Which of the following pumps salt inwards in freshwater and outwards in seawater?

Correct option is C

Correct Answer: (c) Chloride cells
Explanation:
→ Chloride cells (ionocytes) located in gills regulate ionic balance.
→ In freshwater: pump ions (Na⁺, Cl⁻) inward.
→ In seawater: excrete excess salts outward.
Information Booster:
→ Vital for osmoregulation across salinity gradients.
→ Abundant in euryhaline species like salmon.
→ Controlled by hormones such as cortisol & prolactin.
Additional Information: Lamellae are respiratory surfaces, not ion-transporting cells.