frequency or rate of death in a specific population
Scientists observed a sharp increase in mortality rates following the sudden drop in ocean temperature.
- optimal foraging theory noun
A model predicting how an animal behaves when searching for food to maximize its net energy intake
According to optimal foraging theory, predators select prey based on the highest energy return for the effort.
- settlement noun
The process where larval marine organisms leave the open ocean to inhabit a permanent reef environment
The successful settlement of coral larvae is a critical factor in the regeneration of damaged reef ecosystems.
- sheer persistence noun
The quality of continuing firmly in a course of action despite extreme difficulty or opposition
The breakthrough in the reef fish study was achieved through sheer persistence and years of field work.
- trade-off noun
A balance achieved between two desirable but incompatible features; a compromise in biological or economic terms
There is often a trade-off between the speed of growth and the long-term survival of juvenile organisms.
Answers with explanations
- 1. FALSE
The statement claims research has concentrated on **escape speed**. The text states that **body size** (not escape speed) has received the **most attention** from researchers. Answer: FALSE.
- 2. TRUE
The statement claims the hypothesis suggests larger animals have **better eyesight**. The text confirms the theory links larger size to characteristics like **visual development**. Answer: TRUE.
- 2-3: B
2: The statement claims the hypothesis suggests larger animals have **better eyesight**. The text confirms the theory links larger size to characteristics like **visual development**. Answer: TRUE.
3: The statement claims early-juvenile fish share **similar characteristics**. The text explicitly states that these characteristics **vary from individual to individual** at the beginning of the juvenile stage. Answer: FALSE.
- 3. FALSE
The statement claims early-juvenile fish share **similar characteristics**. The text explicitly states that these characteristics **vary from individual to individual** at the beginning of the juvenile stage. Answer: FALSE.
- 3-4: YES
3: The statement claims early-juvenile fish share **similar characteristics**. The text explicitly states that these characteristics **vary from individual to individual** at the beginning of the juvenile stage. Answer: FALSE.
4: The statement makes a comparison between the swimming speeds of **fully developed** fish and **juveniles**. The text discusses size variations among juveniles at settlement but does not compare the speeds of adults and juveniles. Information is missing. Answer: NOT GIVEN.
- 4. NOT GIVEN
The statement makes a comparison between the swimming speeds of **fully developed** fish and **juveniles**. The text discusses size variations among juveniles at settlement but does not compare the speeds of adults and juveniles. Information is missing. Answer: NOT GIVEN.
- 5. open ocean
The note asks where the Larval stage takes place. The text describes an **open ocean** larval phase. Answer: open ocean.
- 6. reef
The note asks where the Juvenile stage takes place. The text states it is followed by a juvenile to adult phase **near the reef**. Answer: reef.
- 7. mortality
The note states **mortality** rates are high in the early part. The text describes **increased levels of mortality** in the first 48 hours. Answer: mortality.
- 8. new moon
The note connects the change of habitat (settlement) to summer and the **new moon**. The text states settlement usually occurs within 2-3 days of a **new moon** during summer. Answer: new moon.
- 9. laboratory
The note mentions the difficulty of moving and settling fish into the **laboratory**. The text confirms that **transporting fish and adapting them to the laboratory** makes research a daunting task. Answer: laboratory.
- 10. artificial light
The note states larval fish are drawn into a trap with the aid of **artificial light**. The text describes traps that use **artificial light** to attract them. Answer: artificial light.
- 11. predatory fish
The note says **predatory fish** are also collected. The text states that the larval fish are transported **along with predatory fish**. Answer: predatory fish.
- 12. mouth size
The note states physical features like **mouth size** affect prey choice. The text confirms the relationship is driven by characteristics such as **mouth size**. Answer: mouth size.
- 13. medium
The note refers to the optimal foraging theory and a preference for prey that is **medium** in size. The text explicitly states this results in a preference for **medium-sized prey**. Answer: medium.